Metabolism Metabolism may be defined as the chemical processes that enable cells to function. Basal metabolic rate (BMR) is the minimum amount of energy required to maintain basic autonomic function and normal homeostasis at rest. In a healthy resting adult,…
The realisation that the enzyme systems and metabolic processes responsible for the maintenance of cellular function are dependent on an environment with stable electrolyte and hydrogen ion concentrations led Claude Bernard to describe the milieu interieur more than 100 years…
The kidneys have a number of diverse functions. The main roles are as follows: Filtration and elimination of metabolic waste products Maintenance of fluid and electrolyte homeostasis Control of acid–base status Production of erythropoietin to stimulate red cell synthesis Hydroxylation…
Control of breathing Breathing is primarily concerned with the homeostasis of blood O 2 and CO 2 to ensure that both remain at appropriate concentrations despite wide variations in the body's metabolic needs. Breathing control is also vital for speaking…
The autonomic nervous system The term autonomic nervous system (ANS) refers to the nervous and humoral mechanisms that modify the function of the autonomous or automatic organs. These include heart rate (HR) and force of contraction; calibre of blood vessels;…
In the last 70 years, neuromuscular blocking drugs have become an established part of anaesthetic practice. They were first administered during abdominal surgery in 1942, when Griffith and Johnson in Montreal used Intocostrin, a biologically standardised mixture of the alkaloids…
It is estimated that up to 80% of patients experience postoperative nausea and vomiting (PONV) within the first 24 h after surgery. If risk factors are identified and acted upon, PONV can be easily managed, but for a small, high-risk cohort…
The International Association for the Study of Pain (IASP) defines pain as ‘an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage’. It is clear from this definition that the…
Local anaesthetics are analgesic drugs that suppress action potentials by blocking voltage-activated sodium ion (Na + ) channels (VASCs) in excitable tissues. Examples include the amides (e.g. lidocaine, bupivacaine, levobupivacaine, ropivacaine) and esters (e.g. cocaine and procaine) ( Table 5.1…
A wide variety of therapeutic and non-therapeutic substances will obtund cerebral function and produce a continuum of cognitive states from almost fully awake to unexpected death ( Table 4.1 ). The clinically useful part of this spectrum is characterised by…