I Birdi

The effects of cardiopulmonary bypass temperature on inflammatory response following cardiopulmonary bypass

OBJECTIVES The inflammatory response to cardiopulmonary bypass is believed to play an important role in end organ dysfunction after open heart surgery and may be more profound after normothermic systemic perfusion. The aim of the present study was to investigate the effects of cardiopulmonary bypass temperature on the production of markers of inflammatory activity after coronary artery surgery. METHODS Forty-five low risk patients undergoing elective coronary artery surgery were prospectively randomized into three groups: hypothermia (28 degrees C, n = 15), moderate hypothermia (32 degrees C, n = 15), and normothermia (37 degrees C, n = 15). All patients received cold antegrade crystalloid cardioplegia and topical myocardial cooling with saline at 4 degrees C. Serum samples were collected for the estimation of neutrophil elastase, interleukin 8, C3d, and IgG under ice preoperatively, 5 min after heparinisation, 30 min following start of CPB, at the end of CPB, 5 min after protamine administration, and 4, 12 and 24 h postoperatively. RESULTS Patients were similar with regard to preoperative and intraoperative characteristics (age, sex, severity of symptoms, number of grafts performed, aortic cross clamp time, cardiopulmonary bypass time). Neutrophil elastase concentration increased markedly as early as 30 min after the onset of cardiopulmonary bypass and peaked 5 min after protamine administration. Levels were not significantly different between the three groups. A similar finding was apparent for C3d release. Interleukin 8 concentrations also demonstrated a considerable increase related to cardiopulmonary bypass in all groups, but there was a significantly more rapid decline in interleukin 8 concentrations in the normothermic group in the postoperative period. Eluted IgG fraction showed a much earlier peak concentration than the other markers, occurring within 30 min of the start of cardiopulmonary bypass. Levels reached a plateau, before declining soon after the end of bypass and remained higher than preoperative values at 24 h. There was no difference between the three groups. The cumulative release of all markers was calculated from the concentration-time curves, and was not statistically different between groups. CONCLUSION Normothermic systemic perfusion was not shown to produce a more profound inflammatory response compared to hypothermic and moderately hypothermic cardiopulmonary bypass.

Emergency reinstitution of cardiopulmonary bypass following cardiac surgery: outcome justifies the cost

OBJECTIVE Crash back on bypass (crash-BOB) is occasionally required in the resuscitation of patients developing life-threatening complications following cardiac surgery. This study aims to determine the incidence, aetiology and cost-effectiveness of such intervention. METHODS Retrospective review of all crash-BOB patients over 5.5 years at one hospital. RESULTS The incidence of crash-BOB was 0.8% and occurred at a mean of 7 h post-operatively (range 1 h-20 days). Pre-operative Parsonnet scores were similar to the overall population of patients undergoing surgery in our institution (mean score 10; range 0-45). The original cardiac operations were coronary revascularization (39), valve surgery (12) and others (4). Indications for crash-BOB were cardiac arrest (23), bleeding (20), hypotension (7), ischaemia (1) and others (4). Of the 55 patients, 20 died on the operating table. Of the remaining 35, a further 12 died in hospital. Overall survival was therefore 42%. Where crash-BOB was for bleeding, 17 of 20 patients (85%) survived to leave theatre, of whom 11 patients (55%) left hospital alive. In the 35 non-bleeders, only 18 (51%) survived crash-BOB and 12 (34%) left hospital alive. Sixteen patients required a second period of aortic cross-clamping of whom 13 (81%) survived to leave theatre, and 11 (69%) left hospital alive. Conversely, of nine patients in whom no specific diagnosis was found during crash-BOB, only two (22%) survived the procedure and none survived to hospital discharge. Multiple logistic regression identified pre-operative Parsonnet score (P=0.045) and the need for aortic cross-clamping to deal with an identified surgical problem (P=0.03) as significant predictors of hospital survival. Indication for crash-BOB (bleeder/non-bleeder) failed to reach significance (P=0.08). Age, sex, intra-aortic balloon pump use at the primary procedure, and time following the primary procedure to crash-BOB were not identified as predictors of hospital survival. Of the 23 hospital survivors, three patients suffered a stroke post-operatively and made a good functional recovery prior to discharge. Two patients developed sternal wound dehiscence requiring surgical rewiring. At follow-up (mean 3 years, range 1-6 years), 19 patients were in NYHA class I and four were in class II. Crash-BOB patients required an average of 8 extra intensive care days and 2 extra ward days. The total cost of these resources was pound164900 (including theatre time, cardiopulmonary bypass and intra-aortic balloon pump use). This was equivalent to pound7170 per life saved. CONCLUSIONS Crash-BOB occurred in 0.8% of cases and was associated with a survival to discharge of 42%, and a justifiable cost of only pound7170 per life saved. Establishing an accurate diagnosis for the cause of clinical deterioration resulting in crash-BOB intervention was important, and the need for a further period of aortic cross-clamping did not preclude a favourable outcome.

