Cardiac output (CO) is an essential component in the evaluation of the critically unwell hospitalised patient’s physiological state. As an estimated measure of cardiac function, CO is of high clinical importance to determine how well nutrients and oxygen are delivered to body tissue. Additionally, as its determinants are related to circulating volume and heart rate, it can be used as a surrogate measure for any homeostatic imbalances, which may require critical medical intervention. This article compares the available clinical measurements of CO. The Pulmonary Artery Catheter (PAC) remains the most accurate and reliable method, however is a highly invasive measure. Minimally invasive techniques reduce the risk of procedural complications, but do so at the expense of reliability. Of these methods, pulse contour analysis is the most extensively studied, with precision being similar, if not equivalent to, PAC. However, until definitive, outcome-based, comparison studies have been completed, the selection of the most appropriate CO measurement modality remains the decision of the treating clinician, the patient and relevant clinical guidelines.

Introduction

When assessing critically unwell hospitalised patients, haemodynamic monitoring is an important indicator of the patient’s condition. Cardiac output (CO) assessment is an essential component of the patient’s physiological state during their perioperative period. CO is an estimated measure of cardiac function calculated by multiplying the heart rate (beats per minute) by stroke volume (volume of blood pumped out of the heart in mL) [1]. CO is of high clinical importance, as it is one of the determinants of how well nutrients and oxygen are delivered to body tissue, with a normal CO defined as 4-8 L/min in healthy individuals, varying with gender and body habitus [1,2]. Additionally, as its determinants are related to circulating volume and heart rate, it can be a surrogate measure for any homeostatic imbalances (such as haemorrhage and volume depletion or sympathetic activation in stress raising heart rate) that may indicate the need for critical medical intervention.

Importantly, CO is also a dynamic way to assess organ perfusion and cardiac function intraoperatively, in addition to providing an indication of likely expected outcomes and complications postoperatively [1].  Other important clinical aspects of care to assess and monitor include the assessment of end organ function.  This includes conscious state, respiratory rate, blood pressure, peripheral perfusion (temperature and capillary refill time), urinary output, and markers of metabolic acidosis [1,3].

Multiple invasive, semi-invasive, and non-invasive methods of assessing CO in the clinical setting are available. Five common and emerging methods are summarised and compared below (Table 1).

	Method	Principle	Advantages	Disadvantages
Invasive	Pulmonary artery catheter (PAC)	Uses the Stewart-Hamilton equation: the rate of blood flow is inversely proportional to the change in temperature over time.	Very accurate Clinical benefit in monitoring multi-factorial shock states and cardiac cases	Risk of: Dysrhythmias Cardiac perforation Tamponade Pneumothorax Valve damage Infection Emboli
Non-invasive	CO2 rebreather	Uses the Fick principle: the conservation of mass, which allows the calculation of blood flow to an organ based on the uptake of a specific marker substance.	Fewer complications Non-invasive Useful in intensive care unit setting	Requires patient intubation and mechanical ventilation Poorer accuracy than invasive methods Not reliable in perioperative cardiac cases
	Aortic and echocardiography Doppler ultrasound	Doppler ultrasound operates on the principle that the shift in frequency of a wave between two points is directly proportional to the velocity of that wave.	Non-invasive Suprasternal and oesophageal methods Simple to operate Very few complications Provides data on heart structure	Reliability depends on operator skill/consistency Requires nomogram which may miss individual variation Individual physiological variables may alter reading (such as expansion of the aorta during systole)
	Bio-impedance	Measures electrical impedance of the thoracic cavity generated during systole and left ventricular outflow into the aorta. The ratio of applied current and measured voltage equals the bio-impedence, which is measured over time.	Easy to use No risk of infection or vascular complications (such as emboli)	Sensitive to movement Unsuitable in hemodynamically unstable and arrhythmic patients Limited use in septic shock and aortic regurgitation Limited in pathology with thoracic fluid (such as pulmonary effusion)
Semi-invasive	Pulse contour analysis	Based on the hydraulic principle between flow, pressure, and time; measures pulse pressure (the difference between diastolic and systolic pressure) as proxy to volume, in order to create a picture or “wave form” that can be analysed mathematically to find stroke volume	Invasive and non-invasive models available Accuracy similar to pulse contour analysis	Requires individual patient calibration Limited in patients with arrhythmias, aortic regurgitation, and intra-aortic balloons Invasive methods have risk of infection and bleeding

Invasive methods: pulmonary artery catheter

The pulmonary artery catheter (PAC) was introduced in 1970 by Harold Swan and is often used as the gold standard for CO monitoring [1]. This technique involves the insertion of a catheter, preferably through the right internal jugular vein because of ease of insertion, proximity to the heart’s right atrium, and rarity in anatomical variation between patients in this vein, although other sites can be used, particularly the subclavian veins.  The device has an inflatable balloon at its tip, which permits it to be floated through the right cardiac chambers and into the pulmonary artery. The PAC estimates CO using a technique called thermo-dilution.  This involves administration of a bolus of 10 mL of saline (0.9% NaCl at room temperature) injected into the right atrium via a proximal catheter port. The difference in temperature is measured through the thermistor (thermally sensitive probe) on the PAC’s tip [1]. From this, a CO value is calculated using the Stewart-Hamilton equation. This equation is based on the principle that the rate of blood flow is inversely proportional to the change in temperature over time (the concentration of the indicator solution divided by the “area under the curve” or integral created by the indicator solution concentration change over time) (Figure 1) [2]. Such a reading can either be continuous or not depending on both the requirement of the clinical setting and the form of PAC [4].

