RESUMO
BACKGROUND: Hypertension is common, affecting over one billion people worldwide. In sub-Saharan Africa, hypertensive disease not only affects the older population but is becoming increasingly prevalent in younger individuals. In South Africa (SA), >30% of the adult population has hypertension, making it the single most common cardiovascular risk factor and the predominant contributor to cardiovascular disease and mortality. Elevated blood pressure is the most common perioperative comorbidity encountered in non-cardiac surgical patients, with an overall prevalence of 20 - 25%, and it remains poorly controlled in low- and middle-income countries. Hypertension in the perioperative setting may adversely affect patient outcome. It therefore not only flags possible perioperative challenges to anaesthesiologists, but also identifies patients at risk of long-term morbidity and mortality. OBJECTIVES: To determine the prevalence and severity of hypertension in elective adult surgical patients in the Western Cape Province, SA. RESULTS: The study population included all elective surgical patients from seven hospitals in the Western Cape during a 1-week period. Hypertension, defined as having had a previous diagnosis of hypertension or meeting the blood pressure criteria of >140/90 mmHg, was identified in 51.8% of patients during preoperative assessment. Significantly, newly diagnosed hypertension was present in 9.9% of all patients presenting for elective surgery. Although 98.1% of the known hypertensive patients were on antihypertensive therapy, 36.9% were inadequately controlled. There are numerous reasons for this, but notably 32.1% of patients admitted to forgetting to take their medication, making patient factors the most common reason for treatment non-compliance. CONCLUSIONS: The perioperative period may be an important opportunity to identify undiagnosed hypertensive patients. The perioperative encounter may have a significant public health implication in facilitating appropriate referral and treatment of patients with hypertension to decrease long-term cardiovascular complications in SA.
RESUMO
Hypertension is not consistently associated with postoperative cardiovascular morbidity and is therefore not considered a major peri-operative risk factor. However, hypertension may predispose to peri-operative haemodynamic changes known to be associated with peri-operative morbidity and mortality, such as intra-operative hypotension and tachycardia. The objective of this study was to determine whether pre-operative hypertension was independently associated with haemodynamic changes known to be associated with adverse peri-operative outcomes. We performed a five-day multicentre, prospective, observational cohort study which included all adult inpatients undergoing elective, non-cardiac, non-obstetric surgery. We recruited 343 patients of whom 164 (47.8%) were hypertensive. An intra-operative mean arterial pressure of < 55 mmHg occurred in 59 (18.2%) patients, of which 25 (42.4%) were hypertensive. Intra-operative tachycardia (heart rate> 100 beats.min-1 ) occurred in 126 (38.9%) patients, of whom 61 (48.4%) were hypertensive. Multivariable logistic regression did not show an independent association between the stage of hypertension and either clinically significant hypotension or tachycardia, when controlled for ASA physical status, functional status, major surgery, duration of surgery or blood transfusion. There was no association between pre-operative hypertension and peri-operative haemodynamic changes known to be associated with major morbidity and mortality. These data, therefore, support the recommendation of the Joint Guidelines of the Association of Anaesthetists of Great Britain and Ireland (AAGBI) and the British Hypertension Society to proceed with elective surgery if a patient's blood pressure is < 180/110 mmHg.