Ola D. Sæther

Causes of Cancellations on the Day of Surgery at Two Major University Hospitals

Cancellations of elective cases on the day of surgery waste valuable operating-room time. The authors studied cancellations at an American hospital and a Norwegian university hospital to test (a) whether the quality of hospital administrative data on cancellations is sufficient for meaningful comparative analysis and (b) whether causes of cancellations at these 2 major academic hospitals are comparable. Large retrospective cause-of-cancellation data sets were obtained from each hospital. The authors then prospectively established root causes of cancellations by on-site investigation and interviews of the hospital personnel involved. The surgical department at the Norwegian hospital cancelled 14.58% of cases in 2003 and 16.07% in 2004. The American hospital cancelled 16.52% of all cases between May 1, 2003, and April 30, 2004. Administrative data may give a rough picture of causes of cancellations. However, most findings at either of the hospitals do not translate easily to the other.

Shunting of the Coeliac and Superior Mesenteric Arteries during Thoracoabdominal Aneurysm Repair

OBJECTIVES To describe our experience with shunting of the coeliac and superior mesenteric arteries during thoracoabdominal aneurysm repair. DESIGN Retrospective study. MATERIAL Eight patients undergoing resection and graft replacement of Crawford type III (5) and type IV (3) thoracoabdominal aortic aneurysms were included in this series. One patient had rupture, four were symptomatic and three were operated on electively. METHODS A vascular graft with a sidearm was applied for the reconstructions. A T-shunt was connected to the sidearm. Following completion of the proximal anastomosis the shunt was inserted into the coeliac and superior mesenteric arteries. The anastomoses to these arteries and the renal arteries were then completed. Finally the distal anastomosis was performed. RESULTS There was no early mortality (30 days). One patient had postoperative paraparesis, but recovered quite well. Reoperation became necessary due to sigmoid necrosis in one patient and due to haemorrhage in another. During the follow-up period four patients died but the other patients are alive between 3 and 8 years after surgery. CONCLUSION The application of shunting of the superior mesenteric and coeliac arteries during thoracoabdominal aortic surgery is feasible and the results have been acceptable. Further investigation of the optimal blood flow needed to avoid intestinal ischaemia in a larger series of patients is desirable.

Microdialysis of the spinal cord during thoracic aortic cross-clamping in a porcine model.

Objective: Utilising microdialysis to measure the changes of glucose, lactate, pyruvate and glutamate levels in the spinal cord after cross-clamping of the thoracic aorta in an established porcine model to monitor the degree of ischaemia. Design: Experimental study with a porcine model. Setting: University Hospital, Trondheim. Subjects: Six pigs. Main outcome measure: Lactate, pyruvate and glutamate concentrations in the microdialysis perfusate from the spinal cord. Results: A significant increase of the lactate-pyruvate ratio during the last 30 min of the 1 h clamping period, with a maximum increase of 169% from the basal value the last 10 min before declamping. No evident change in this ratio between the clamping and the reperfusion period. No significant change in glutamate levels during clamping or reperfusion period. Conclusion: Microdialysis reflects the ischaemic state of the spinal cord during cross-clamping of the thoracic aorta in pigs, and is well suited to study each phenomena. Spinal Cord (2000) 38, 153–157.

Cardiac output measurements during cross‐clamping of the descending thoracic aorta in pigs

Background: Cross‐clamping of the descending thoracic aorta (XC) induces an increase in cardiac output (CO). The intention of this study was to evaluate the high CO during XC by the use of clinically available methods (thermodilution and pulsed Doppler ultrasound) compared to transit‐time ultrasound flowmetry of the ascending aorta as the gold standard.