Figure 1: Modified Stewart-Hamilton equation applied in PAC Thermal dilution during CO monitoring [2].

The use of the PAC method for CO monitoring has many advantages over other techniques. Conversely, due to it being an invasive device, it does carry inherent risks including an increased possibility of dysrhythmias such as complete heart block, perforation of heart chambers, cardiac tamponade, pneumothorax, valve damage, infection, and emboli [1]. Post hoc analyses of larger studies have also reported no benefit in using the PAC method, other than in elective surgical patients [5]. However, given that elective surgical patients are often healthier than non-elective intensive care patients, queries over confounding factors within the population have been raised [5]. This demonstrates that it can be used safely, but brings into question its patient-related value in situations arising from the critical care environment [6]. Despite the relatively high reliability of this device, debate still exists around whether it actually improves outcomes in various patient groups [6]. Regardless, its clinical benefit in monitoring both undifferentiated, multi-factorial shock states and cardiac cases is well documented [6].

Minimally invasive methods: CO2 re-breather, Doppler ultrasound, and bio-impedance

Indirect Fick principle (CO2 re-breather)

The pulmonary circulation is the part of the cardiovascular system that involves deoxygenated blood flowing from the right heart, through the lungs, and back into the left side of the heart (now oxygenated blood). This circulation can be used to estimate CO via the use of a mathematical equation called the “Fick” principle [7]. The Fick principle is a mathematical interpretation of gasses, based on the conservation of mass, which allows the calculation of blood flow to an organ based on the uptake of a specific marker substance [2]. In more clinical terms, it grants the ability to observe the amount of gas release, classically oxygen (O2) or carbon dioxide (CO2), that occurs in the pulmonary circuit, via the alveolar blood flow, and the difference in gas concentration in the arterial and venous circulation (by collecting venous and arterial blood samples) [7]. By measuring alveolar blood flow via the rate of carbon dioxide volume (VCO2) produced from the lungs and body over the arterio-venous carbon dioxide gradient of arterial carbon dioxide partial pressure (PaCO2) and venous carbon dioxide partial pressure (PvCO2), one can extrapolate CO from the difference between these CO2 gradients [8]. Mathematically, with Q representing CO and VO2 being volume of oxygen consumed, the generic formula is as follows:

VO2 = Q (PaCO2 – PvCO2) [8]

For example, if the concentration of CO2 being delivered to an organ is known, and the amount this concentration increases after perfusing the organ (venous and arterial difference) is also known, it is possible to divide the two in order to determine the “flow” of gas, and therefore blood, to that organ [7]. In CO monitoring, the use of the pulmonary circuit to represent “the body”, with a sample taken before (venous) and after (arterial) allows us to determine the change in CO2 concentration as the blood flows to the heart. Concurrently, the patient in which CO is being measured must be intubated and under mechanical ventilation in order to control this gas exchange and its volume parameters [8].

The advantages of using the Fick technique are largely associated with it being a minimally invasive technique (such as relatively fewer contraindications and adverse outcomes than comparable methods) [7]. However, this method has limitations in that it has a lower level of accuracy than invasive methods, and requires the patient to undergo intubation [7]. Additionally, it was found that in the determination of CO for patients undergoing cardiac surgery, an underestimation preoperatively and an overestimation postoperatively commonly occurred [9]. This brings into question its clinical reliability in the vital perioperative setting [9]. Thus, although it has clinical advantages in patients who cannot tolerate more invasive methods, its reliance clinically is not as consistent as that of PAC.

Doppler ultrasound: aortic and echocardiography

Doppler ultrasound operates on the principle that the shift in frequency of a wave is directly proportional to the velocity of the moving plasma [10]. By measuring plasma velocity, Doppler ultrasound can be used to estimate CO. Typically, Doppler ultrasound calculates CO by measuring the velocity of blood plasma at the level of the thoracic aorta, generating an estimation of blood flow (stroke volume) by measuring plasma flow across the cross-sectional area of the aortic vessel or valve. This velocity can then be multiplied by the heart rate to provide an estimation of CO [7]. This technique is commonly combined with echocardiography, which measures left-side cardiac filling pressures via a two-dimensional ultrasound, and Doppler measurement of the aortic annulus diameter [11]. Additional benefits derived from this method include the provision of clinically relevant information on the global structure of the heart, in addition to valvular anatomy and presence of pericardium pathology (including tamponade or constrictive pericarditis) [11]. This allows for accurate, non-invasive measurement of left ventricular diastolic dysfunction, which is predictive of mortality in hospitalised patients [10]. Furthermore, echocardiography can also measure the response of stroke volume to both fluid bolus and diuretic therapy, while monitoring left (trans-mitral) and right (vena cava) arterial pressure [12]. This may be critical in patients at risk of both systolic and diastolic heart failure [12].  Importantly, these changes can be monitored serially after interventions have been performed.

Significant drawbacks of this method include its inability to provide continuous monitoring and difficulty in measuring sample volume placement; probe placement and beat-to-beat variation in stroke volume both impact accuracy [11]. Additionally, in the setting of decompensated systolic heart failure, tissue Doppler imaging can be inaccurate for monitoring filling pressures [11]. Since this technique also requires particular placement of the probe, as this is an important variable for reproducible results, significant operator training and skill is required [12]. Therefore, while this method is both reliable and has multiple reasons for use in the clinical setting, consideration needs to be given to operator skill and reproducible monitoring.  An additional limitation is that echocardiography requires considerable skill to perform well.

