2023 First Sitting

2023A 01: 21% of candidates passed this question. High performing answers correctly outlined the ABG findings including consideration of electrolyte abnormalities, A-a gradient, acid-base disturbance (including anion gap and strong ion difference) and whether compensation was appropriate. The best explanations of the Stewart approach described its physicochemical basis, discussed the independent variables (strong ions, total weak acids, and pCO2) in detail, and described their effect on the dependent variables and how they result in acid-base derangements. The ABG provided depicted an incorrect base excess with an omission of (-) symbol. Candidates were marked accordingly depending on their response to this and all candidates were compensated equally for the confusion that this may have caused.

2023A 02: 39% of candidates passed this question. This question required candidates to draw on knowledge across the syllabus. Many candidates did not appreciate the breadth required to adequately address this question unfortunately providing very detailed information on only aspects of the answer required to pass. Excellent answers described the following: differences between different GI routes/ sites of absorption, mechanisms of absorption including Fick's law of diffusion, drug formulations, drug factors (including concentration gradient, lipid solubility, ionisation, and molecular weight), site factors (including surface area, first pass metabolism, GI wall thickness, blood flow, and GI motility/ transit time). Marks were also given for consideration of drug interactions, enterohepatic recycling, and luminally active drugs.

2023A 03: 21% of candidates passed this question. The principles of infrared (IR) measurement of expired CO2 was answered in acceptable detail by most candidates. Sources of error were rarely identified nor explained in acceptable detail. Many candidates demonstrated errors of understanding when attempting to answer this section. Important concepts not covered by numerous candidates included side-stream vs mainstream techniques; how the Beer-Lambert law is applied and how concentration is used for partial pressure; what is the role of sapphire glass and the difference between collision broadening and additional IR absorption by N2O.

2023A 04: 14% of candidates passed this question. The question asked for an explanation of the structural features of the alveolus that facilitate its function. Candidates who scored well integrated the specific anatomical and structural elements of the alveolus with the multiple functions of the alveolus, including the relevant explanation regarding mechanisms. No marks were given for simply listing the structural features of an alveolus without an explanation on how this facilitates function, nor for listing functional requirements of an alveolus without explaining whether or how they are met by its structure. For the same reason, this was one question where simply listing equations with no discussion as to how these relate to the structure and function of the alveoli garnered no marks. Equations were not required for full marks but may be an efficient way to represent physical relationships that are hard to write in a few words. Common omissions included a description and the role of collagen and elastin fibres, capillary structure, the filtration function of the membrane, lymphatic drainage, recruitment and distensibility and metabolic functions. Candidates are encouraged to practice model answer templates for these integrative questions in the months leading up to the exam.

2023A 05: 33% of candidates passed this question. This question related to the renal handling of potassium, the physiology of potassium in the rest of the body was not relevant. Ultimately net potassium flux is a function of filtration, reabsorption, secretion and excretion. Good candidates divided the nephron into relevant sections and described how potassium was handled in each section. They correctly described the percentage reabsorption along each section, as well as the relevant active and passive pathways for reabsorption and/or secretion including the cells and channels/pumps involved. The physiological factors regulating each of these mechanisms were then described in correct detail.

2023A 06: 21% of candidates passed this question. It was vital to recognise and describe both the exocrine and endocrine secretions of the pancreas and their regulation. Insulin, glucagon, and somatostatin are all secreted from the pancreas and their omission was the most common reason for not passing this question. Many candidates unfortunately wrote solely on exocrine secretions. Satisfactory answers provided a moderate amount of detail on both the endocrine (insulin, glucagon and somatostatin) and exocrine (bicarbonate and digestive enzymes; trypsin/chymotrypsin, pancreatic amylase and lipase) secretions of the pancreas including what determines their secretion.

2023A 07: 64% of candidates passed this question. The first part of the question required candidates to define basal metabolic rate (BMR), identify the standardised conditions under which it is estimated and then elaborate on those conditions which affect it. Most candidates provided reasonable definitions but lost marks for not describing the standard conditions under which it is defined. Many were able to give a comprehensive list of factors that affected BMR however lacked the additional pertinent facts required in an outline question to achieve full marks. Candidates are again referred to the glossary to understand the difference between a list and outline question. The second part of the question pertained to the measurement of BMR which was not as well answered and understood. Overall, there was a limited ability to discuss direct and indirect calorimetry clearly and some responses confused the two.

2023A 08: 21% of candidates passed this question. This question required a breadth of response that was largely unrepresented in the answers provided by candidates. Better answers divided responses into cardiovascular effects and respiratory effects however many did not provide sufficient detail or provided only detail on some of the effects and missed the breadth of the question. Cardiovascular effects could be grouped into effects on the; right heart, left heart, ventricular interdependence, cardiac output, other circulations, baroreceptor and hormonal reflexes. Respiratory effects could be grouped into lung volumes, dead space, V/Q matching, compliance, airway resistance and the effect of excessive pressures on the lung. Despite this division in the question many candidates abandoned a structure which made their answers and explanations lack clarity. The examiners commented that most candidates who wrote an answer in paragraph format were likely to provide long vague answers rather than those more factual and succinct answers presented in a format with headings as above and pertinent associated dot point descriptions underneath these headings.

