Feasibility and first long-term results after laparoscopic rectal segment resection and vaginal specimen retrieval for deep infiltrating endometriosis.

INTRODUCTION: Radical resection of deep infiltrating endometriosis (DIE), including bladder and bowel resection, provides relief from pain in symptomatic patients. The laparoscopic approach to treatment is well established for bowel resection but normally requires additional abdominal incisions for specimen retrieval. Here we describe our technique of laparoscopically assisted rectal resection and transvaginal specimen retrieval (LARRT) and provide follow-up information on pain scores and complications. MATERIALS AND METHODS: Retrospective observational monocentric study on all DIE patients with rectal infiltration treated between 2008 and 2010 with LATRR at our department. Follow-up was obtained for at least 3 years, including baseline 1-year and 3-year pain scores. RESULTS: We identified four patients undergoing LARRT available for follow-up. DIE was confirmed by histology in all cases. There were no intraoperative complications. Two patients had transient postoperative urinary retention, one patient developed recto-vaginal fistula and required transient colostomy. One patient suffered from persistent vaginal dryness. All patients, however, reported persistent pain relief, including at the end of follow-up period. CONCLUSION: LARRT is a feasible variation of laparoscopic bowel resection for DIE with rectal infiltration. In our study it has promising results with respect to pain control. Larger studies will, however, be required to determine the safety of this procedure.

In situ liver transection with portal vein ligation for rapid growth of the future liver remnant in two-stage liver resection.

BACKGROUND: Portal vein embolization (PVE) has become a standard procedure to increase the future liver remnant (FLR) and enable curative resection of initially unresectable liver tumours. This study investigated the safety and feasibility of a new two-stage liver resection technique that uses in situ liver transection (ISLT) and portal vein ligation before completion hepatectomy. METHODS: A consecutive series of patients undergoing ISLT and extended right hepatectomy between 2009 and 2011 were compared with consecutive patients undergoing extended right hepatectomy after PVE. All patients had initially unresectable primary or secondary liver tumours, owing to an insufficient FLR (liver segments II/III). RESULTS: Fifteen patients who had PVE and seven who underwent ISLT before extended right hepatectomy were evaluated. ISLT induced rapid growth of the FLR within 3 days, particularly after insufficient PVE, from a mean(s.d.) of 293(58) ml to 477(85) ml, corresponding to a volume increase of 63(29) per cent. All patients who had ISLT underwent completion extended right hepatectomy within 8 days (range 4-8 days). CONCLUSION: ISLT is an effective and reliable technique to induce rapid growth of the FLR, even in patients with insufficient volume increase after PVE.

[Stem cell-induced liver regeneration]. / Stammzell-induzierte Leberregeneration.

BACKGROUND: The liver has an excellent regenerative capacity after resection. However, below a critical level of future liver remnant volume (FLRV), partial hepatectomy is accompanied by a significant increase of postoperative liver failure. There is accumulating evidence for the contribution of bone marrow stem cells (BMSC) to participate in liver regeneration. Here we report our experience with portal vein embolisation (PVE) and CD133+ BMSC administration to the liver, compared with PVE alone, to augment hepatic regeneration in patients with critically low FLRV or impaired liver function. PATIENTS AND METHODS: Eleven patients underwent PVE of liver segments I and IV-VIII to stimulate hepatic regeneration prior to extended right hepatectomy. In these 11 patients with a FLRV below 25% and/or limited quality of hepatic parenchyma, PVE alone did not promise adequate proliferation. These patients underwent additional BMSC administration to segments II and III. Two radiologists blinded to patients' identity and each other's results measured liver and tumour volumes with helical computed tomography. Absolute, relative and daily FLRV gains were compared with a group of patients that underwent PVE alone. RESULTS: The increase of the mean absolute FLRV after PVE with BMSC application from 239.3 mL±103.5 (standard deviation) to 417.1 mL±150.4 was significantly higher than that from 286.3 mL±77.1 to 395.9 mL±94.1 after PVE alone (p<0.05). Also the relative gain of FLRV in this group (77.3%±38.2%) was significantly higher than that after PVE alone (39.1%±20.4%) (P=0.039). In addition, the daily hepatic growth rate after PVE and BMSC application (9.5±4.3 mL/d) was significantly superior to that after PVE alone (4.1±1.9 mL/d) (p=0.03). Time to surgery was 27 days±11 in this group and 45 days±21 after PVE alone (p=0.02). Short- and long-term survival were not negatively influenced by the shorter waiting period. CONCLUSION: In patients with malignant liver lesions, the combination of PVE with CD133+ BMSC administration substantially increased hepatic regeneration compared with PVE alone. This procedure bears the potential to allow the safe resection of patients with a curative intention that would otherwise carry the risk post-operative liver failure.

