Safety Of Cardiac Surgery Research Articles

Prospective assessment of intraoperative precursor events during cardiac surgery☆

Increasing attention has been afforded to the ubiquity of medical error and associated adverse events in medicine. There remains little data on the frequency and nature of precursor events in cardiac surgery, and we sought to characterize this. Detailed, anonymous information regarding intraoperative precursor events (which may result in adverse events) was collected prospectively from six key members of the operating team during 464 major adult cardiac surgical cases at three hospitals and were analyzed with univariable statistical methods. During 464 cardiac surgical procedures, 1627 reports of problematic precursor events were collected for an average of 3.5 and maximum of 26 per procedure. 73.3% of cases had at least one recorded event. One-third (33.3%) of events occurred prior to the first incision, and 31.2% of events occurred while on bypass. While 68.0% of events were regarded as minor in severity (e.g., delays and missing equipment), a substantial proportion (32.0%) was considered major and included anastomotic problems, pump failure, and drug errors. Most problems (90.4%) were reported as being compensated for, although many (30.9%) were never discussed among the team. Major events were more likely to be discussed (p<0.0001) and less likely to have been previously encountered (p=0.0005). Perceptions of the severity and compensation of events varied across the team, as did temporal patterns of reporting (p<0.0001). A wide range of problematic precursor events occurs during the majority of cardiac surgery procedures. Attention to causes and ways of preventing these precursor events could have an impact on the rate of significant errors and improve the safety of cardiac surgery.

Pediatric cardiac surgery after exclusively echocardiography-based diagnostic work-up

This study was performed to evaluate the accuracy of exclusively non-invasive preoperative diagnostic work-up based on echocardiography and to assess the safety of cardiac surgery using this diagnostic approach in children with heart disease. During a 3.5-year period, accuracy of preoperative (invasive and non-invasive) diagnostic work-up was prospectively tested by comparison with the intraoperative findings obtained by surgical inspection and transoesophageal echocardiography. Included were all consecutive 358 children undergoing cardiac surgery (except pulmonary artery bandings and ductus ligations) during the study period at our institution. Of the patients, 44% were operated on in infancy, 84% of procedures were on cardiopulmonary bypass. Echocardiography as the only preoperative imaging modality was used in 231 patients (65%), in the other children, a diagnostic catheter was done. Diagnostic errors occurred in 3.9% ( n=5) of patients after diagnostic catheter and in 6.9% ( n=16) of patients with echocardiography only. Major diagnostic errors (resulting in prolongation of cardiac bypass time) were observed at equal frequency in both groups (1.7% or four children in the echo-only group and 1.6% or two patients in the catheter group). In no case was the outcome affected by the previously unrecognized findings. It was shown that diagnostic cardiac catheterization could be avoided in a majority of pediatric patients prior to surgical palliation or correction of cardiac defects, without increasing the risk of complications or the overall outcome.

Cardioplegia Solutions

The mechanism of action, characteristics and components, dosage and administration, and adverse effects of cardioplegia solution are described. The pharmacist's role in the formulation, preparation, and quality control of cardioplegia solution is also discussed. The use of cardioplegia solution has substantially increased the safety of cardiac surgery. It protects the myocardium by inducing a rapid and complete diastolic arrest, minimizing myocardial energy requirements and preventing ischemic damage during the arrest phase, and minimizing or preventing reperfusion injury once coronary blood flow is restored. Chemical components added to the cardioplegia solution, such as potassium and glucose, are largely responsible for this protective effect. Basic characteristics of cardioplegia solutions include temperature, osmolarity, and pH. Crystalloid solution has traditionally been used as a vehicle for cardioplegia solution; however, laboratory and clinical studies have demonstrated favorable effects of blood-based cardioplegia solution. Single-pass and recirculating delivery systems can be used to administer either crystalloid or blood cardioplegia solutions. Pharmacists can play a major role in the formulation, preparation, distribution, and quality control of cardioplegia solutions; these solutions prevent myocardial injury during the arrest and reperfusion phases of cardiac surgery.

Cardiac surgery in the octogenarian

The increasing safety of cardiac surgery has led to the frequent referral of octogenarians for operation. Between 1980 and 1989, we reviewed our experience with 103 octogenarians (59 male, 44 female; mean age 82 years) to determine the surgical risk factors and outcome in the elderly population. There were 71 coronary bypasses (CABG), 11 aortic valve replacements (AVR), 11 AVR-CABG, 4 mitral valve replacements (MVR), 3 MVR-CABG and 3 AVR-MVR-CABG. Seventeen patients died during hospitalization (16.5%) including 9 CABG (13%); 1 AVR (9%), 2 AVR-CABG (18%), 2 MVR (50%), 1 MVR-CABG (33%) and 2 AVR-MVR-CABG (67%). Statistical analysis of 22 perioperative variables suggested that a preoperative intraaortic balloon, a history of congestive heart failure, mitral valve replacement, urgent operation, need for preoperative inotropic support and the number of anastomoses performed were significant or marginally significant (P less than 0.15) univariate predictors of operative mortality. Multivariate analysis revealed that the need for a preoperative intraaortic balloon (F = 13.1), history of congestive heart failure (F = 6.8), and MVR (F = 6.7) were significant (P less than 0.001) independent predictors of mortality. Postoperative complications included arrhythmias in 36 patients (35%), respiratory insufficiency in 11 (11%), reversible neurological deficit in 15 (14%), and a permanent neurological deficit in 6 patients (6%). Actuarial survival was 90% and 82% at 1 and 2 years, respectively. Seven of 86 (8%) long term survivors sustained a stroke in the follow-up interval. The mean follow-up of survivors was 23 +/- 19 months with a mean improvement in NYHA class of 1.4 (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

A Textbook of Clinical Cardioplegia

This comprehensive volume (498 pages) represents an authoritative reference work on the most important clinical adjunct to the safety of cardiac surgery. The recent resurgence of interest in this modality—introduced by Dennis Melrose in 1955 and soon thereafter abandoned—has led to more investigation and publication during the last five years than any other subject in cardiac surgery. The editors have collected and organized the papers presented at the 1980 International Symposium on Cardioplegia held in London; the invited participants at this symposium were the world's leading authorities on the subject. These presentations by 67 authors are arranged in 34 chapters that address the multiple and controversial aspects of myocardial protection from several viewpoints. That material provides the reader with a plethora of scientific evidence, opinion, and recommendation from which he can derive a sophisticated perspective on the state of the art. The comprehensive material from such multiple sources is inevitably

Prediction of cerebral outcome after extracorporeal circulation.

50 open-heart patients were investigated using simultaneous clinical, electroencephalographical (EEG) and neuropsychological evaluation in order to assess the possibilities of predicting the postoperative outcome with preoperative measures. The presence of one or more of the following indices was prognostically unfavourable: a history of cerebrovascular diseases or syncope; delta or sharp wave EEG abnormalities or low quantitative EEG mean frequency; a poor performance score in one of the psychometric tests (colour naming). Using these measures, 28 cases with presumably high risks were indicated, and 24 (86%) sustained cerebral complications attributable to the operation. The observations contrast clearly with previous studies whose predictions, using only one single criterion, have proved invalid. A significant level of prediction seems to be obtainable, but only by the simultaneous consideration of several different cerebral functions. The prognostic approach may offer one way of achieving the necessarily needed improved cerebral safety in cardiac surgery.