Colin Royse

Prospective randomized trial of high thoracic epidural analgesia for coronary artery bypass surgery

BACKGROUND Postoperative pain may be severe after coronary artery bypass surgery. High thoracic epidural analgesia (HTEA) provides intense analgesia. METHODS Eighty patients were randomized to HTEA or intravenous morphine analgesia (control). Patients received coronary artery bypass surgery (CABG) with cardiopulmonary bypass. Pain was measured by visual analogue scale 0 to 10. Psychologic morbidity, intraoperative hemodynamics, ventricular function, lung function, and physiotherapy cooperation were also assessed. On the third postoperative day HTEA and morphine were ceased and only oral medications were used. Acetaminophen, indomethacin, and tramadol were allowed as supplemental analgesics in both groups. RESULTS The primary endpoint of pain scores was significantly less with HTEA on postoperative days 1 and 2 at rest, 0.02 +/- 0.2 versus 0.8 +/- 1.8 (p = 0.008) and 0.1 +/- 0.4 versus 1.2 +/- 2.7 (p = 0.022), respectively, and with coughing 1.2 +/- 1.7 versus 4.4 +/- 3.1 (p < 0.001) and 1.5 +/- 2.0 versus 3.6 +/- 3.1 (p = 0.001), respectively. When HTEA and morphine were ceased on day 3, there were no significant differences. The secondary endpoints of postoperative depression (p = 0.033) and posttraumatic stress subscales (p = 0.021) of the Minnesota Multiphasic Personality Inventory were lower with HTEA. Extubation occurred earlier with HTEA, 2.6 versus 5.4 hours (p < 0.001). HTEA showed improved physiotherapy cooperation (p < 0.001), arterial oxygen tension (p = 0.041), and peak expiratory flow rate (p = 0.001). Mean arterial pressure was lower with HTEA (p = 0.036), otherwise there were no differences in intraoperative hemodynamics or ventricular function. CONCLUSIONS Epidural analgesia reduces pain after coronary operation and is associated with improved physiotherapy cooperation, earlier extubation, and reduced risk of depression and posttraumatic stress.

Plasma ropivacaine concentrations after ultrasound-guided transversus abdominis plane block

BACKGROUND The transversus abdominis plane block is a novel technique involving injection of local anaesthetic between the internal oblique and the transversus abdominis muscles of the abdominal wall. It is possible that injection of a large dose of local anaesthetic into a relatively vascular plane may result in toxic concentrations. One previously published study examined plasma lidocaine concentrations after transversus abdominus plane block and showed potentially toxic plasma concentrations. Although ropivacaine is most commonly used for this technique, plasma concentrations of ropivacaine after this block have not been reported previously. METHODS Adult female patients undergoing elective open gynaecological surgery received bilateral ultrasound-guided transverse abdominal plane blocks before surgical incision (3 mg kg(-1) of ropivacaine diluted to 40 ml). Venous blood was collected each 15 min for the first hour, each 30 min for the second hour, and then at 3, 4, 12, and 24 h post-block. RESULTS Twenty-eight patients were recruited. The mean (sd) peak total ropivacaine concentration occurred 30 min post-injection and was 2.54 (sd 0.75) µg ml(-1). The highest measured concentration was 4.00 µg ml(-1), also 30 min post-injection. Mean total concentrations remained above 2.20 µg ml(-1) for up to 90 min post-injection. The mean unbound peak venous concentration was 0.14 (0.05) µg ml(-1), and the peak was 0.25 µg ml(-1). CONCLUSIONS Transversus abdominus plane block using 3 mg kg(-1) of ropivacaine produces venous plasma concentrations that are potentially neurotoxic, although broadly consistent with plasma levels found after injection at other comparable sites.

Development and feasibility of a scale to assess postoperative recovery: the post-operative quality recovery scale.

Background:Good postoperative recovery is increasingly recognized as an important outcome after surgery. The authors created a new Post-operative Quality Recovery Scale (PQRS) that tracks multiple domains of recovery from immediate to long-term time periods in patients of varying ages, languages, and cultures. Methods:The parameters of importance to both clinicians and patients were identified. After an initial pilot study of 133 patients, the PQRS was refined. It consists of six domains (physiologic, nociceptive, emotive, activities of daily living, cognitive, and overall patient perspective). An observational study of 701 patients was performed with the refined PQRS to assess its capacity to evaluate and track recovery and to discriminate between patients. It was conducted in eight countries and in five languages, involving patients more than or equal to 6 yr undergoing elective surgery with general anesthesia. Recovery was assessed before surgery and at multiple time periods postoperatively. Recovery was defined as return to baseline values or better. Results:Seven hundred one patients completed the PQRS. Mean completion time was 4.8 (SD 2.8) min. Recovery scores improved with time. Physiologic recovery was complete in 34% of subjects by 40 min. By the third postoperative day, complete recovery was obtained in 11% of cases (all domains): 48.7% nociceptive, 81.8% emotive, 68.8% activities of daily living, and only 33.5% cognitive. Overall, 95.8% of the patients reported that they were “satisfied or totally satisfied” with their anesthetic care. Conclusion:The scores on the PQRS demonstrated an improvement over time, consistent with an expected recovery after surgery and anesthesia, and an ability to discriminate between individuals. Many patients had incomplete recovery by the third postoperative day.

