TABLE 1.

Common medical conditions and associated risks in the perioperative period.

Condition	Peri-anaesthetic and clinical implications
Uncontrolled hypertension	Exaggerated cardiovascular response resulting in: Raised BP during laryngoscopy and intubation, swinging blood pressure, with an increased risk of myocardial infarction and cerebrovascular ischemia and haemorrhage Electrolyte derangement from use of diuretics.
Recent myocardial infarction in the last 3 months	Increased risk of reinfarction. Recent history or cardiovascular instability should trigger referral to a secondary or tertiary level of care.
Heart failure	Problems with fluid control and cardiac contractility and output. Is a significant predictor of adverse events in the perioperative period. Anaesthetics for these patients, especially those with NYHA class II (mild limitation of daily activities) or more severe disease, should not be managed in the district hospital because they require echocardiograph and cardiology consult preoperatively, invasive monitoring, intensive care unit (ICU) postoperatively and should be managed by specialist anaesthesiologists.
Peripheral vascular disease	Is a pointer to the presence of other cardiovascular diseases. Check for smoking, diabetes, hypertension and hypercholesterolaemia
Cardiac dysrhythmias	Increased risk of thromboembolic events, heart failure, sudden cardiac arrest and increased risk of bleeding from use of anticoagulants. May require anticoagulation (check clotting profile), rate control, invasive monitoring, ICU and advanced life support
Diabetes mellitus	Increased risk of cardiovascular and renal events, especially with history of ischaemic heart/peripheral vascular diseases.
Neuromuscular disorders	Other skeletal muscles (respiratory and cardiac) and congenital disorders may be involved. May have exaggerated response to muscle relaxants, especially non-depolarising types. May require ventilatory support postoperatively May have poor sputum clearance resulting in respiratory infections and atelectasis.

Source: Please see the full reference list of the article Klocke M. How to do a pre-anaesthetic assessment. In: Mash B, Blitz J, editors. South African family practice manual. 3rd ed. Pretoria: Van Schaik, 2015; p. 422–425, for more information

NYHA, New York Heart Association.