A Comparison of Three Fluid-Vasopressor Regimens Used to Prevent Hypotension during Subarachnoid Anaesthesia in the Elderly

Abstract

We aimed to compare the efficacy of fluid preloading with two recently recommended fluid-vasopressor regimens for maintaining blood pressure during subarachnoid anaesthesia in the elderly. Sixty elderly patients requiring surgery for traumatic hip fractures received subarachnoid anaesthesia using 0.05 ml/kg of 0.5% heavy bupivacaine. Hypotension, i.e. systolic arterial pressure <75% of baseline, was prevented or treated by: A—normal saline 16 ml/kg plus intravenous ephedrine boluses (0.1 mg/kg); B—normal saline 8 ml/kg plus intramuscular depot ephedrine (0.5 mg/kg); or C—Haemaccel 8 ml/kg plus metaraminol infusion. Systolic arterial pressure and heart rate were recorded using custom-written computer software (Monitor, version 1.0). Systolic arterial pressure decreased in all groups after five minutes (P<0.001). Decreases were greatest in group A (P<0.05). Heart rate increased by 7% group A and decreased by 9% in group C (P<0.05). During the first hour, hypotension was present for 47%, 25% and 20% of the time in groups A, B and C respectively and overcorrection of systolic arterial pressure occurred in 19% of the time in group C. We conclude that treatment A was inadequate in preventing hypotension. Treatments B and C were more effective but were associated with an increased heart rate and overcorrection of systolic arterial pressure respectively.

Documented Intraoperative Hypotension According to the Three Most Common Definitions Does Not Match the Application of Antihypotensive Medication

“…An association between hypotension after spinal anaesthesia induction and hypertension in the past medical history has also been previously shown. 21 The effect of increased age on the occurrence of hypotension was reported several years ago 30 and has been confirmed by others 1,31 as well as shown in the present study. The minimal improvement in accuracy when definition 1 (67%) was compared with definition 4 (68%) shows a limitation in detecting IOH based on documented BP alone.…”

Crystalloid and colloid preload for maintaining cardiac output in elderly patients undergoing total hip replacement under spinal anesthesia

“…Therefore, optimizing cardiac preload may be fundamental to preventing spinal hypotension and organ dysfunction in elderly patients. However, to date, there are many literatures debating the type and amount of fluid preload[11]–[13]. The present study showed that a fluid preload of 8 mL/kg increased cardiac output.…”

“…To prevent spinal anesthesia-induced hypotension, intravenous fluid preload is commonly used. However, based on previous studies in which only blood pressure and heart rate were used to assess the efficacy of fluid preload, the type and amount of fluid preload for preventing spinal hypotension are still controversial[11]-[13].…”

Evidence‐based guidelines for fixing broken hips: an update

“…Potential complications which may have limited its use include hypotension and spinal haematoma. There is new evidence to support a number of interventions aiming to reduce the incidence of hypotension 62 . ‐ 66 , 68 In the recent Pulmonary Embolism Prevention trial, 56 no occurrences of spinal haematoma were documented in the 4603 hip‐fracture patients who received regional anaesthesia (including those with and without aspirin and other anticoagulant therapy).…”