A multicentre cross-sectional descriptive study evaluating the cardiovascular risk profile of preoperatively identified patients with hypertension.

BACKGROUND: The prevalence of hypertension in adults in South Africa (SA) is 35%. Hypertension is the most important modifiable risk factor for cardiovascular (CV) and chronic kidney disease (CKD) in sub-Saharan Africa. However, 49% of people are unaware of their blood pressure status. Screening for hypertension prior to surgery provides a unique opportunity to diagnose and treat affected individuals. Furthermore, assessing overall CV risk identifies patients at highest risk for complications, and improves the utilisation of scarce resources. OBJECTIVES: To evaluate the CV risk profile of hypertensive patients in the adult population of the Western Cape Province presenting for elective non-cardiac, non-obstetric surgery. METHODS: This report documents the CV risk profile of patients recruited to the HASS-2 study (Hypertension and Surgery Study 2), which was undertaken in seven Western Cape hospitals. Patients were screened for hypertension and pharmacological treatment was initiated or adjusted in patients with stages 1 and 2 disease. Stage 3 patients were referred to a physician. In the present substudy, patients with stages 1 and 2 hypertension were assessed for associated CV risk factors, the presence of target organ damage, and documented CV or kidney disease; they received an overall risk stratification according to the 2018 European Society of Cardiology and the European Society of Hypertension Guidelines. RESULTS: Sixty-one patients with stage 1 and 12 with stage 2 hypertension were analysed. Established CV disease was present in 13.7% of the study population, and CKD (eGFR <60 mL/min) in 10.8%. Seventy-one percent of the study group had a raised body mass index, and 55.9% underlying metabolic syndrome. Prediabetes and diabetes were present in 16.1% and 14.5%, respectively. According to the 2018 European guidelines, 34.7% were at moderate, 33.3% at high and 16.7% at very high risk for a CV event in the following 10 years. CONCLUSIONS: The perioperative period is a critical time during which surgeons, nurses and anaesthetists can influence patients' CV risk of adverse events. This involves appropriate screening, education and treatment. In this study population, nearly 9 out of 10 elective surgical patients with stage 1 or 2 hypertension had CV risk factors placing them at moderate to very high risk. The simultaneous assessment of these additional CV risk parameters, in addition to diagnosis and management of hypertension, may further decrease the health and financial burden in resource-limited facilities in SA, and improve CV outcomes.

A multicentre prospective observational study of the prevalence of preoperative anaemia and iron deficiency in adult elective surgical patients in hospitals in Western Cape Province, South Africa.

BACKGROUND: Preoperative anaemia has been shown to be an independent risk factor for postoperative morbidity and mortality. Iron deficiency is the leading cause of anaemia globally. There are limited data describing the burden of perioperative anaemia and the relative contribution of iron deficiency in South Africa (SA). OBJECTIVES: To determine the prevalence and severity of preoperative anaemia in adults presenting for elective surgery in Western Cape Province, SA, and to investigate the contribution of iron deficiency as a cause of the anaemia. For this purpose, an investigative protocol from a recent consensus statement on the management of perioperative anaemia was applied. METHODS: We performed a prospective, observational study in adult patients presenting for elective non-cardiac, non-obstetric surgery over a 5-day period at six Western Cape government-funded hospitals. The World Health Organization patient classification was applied, and patients with anaemia were investigated for iron deficiency. RESULTS: The prevalence of preoperative anaemia was 28% (105/375; 95% confidence interval (CI) 23.5 - 32.5); 55/105 patients (52%) had moderate and 11/105 (11%) severe anaemia. Iron deficiency was the cause of anaemia in 37% (32/87; 95% CI 26.6 - 46.9), but only 9% of iron-deficient patients received iron supplementation prior to surgery. CONCLUSIONS: Preoperative anaemia was common in this study, and more than half of the affected patients had moderate to severe anaemia. Iron deficiency was responsible for almost 40% of cases. Iron supplementation was under-utilised in the preoperative period as a means of increasing haemoglobin. The introduction of system-wide policies would empower perioperative physicians to mitigate the risk associated with preoperative anaemia in the Western Cape.

A multicentre prospective observational study of the prevalence and glycaemic control of diabetes mellitus in adult non-cardiac elective surgical patients in hospitals in Western Cape Province, South Africa.