Finally, while not commonly used in Australia, oesophageal and transthoracic Doppler methods also exist. As with Doppler echocardiography, monitoring has a similar level of reliability as more invasive methods, but is predicated upon three factors: the aortic cross-section accuracy, the parallel placement of the transducer, and the maintenance of constant beam direction between measurements [7]. Even controlling for these variables, inherent factors limit this technique, including physiological expansion of the aorta during systole, noted to be approximately 12% [10]. Furthermore, the use of a nomogram (a pre-determined graph using three or more logarithmic scales to show a relation between them, such as occurs in weight and height charts to calculate body mass index) introduces potential measurement error secondary to variation with vascular tone and volume status that needs to be considered for all measurements [10].

Bio-impedance

CO can also be estimated via bio-impedance in a technique known as impedance cardiography. This technique measures the electrical impedance of the thoracic cavity generated during systole and left ventricular outflow into the aorta through the conductive properties of blood via four electrodes placed around the thorax; two placed on the left neck and another two upon the lower thorax, focus alternating current toward the ascending and descending aorta, within which blood is the most conductive material [13]. Put simply, the electrodes emit a small electrical current that is then “bounced” off conductive tissue, of which blood produces the strongest “bounce”. This current is then received by the electrode, wherein the change of impedance (current “bounced” from the blood tissue and received by the electrode) correlates to stroke volume [1].

Similar to all minimally invasive techniques, impedance cardiography nullifies the risk of infection and haemorrhage, however, it remains particularly sensitive to movement and is unsuitable for use in patients with arrhythmias or who are haemodynamically unstable [7]. This limits its use in Australian medical settings and so it is not commonly seen in practice [7,13].

Semi-invasive: pulse contour analysis

The final, commonly used method of estimating CO is pulse contour analysis. Pulse contour analysis utilises arterial waveforms, obtained either from an arterial catheter (invasive) or a peripheral finger probe (minimally invasive), in order to extrapolate stroke volume and systemic vascular resistance [2]. This technique relies on measuring pulse pressure, that is, the difference between diastolic and systolic pressure (as proxy to volume), in order to create a picture or “wave form” that can be analysed mathematically to find the area under the curve. Initially, this method assumed compliance of aortic wall to be uniform, regardless of patient demographics and co-morbidities (as the compliance of a vessel alters its distensibility). However, via the use of an algorithm developed by Wesseling et al. [14], it become possible to gauge stroke volume by integrating the area under the curve measured during systole to minimise this error. Concurrently, the estimated stroke volume can then be multiplied by heart rate to give CO [7,14,15]. Many devices rely on the principle of pulse contour analysis, such as Pulse Contour Cardiac Output Monitoring (Pulsion Medical Systems, Munich, Germany) and Lithium Chloride Dilution (LiDCO Ltd., Cambridge, UK), are invasive, needing arterial lines. However, the Vigileo™/FloTrac™ system (Edwards Lifesciences, Irvine, CA, USA) and the Nexfin® system (BMEYE, Amsterdam, Netherlands), which uses a finger cuff to measure pulse pressure of the digital arteries, are non-invasive options. Currently, all of these devices are limited by the fact that they require inter-patient calibration [16].

As in the bio-impedance method, this technique is limited in patients with cardiac arrhythmias, aortic regurgitation and intra-aortic balloons as they alter measurement accuracy [4]. Equally, the use of arterial catheters introduces an additional risk of infection and haemorrhage. Despite this, a recent meta-analysis performed by Mayer et al. determined that a strong positive correlation exists between the contemporary pulse contour analysis devices (FloTrac/Vigileo) and the PAC method when measuring CO [16]. Concurrently, this method possesses a high clinical applicability with significant potential for future development.

In conclusion, accurate CO assessment and monitoring in the perioperative patient remains critically important. While PAC remains the most accurate and reliable method, its invasiveness and the subsequent risk of complications makes it unsuitable for specific patient subsets. Conversely, while minimally invasive techniques reduce the risk of procedural complications, this is often at the expense of reliability. Of these methods, pulse contour analysis is the most extensively studied, with precision being similar, if not equivalent to, PAC. Until definitive, outcome-based comparison studies have been completed, the selection of the most appropriate CO measurement modality remains the decision of the treating clinician, the patient, and faculty clinical guidelines.

Acknowledgements

Dr M. Peach.

Conflicts of Interest

None declared.

References

[1]  Wigfull J, Cohen AT. Critical assessment of haemodynamic data. Contin Educ Anaesth Crit Care Pain. 2005 Jun 1;5(3):84-8.

[2]  Scheer BV, Perel A, Pfeiffer UJ. Clinical review: complications and risk factors of peripheral arterial catheters used for haemodynamic monitoring in anaesthesia and intensive care medicine. Crit Care. 2002 Apr 18;6(3):199.

[3] Calzia, E, Iványi, Z, Radermacher P. Functional haemodynamic monitoring. Berlin: Springer Berlin Heidelberg; 2005. Determinants of blood flow and organ perfusion; p.19-32.

[4] Lavdaniti M. Invasive and non-invasive methods for cardiac output measurement. Int J Caring Sci. 2008 Sep 1;1(3):112.

[5] Harvey SE, Welch CA, Harrison DA, Rowan KM, Singer M. Post hoc insights from PAC-Man—the UK pulmonary artery catheter trial. Crit Care Med. 2008;36(6):1714-21.

[6] Harvey S, Harrison DA, Singer M, Ashcroft J, Jones CM, Elbourne D et al. Assessment of the clinical effectiveness of pulmonary artery catheters in management of patients in intensive care (PAC-Man): a randomised controlled trial. Lancet. 2005 Aug 6;366(9484):472-7.

