Use of high spinal anaesthesia in cardiac surgery improves the quality of postoperative recovery and, anecdotally, patient comfort, according to results of a retrospective study presented here at the 2014 Annual Meeting of the Canadian Anesthesiologists’ Society (CAS).
Presentation title: Perioperative Outcomes of High Spinal Anesthesia for Cardiac Surgery. Abstract 3725
No benefits were apparent in regard to death, stroke, bleeding-related reoperation, hospitalisation course, vasopressor use, and renal injury.
Although the detection of rare events, principally neuraxial haematoma, was beyond the scope of this (and most) studies, the results indicate the value of high spinal anaesthesia in this patient setting, noted lead investigator Daniela Goldie, MD, University of Manitoba, Winnipeg, Manitoba, on June 15.
High spinal anaesthesia using local anaesthetics has been linked with various clinical benefits; however, the findings have been from case studies or small studies. Furthermore, prior reports did not address morbidity and mortality.
In this single-institution study, medical records of all patients who underwent cardiac surgery from December 2003 to December 2010 were examined. Billing codes were used to identify patients who received intrathecal narcotics. The 153 patients who received high spinal anaesthesia were matched by age, sex, procedure, surgeon, and surgery date with 153 control patients not receiving this anaesthesia.
The primary outcome was a composite of major morbidity involving death, stroke, and the need for additional surgery because of bleeding.
Patients receiving high spinal anaesthesia required significantly less infused insulin than did control patients (21% vs 42%; P = .0001).The same was true for opioids (P = .0001) and ketamine (P = .01).
A postoperative comparison revealed that those receiving high spinal anaesthesia were extubated in the operating room more frequently (78% vs 48%; P = .0001), experienced less nausea and vomiting (12% vs 43%; P less than .01), needed less morphine and acetaminophen (P less than .01), and showed a trend toward fewer postoperative transfusions (P = .10). Those receiving high spinal anaesthesia, however, did display more ventricular arrhythmias than control subjects (6% vs 1%; P = .02).
No significant differences were evident between the spinal anaesthesia and control groups in the composite primary outcome (odds ratio [OR] = 1.50; 95% confidence interval [CI], 0.72-3.11), length of stay in the intensive care unit (1.9 ± 2.3 vs 1.8 ± 1.6 days; P = .80), or length of hospitalisation (8.1 ± 6.1 vs 8.4 ± 7.8 days; P = .60), respectively.
Intraoperatively, the groups were similar, with no significant differences in type of surgery performed (coronary artery bypass graft and/or valve surgery, elective/urgent procedure, and resternotomy), cardiopulmonary bypass time, aortic cross-clamp time, intraoperative haemoglobin, or glucose levels.
The groups also were similar in their preoperative demographics, with the exceptions of a greater prevalence of coronary obstructive pulmonary disease in those receiving high spinal anaesthesia compared with controls (18% vs 9%; P = .02), less prevalence of angina in those receiving high spinal anaesthesia (72% vs 86%; P less than .01), less incidence of stroke/transient ischaemic attack in those receiving high spinal anaesthesia (7.5% vs 12%;P = .01), and less use of beta blockers in those receiving high spinal anaesthesia (68% vs 83%; P less than .01).
“Although the use of high spinal anaesthesia for cardiac surgery reduced the need for postoperative analgesia, which suggested an improvement in patient quality of recovery, it did not appear to reduce the overall incidence of major adverse outcomes or affect hospital length of stay,” concluded Dr. Goldie.
She added that the evident benefits of high spinal anaesthesia need to be weighed against the risk of neuraxial haematoma formation.
“Neuraxial hematoma is rare, about 1 case per 100,000, and so it could not be assessed in a study of about 300 patients. In 15 years at our institution, we have not had this complication,” Dr. Goldie noted.