BACKGROUND: Diabetes mellitus (DM) is a common condition. The high burden of undiagnosed DM and a lack of large population studies make accurate prevalence estimations difficult, especially in the surgical environment. Furthermore, poorly controlled DM is associated with an increased risk of perioperative complications and mortality. OBJECTIVES: The primary objective was to establish the prevalence of DM in elective adult non-cardiac, non-obstetric surgical patients in hospitals in Western Cape Province, South Africa. The secondary objectives were to assess the glycaemic control and compliance with treatment of known diabetics. METHODS: A 5-day multicentre, prospective observational study was performed at six government-funded hospitals in the Western Cape. Screening for DM was done using finger-prick capillary blood glucose (CBG) testing. Patients found to have a CBG ≥6.5 mmol/L had their glycated haemoglobin (HbA1c) level measured. DM was diagnosed based on the Society for Endocrinology, Metabolism and Diabetes of South Africa (SEMDSA) diagnostic criteria. Patients known to have DM had their HbA1cmeasured and completed a Morisky Medication Adherence Scale (MMAS-4) questionnaire to assess glycaemic control and compliance with treatment. RESULTS: Of the 379 participants, 61 were known diabetics (16.2%; 95% confidence interval (CI) 12.4 - 19.8). After exclusion of 8 patients with incomplete results, a new diagnosis of DM was made in 5/310 patients (1.6%; 95% CI 0.2 - 3.0). The overall prevalence of DM was 17.8% (66/371; 95% CI 13.9 - 21.7). HbA1c results were available for 57 (93.4%) of the 61 known diabetics. Of these, 27 (47.4%; 95% CI 34.4 - 60.3) had an HbA1c level ≥8.5% and 14 (24.6%; 95% CI 13.4 - 35.8) had a level ≤7%. Based on positive responses to two or more questions on the MMAS-4 questionnaire, 12/60 participants (20.0%) were deemed non-compliant. CONCLUSIONS: There is a low rate of undiagnosed DM in our elective surgical population, but in a high proportion of patients with DM the condition is poorly controlled. Poorly controlled DM is known to increase postoperative complications and is likely to increase the burden of perioperative care. Resources should be focused on improvement of long-term glycaemic control in patients presenting for elective surgery.

The relationship between pre-operative hypertension and intra-operative haemodynamic changes known to be associated with postoperative morbidity.

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.

Transthoracic echocardiographic assessment of haemodynamics in severe pre-eclampsia and HIV in South Africa.

Haemodynamic and cardiac structural changes in severe pre-eclampsia and in pregnant women with human immunodeficiency virus (HIV) infection have not been clearly established. We performed transthoracic echocardiography on 105 women. Women with pre-eclampsia demonstrated (mean (SD), untreated vs treated) preserved fractional shortening (40 (7.1)% vs. 41 (8.6)%), a non-dilated left ventricle (4.5 (0.49) cm vs. 4.4 (0.44) cm), increased mitral valve E/septal e' (10.5 (3.3) vs. 10.6 (2.8)), and preserved tricuspid annular plane systolic exertion (2.6 (0.36) cm vs. 2.4 (0.51) cm). Women with HIV infection demonstrated (mean (SD), HIV-positive vs healthy) a reduced cardiac index (2.8 (0.64) ml.min(-1) .m(-2) vs. 3.1 (0.7) ml.min(-1) .m(-2) , p = 0.029), reduced septal s' tissue Doppler velocity (8.5 (1.5) cm.s(-1) vs. 9.3 (1.7) cm.s(-1) , p = 0.042), increased left ventricular end-diastolic area (7.6 (2.1) cm2 vs. 6.3 (1.7) cm2 , p = 0.004), and reduced right ventricular s' and e' velocity (s' velocity 14.7 (3.1) cm.s(-1) vs. 7.0 (2.9) cm.s(-1) p = 0.001, e' velocity 16.3 (4.1) cm.s(-1) vs. 18.7 (3.4) cm.s(-1) , p = 0.013). The mitral value E/septal e' was > 8 in 39% of patients with HIV. Fractional shortening (< 28%) was reduced in 10% of healthy women, and mitral valve E/septal e' ratios were > 8 in 38% of that group. Women with pre-eclampsia demonstrated preserved systolic function, with diastolic dysfunction. Women with HIV demonstrated reduced left and right ventricular systolic function, with increased ventricular dilatation.

Postoperative extracorporeal membrane oxygenation for severe intraoperative SIRS 10 h after multiple trauma.

A 34-yr-old male suffered multiple trauma in a road traffic accident. He required right thoracotomy and laparotomy to control exanguinating haemorrhage, and received 93 u blood and blood products. Intraoperatively, he developed severe systemic inflammatory response syndrome (SIRS) with coagulopathy and respiratory failure. At the end of the procedure, the mean arterial pressure (MAP) was 40 mm Hg, arterial blood gas analysis showed a pH of 6.9, Pa(CO(2)) 12 kPa, and Pa(O(2)) 4.5 kPa, and his core temperature was 29 degrees C. There was established disseminated intravascular coagulation. The decision was made to stabilize the patient on veno-venous extracorporeal membrane oxygenation (ECMO) only 10 h after the accident, in spite of the high risk of haemorrhage. The patient was stabilized within 60 min and transferred to the intensive care unit. He was weaned off ECMO after 51 h. He had no haemorrhagic complications, spent 3 weeks in the intensive care unit, and has made a good recovery.