Interventional management of intractable sympathetically mediated pain by computed tomography-guided catheter implantation for block and neuroablation of the thoracic sympathetic chain: technical approach and review of 322 procedures.

We retrospectively evaluated the safety and efficacy of computed tomography-guided placement of percutaneous catheters in close proximity to the thoracic sympathetic chain by rating pain intensity and systematically reviewing charts and computed tomography scans. Interventions were performed 322 times in 293 patients of mean (SD) age 59.4 (17.0) years, and male to female ratio 105:188, with postherpetic neuralgia (n = 103, 35.1%), various neuralgias (n = 88, 30.0%), complex regional pain syndrome (n = 69, 23.6%), facial pain (n = 17, 5.8%), ischaemic limb pain (n = 7, 2.4%), phantom limb pain (n = 4, 1.4%), pain following cerebrovascular accident (n = 2, 0.7%), syringomyelia (n = 2, 0.7%) and palmar hyperhidrosis (n = 1, 0.3%). The interventions were associated with a total of 23 adverse events (7.1% of all procedures): catheter dislocation (n = 9, 2.8%); increase in pain intensity (n = 8, 2.5%); pneumothorax (n = 3, 0.9%); local infection (n = 2, 0.6%); and puncture of the spinal cord (n = 1, 0.3%). Continuous infusion of 10 ml.h(-1) ropivacaine 0.2% through the catheters decreased median (IQR [range]) pain scores from 8 (6-9 [2-10]) to 2 (1-3 [0-10]) (p < 0.0001). Chemical neuroablation was necessary in 137 patients (46.8%). We conclude that this procedure leads to a significant reduction of pain intensity in otherwise obstinate burning or stabbing pain and is associated with few hazards.

Necrotizing fasciitis: microbiological characteristics and predictors of postoperative outcome.

OBJECTIVE: Necrotizing fasciitis is a life threatening soft-tissue infection with a high morbidity and mortality. Prompt treatment based on extensive surgical debridement and antibiotic therapies are the therapeutic principles. METHODS: The medical records of patients with necrotizing fasciitis (n = 26) from 1996 to 2005 were retrospectively analyzed. RESULTS: The localization of necrotizing fasciitis was most commonly the trunk (42.3 %). Type I polymicrobial infection was the dominating infection. The involvement of anaerobic bacteria was associated with an increase in the number of surgical revisions (p = 0.005). Length of postoperative intensive care unit stay, duration of postoperative ventilation and mortality were significantly increased in the ASA IV-V group. Computed tomography displayed only a limited significance as diagnostic tool for initial diagnosis. CONCLUSIONS: In severe cases the combination of necrotic skin and soft tissue gas facilitates the correct diagnosis, which should than be followed by immediate - and most often - repeated debridement. If anaerobes are isolated an early and aggressive second look is necessary.

Inflammatory peritoneal reaction after perforated appendicitis: continuous peritoneal lavage versus non lavage.

