Pulmonary graft function after long-term preservation of non-heart-beating donor lungs

BACKGROUND: Critical organ shortage in lung transplantation could be attenuated by the use of non-heart-beating donor (NHBD) lungs. In addition, prolonged ischemic tolerance of the organs would contribute to the alleviation of organ shortage. The aim of this study was to investigate pulmonary graft function of NHBD lungs after long-term hypothermic storage. METHODS: Twelve native-bred pigs (bodyweight 20 to 30 kg) underwent left lung allotransplantation. In the heart-beating donor (HBD) group, lungs were harvested immediately after cardiac arrest. In the NHBD group, lungs were subjected to a warm ischemic period of 90 minutes before harvesting. After a total ischemic time of 19 hours, pulmonary grafts in both groups were reperfused and pulmonary graft function was assessed. All values were compared with a sham-operated control group. RESULTS: Pulmonary graft function in the HBD group was excellent. In the NHBD group, pulmonary gas exchange was impaired, but still provided good graft function compared with the excellent graft function in the HBD group. Pulmonary vascular resistance was even lower in the NHBD group. In the NHBD group, calculated intrapulmonary shunt fraction (Qs/Qt) was significantly increased compared with the sham-group. Histologic alteration and wet-to-dry ratio did not differ significantly between the HBD and NHBD group. CONCLUSIONS: We conclude that NHBD lungs (90 minutes of warm ischemic time) have the potential to alleviate organ shortage in lung transplantation even after an extended total ischemic time.     

Peripartale Blutungen,Diagnostik und Therapie

Die Anaesthesiologie - Anhand einer fiktiven Kasuistik wird die aktuelle Leitlinie „Peripartale Blutungen, Diagnostik und Therapie“ mit einem Schwerpunkt auf die anästhesiologische...     

Entwicklung eines neuen Moduls für das TraumaRegister DGU®

Die Unfallchirurgie - Lebensbedrohliche Verletzungen während der Schwangerschaft sind ein seltenes Ereignis. Das TraumaRegister DGU® (TR-DGU) erfasst seit 2016, ob bei weiblichen...     

Akutbehandlung schwangerer Patientinnen nach schwerem Trauma – eine retrospektive Multicenteranalyse

Die Unfallchirurgie - Die Versorgung schwangerer Traumapatientinnen stellt das gesamte medizinische Team vor eine besondere Herausforderung. Ziel unserer Studie war es, diese Daten zu erheben und...     

Lung injury following thoracic aortic occlusion: comparison of sevoflurane and propofol anaesthesia

Background: Halogenated anaesthetics have been shown to reduce ischaemia–reperfusion injuries in various organs due to pre- and post-conditioning mechanisms. We compared volatile and total intravenous anaesthesia with regard to their effect on remote pulmonary injury after thoracic aortic occlusion and reperfusion.
Methods: Eighteen pigs were randomized after sternotomy and laparotomy (fentanyl–midazolam anaesthesia) to receive either sevoflurane or propofol in an investigator-blinded fashion. Ninety minutes of thoracic aortic occlusion was induced by a balloon catheter. During reperfusion, a goal-directed resuscitation protocol was performed. After 120 min of reperfusion, the anaesthetic regimen was changed to fentanyl–midazolam again for another 180 min. The oxygenation index and intra-pulmonary shunt fractions were calculated. After 5 h of reperfusion, a bronchoalveolar lavage was performed. The total protein content and lactate dehydrogenase activity were measured in epithelial lining fluid (ELF). Alveolar macrophage oxidative burst was analysed. The wet to dry ratio was calculated and tissue injury was graded using a semi-quantitative score. Ten animals ( n =5 for each anaesthetic) without aortic occlusion served as time controls.
Results: The oxygenation index decreased and the intra-pulmonary shunt fraction increased significantly in both occlusion groups. There were no significant differences between sevoflurane and propofol with respect to the oxygenation index, ELF composition, morphologic lung damage, wet to dry ratio and alveolar macrophage burst activity. Differences were, however, seen in terms of systemic haemodynamic stability, where catecholamine requirements were less pronounced with sevoflurane.
Conclusion: We conclude that the severity of remote lung injury was not different between sevoflurane and propofol anaesthesia in this porcine model of severe lower-body ischaemia and reperfusion injury.     

