The incidence of acute mesenteric ischaemia is 0.49% of all cases undergoing CPB. A.M.Isc. is a common association with death following CPB (11%). It appears to be significantly associated with the presence of peripheral vascular disease, IABP use, the development of post-operative renal failure, operation type and priority, smoking, duration of CPB and cross-clamp time. Surprisingly, it was not linked to general risk factors for vascular disease.

A raised hemidiaphragm has been reported as an uncommon complication of cardiopulmonary bypass, possibly resulting from cold injury to the phrenic nerve. At Papworth Hospital myocardial protection during cardiac arrest relies in part on irrigation of the pericardial cavity with large volumes of Hartmann's solution at 40C. Retrospective review of the chest radiographs of 100 consecutive patients undergoing cardiopulmonary bypass showed that 31 had a raised left hemidiaphragm soon after operation. The only significant correlation was with aortic cross clamp time (p < 0.03). A prospective study of 36 consecutive patients undergoing cardiopulmonary bypass was then undertaken with diaphragmatic screening and chest radiography. Preoperative screening gave normal results in all patients. In the early postoperative period 16 (44%) had left diaphragmatic weakness or paralysis, two (5.5%) right sided weakness, and two (5.5%) bilateral weakness. Repeat screening of these patients showed resolution in all but four cases (80%) at six months and in all but two (90%) at one year. The greater number of left sided lesions than of right (8:1) is probably due to the fact that the cold jet of irrigating fluid is directed towards the left phrenic nerve. These findings have implications with regard to the optimum temperature of the irrigant fluid for myocardial protection during cardiopulmonary bypass.A raised hemidiaphragm complicating cardiopulmonary bypass has been previously reported.' The incidence is variable and the aetiology remains uncertain but has been attributed to cold injury of the left phrenic nerve.' 2 Gastric distension, left lower lobe atelectasis, pulmonary trauma,2 stretch trauma,6 and association with dissection of the left internal mammary artery-have also been proposed.We recently noted that a raised left hemidiaphragm on postoperative chest radiographs of patients undergoing open heart operations was relatively common in our unit. These investigations were undertaken to define the incidence, duration, and possible aetiology of this complication. Patients and methodsA retrospective review of the previous 100 consecutive patients undergoing operations with cardiopulmonary bypass during 1982 was undertaken. Their Address for reprint requests: Mr SR Large, Surgical Unit, Papworth Hospital, Papworth Everard, Cambridge CB3 8RE.Accepted 10 January 1985 mean age was 54 years (range 11-77) and 27 were women. The immediate preoperative, early postoperative (8-10 days), and late postoperative (6 months) posteroanterior chest radiographs were studied. The highest point of the left hemidiaphragm was compared with that of the right. If the point on the left was at the same horizontal level or higher than that on the right it was described as raised. An estimate of the incidence of raised left hemidiaphragm soon after operation and its subsequent resolution by six months was made.To investigate the aetiology of this complication the early postoperative incidence was compared in different groups of patients with rega...

Argatroban may be useful as an anticoagulant in the field of cardiovascular surgery as a substitute for heparin, without causing any post-surgery bleeding complication, or influencing the fibrinolytic activities or platelet functions.

Severe pulmonary oxygenation impairment resulting from peripheral lung atelectasis occurred in some patients with pleurotomy during the harvest of the internal mammary artery graft followed by coronary artery bypass grafting (CABG). We studied the efficacy of intraoperative positive end-expiratory airway pressure (PEEP) therapy for the prevention of postoperative pulmonary oxygenation impairment. A total of 66 patients with solitary CABG procedure were included in this study. The pleural cavity was intraoperatively opened in 44 patients and not opened in 22. PEEP therapy was not used in any patient before May 1996 (referred to herein as the former period) and was used more recently in eight patients with pleurotopmy (referred to herein as the latter period). PEEP was initiated immediately after pleurotomy during the harvest of the internal mammary artery graft. Without PEEP therapy, values of PaO2, A-aDO2, and respiratory index (RI) were worse in patients with pleurotomy than in those without pleurotomy. Meanwhile, there were no major differences in these values between patients with or without pleurotomy after the induction of PEEP therapy. Respiratory insufficiency (A-aDO2 > 400 mmHg and RI > 1.5) was detected in six patients with pleurotomy in the former period. Three of these six patients required over 1 week of long-term mechanical respiratory support. No respiratory insufficiency occurred in patients of the latter period. In conclusion, PEEP therapy, which is initiated just after pleurotomy, may prevent oxygen impairment and pulmonary atelectasis after extracorporeal circulation (ECC) and is recommended for patients with pleurotomy, especially for patients with preoperative low respiratory function.

A man with a crush injury of his upper abdomen developed bilateral pulmonary empyema after repair of tears of the oesophagus and liver. Attempts to withdraw chest drains led to recurrent septicaemia, treated by reinsertion of the drains plus administration of antibiotics. The communication of the empyema space with both the bronchial tree and the oesophagus was managed successfully with intermittent positive pressure ventilation and with a double lumen endobronchial tube isolating the right lung for 10 days. Traumatic rupture of the thoracic oesophagus carries a high mortality and prompt repair is vital.Reports of oesophageal rupture following blunt thoracic or abdominal trauma are rare. The first, in 1936,' described the unsuccessful result in a case of blunt traumatic rupture of the lower third ofthe thoracic oesophagus. A review ofpublished reports of this unusual and therefore unsuspected injury follows the presentation of our case. Case reportA 19 year old labourer was transferred to St Bartholomew's Hospital, having sustained a crush injury of his upper abdomen after being pinned to a wall by a dumper truck for seven minutes. His presenting complaint was of lower chest and upper abdominal pain, and on examination he had bruising over this region. His blood pressure was 90/ 60 mm Hg and pulse rate 145 beats/minute, and he was afebrile. The chest radiograph confirmed the clinical signs of a left pleural effusion and showed no evidence of traumatic gastric herniation. A left sided intrathoracic chest drain was inserted and partially digested food was drained.The patient was taken to the operating theatre with a presumptive diagnosis of a ruptured oesophagus. Through a left thoracolaparotomy the left pleural cavity, soiled by gastric contents, was washed out. The mediastinal pleura and disrupted lower third of the oesophagus could then be seen. The oesophageal tear was primarily repaired with two layers of prolene sutures. Bleeding was noted from below the diaphragm. This was from a linear tear in the diaphragmatic surface of the right lobe of the liver, and was repaired by direct suture via a right thoracotomy. The right chest cavity was also soiled, and was therefore cleaned and drained. His Address for reprint requests: Mr S