INTRODUCTION: Bacterial peritonitis is a severe medical condition associated with a natural mortality rate of 80-100%. Progress in surgical techniques, new developments in intensive care medicine and antibiotic therapy reduced this rate significantly. Aim of this study was to evaluate sepsis parameter in perforated appendicitis and different postoperative management. METHODS: In 50 consecutive patients with diffuse bacterial peritonitis and perforated appendicitis, laparotomy was performed. Subsequently, 25 patients were treated with adjuvant, continuous peritoneal lavage (CPL) using standard peritoneal dialysis (CAPD)-solution. The remaining 25 patients were peritoneally drained without postoperative irrigation (Non-CPL). In all patients endotoxin, tumor necrosis factor-alpha (TNF-alpha), interleukin (IL-6), C-reactive protein (CRP) and myeloid-related protein (MRP-8, MRP-14 and Heterocomplex) were determined. RESULTS: No difference in clinical outcome between CPL and Non-CPL could be established. An uncomplicated clinical outcome was associated with lower levels of inflammation markers. Furthermore, clinical data revealed that mortality depended on co-morbidity, and patient's age. SUMMARY: In perforated appendicitis a faster decrease of mediator release could not be achieved with either method. In addition, no difference could be established for the clinical parameters like hospitalization, duration of intensive care and morbidity.

C1840-T mutation in the human skeletal muscle ryanodine receptor gene: frequency in northern German families susceptible to malignant hyperthermia and the relationship to in vitro contracture response.

In swine, a point mutation in the ryanodine receptor gene can account for all cases of malignant hyperthermia (MH). The frequency of a corresponding mutation in humans (C1840-T) and its relationship to the in vitro contracture profile is unknown. We screened 192 patients from 28 unrelated northern German families for the C1840-T mutation in the human ryanodine receptor gene and tested for MH susceptibility using the in vitro contracture test (IVCT) according to the European MH Protocol. In our patients 106 revealed MH susceptible (MHS), 56 MH nonsusceptible and 30 MH equivocal status following IVCT. In each family one or two individuals had developed clinical signs of MH or a MH crisis. All of these patients were classified MHS. The C1840-T mutation was found in 2 of 28 families (7.1%). All eight individuals of the two families characterized by this mutation revealed MHS status following IVCT. The thresholds for halothane- and caffeine-induced contractures as well as the contracture profiles following cumulative (0.4-10.0 mumol/l every 3 min) and bolus (10 mumol/l) administration of ryanodine were found to be similar in MHS patients with and without the C1840-T mutation. In conclusion, the C1840-T mutation in the human ryanodine receptor gene is a rare abnormality in MHS families. Similar contracture profiles in the presence and absence of this mutation might imply no major functional role with respect to the contracture response. At present, molecular genetic analysis cannot replace IVCT to discover MH susceptibility in humans.

Xenogeneic endothelial cells activate human prothrombin.

BACKGROUND: Delayed xenograft rejection is characterized by platelet activation and fibrin deposition and is thought to occur independently of complement activation. We have therefore investigated the potential for xenogeneic endothelial cells (EC) to regulate the conversion of prothrombin to thrombin, a central component of the final common pathway of coagulation and an important platelet agonist. METHODS AND RESULTS: Quiescent porcine aortic EC (PAEC) were found to convert high levels of human prothrombin to thrombin (0.234+/-0.019 IU/ml) when compared with human aortic EC (0.017+/-0 IU/ml, 30-min time point, chromogenic assay; P<0.001). PAEC activation by human complement resulted in comparable levels of thrombin generation. Prothrombin conversion by PAEC as determined by generation of F1+2 (1.909+/-0.119 nmol/L) and formation of thrombin-antithrombin III complexes (125.611+/-6.373 microg/L) was significantly greater than the matched human aortic EC values (F1+2: 1.539+/-0.03 nmol/L, P<0.001; thrombin-antithrombin III: 1.833+/-0.104 microg/L, P<0.001). Sequential analysis of prothrombin activation by PAEC indicated generation of the intermediate meizothrombin followed by autolytically accelerated thrombin formation. Subsequent experiments established important cross-species' incompatibilities with respect to porcine thrombomodulin interaction with human thrombin and protein C in that PAEC had a reduced capacity to generate activated human protein C in vitro. CONCLUSION: These observations indicate a potentially important molecular barrier involving blood coagulation that may impact on the planned clinical application of porcine transgenic organs.

One year of experience with extended application and modified techniques of split liver transplantation.