[7]  Drummond KE, Murphy E. Minimally invasive cardiac output monitors. Contin Educ Anaesth Crit Care Pain. 2011 Oct 3:mkr044.

[8]  Chaney JC, Derdak S. Minimally invasive hemodynamic monitoring for the intensivist: current and emerging technology. Crit Care Med. 2002 Oct 1;30(10):2338-45.

[9]  Alhashemi JA, Cecconi M, Hofer CK. Cardiac output monitoring: an integrative perspective. Crit Care. 2011 Mar 22;15(2):214.

[10] Dark PM, Singer M. The validity of trans-esophageal Doppler ultrasonography as a measure of cardiac output in critically ill adults. Intens Care Med. 2004 Nov 1;30(11):2060-6.

[11] Porter TR, Shillcutt SK, Adams MS, Desjardins G, Glas KE, Olson JJ et al. Guidelines for the use of echocardiography as a monitor for therapeutic intervention in adults: a report from the American Society of Echocardiography. J Am Soc Echocardiog. 2015;28(1),:40-56.

[12] Konstadt SN, Shernan SK, Oka Y, editors.  Clinical transesophageal echocardiography: a problem-oriented approach. Philadelphia: Lippincott Williams & Wilkins; 2003.

[13] Mehta Y, Arora D. Newer methods of cardiac output monitoring. World J Cardiol. 2014 Sep 26;6(9):1022.

[14] Wesseling KH, Jansen JRC, Settels JJ, Schreuder JJ. Computation of aortic flow from pressure in humans using non-linear, three element model. J Appl Physiol, 1993; 74:2566-73.

[15] Mathews L, Singh KR. Cardiac output monitoring. Ann Card Anaesth. 2008 Jan 1;11(1):56.

[16] Mayer J, Boldt J, Poland R, Peterson A, Manecke GR. Continuous arterial pressure waveform–based cardiac output using the FloTrac/Vigileo: a review and meta-analysis. J Cardiothor Vasc An. 2009 Jun 30;23(3):401-6.

Modern health professionals are well versed in the value of person-centred care for their patients. However, the way we are taught to view our patients through a problem-based lens is counterintuitive to this person-centred approach. Medical professionals have learned to consider the diverse sociocultural contexts of patients as a “risk” to their overall wellbeing, rather than acknowledging the unique strengths of all individuals and communities. This focus entrenches assumptions into the way we approach patients of diverse backgrounds. These assumptions and the subsequent expectations that we hold of our patients have been evidenced to serve as powerful self-fulfilling prophecies for an individual’s overall health and wellbeing. Individuals will internalise negative health identities and have poorer health outcomes if health professionals hold low expectations of them based on their sociocultural “risks”. Strengths-based practice recognises resilience and focuses on the strengths, abilities, knowledge, and capacities of all individuals, rather than on their deficits, limits, or weaknesses. It provides a framework for health professionals to better support their patients in achieving their best health outcomes. A strengths-based approach has the ability to shift the broader deficits-based discourse that exists around the diverse sociocultural groups that exist in Australia. Changing this conversation is of immeasurable importance if we are to improve the health outcomes and agency of our patients and mitigate the persistent health inequities that exist within the Australian health system.

As modern health professionals in training, we have been well conditioned to consider all biological, psychological, and sociocultural factors that may contribute to poorer health outcomes in any given patient. We are familiar with the World Health Organisation’s definition of health as “a state of complete physical, mental, and social wellbeing, and not merely the absence of disease or infirmity [1]”. But how does this translate into our practice? High patient caseloads and the sheer breadth of medicine compel us to streamline history-taking processes and problem formation through pattern recognition. We are taught to cluster “risk” factors – to make assumptions about disease, prognosis, compliance, and life expectancy, based upon sociocultural “risks”. We tick boxes. “Now, this is a question that we have to ask everyone, but do you have a history of previous intravenous drug use?”, “Do you identify as an Aboriginal or Torres Straight Islander?”, “Are you from a refugee or migrant background?”, and “Do you live in a rural or remote area?” We turn our attention to “vulnerabilities” and “high-risk groups” without much consideration of the impact of this focus and our subsequent assumptions on individual health identity.

The expectations we consciously or subconsciously hold of our patients, and the language we use toward or about them, inherently impact their health outcomes. In medical school, we are often taught to view our patients through a lens of deficit, by focusing on health problems rather than the opportunities that come from realising patients’ individual strengths. Strengths-based practice can shift this problem-based approach, and is a means of acknowledging the importance of our patients’ environments and diverse sociocultural contexts in the trajectory of their health attainment [2]. Strengths-based practice is an ecological approach to individuals, families, and communities that recognises resilience and focuses on the strengths, abilities, knowledge, and capacities of all individuals, rather than on their deficits, limits, or weaknesses [2]. A strengths-based approach is of immeasurable importance if we are to improve the health outcomes and agency of our patients, and mitigate the persistent health inequities that exist within the Australian health care system. This article will examine the impact of assumptions on patient health attainment and identity, the value and practicality of a strengths-based approach in the clinical setting, and the broader implications of our deficits discourse in the Australian public health arena.

