A Multicenter, Cross-Sectional Quality Improvement Project: The Perioperative Implementation of a Hypertension Protocol by Anesthesiologists.

BACKGROUND: Hypertension is a common risk factor for cardiovascular morbidity and mortality, with a high prevalence in patients presenting for elective surgery. In limited resource environments, patients have poor access to primary care physicians, limiting the efficacy of lifestyle modification for the management of hypertension. In these circumstances, the perioperative period presents a unique opportunity for diagnosis and initiation and/or modification of pharmacotherapy of hypertension. Anesthesiologists are ideally placed to lead this aspect of perioperative medicine. The study objective was for anesthesiologists to identify patients at the preoperative visit with previously undiagnosed or poorly controlled chronic hypertension and follow a simple management algorithm. METHODS: In collaboration with expert physicians, we designed and implemented an algorithm for the diagnosis and management of chronic hypertension. This was a multicenter, cross-sectional quality improvement project in 7 hospitals in the Western Cape, South Africa. On the day before scheduled elective surgery, adult in-patients had 2 sets of blood pressure (BP) readings taken, one by nurses and the other by anesthesiologists, using a noninvasive automated BP device. These were averaged on an electronic database, to diagnose hypertension. Patients with normal BP or well-controlled hypertension required no further management. Those with borderline BP received educational pamphlets. Patients with stage 1 or 2 hypertension were managed with medication according to the algorithm, starting 1 day postoperatively, and provided with educational pamphlets. Patients with stage 3 disease had their surgery postponed and were referred to a physician. The primary outcome was adherence by the anesthesiologist to the algorithm in the diagnosis and management of hypertension. An 80% adherence rate was considered successful implementation. The secondary outcome was the adherence to the algorithm at discharge. RESULTS: Two hundred ninety-eight patients were screened for hypertension. One hundred six patients were eligible for the quality improvement project. Thirty-seven (34.9%) had borderline BP readings, 43 (40.6%) had stage 1, 22 (20.8%) stage 2, and 4 (3.8%) stage 3 hypertension, respectively. The adherence rate by the anesthesiologist in initiating treatment according to the algorithm was 89 of 106 (84.0%; 95% confidence interval [CI, 77.0-91.0). There was full adherence to the algorithm in 59 of 106 (55.5%; 95% CI, 46.2-65.1) at the time of discharge from hospital. CONCLUSIONS: Anesthesiologists successfully implemented a quality improvement project for diagnosis and management of hypertension in the perioperative period. This has the potential to reduce the public health burden of hypertension in limited resource environments. Successful ongoing prescription and follow-up requires cooperation within a multidisciplinary team.

Resting Hemodynamics and Response to Exercise Using the 6-Minute Walk Test in Late Pregnancy: An International Prospective Multicentre Study.

BACKGROUND: Cardiac disease is the leading cause of maternal death. Assessment of cardiovascular fitness is important in pregnant women because it is linked to increased risk of cardiac disease but is rarely undertaken or studied. The 6-Minute Walk Test (6MWT) is a safe exercise test but is not used in pregnancy. We determined the 95% reference interval for resting heart rate (HR) and distance walked for the 6MWT, as well as hemodynamic recovery variables, and quantified expectations and actual experiences of exertion and breathlessness with exercise in late pregnancy. METHODS: After institutional research board approval (Australian and New Zealand Clinical Trials Registry Number: 12615000964516), 300 healthy term nulliparous pregnant women performed the 6MWT at 3 tertiary referral obstetric hospitals using a standardized protocol. Each woman underwent two 6MWT with maximum 15-minute recovery period after each test. Hemodynamic variables were measured at rest and after exercise. Participants were asked 4 questions, 2 regarding expectation and 2 regarding actual experience, using the Rating of Perceived Exertion scale and Modified Borg Dyspnea scale. RESULTS: Participant characteristics and resting variables were mean (standard deviation [SD]); age, 31 years (4.2 years); body mass index, 27 kg/m (2.9 kg/m); gestational age, 37 weeks (1.3 weeks); HR, 85 bpm (10.8 bpm) with 95% reference interval 64-106 bpm; systolic blood pressure, 112 mm Hg (10.2 mm Hg); diastolic blood pressure, 72 mm Hg (8.6 mm Hg); oxygen saturation, 98% (0.9%); and respiratory rate, 18 breaths/min (5.7 breaths/min). The mean (SD) average distance walked was 488 m (94.9 m) with a speed of 3.0 mph (0.64 mph) with a 95% reference interval of 302-674 m. The mean (SD) HR increase with exercise was 12 bpm (11.0 bpm) with a median [quartile] recovery time of 5.0 minutes [1-8 minutes]. A lower resting HR was associated with increased distance walked (r = -0.207; 95% confidence interval, -0.313 to -0.096; P < .001). A greater HR change with exercise was associated with increased recovery time from exercise (r = 0.736; 95% confidence interval, 0.697-0.784; P < .001). Sixty-three percent and 83% of participants, respectively, expected to be more exerted and breathless than they actually were with exercise. CONCLUSIONS: The 6MWT is feasible and applicable in term pregnant women. The reference intervals for resting HR and distance walked in the 6MWT have been generated. HR increases by approximately 12 bpm with submaximal exercise, and half of the women recovered within 5 minutes of submaximal exercise. Women expected to be more exerted and breathless than they actually were with exercise.

How does sevoflurane induction, followed by a ketamine maintenance infusion, affect intraocular pressure? Establishment of an anaesthetic protocol for paediatric glaucoma examinations under anaesthesia.

Accurate measurement of intraocular pressure (IOP) is essential in paediatric glaucoma management. Children require serial measurements and examination under anaesthesia (EUA). Most anaesthetic agents reduce IOP, and the ideal time to measure IOP under anaesthesia is questionable. STUDY PURPOSE: To determine the effect of sevoflurane induction, followed by intravenous ketamine infusion on IOP, in children undergoing EUA for glaucoma or suspected glaucoma, and to establish the earliest time point at which reliable, repeatable IOP measurements can be obtained under anaesthesia. METHOD: A prospective, descriptive study of IOP changes occurring in children requiring EUAs. A standardised anaesthetic protocol: sevoflurane induction, intravenous cannulation, 2 mg/kg intravenous ketamine bolus and 4 mg/kg/hour maintenance for 15 min. IOP measurements (taken supine with a Perkins applanation tonometer) and physiological variables were recorded. RESULTS: IOPs were measured in 25 children (50 eyes). Twenty-six eyes (52%) were glaucomatous. Mean patient age was 29 months (2-88 months). Physiological variables returned to baseline at 8 min, correlating with recorded sevoflurane elimination. Mean IOP after sevoflurane induction was 3.68 mm Hg lower than with ketamine maintenance at 15 min (95% CI 1.35 to 6.02 mm Hg) (p=0.002). Contrastingly, the difference in IOP between ketamine anaesthesia at 15 min and near wakefulness was 0.28 mm Hg (95% CI -2.23 to 2.79 mm Hg) (p=0.826). CONCLUSION: Sevoflurane's IOP-lowering effect is reversed 15 min after the discontinuation of the inhalational gas, if anaesthesia is maintained with an intravenous ketamine infusion. IOP measurements appear to stabilise at this time point until the point of near wakefulness and may reflect awake values.