In non-COPD patients with persistent acute respiratory failure after early extubation, NPPV improved pulmonary gas exchange and breathing pattern, decreased intrapulmonary shunt fraction, and reduced the work of breathing.

Cardiac surgery using cardiopulmonary bypass (CPB) often induces a systemic inflammatory response syndrome (SIRS). The concept of minimally invasive direct coronary artery bypass (MIDCAB) eliminates cardiopulmonary bypass. We evaluated the perioperative time course of procalcitonin (PCT) to compare the inflammatory response due to these two different surgical procedures. 57 patients were studied: CABG with CPB (n = 30), MIDCAB without CPB (n = 27). The following data were measured preoperatively, after induction of anesthesia, after separation from CPB in the CABG group or after left internal mammary artery (LIMA)-to-left anterior descending artery (LAD) anastomosis in MIDCAB group, and every 3 hours for the first 42 hours in the ICU: PCT, C-reactive protein (CRP), body temperature, hemodynamic parameters, and the need for catecholamines. Leucocyte counts were measured daily. For statistical analyses the Friedmann, Wilcoxon, or Mann-Whitney U tests were used. PCT in the CABG group rose to a maximum of 2.0 ng/ml (median) at 15 hrs postoperatively. In the MIDCAB group maximal PCT concentration was 0.7ng/ml (median) (p < 0.05). CRP was elevated to 17.1 mg/dl in the CABG and 18.5mg/dl in the MIDCAB group (n.s.). The leucocyte counts were increased on day 2 in the CABG group (p < 0.05). In the CABG group about 25% of the patients needed noradrenaline, but in the MIDCAB group none (p < 0.05). Body temperature did not differ between both groups. The increase in PCT concentration was more pronounced after CABG, indicating a reduced inflammatory response after MIDCAB. CRP was increased after both procedures. PCT reflects the inflammatory response after cardiac bypass surgery with or without CPB.

We report a 56-year-old male patient developing hypoxemia after surgical replacement of infected valves of a left ventricular assist device (LVAD, Novacor) which had supported him during the previous 15 months. Contrast transesophageal echocardiography (TEE) revealed an atrial septal defect with intermittent right-to-left shunt across a patent foramen ovale. We postulate that the shunt detected in this patient occurred as a consequence of reduced pulmonary vascular compliance due to positive end-expiratory pressure (PEEP) and an increase of mean intrathoracic pressure. Furthermore, we hypothesize that synchronized LVAD operation exacerbates any potential right-to-left shunt due to the profound left ventricular unloading which occurs during LVAD support. In this first report of a right-to-left shunt from a previously unrecognized patent foramen ovale in a Novacor patient, the subsequent transient hypoxemia could be managed by avoiding PEEP of more than 3 mmHg, and mean airway pressure of more than 11 mmHg and by careful volume replacement in order to prevent the pump from completely emptying the left ventricle (LV) and the left atrium (LA). Thus, prior to every LVAD implantation a transesophageal contrast echocardiography with Valsalva maneuver should be performed to identify intracardiac right-to-left shunt.

No abstract

Although impairment of splanchnic perfusion may induce mucosal hypoxia and endotoxaemia during orthotopic liver transplantation (OLT), little is known about the changes in mucosal oxygenation during and after the procedure. To study the effects of liver surgery itself on mucosal pH (pHi) and the response of pHi to acute changes in portal flow, we measured gastric pHi during six liver resections using tonometry: in two patients, after clamping of the hepatoduodenal ligament, pHi decreased within 30 min and recovered promptly after reperfusion. We then investigated gastric and sigmoid pHi (pHig, pHis) during the perioperative phase in 18 OLT. Median pHi values were low before surgery (pHig 7.28 (first/third quartiles 7.22/7.34); pHis 7.27 (7.12/7.36)). Although global oxygen delivery and haemodynamic variables remained constant and veno-venous bypass (VVB) was used to maintain portal flow, pHi declined during the anhepatic phase (pHig 7.19 (7.13/7.23), P < 0.01; pHis 7.13 (7.06/7.24), P < 0.05). After reperfusion of the graft, pHi recovered and did not differ from baseline values by the end of OLT. After operation pHig increased further, reaching the highest values 30 h after ICU admission (7.34 (7.26/7.38)). In the intraoperative period, no significant endotoxaemia was observed either in portal or systemic blood. The maximum reduction in pHi was related neither to the duration of VVB and OLT nor to the number of red cell units transfused. pHi after reperfusion did not correlate with graft viability or dysfunction of the lung or kidney. We conclude that pHi indicates mucosal ischaemia during OLT which is not necessarily associated with endotoxaemia, and intraoperative pHi monitoring does not appear to be a valuable predictor of postoperative graft failure and organ dysfunction.