Expectations and health identity

The expectations we hold of our patients can serve as powerful self-fulfilling prophecies for their overall health outcomes and identity. More than once I have heard a doctor use the phrase, “We save smart solutions for smart people”. This approach, however well intended, is damaging. Our clinical decision-making should not be influenced by expectations of noncompliance or assumptions of deficit. This is because health often exists at the nexus of societal expectations and our subsequent internalised perception of self. Essentially, if health professionals have high expectations of their patients, their patients are likely to have higher expectations of themselves, and subsequently experience better overall outcomes. This phenomenon is known in the behavioural psychology sphere as the Rosenthal effect, whereby our interpersonal expectations have been shown to significantly impact the learning, abilities, and health attainment of the subjects of our expectations [3,4]. We subconsciously facilitate “warmer” socio-emotional environments for individuals of whom we have higher expectations [3]. We have also been shown to input more effort into maximising the outcomes of individuals we see as having greater potential [3]. These subtle changes in the behaviour of care providers are internalised by patients and shape the expectations an individual holds of themselves [3]. Negative internalised expectations have been shown to directly lead to poorer mental and physical health outcomes in patients [5]. Internalised expectations may also directly act to motivate or discourage patients in their personal attainment of better health outcomes [5]. Essentially, negative health care provider assumptions and expectations demoralise an individual’s health identity, and this in turn impacts the mental and physical health outcomes of patients [3,6].

Our clinical approach to Indigenous patients in Australia offers an obvious example of how health care provider expectations may demoralise an individual’s health identity. At the beginning of any consultation, we are taught to ask all patients if they identify as Aboriginal or Torres Straight Islander. Identification of Aboriginal or Torres Straight Islander descent is essential in creating safety for our Indigenous patients. Too often however, doctors aren’t asking about Indigenous identity in order to practice their (often limited) cultural competencies, but rather to unfold a new list of differential diagnoses, and to remember to ask about smoking, alcoholism, substance use, diet, and exercise. On examination of Indigenous patients, we are also taught to check specifically for signs of cardiovascular disease, hypertension, type-2 diabetes, and chronic renal disease. While such a comprehensive approach to all patient consultations is desirable, our underlying assumptions relating to our Indigenous patients’ health-seeking behaviours, and our expectations for their health prognoses, is problematic. These assumptions are one of the means by which racism is maintained within our health system. As health professionals who work to support others in achieving their best possible health outcomes, we are terrified to talk about racism, or to consider that we might be contributing to its perpetuation in the Australian health system. However, it is important to define what racism in our health system actually means, in order to understand our role in it.

There are three levels of racism that contribute to poor health outcomes for Indigenous people: institutional, interpersonal, and internalised racism [7-12]. Institutional racism is often established in political systems and sustained by the policies of governments and health institutions that discriminate against Indigenous peoples [8]. Interpersonal racism in the health setting occurs when a health care provider makes assumptions about a patient on the basis of their Indigenous identity, or discounts Indigenous beliefs and practices [9]. These discriminatory interactions may be communicated to patients through non-verbal or verbal means, and often alter the course of care for an Indigenous patient [8,9]. Internalised racism occurs when an Indigenous patient accepts the stereotypes of interpersonal and institutional racism, and allows these stereotypes to shape their health identity. Institutional and interpersonal racism are often not intentional, but remain uninterrogated and largely invisible in our health system. Sometimes it is highly visible, but still unchallenged and unchanged. By not acknowledging or confronting the racism that exists within our health institutions, we are reinforcing negative internalisation among Indigenous individuals, leading to negative mental and physical health outcomes [6,8,9]. If a patient is conscious of interpersonal racism, this has been shown to influence their participation in unhealthy behaviours, and directly contribute to the long-term development of cardiovascular disease, hypertension, renal disease, and alter some of the neurochemical processes involved in diabetes [6,8]. The high prevalence of these chronic conditions within Indigenous populations is therefore something that is perpetuated, rather than mitigated, through our current approach to Indigenous health. As health professionals, we must challenge our conventional health paradigms and disrupt the processes that blame such systemic problems on the “unhealthy behaviours” of an entire culture [9].

By utilising reductionist techniques to simplify care provision for our patients, we are limiting our patients’ ability to attain their highest standard of health, as well as restricting their agency and self-aspiration [13]. An individual’s health is more than the sum of their medical issues – it is also determined by their personal resources. In medical school, we are not taught to identify the inherent strengths of all individuals, but rather to focus on health risks, problems, and limitations. That is, instead of seeing the potential that exists in celebrating the diverse sociocultural contexts of our patients, we regularly view sociocultural identity as a “risk” to overall wellbeing. This deficits-based understanding of health identity and our subsequent interpersonal communication is internalised by our patients, shaping their health behaviour and outcomes. We have the opportunity to change the conversation.

The strengths-based approach

Strengths-based practice is a well-evidenced approach in ensuring people have agency in their own health outcomes and identity. Strengths-based practice appreciates the centrality of people’s environments and sociocultural contexts in the attainment of their optimal health outcomes, and builds upon these strengths to reinforce health identity [2]. A strengths-based practice framework involves six core principles [2]:

1. All individuals, families, groups, and communities have strengths, and the emphasis is on these strengths rather than on pathologies
2. Communities are an abundant source of resources
3. Interventions are built on the self-determination of the patient
4. Collaboration is key, and a positive practitioner-patient relationship essential
5. Outreach is utilised as a preferred mode of intervention, and
6. All people have the inherent capacity to learn, grow, and change.