Radial artery harvest technique, use and functional outcome

OBJECTIVE To develop a simple harvest technique for radial artery (RA). To investigate the morbidity and functional outcome of RA harvest. METHODS The neurovascular fascia surrounding the RA is divided. Only loose areolar tissue surrounds this artery making harvest of RA simple and allowing minimal trauma to the RA and surrounding muscles. Topical and intraluminal vasodilators but no systemic vasodilators are used. RESULTS RA harvest commenced in December 1994. Between 1996 and 30 June 1998, 2167 RA were harvested and used to construct 3105 coronary anastomoses. A dramatic rise in RA use occurred during 1996. More than 80% of patients undergoing coronary artery bypass surgery (CABG) have RA harvested since this time. Total arterial revascularization rate also rose dramatically and is currently 80% of all CABG. This rate has been assisted by a rapid rise in the use of composite arterial grafting where aortic anastomoses can be avoided and currently represents 40% of all CABG. Hand strength was tested in 328 non-selected patients and was not reduced by RA harvest when hand dominance was taken into account. Objective sensation loss was present in 0.3% for the superficial radial nerve and 2.1% for the lateral cutaneous nerve of forearm. Pulse oximetry observations detected statistically significant but clinically irrelevant differences. Scar hypersensitivity occurred in 20%. Only two patients of all patients undergoing RA harvest reported late hand ischaemia. CONCLUSIONS Harvest of the RA within the neurovascular plane is simple and associated with low morbidity.

Blood Flow in Composite Arterial Grafts and Effect of Native Coronary Flow

BACKGROUND Total arterial coronary revascularization can be achieved by joining arteries together as a composite graft with the proximal left internal mammary artery as the only source of blood inflow. Proof of the capacity of this composite conduit to provide adequate blood flow to the coronary circulation is required. METHODS The radial artery was anastomosed to the left internal mammary artery as a Y graft in 17 patients and all coronary arteries grafted. Intraoperative blood flow through the composite grafts was evaluated by the transit-time Doppler technique. RESULTS Against no resistance, blood flow in the left internal mammary artery alone was 99 +/- 9 mL/min and rose to 173 +/- 16 mL/min when the radial artery was anastomosed as a Y graft. Composite-graft flow following grafting was 88 +/- 9 mL/min, 49 +/- 6 mL/min when the aortic clamp was removed and native coronary flow restored and 82 +/- 13 mL/min following weaning from cardiopulmonary bypass. The maximal potential flow through the composite graft was 2.3-fold (95% CI 1.6 to 3.2) greater than that after cardiopulmonary bypass. CONCLUSIONS Total arterial revascularization, using a composite graft, provided a 2.3-fold reserve of blood flow to the coronary vascular bed through the grafts.

Routine immediate extubation after cardiac operation: a review of our first 100 patients

BACKGROUND Early extubation after cardiac operation is an important aspect of fast-track cardiac anesthesia. Immediate extubation is an extension of this concept. We describe a technique that allows immediate extubation in the majority of patients. METHODS To allow rapid emergence, anesthesia was modified from a high-dose opioid technique to intravenous propofol anesthesia supplemented with sevoflurane. Normothermic cardiopulmonary bypass was used with routine intermittent antegrade and retrograde tepid blood cardioplegia. High thoracic epidural analgesia was used to facilitate immediate extubation in the majority of patients. Contraindications to immediate extubation were prolonged cardiopulmonary bypass (CPB) (>2.5 hours), hemodynamic instability, uncontrolled bleeding, morbid obesity, severe pulmonary hypertension, congestive cardiac failure, or if the operation was emergent. RESULTS Of 109 consecutive patients, 100 were immediately extubated (92%). No patient required reintubation within the first 24 hours after operation. One patient required reintubation 3 days after operation for sputum retention, and 2 patients required reoperation. There was no mortality and the incidence of perioperative morbidity was low. CONCLUSIONS Immediate extubation after cardiac operation can be safely achieved and is possible in a majority of patients.

Symptomatic local anaesthetic toxicity and plasma ropivacaine concentrations after transversus abdominis plane block for Caesarean section

BACKGROUND The transversus abdominis plane (TAP) block involves injecting a large volume of local anaesthetic between the muscles of the abdominal wall. Plasma concentrations of ropivacaine after gynaecological laparotomy are potentially high enough to result in systemic toxicity, and there are pharmacokinetic reasons why pregnancy may increase susceptibility to local anaesthetic toxicity. METHODS Adult female patients (n=30) undergoing elective Caesarean section under spinal anaesthesia received bilateral ultrasound-guided TAP blocks after wound closure (2.5 mg kg(-1) of ropivacaine diluted to 40 ml). Venous blood samples were collected at 10, 20, 30, 45, 60, 90, 120, 180 and 240 min following the block. Blood samples were assayed for total and free ropivacaine concentrations. Patients were assessed for symptoms of local anaesthetic toxicity. RESULTS The mean [standard deviation (SD)] peak total concentration of ropivacaine occurred at 30 min post-injection and was 1.82 (0.69) μg ml(-1). The maximum detected concentration in any patient was 3.76 μg ml(-1) (at 10 min post-injection). Three patients reported symptoms of mild neurotoxicity, and the mean (SD) peak levels were elevated in these patients, 2.70 (0.46) µg ml(-1). CONCLUSIONS TAP blocks can result in elevated plasma ropivacaine concentrations in patients undergoing Caesarean section, which may be associated with neurotoxicity.