Validation of pulse contour derived stroke volume variation during modifications of cardiac afterload

Background: Left ventricular stroke volume variation (SVV) or its surrogatesare useful tools to assess fluid responsiveness in mechanicallyventilated patients. So far it is unknown, how changes in cardiacafterload affect SVV. Therefore, this study compared left ventricularSVV derived by pulse contour analysis with SVV measured usingan ultrasonic flow probe and investigated the influence of cardiacafterload on left ventricular SVV. Methods: In 13 anaesthetized, mechanically ventilated pigs [31(SD 6)kg], we compared cardiac output (CO), stroke volume (SV), andSVV determined by pulse contour analysis and by an ultrasonicaortic flow signal (Bland–Altman analysis). After obtainingbaseline measurements, cardiac afterload was increased usingphenylephrine and decreased using adenosine (both continuouslyadministered). Measurements were performed with a constant tidalvolume (12 ml kg^–1) without PEEP. Results: Neither increasing mean arterial pressure (MAP) [from 59 (7)to 116 (19)] nor decreasing MAP [from 63 (7) to 39 (4)] affectedCO, SV, and SVV (both methods). Method comparison revealed abias for SVV of 0.1% [standard error of the mean (SE) 0.8] atbaseline, –1.2% (SE 0.8) during decreased and 4.0% (SE0.7) during increased afterload, the latter being significantlydifferent from the others (P < 0.05). Thereby, pulse contouranalysis tended to underestimate SVV during decreased afterloadand to overestimate SVV during increased afterload. Limits ofagreement were approximately 6% for all points of measurement. Conclusions: Left ventricular SVV is not affected by changes in cardiac afterload.There is a good agreement of pulse contour with flow derivedSVV. The agreement decreases, if afterload is extensively augmented.     

Elevated plasma concentrations of lipoprotein(a) in medicated epileptic patients

Lipoprotein(a) [Lp(a)] has been identified as an independent risk factor for vascular diseases. There are no data on Lp(a) levels in patients on long-term medication with carbamazepine, phenytoin, phenobarbital, or valproate. To investigate the effects of such treatment on Lp(a) levels and common carotid artery intima media thickness we studied 51 epileptic outpatients on long-term antiepileptic medication and 51 age- and sex-matched controls. Lp(a) levels above 45 mg/dl were found in 11 of 50 patients, but in only 4 of 51 controls (P<0.05). The mean serum concentration of Lp(a) was 33.0±7.0 mg/dl in patients and 16.9±2.7 mg/dl in controls (P<0.05). Epileptic patients also had a thicker intima media of the common carotid artery (0.79±0.04 mm) than controls (0.69±0.02 mm, P<0.05) as measured by B-mode ultrasonography. Our results suggest an untoward effect of long-term antiepileptic medication on Lp(a) serum concentrations. Elevated Lp(a) levels might be a risk factor for arteriosclerosis in epileptic patients. Received: 26 November 1999/Received in revised form: 16 March 2000/Accepted: 9 April 2000     

Propofol-related infusion syndrome induced by "moderate dosage" in a patient with severe head trauma

Propofol is widely used for sedating critically ill adult patients because of its rapid onset and short recovery times, even after prolonged use. Propofol may be associated with a life-threatening syndrome, propofol-related infusion syndrome (PRIS), which includes cardiac failure, severe metabolic acidosis, renal failure, and rhabodomyolysis. The pathophysiology is incompletely understood. Propofol-related infusion syndrome seems to be dose-related, and it occurs generally in patients undergoing long-term (> 48 hrs) sedation at higher doses (> 4 mg/kg/hr). A case of PRIS in a patient after severe head injury is presented.     

The influence of positive end-expiratory pressure on stroke volume variation and central blood volume during open and closed chest conditions.

OBJECTIVE: Intermittent positive pressure ventilation and positive end-expiratory pressure (PEEP) affect cardiac preload. Their effect is dependent on chest wall compliance. This study compares the effects of intermittent positive pressure ventilation and PEEP on stroke volume variation and central blood volume during open and closed chest conditions. MATERIALS AND METHODS: Fourteen anesthetized and mechanically ventilated pigs (25-40 kg) were studied. Central blood volume was assessed using global end-diastolic volume and right ventricular end-diastolic volume measured by thermodilution. Further, left and right ventricular stroke volume variations were determined with ultrasonic flow probes placed around the pulmonary artery and ascending aorta, respectively. Measurements were performed during mechanical ventilation without and with PEEP (15 cmH(2)O) in open and closed chest conditions. RESULTS: With the chest closed mean arterial pressure, cardiac output, stroke volume, global end-diastolic volume, and right ventricular end-diastolic volume were significantly lower when compared to open chest conditions. Concomitantly, right ventricular, but not left ventricular stroke volume variation increased significantly. Applying PEEP led to a significant reduction of cardiac output, stroke volume and right ventricular end-diastolic volume, with a concomitant increase in left and right ventricular stroke volume variation both during open and closed chest conditions (all P-values<0.05). CONCLUSIONS: We conclude that PEEP increases right and left ventricular stroke volume variation both during open and closed chest conditions. The concomitant reduction of right ventricular end-diastolic volume further indicates that PEEP has a preload reductive effect during open chest conditions, too.