Excessive increase in circulating catecholamines during cross-clamping of the descending thoracic aorta in pigs

The purpose of this study was to determine the plasma catecholamine response to cross-clamping of the descending thoracic aorta in pigs and to relate the plasma catecholamine response to cardiac output during cross-clamping. This prospective, controlled animal study was done at the University Hospital of Trondheim, Norway. Eight pigs (19–25 kg) underwent cross-clamping of the descending thoracic aorta for 30 minutes. The time course of plasma adrenaline, plasma noradrenaline, and ascending aortic blood flow were measured. It was found that the increase of plasma catecholamines during cross-clamping of the descending thoracic aorta in pigs was parallel to the increase of aortic blood flow during cross-clamping. Plasma adrenaline increased from 0.22 nmol/L to a maximum of 11.75 nmol/L and plasma noradrenaline increased from 0.17 nmol/L to a maximum of 46.92 nmol/L after 10 minutes of cross-clamping (p=0.01). Ascending aortic blood flow increased from 2.6 L/minute to a maximum of 4.7 L/minute after 10 minutes of cross-clamping (p=0.01). Our findings support the theory that increased plasma catecholamines might be a mechanism of increased cardiac output during cross-clamping of the descending thoracic aorta. The increase of plasma catecholamines during cross-clamping is most likely due to distal hypotension with increased sympathetic activity.

Proximal subcutaneous interstitial fluid pressure during cross-clamping of the descending thoracic aorta: A study of patients operated on for thoracic-or thoracoabdominal aortic aneurysms

Seven patients were operated on for thoracic (n=2) or thoracoabdominal (n=5) aortic aneurysms during cross-clamping of the aorta. Interstitial tissue fluid pressure was measured at the neck during cross-clamping of the descending thoracic aorta by the wick-in-needle technique, whereas control measurements were obtained prior to cross-clamping. The subcutaneous interstitial fluid pressure was significantly higher on the neck during cross-clamping of the thoracic aorta compared with control measurements (median 3.7 mmHg vs −0.6 mmHg, p<0.05). Increased subcutaneous interstitial tissue pressure of the upper part of the body is probably caused by increased capillary filtration rate induced by inhibited autoregulatory functions during aortic cross-clamping. The pressure measurements objectively confirm the problem of edema formation of the head and neck during these operations. The edema may occasionally affect the upper airways and represent a problem for intubation of the patient in the postoperative phase.

Haemodynamic effects of thoracic epidural anaesthesia during proximal aortic cross-clamping in pigs

Cross‐clamping (XC) of the thoracic aorta induces a hyperdynamic circulation proximal to the aortic clamp. In this investigation, the effects of thoracic epidural anaesthesia (TEA) on the haemodynamic response to XC were studied in pigs. Seventeen pigs were anaesthetized with ketamine, and the thoracic aorta was cross‐clamped for 30 minutes. In eight of the animals (TEA‐group) a thoracic epidural block (3 ml 0.5% bupivacaine) was added to the general anaesthesia.

Delayed-onset Paraplegia after Thoracic and Thoracoabdominal Aortic Aneurysm Repair: Reversal with Cerebrospinal Fluid Drainage

Abstract Objectives: To discuss the management of late paraplegia following thoracic and thoracoabdominal aortic surgery. Design: Retrospective description of patients. Materials: Two case reports. Results: Recovery from late paraplegia was obtained by removal of cerebrospinal fluid. Conclusions: The immediate recovery from symptoms following CSF drainage strongly supports the effect of this measure in the treatment of late paraplegia following thoracic/thoracoabdominal surgery.

Rate of avoidable deaths in a Norwegian hospital trust as judged by retrospective chart review

Background The proportion of avoidable hospital deaths is challenging to estimate, but has great implications for quality improvement and health policy. Many studies and monitoring tools are based on selected high-risk populations, which may overestimate the proportion. Mandatory reporting systems, however, under-report. We hypothesise that a review of an unselected sample of hospital deaths will provide an estimate of avoidability in-between the estimates from these methods. Methods A retrospective case record review of an unselected population of 1000 consecutive non-psychiatric hospital deaths in a Norwegian hospital trust was conducted. Reviewers evaluated to what degree each death could have been avoided, and identified problems in care. Results We found 42 (4.2%) of deaths to be at least probably avoidable (more than 50% chance of avoidability). Life expectancy was shortened by at least 1 year among 34 of the 42 patients with an avoidable death. Patients whose death was found to be avoidable were less functionally dependent compared with patients in the non-avoidable death group. The surgical department had the greatest proportion of such deaths. Very few of the avoidable deaths were reported to the hospital’s report system. Conclusions Avoidable hospital deaths occur less frequently than estimated by the national monitoring tool, but much more frequently than reported through mandatory reporting systems. Regular reviews of an unselected sample of hospital deaths are likely to provide a better estimate of the proportion of avoidable deaths than the current methods.