Gastric mucosal oxygen delivery decreases during cardiopulmonary bypass despite constant systemic oxygen delivery.

UNLABELLED: Previous studies report a decrease in gastric mucosal oxygen delivery during cardiopulmonary bypass (CPB). However, in these studies, CPB was associated with a reduction in systemic oxygen delivery (DO2). Conceivably, this decrease in DO2 could have contributed to the observed decrease in gastric mucosal oxygen delivery. Thus, in the present study, we assessed the effects of the maintenance of DO2 (at pre-CPB values) during hypothermic (30-32 degrees C) CPB on the gastric mucosal red blood cell flux (GMRBC flux) using laser Doppler flowmetry. In 11 patients requiring cardiac surgery, the pump flow rate during CPB was initially set at 2.4 L x min(-1) x m(-2) and was adjusted to maintain DO2 at pre-CPB values (flow 2.5-2.7 L x min[-1] x m[-2]). Despite a constant DO2, the GMRBC flux was decreased during CPB. These decreases averaged 50% +/- 16% after 10 min, 50% +/- 18% after 20 min, 49% +/- 21% after 30 min, and 49% +/- 19% after 40 min of CPB. The rewarming period was associated with an increase in GMRBC flux. Thus, maintaining systemic DO2 during CPB seems to be an ineffective strategy to improve gastric mucosal oxygen delivery. IMPLICATIONS: In the present study, we tested the hypothesis that gastric mucosal red blood cell flux assessed by laser Doppler flowmetry could be improved by maintaining baseline systemic flow and oxygen delivery during hypothermic cardiopulmonary bypass. Despite this strategy, gastric mucosal red blood cell flux decreased by 50% during hypothermic cardiopulmonary bypass.

[Morphine in cesarean section and postoperative analgesia]. / Les morphiniques dans les césariennes et en analgésie postopératoire.

Epidural opioids for caesarean section are routinely used by many anaesthesists. Combined epidural injection of a local anaesthetic and an opioid provides a more rapid onset of profound analgesia. No side effects are observed in either the mother or the neonate with epidural "microdoses" of sufentanil or fentanyl, but the postoperative analgesia is of short duration. Combined intrathecal injection on 0.1-0.2 mg morphine and 0.5% hyperbaric bupivacaine provides a better intra- and postoperative analgesia. Opiates used during anaesthesia in toxemic women before delivery imply strict subsequent paediatric care. Good postoperative analgesia can be obtained with intrathecal morphine or patient-controlled analgesia. Using other techniques depends on care and surveillance facilities. Opiates by spinal or intravenous route are not dangerous for breast-fed newborns.

[Cardiorespiratory management of severe injured patients in intensive care units]. / Prise en charge cardio-respiratoire des traumatisés graves en réanimation.

Late mortality of severely injured patients could be prevented by the quality of early cardiorespiratory management. Indeed traumatized patients with high risk of multiple organ failure (according to age, ISS, amount of blood transfused, and/or metabolic acidosis) need a pulmonary artery catheterization as soon as possible (postdefinitive phase: during the surgical period or at the admission in the ICU). Such a procedure allows the intensivist to determine therapeutic goals in term of O2 delivery (DO2) and O2 uptake (VO2) in front of a frequent increased peripheral O2 demand, These goals (usually DO2 > or = 600 ml.min-1m-2 and VO2 > or = 150 ml.min-1.m-2) may be reached by the combination of prolonged mechanical ventilation (adapted to the pulmonary status), subnormal O2 carrying capacity (hematocrite between 30 and 35% in the absence of persistent bleeding), and increased cardiac output through an additional volume loading (without an excessive positive cumulated fluid balance on the second posttraumatic day) and the early administration of inotropic drugs (dobutamine). Reaching these goals usually permits a 61% reduction in the posttraumatic incidence of organ failure.