Audit of anaesthetist-performed echocardiography on perioperative management decisions for non-cardiac surgery

BACKGROUND Intraoperative transoesophageal echocardiography is increasingly used for guiding intraoperative management decisions during non-cardiac surgery. Transthoracic echocardiography (TTE) equipment and training is becoming more available to anaesthetists, and its point-of-care application may facilitate real-time haemodynamic management and preoperative screening. METHODS We conducted an audit of transthoracic and transoesophageal echocardiograms, performed by an anaesthetist at a tertiary referral centre over a 9-month period, to identify the effect of echocardiography on clinical decision-making in patients undergoing non-cardiac surgery. The indications for echocardiography followed published guidelines. RESULTS Echocardiographic examinations of 97 patients included 87 transthoracic, and 14 transoesophageal studies. Of 36 studies conducted in the preoperative clinic, eight revealed significant cardiac pathology, necessitating cardiology referral or admission before surgery. Preoperative transthoracic echocardiograms performed on the day of surgery (n=39) led to two cancellations of surgery owing to end-stage cardiac disease, the institution of two unplanned surgical procedures (drainage of pleural and pericardial effusions), and to significant changes in anaesthetic and haemodynamic management, or both in 18 patients. Greater influence on management occurred with emergency surgery (75%) than elective surgery (43%). Intraoperative transthoracic (n=10) and transoesophageal (n=14) echocardiography also altered management (altered surgery in two patients, cancellation in one, and altered haemodynamic management in 18 patients). CONCLUSIONS Anaesthetist-performed point-of-care TTE and thoracic ultrasound may have a high clinical impact on the perioperative management of patients scheduled for non-cardiac surgery.

Transversus abdominis plane block does not provide additional benefit to multimodal analgesia in gynecological cancer surgery.

BACKGROUND: The transversus abdominis plane (TAP) block is a recently described technique involving injecting local anesthetic between the internal oblique and transversus abdominis layers of the abdominal wall. It has been shown to be effective in reducing morphine consumption and improving postoperative pain relief in several clinical settings. METHODS: We performed a randomized placebo-controlled trial comparing bilateral ultrasound-guided TAP blocks (2 × 20 mL 0.5% ropivacaine or 0.9% saline) in adult female patients undergoing midline laparotomy for known or presumed gynecological malignancy. Both groups received multimodal IV analgesia. The primary outcomes for the study were defined as the incidence of “inadequate” analgesia (defined as a score >50 mm on a visual analog scale) with forced expiration at 2 hours postoperatively and total postoperative morphine consumption at 2 hours and 24 hours. RESULTS: Data from 65 patients were included in the study. The groups were comparable in terms of age, weight, surgical duration, and intraoperative morphine doses. There were no significant differences between the control and treatment groups in the proportion of patients with inadequate analgesia either at rest (39% vs. 22%, P = 0.13) or with coughing (61% vs. 53%, P = 0.54) at 2 hours. There was no significant difference in postoperative morphine consumption between the placebo and treatment groups at 2 hours (13.5 mg vs. 11.87 mg, P = 0.53) or 24 hours (34.0 mg vs. 36.1 mg, P = 0.76). There were no significant differences in the incidence of opioid side effects or patient satisfaction. CONCLUSION: This study demonstrated that TAP blockade conferred no benefit in addition to multimodal analgesia in women undergoing major gynecological cancer surgery.

Exclusive Y graft operation for multivessel coronary revascularization

BACKGROUND The pedicled (in-situ) left internal mammary artery grafted to the left anterior descending artery has a very high late patency and reduces late mortality following coronary artery bypass surgery. A technique is described which achieves total arterial revascularization in patients with multivessel coronary disease and which is also entirely pedicled. METHODS Using the left internal mammary artery and radial artery joined as a composite Y graft, all coronary territories may be grafted. RESULTS One in-hospital death from 464 patients (0.2%) occurred. Age (mean +/- standard error) was 64.7 +/- 0.5 years and number of distal anastomoses 3.4 +/- 0.04. Of 1,681 patients from Royal Melbourne Hospital, 346 had this operation. Comparison found no preoperative selection bias and no postoperative differences in complications. Actuarial survival was 0.98 +/- 0.01 at 36.1 +/- 0.3 months. CONCLUSIONS Total arterial revascularization may be performed using the left internal mammary artery and radial artery as a composite Y graft. There was no increase in complications. This technique preserves the left internal mammary artery to left anterior descending artery graft.