Question 16

Outline the impact of sedative agents on thermoregulation (40% marks) and describe the physiological effects of a low body temperature (60% marks).

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College Answer

Sedation reduces body temperature by interfering with heat production and increasing heat loss, along with widening of hypothalamic inter-threshold range. This portion of the question was generally well answered. The question asked to "outline" the answer. Many candidates actually "described" the thermoregulation process in general but were unable to relate those with the impact of sedation. The second part of the question (physiological effect of low body temperature) was answered by most of the candidates with the structure of organ-system wise description. A few candidates scored extra marks by relating these effects with degree of hypothermia and by describing how thermogenesis responses (including shivering) can influence those effects. Some candidates restricted their answers to the effect of thermogenesis in response hypothermia and did not include the overall physiological consequences of low body temperature. Better answers displayed an understanding of core temperature regulation, inter-threshold range and the effects of sedatives on thresholds for thermogenic responses, although only a few mentioned gain and maximal response. Better answers included specific detail (mentioned bradyarrhythmia, slow AF, VF, prolonged PR/QRS / J waves rather than just stating arrhythmia) across several organ systems. Marks were not awarded for generic statements such as 'decreased liver function' without some additional detail. Inadequate depth of knowledge was main reason behind overall poor scores.