Wound colonisation following cardiac surgery. Reduction by adjuvant use of preincisional, presternal antibiotic infiltration: a double blind prospective randomised study.

In a double blind, prospective, randomised study of 100 patients undergoing elective cardiac surgery, a significant (p less than 0.01) reduction in wound colonisation, defined as positive culture of any wound discharge irrespective of wound appearance, occurred in those receiving preincisional presternal antibiotic infiltration (2%) as compared to a control group who received a similar volume of normal saline by the same route (24%). Both groups received, in addition, the same conventional intravenous regimen of broad spectrum antibiotic. A comparable concurrent group of patients, not entered into the study, demonstrated a wound colonisation rate similar to the trial control group (22%), thus excluding an adverse bias from the control saline infiltration. Analysis of control cases demonstrated a significant (p less than 0.001) discriminant effect in the degree of preoperative haemodilution with haematocrit falling on bypass by a mean of 25% in those who developed wound colonisation as compared to 13% in those who did not.

Wound prophylaxis in thoracic surgery: a new approach.

A prospective double blind, randomised study was performed in 100 patients undergoing major elective thoracic surgery to assess a new method of prophylaxis of wound infection using one preincisional intraparietal infiltration of cefuroxime sodium along the line of proposed incision as the sole protection against wound infection. A significant (p less than 0.01) reduction in the incidence of wound infection occurred in the antibiotic treated group (2%) compared with the control group (20%), who received by the same route the same volume of saline only. The groups were comparable with respect to age, sex, pathological condition, and operative variables. The use of additional antibiotics was significantly greater in the control group (p less than 0.01), largely owing to a much greater incidence of postoperative pulmonary infection in the control group (60%) than in the antibiotic treated group (40%). No morbidity was associated with this technique. The organisms found in oesophageal and bronchial operative luminal specimens did not correlate with postoperative wound or pulmonary infection or with organisms causing these infections. Reductions in wound and pulmonary infection rates equivalent to those produced by conventional multiple dose parenteral regimens were achieved by this technique.

Surgical management of prosthetic valve endocarditis.

Operative mortality in patients with prosthetic valve endocarditis (PVE), who already have severe hemodynamic failure, is extremely high (35% to 84%). Over a period of 10 years, between 1972 and 1981, fourteen consecutive urgent operations were performed for PVE in 12 patients. On thirteen occasions the patients were in severe hemodynamic failure (NYHA Functional Class IV), and five of them had early PVE (within 60 days of previous operation). In all patients at least two of the other recognized risk factors, such as presence of non-streptococcal organisms, detachment of the prosthesis, and myocardial invasion, were present. All of the patients but one were operated upon within 48 hours of their hemodynamic deterioration, and there was one postoperative death (operative mortality 7%). Our results indicate that an acceptable surgical mortality in patients with intractable heart failure due to early and late PVE can be achieved by prompt surgical intervention despite the presence of multiple risk factors.

Surgical management of native valve endocarditis.

From 1972 to 1981 40 patients have required urgent valve replacement for left-sided bacterial endocarditis. The aortic valve was replaced in 31 patients, the mitral valve in four, and both in five patients. Twenty-six patients (65.5%) were in functional class IV heart failure according to the New York Heart Association criteria, and 13 patients (32.5%) were in class III heart failure at the time of operation. One patient in class II was operated on urgently for multiple cerebral embolism but died of fatal cerebral haemorrhage. In 22 patients (55%) there were no pre-existing valvular lesions and these patients were found to be more liable to develop severe haemodynamic failure. Premature closure of the mitral valve, documented by M-mode echocardiography, was a useful diagnostic aid and successfully determined the best timing of surgery in 14 out of 20 patients with severe aortic regurgitation. Cardiac arrest before operation appeared to be a significant risk factor (p = 0.0015) unless followed by immediate cardiopulmonary bypass. There were eight operative deaths (20%). Of 26 patients who were in functional class IV heart failure, 19 were operated on within four days of their haemodynamic deterioration and all survived. The operation was delayed in the remaining seven patients and none of them survived (p = 0.000003). There were no operative deaths among the patients in class III heart failure. There was only one episode of reinfection in the 16 patients followed up for at least three years. The duration of postoperative antibiotic treatment (four to six weeks in our patients), rather than any preoperative antibiotic regimen, seems to be important for preventing reinfection. At present there are 28 survivors, of whom 24 are in functional class I and four in class II.