Alveolar recruitment strategy and high positive end-expiratory pressure levels do not affect hemodynamics in morbidly obese intravascular volume-loaded patients.

We evaluated the effect of the alveolar recruitment strategy and high positive end-expiratory pressure (PEEP) on hemodynamics in 20 morbidly obese (body mass index 50 +/- 9 kg/m2), intravascular volume-loaded patients undergoing laparoscopic surgery. The alveolar recruitment strategy was sequentially performed with and without capnoperitoneum and consisted of an upward PEEP trial, recruitment with 50-60 cm H2O of plateau pressure for 10 breaths, and a downward PEEP trial. Recruitment and high PEEP did not cause significant disturbances in any hemodynamic variable measured by systemic and pulmonary artery catheters. Transesophageal echocardiography revealed no differences in end-diastolic areas or evidence of segmental abnormalities in wall motion.

Improvement of impaired microcirculation and tissue oxygenation by hemodilution with hydroxyethyl starch plus cell-free hemoglobin in acute porcine pancreatitis.

AIMS: To avoid the progression from mild edematous acute pancreatitis (AP) to the severe necrotizing form, one therapeutic option is to improve pancreatic microcirculation and tissue oxygenation. The aim of the study was to evaluate the influence of improved rheology (isovolemic hemodilution) plus enhanced oxygen supply (bovine hemoglobin HBOC-301) on pancreatic microcirculation, tissue oxygenation and survival in severe acute experimental pancreatitis. METHODS: Severe AP was induced in 39 pigs (25-30 kg BW) by stimulation with intravenous administration of cerulein plus a pressure- and volume-controlled 10-min intraductal infusion of glycodeoxycholic acid. Seventy-five minutes after induction of AP, animals were randomized and hemodiluted isovolemically (PAOP constant) with either 10% hydroxyethyl starch (HES) 200,000/0.5 plus HBOC-301 (+0.6 g/dl plasmatic hemoglobin; Oxyglobin, Biopure, Cambridge, Mass., USA), or 10% HES 200,000/0.5, or Ringer's solution to a hematocrit of 15%. Hemodynamics, oxygen transport parameters, pancreatic microcirculation and tissue oxygen tension were evaluated over 6 h. Then the abdomen was closed, animals were extubated and observed for 6 days. After that, the surviving animals were sacrificed and specimens were taken from the pancreas. The histopathologic findings were scored by two blinded pathologists who quantified acinar necrosis, fat necrosis, inflammation and edema. RESULTS: Isovolemic hemodilution with HES plus HBOC-301 reduced mortality and preserved pancreatic microcirculation compared with Ringer's solution, but was not significantly different from hemodilution with HES alone. Only treatment with HES plus HBOC-301 normalized pancreatic tissue oxygen tension compared with IHD with HES or Ringer's solution alone. CONCLUSIONS: IHD with HES plus HBOC-301 as a combination of rheologic and O(2)-delivering therapy may represent a novel therapeutic option for treatment of AP.

Enhanced central organ oxygenation after application of bovine cell-free hemoglobin HBOC-201.

PURPOSE: While the effects of dilutional anemia or isovolemic hemodilution (IHD) on the oxygen extraction and tissue oxygenation in peripheral organs after application of hemoglobin-based oxygen carriers like HBOC-201 have been studied intensively, little is known about tissue oxygenation properties of hemoglobin solutions in central organs like the liver. METHODS: Twelve Foxhounds were anesthetized and then randomized to either a control group without hemodilution (Group 1) or underwent first step isovolemic hemodilution (pulmonary artery occlusion pressure constant) with Ringer's solution (Group 2) to a hematocrit of 25% with second step infusion of HBOC-201 until a hemoglobin concentration of +0.6 g.dL(-1) was reached. Tissue oxygen tensions (tpO2) were measured in the gastrocnemius muscle using a polarographic needle probe, and in the liver using a flexible polarographic electrode. RESULTS: While arterial oxygen content and oxygen delivery decreased with hemodilution in Group 2, global liver and muscle oxygen extraction ratio increased after hemodilution and additional application of HBOC-201. Hemodilution and application of HBOC-201 provided augmentation of the mean liver tpO2 (baseline: 48 +/- 9, 20 min: 53 +/- 10, 60 min: 67 +/- 11*, 100 min: 68 +/- 7*; *P < 0.05 vs baseline and Group 1), while oxygen tensions in Group 1 remained unchanged. Oxygen tension in the skeletal muscle increased after hemodilution and additionally after application of HBOC-201 in comparison to baseline and to the control group (P < 0.05). CONCLUSION: In the present animal model, IHD with Ringer's solution and additional application of HBOC-201 increased oxygen extraction and tpO(2) in the liver and skeletal muscle, in parallel and in comparison with baseline values and a control group.

Pre- and intraoperative epidural ropivacaine have no early preemptive analgesic effect in major gynecological tumour surgery.

PURPOSE: Thoracic epidural analgesia (TEA) is an established technique for postoperative pain relief after major abdominal surgery. However it is still under discussion whether pre-incisional TEA can reduce postoperative pain perception or postoperative analgesic consumption. METHODS: The present prospective, randomized, double-blind study was performed to investigate the effects of intra- and postoperative TEA vs only postoperative TEA using ropivacaine 0.375% in 30 women scheduled for major abdominal tumour surgery. Prior to induction of general anesthesia patients received an epidural bolus of 10 mL saline in Group I (GI) and 10 mL ropivacaine 0.375% in Group II (GII) followed by an infusion of 6 mL x hr(-1) of the respective solution during surgery. Postoperatively all patients received an epidural infusion of 6 mL x hr(-1) ropivacaine 0.375% during 24 hr followed by patient controlled epidural analgesia for the next 72 hr. Operative data, dynamic pain scores, consumption of local anesthetics and standardized supplemental analgesics were analyzed. RESULTS: No difference was seen between groups with respect to the amount of required postoperative local anesthetics and supplemental analgesics, pain scores and side effects during the first 96 hr following surgery except a reduction of intraoperative sufentanil consumption (GI: 143.2 +/- 52.6 vs GII: 73.3 +/- 32.6 microg, P < 0.001). CONCLUSION: Intraoperative TEA with ropivacaine 0.375% did not significantly reduce the amount of analgesics required after major abdominal gynecological tumour surgery.