2023A 09: 26% of candidates passed this question. Candidates were expected to give a reasonable definition of pain incorporating the experience and tissue damage. Most candidates only partially incorporated both the actual or perceived harm and the sensory and emotional experience that is included in its formal definition. This question was then best answered by breaking down pain transmission and modulation into; peripheral, spinal cord, cortex, and central downregulation pathways. Good answers provided detailed and specific descriptions of the sensors, neural pathways, synapses, receptors, and neurotransmitters. Whilst pain transmission at the level of the spinal cord is complex, breaking this down into 1st and 2nd order neurons, main neurotransmitters and accessory neurotransmitters from interneurons and descending pathways was helpful. Whilst many covered some of this conceptually most answers did not provide sufficient detail to be considered a pass level answer. Many candidates described the withdrawal reflex to pain in detail which was not asked for and therefore did not attract marks.

2023A 10: 20% of candidates passed this question. Good candidates answered this question in 4 parts; pharmaceutics, pharmacokinetics, pharmacodynamics and delivery devices. The most common reason for not passing this question was providing vague statements without explanation or the specific information required. Candidates were expected to comment on importance of particle size and drug delivery, patient compliance, the effect of a spacer and systemic effects of different routes of administration. Whilst some candidates did make reference to this it lacked the detail required to demonstrate that they understood the concepts.

2023A 11: 67% of candidates passed this question. The high pass rate of this question was largely due to the ability of most candidates to reproduce the VW classification, with correct information regarding each class with examples. The pharmacology of adenosine was less consistently covered and whilst most kept to the usual pharmacology structure correct detail was often lacking to achieve high marks for this section.

2023A 12: 88% of candidates passed this question. This question has been repeated multiple times. Better answers demonstrated a structured approach to discussing the physiology of CSF dividing concepts into; Formation and Composition, Regulation and Circulation, and Functions of CSF with the appropriate level of detail.

2023A 13: 25% of candidates passed this question. Good answers provided detail about the specific composition of haemoglobin and related the pertinent features of the molecule to its functions in the carriage of oxygen, carbon dioxide and its role in acid-base balance, including the appropriate mechanistic description. Many candidates provided information on the production and breakdown of haemoglobin which was not required. Many candidates provided an unnecessary amount of detail and diagrams of the oxygen haemoglobin dissociation curve which did not score additional marks.

2023A 15: 66% of candidates passed this question. For this question a good answer should have encompassed a description of the following components; the arterial supply (epicardial, endocardial supplies), venous supply (major and minor venous drainage), the phasic ventricular blood supply, a description of and the relevance of the high oxygen extraction ratio, an emphasis on metabolic autoregulation whilst including any other mechanisms of physiological regulation. Most candidates provided reasonable detail surrounding the arterial-circulation and the area of the heart these vessels supply. Less well described were the perforating branches, the capillary network and the venous drainage, these components were often incorrectly described or left out of the candidate answers. Most candidates correctly identified the phasic flow and the difference in flow that occurs between the right and left ventricle. Those candidates that used diagrams to explain this were rewarded when these diagrams were labelled and accurate with respect to their systolic and diastolic distinction. The control of regulation was less well answered with generic statements not specifically identifying the local metabolic controls importance over any other mechanism. Those answers that scored well coupled the metabolic control to the flow dependence highlighting the high oxygen extraction within the coronary circulation.

2023A 16: 29% of candidates passed this question. This question required candidates to integrate parts of the syllabus that are often not presented together in the reference texts. Many candidates provided only an incomplete list of the roles of the hypothalamus as their answer which did not score enough marks to pass. Additionally, presenting information succinctly and in a format that demonstrated an understanding of priority of function with respect to the CICM syllabus, was critical for time management and ensuring that more the important/major roles were presented in more detail. This question required candidates to cover roles including autonomic control, thermoregulation, hormonal regulation, body rhythms and regulation of drives with feedback control mechanisms where appropriate. Those who scored well demonstrated a comprehensive breadth of knowledge of these areas as well as giving the pertinent points around areas of positive and negative feedback and the sensor areas and effector responses required to answer an outline question.

2023A 17: 39% of candidates passed this question. Good answers described electrode components, intensity of signals measured (requirement for and levels of amplification), lead position and differences between unipolar and bipolar leads. Rationale and mechanisms of filtering were less well described. Description of highand low-pass filtering along with detail on monitoring and diagnostic modes scored marks. Patient-related, electrical and environmental methods of reducing artefact attracted marks.

2023A 18: 43% of candidates passed this question. Good answers addressed the following in an ordered way: anatomic changes (including to airway, thoracic dimensions, dead space, airways resistance); what changes there are to respiratory volumes, capacities, and compliance; what happens to oxygen consumption and oxygen tension; and the acid-base changes that occur. Good answers didn't just list these changes, but also provided an explanation for them. Few candidates mentioned the changes in oxygen tension and oxygen consumption, and why these occurred.

2023A 19: 20% of candidates passed this question. The first part of the question required a description of the factors prolonging neuromuscular blockade which would include a description of the reasoning behind the prolongation. Many candidates missed the important factors and most did not include any explanation. Some candidates confused the causes of "delayed onset" and "prolonged action". For vecuronium mechanism of action all the details were expected, superficial explanations did not score well. The following key words were expected to be included in the mechanism description; competitive binding/ Nicotinic ACH (N2)/alpha subunit/post synaptic. In pharmacokinetics, details on hepatic metabolism to active metabolites, renal and biliary excretion along with accurate values of the volume of distribution, protein binding and half-life were expected to score full marks. These facts were frequently lacking in candidate answers.