While strengths-based practice has not been formally implemented in the medical system, analysis of its feasibility in the social work setting may inform its rollout across the broader health sector. There are three developmental stages of health professional learning: socialisation, internalisation, and identification [2]. Socialisation involves health professionals learning how to enable a strengths-based dialogue among their colleagues, so that their colleagues may then develop the knowledge and skills to empower others [2]. Internalisation in this context is the process whereby health professionals internalise strengths-based principles in order to counter any barriers to enabling patients to see their strengths [2]. Identification involves the recognition of tacit assumptions about patients, and the impact of these assumptions on health provider practice and their patient’s cultural context of empowerment [2]. To shift our deficits-based approach to health care in Australia, health professionals must first be socialised to the concept of strengths-based practice, before we can then internalise its importance, and address any negative expectations we inadvertently hold of our patients.

The language we use to converse with our patients is often a product of the expectations and assumptions we hold of them. Paradoxically, our expectations are shaped by the broader public health discourse and problem-based learning that is indoctrinated into many doctors throughout their training. The rigidity of our health and medical education systems that institutionalise this deficits-based discourse make it difficult to universally adopt strengths-based practice across Australia. However as health professionals, we are still able to begin shifting this conversation and challenging the assumptions that we usually accept of our patients. Indigenous peoples in Australia are well versed in the power of strengths-based practice, and have identified three crucial ways we might enable positive change and start shifting our health discourse away from a mindset of deficit [13]:

1. Create safety: enable a space and process for robust discussion.
2. Challenge mindsets, habits, and conversations: take responsibility, find courage, and lead by example.
3. Co-create transformative pathways: engage with community groups to develop change and spread the word to engage in a national dialogue.

A deficits-based health discourse extends beyond interpersonal interactions of doctor and patient. As health professionals, our opinions are respected and hold legitimacy in public health discourse. How we talk about people matters because it plays a major role in shaping the public dialogue, and subsequently assists in setting a national health agenda for our politicians to action. We should be engaging in strengths-based health rhetoric and promoting the wellbeing of all individuals, rather than focusing on their limitations. As a result of our privilege, we have a duty to amplify the voices of individuals and communities who are working hard to shift our national dialogue to a narrative of strength, resilience, and opportunity.

Changing the conversation

Over recent decades, an emerging theme in the public health discourse has been a focus on health disparities between your “average Australian” and specific sociocultural groups. Arguably, this well-intentioned advocacy has been successful in fostering the next generation of compassionate and socially conscious health professionals. Many of my fellow students would attest that they entered their medical degree because they saw it as an effective means of helping people they perceived to be marginalised in our society. This motivation is exciting and provides fertile ground to generate unprecedented change to the inequities that persist in the Australian health system. But the fundamental assumption that our current deficits-based medical curriculum will enable us to effect positive change for marginalised groups is flawed. We assume that a medical degree, taught through problem-based learning, will provide us with the knowledge, skills, and sensitivity to offer the help that is needed. However, without realising the strengths of all individuals and communities, we are missing out on an enormous opportunity to celebrate resilience, reinforce positive health identities, and improve health outcomes for all.

Attention to sociocultural determinants of health has allowed us to raise awareness of persistent inequalities in our health system. However, focusing solely on deficits is detrimental to the broader narrative of the diverse sociocultural groups in our society. Drawing back upon the example of Indigenous health in Australia, large health promotion campaigns have been incredibly valuable in shedding light on the inequalities that persist between Indigenous and non-Indigenous Australians. These campaigns have also ensured that Indigenous health and education remain on political agendas, and they have secured funding for important programs. However, these awareness-building education and health promotion strategies have inherently focused on the “gaps” experienced by Indigenous people, and are an ineffective substitute for a whole government commitment to address the broader social determinants of health and shift our discourse away from deficit [9]. If we constantly emphasise life expectancy “gaps” in our public discourse, without closely examining our role in the discriminatory policies and practices that maintain these “gaps”, we will only perpetuate the inequities that exist between Indigenous and non-Indigenous Australians. By continuing to allow deficits to eclipse individual strengths, we are doing our patients, their communities, and our broader society, a colossal disservice.

Our health discourse does not exist in a vacuum. As modern health professionals, we have an obligation to celebrate the individual strengths of each of our patients, and a duty to use our respected voice to shape the rhetoric that currently marginalises the diverse sociocultural groups that exist in Australia. So challenge expectations, transform mindsets, and check your assumptions at the door – together we can ensure better health outcomes for all.

Acknowledgements

Scott Gorringe, for his patience, persistence, resilience, strength, and friendship.

Nicholas Fava, for his invaluable assistance in proofreading this piece.

Conflicts of interest

None declared.

References

[1] World Health Organization. Constitution of the World Health Organization. Geneva, Switzerland: 2006 October.

[2] Scerra N. Strengths-Based Practice: The Evidence. Parramatta, Australia: Uniting Care, Social Justice Unit; 2011 July.

[3] Rosenthal R. Interpersonal Expectancy Effects: A 30-Year Perspective. Curr Dir Psychol. 1994;3(6):176-9.

[4] Learman LA, Avorn J, Everitt DE, Rosenthal R. Pygmalion in the nursing home the effects of caregiver expectations on patient outcomes. J Am Geriatr Soc. 1990;38(7):797-803.

[5] Mondloch MV, Cole DC, Frank JW. Does how you do depend on how you think you’ll do? A systematic review of the evidence for a relation between patients’ recovery expectations and health outcomes. Can Med Assoc J. 2001;165(2):174-9.