Surgical correction of postpneumonectomy stridor by saline breast implantation.

Postpneumonectomy syndrome is a rare complication of pneumonectomy and is characterized by progressive dyspnea, stridor, and repeated chest infections. It is caused by displacement and rotation of the mediastinal structures into the pneumonectomy space, producing compression and malacic changes in the trachea and remaining bronchus. We report the successful long-term results of mediastinal correction, cardiopexy and plombage with saline breast prostheses in a 59-year-old man after right pneumonectomy for carcinoma of the lung.

DETECTION AND PREVENTION OF MYOCARDIAL DAMAGE DURING OPEN HEART SURGERY

Perioperative myocardial injury is a major cause of morbidity and mortality after open heart surgery. Advances in myocardial protection and a greater understanding of the mechanisms of cellular damage have been central to the improving results of adult and paediatric cardiac surgery. The development of reliable methods to quantify the degree of perioperative myocardial injury is of particular importance for the evaluation of different cardioprotective, operative, anaesthetic, and perfusion strategies.

Intraoperative confirmation of ulnar collateral blood flow during radial artery harvesting using the “squirt test”

Hand ischemia is a major concern after radial artery harvesting for coronary revascularization. Although a number of preoperative tests have been described to assess the adequacy of ulnar collateral blood flow, many of them are subjective and unreliable. In addition, the presence of arterial connections between the radial and ulnar systems in the elbow and forearm and variability in forearm angiology imply that assessment of alternative blood supply to the hand can only be made once collateral branches of the radial artery have been divided. We describe a technique for intraoperative assessment of ulnar collateral blood flow after mobilization and division of collateral branches of the radial artery.

In-hospital audit underestimates early postoperative morbidity after cardiac surgery.

BACKGROUND--The demand for open heart surgery has driven current practice towards early postoperative discharge and interhospital transfer to maximise patient throughput. The extent to which this redirects morbidity to other healthcare providers is unknown. OBJECTIVE--To define the incidence of inhospital and early postoperative morbidity within 6 weeks of primary hospital discharge after cardiac surgery. DESIGN--Prospective inhospital data for 322 consecutive adult patients undergoing cardiac surgery were compared with retrospective information obtained by postal questionnaire. RESULTS--Mean (SD) primary postoperative hospital stay was 8.3 (3.1) days. There were 13 inhospital deaths (4%), and three patients died within 6 weeks of primary discharge. Retrospective information was obtained from 297 patients (96%). Of these, 77% patients were discharged home directly, while 23% were transferred to other hospitals for continued medical care. Mean (SD) hospital stay after transfer was 12 (8.4) days and required 741 additional hospital bed days. Thirty nine patients (13%) were readmitted to hospital, requiring a further 275 hospital bed days. The readmission rate was lower in patients sent home directly (10%), than in those who were transferred (22%; P < 0.001). CONCLUSIONS--Inhospital audit underestimates early morbidity after cardiac surgery. The burden transferred to other healthcare providers is considerable and has important financial implications for purchasers.