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Indigenous health education is an important part of the curriculum for medical students. However, there are limited opportunities within the course for students to interact with patients from an Indigenous background. Following an Indigenous health placement in a remote community in the Eastern Kimberley region, a final year medical student reflects on how her medical education did not prepare her for the overwhelming social issues impacting on the health of Indigenous Australians. This article explores how, in the author’s experience, the current medical curriculum offers limited opportunities for first-hand exposure to Indigenous health, with a large proportion of Indigenous health content delivered in a lecture format. This style of teaching does not allow students to discuss, explore, and understand the many complex social issues that contribute to the health of Indigenous Australians. This combination of suboptimal teaching style and little or no first-hand experience results in medical students that are not well prepared to deal with these issues as junior doctors. It is necessary to review the current teaching methods and consider implementing interactive workshops to improve Indigenous Health education, which will in turn improve the health of Indigenous Australians.

This year, I spent my six-week elective rotation in Kununurra, a small town in the Eastern Kimberley region with a population of about 8,000 people [1]. Kununurra is a remote town situated approximately 500 km, 800 km, 1,000 km and 3,000 km from Katherine, Darwin, Broome and Perth respectively, which are the nearest major centres. There is a relatively large Indigenous population, with 34.8% of residents identifying as either Aboriginal or Torres Strait Islander [1]. The traditional owners of the Kununurra area are the Miriwoong Gajerrong peoples, and Kununurra is an anglicised version of Goonoonoorrang, the name of the Ord River that flows west of Kununurra. Colonisation has led to much disruption for this community, having serious impacts on health and wellbeing [2].

My placement was with an Aboriginal Health Service, a GP clinic with visiting allied health and specialist services, so the vast majority of patients that I saw were Aboriginal. I was unprepared for what I observed in this placement in remote Western Australia, in particular the social and environmental determinants of health that contribute significantly to the health of Indigenous Australians. The variety of issues that I experienced in Kununurra brought into relief the difference between my understanding of Indigenous Health from the taught medical curriculum, and the reality in Kununurra. This essay explores this gap by illustrating with anecdote some of my personal experiences of social determinants of Indigenous health, with comment on how student understanding might be improved in the teaching of medical students. The examples relate to my experiences in Kununurra only; it is important to note that each community has its own unique issues and that what is pertinent in Kununurra may not accurately reflect Indigenous health in a broader sense.

Prior to my brief placement in Kununurra, I had very little exposure to Indigenous health other than what I had learnt in the classroom. My lack of knowledge and experience became immediately apparent; I felt completely out of my depth with regard to the many complex medical and social issues that I was seeing, hearing, and learning about. One particular morning, as I left my house at quarter to eight, there was a man walking down the street with his young family; he had a bottle of wine in one hand and was pushing a stroller with the other. When I arrived at the clinic I jumped into the 4WD with one of the nurses and we drove to a community over 90 minutes away. This outreach clinic used to be serviced regularly by staff from Kununurra, but due to staff shortages it was months since the clinic had been open. In near 40-degree heat, bare-footed patients walked down the road to the clinic, which itself was covered in dirt, dust, and cobwebs, with overgrown weeds outside, broken windows, and blocked plumbing. Dead frogs were swept out from behind toilets and under desks. It was certainly not something I ever thought I would see in Australia, yet the patients were just grateful to have the clinic up and running again. We went to the school to see if any of the 11 students required immediate attention; as there was no doctor with us, anything less urgent would have to wait. While we were there, we provided dressings and antibiotics for a child with boils (a very common complaint) and removed a foreign body from a boy’s ear that thankfully turned out to be paper rather than a maggot.

Over the course of my stay in Kununurra, I saw a heavily-pregnant woman who smoked 80 cigarettes a day with no intention of stopping, a lady with a total thyroidectomy who had stopped taking thyroxine, a man who refused treatment and further investigation for a cryptococcal infection because he “felt fine”, and patients in their forties on dialysis. I had patients tell me they share a three-bedroom house with 20 people and saw children who had not attended school for weeks, and who wandered the streets with their friends at night, completely unsupervised. I had a 17 year-old boy openly tell me that he smoked cigarettes and “gunja” (marijuana), but who vehemently denied drinking alcohol because “it only causes violence”; and for the first three weeks of my placement, there was at least one person every week who presented after an attempted hanging, the youngest of which was 12 years-old. This was also highlighted in a speech given by Dr Marion Scrymgour, the CEO of the Wurli Wurlinjang Health Service and Chair of the Aboriginal Medical Services Alliance NT [3]. After six weeks in a remote Indigenous community, I was only just beginning to understand the complexity of a problem for which there is no simple solution. I began to reflect on why it had been so overwhelming; was there something missing from my education that could have better prepared me for this experience?

To understand what is lacking, we must first identify what is included in the Indigenous health curriculum. In a packed medical course, my education skimmed the surface, with lectures on culture and history that included topics such as the Stolen Generation, traditional medicine, and the different family structure of Aboriginal communities. I learned that the burden of chronic disease is much higher in the Aboriginal population, and that this is the primary reason that the life expectancy is, on average, ten years less for Aboriginal people than the rest of the Australian population. While this is worthwhile knowledge, it is an inadequate summary that only superficially touches on Indigenous health issues because it does not allow us to delve into the much more important discussion of why these discrepancies exist and how they can be rectified.

In 2004, the Committee of Deans of Australian Medical Schools (CDAMS) audited existing Indigenous health content and released the Indigenous Health Curriculum Framework, now called the Medical Deans Indigenous Health Project, which has become part of the accreditation requirements for all Australian medical schools [4]. This framework is comprehensive and meticulously developed by people with a significant amount of experience in the field. It is important to acknowledge that Indigenous health teaching is not the same across all universities and has been constantly evolving since I started my degree five years ago. However, based on my own education, I still felt very under-prepared.

There are numerous and varied reasons as to why current Indigenous health education is inadequate preparation for medical practice. Firstly, as outlined by the Indigenous Health Curriculum Framework, Indigenous people are a “non-homogenous population” with a “diversity of cultures, experiences, histories and geographical locations” [5]. It is difficult to convey that the issues encountered by urban, rural, and remote Indigenous communities seeking health care can be so vastly different. For example, the education that I received gave me essential background knowledge and an understanding of Indigenous health issues in urban areas, but failed to convey the difference between this and the difficulties faced by Indigenous Australians in remote areas. Furthermore, even within a particular setting (for example, a remote setting), there is a large variation between communities, so that the issues seen in one remote community may not be the same as those seen in other nearby communities. Secondly, thorough assessment of even the most well-constructed learning objectives is difficult to achieve. Assessment, often in the form of assignments and examinations, determines if students are meeting the desired outcomes, and from this we can extrapolate about the quality of teaching. Without this data, we are unable to accurately identify the effectiveness of teaching strategies, and are therefore unable to make appropriate changes and improvements.  Professor Richard Murray, a doctor with 14 years of clinical experience in Aboriginal health services in the Kimberley region, and the current Dean of James Cook University Medical School, illustrated this point beautifully when he said in a personal email addressing my enquiries about the Indigenous Health curriculum, “course or subject outcomes are too high level and abstract to satisfy” [6]. Therefore, not only is the curriculum difficult to implement, it is also difficult to assess its effectiveness.

One of the biggest challenges associated with Indigenous Health education is that many of the learning objectives and concepts are difficult to grasp in a classroom, especially with regard to the social determinants of health. One of the guiding principles of the Indigenous Health Curriculum Framework states that the health of Indigenous people is more associated with “historical and social determinants of health than with inherent Aboriginality” [5]. My experiences demonstrate this as well; the previously-mentioned examples are all symptoms of many complex underlying issues affecting the health of people in these communities. Many of the cases I saw would not occur if it were not for the effects of low socioeconomic status and deficits in the other social determinants of health seen across the globe: inadequate access to health care and education, health literacy and compliance issues, alcohol and drug dependence, physical and sexual assault, mental health issues and suicide, poor living conditions, and overcrowding.

For example, only 76% of Indigenous children aged 5-14 years in the Northern Territory have access to schooling, as compared to 95% of non-Indigenous children of the same age [7]. Indigenous people are less likely to drink alcohol, but twice as many drink at levels considered to be risky or high-risk for long-term harm compared to their non-Indigenous counterparts. 15% of homes with Indigenous people are considered overcrowded, which increases up to 42% in very remote areas, as opposed to 4% of other households. Furthermore, some of these houses do not have reliable water and electricity, or adequate sewerage [7]. Despite these appalling statistics, Indigenous Australians have the oldest, continuous living culture in the world, showing an incredible ability to adapt to change [8]. As a student, it is very difficult to imagine the enormity of the impact that all these factors have on health. As an example, it is difficult to explain complex health issues and the importance of treatment to patients with little or no education and health literacy.  It is even more challenging to treat and prevent the spread of communicable diseases. Consider the management of scabies or head lice which often require the entire household to be treated concomitantly; it is near impossible to achieve this in communities where overcrowding is rife. True understanding of this only comes from seeing it first-hand [9]. However, providing every student with the opportunity to go to an Indigenous or remote community is not a financially viable option for most universities, and accommodating large numbers of health science students is not necessarily feasible (or wanted) in Indigenous communities. This is one of the largest obstacles to providing the educational opportunities required to meet the outcomes outlined in the curriculum framework. Without the ability to provide the correct learning environment, it is unreasonable to expect that graduates will have an in-depth understanding of the complex interplay between these particular social determinants and health outcomes.

It is not the quality of the learning objectives and curriculum framework that limit Indigenous Health education, but rather the difficulties associated with the implementation and assessment of these objectives. The best teaching format, particularly with regard to the social determinants of health, is experience-based learning. While this is not feasible for every student, the lecture based format of Indigenous health education is suboptimal. The content is often too robust to really impart understanding of the complex health and social issues that many Indigenous people face. Other options must be considered and implemented; for example, workshops may allow educators to facilitate the discussion required to dissect more complex issues, such as why these disparities exist and how they may be overcome. Indigenous community members speaking to small groups of students about their life experiences, medical issues, and involvement with healthcare services would give students the opportunity to interact and ask questions, whilst fostering understanding and practising cultural sensitivity. Regardless of how the content is delivered, it is imperative that the social issues are emphasised within the curriculum, so that medical students graduate considering the patient in the context of their community and surroundings, because it is difficult to improve health without first improving the foundations. Students must learn that it is not enough to simply treat the presenting complaint; even our best medical efforts are not nearly as effective in promoting positive health outcomes as advocating to ensure the basic social needs (safety from violence, basic education, and adequate housing and nutrition) of our patients and communities are being met. Only when this is achieved will we see significant change in the health outcomes of Indigenous Australians. This is perhaps the biggest lesson omitted from the Indigenous health curriculum, and it is unlikely to be learnt in a classroom.

Acknowledgements

I would like to acknowledge Professor Michelle Leech and Professor Richard Murray for their helpful advice during the information gathering stages. I would like to thank Associate Professor Karen Adams, who suggested resources and ensured the article was written in a culturally-sensitive manner. I would also like to acknowledge the Deans and their representatives of all the Australian medical schools who provided me with their Indigenous health objectives or other resources. Thanks also to Dr Alexandra Van Rijn, who provided advice during the drafting stages of this project.

Conflicts of interest

None declared.

References

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