As organ donation rates decreased in Europe, the authors started a systematic approach of liver splitting in their center in 1994. During this 1-year experience, 73 cadaveric liver transplantations were performed in 66 patients. Sixteen of these transplantations were the result of split-liver transplantation (21.9% of grafts, 24.2% of patients). Patient and graft survival rates at 3 months were 81.2% and 75%, compared with 89.1% and 76.9 % for whole organs. Two modified techniques were developed, based on the technique of living related liver procurement, and applied in 10 cases. With these new techniques, patient and graft survival rates were 90% and 90%. This systematic approach allowed the total number of transplantations in our program to be maintained, despite the decrease in organ availability.

Expression of human thrombomodulin cofactor activity in porcine endothelial cells.

BACKGROUND: Xenograft rejection may predispose to vascular thrombosis because of putative cross-species' functional incompatibilities between natural anticoagulants present on the donor endothelium and host activated coagulation factors. For example, porcine thrombomodulin expressed on porcine aortic endothelial cells (PAEC) does not provide the expected thrombomodulin (TM)-cofactor activity for human protein C in the presence of human thrombin. In addition, TM may be down-regulated after cellular activation. Our aim was to express human TM cofactor activity in PAEC and to study the proinflammatory effect of tumor necrosis factor-alpha (TNF-alpha) on stable expressed human thrombomodulin in vitro. METHODS AND RESULTS: Retroviral transduction of PAEC with the gene encoding for human thrombomodulin (hTM) resulted in expression of high levels of specific TM cofactor activity on PAEC (0.62 microg/ml activated protein C/10(5) cells). High-level expression of hTM resulted in a 620-fold higher activation of human protein C in the presence of human thrombin when compared with mock-transduced PAEC (0.0001 microg/ml/10(5) cells; P<0.001). Transduced PAEC expressing hTM also bound more human thrombin than control PAEC, as determined by inhibition of thrombin-induced platelet activation (P<0.05). We noted that exposure to TNF-alpha significantly reduced exogenous hTM cofactor activity on transduced PAEC in a time- and dose-dependent fashion; this occurred despite the relatively stable expression of hTM mRNA and hTM antigen in these cells. Treatment of transduced PAEC with selected antioxidants could protect against the loss of hTM cofactor activity directly associated with the oxidative stress induced by TNF-alpha activation responses. CONCLUSIONS: Our data show that the functional deficiency of the anticoagulant protein C pathway in PAEC may be corrected by viral transduction of these cells. As analysis of the hTM function showed modulation under conditions of cellular activation, we suggest that expression of hTM mutants resistant to oxidation may have greater therapeutic utility in the genetic modification of porcine xenografts.

Safety and efficacy of spinal vs general anaesthesia in bone marrow harvesting.

Bone marrow harvesting (BMH) can be performed with either general (GA) or spinal anaesthesia (SPA). Whether SPA is advantageous in BMH and if this technique is safe for procedures performed in the prone position is still controversial. To evaluate the safety and efficacy of both anaesthetic techniques in BMH, 37 allogeneic donors (nine female, 28 male; 34.3 +/- 9 years; ASA class 1-2) received either spinal (group 1, n =20) or general anaesthesia (group 2, n = 17) according to their personal wishes. Under standardised harvesting conditions, haematology parameters, cell counts (MNC, CD34+), haemodynamic parameters, adverse reactions and patient satisfaction were registered. No differences were seen between groups with respect to demographic data, harvesting time (55 +/- 17 vs 60 +/- 16 min) and bone marrow cell counts (MNC: 6.68 +/- 2.1 vs 5.7 +/- 1.7 ml/10(6)). The incidence of hypotension was higher in group 1 (45 vs 10.8%; P =0.042). Postoperative analgesic requirement and emesis were increased in group 2 (P < 0.04) in comparison to group 1. In conclusion, the present study failed to show superiority of spinal over general anaesthesia with regard to the quality of the harvested bone marrow. However, the lower incidence of complaints after spinal anaesthesia appears to offer an advantage over GA in healthy allogeneic bone marrow donors.

Factors in xenograft rejection.

Important mechanisms underlying immediate xenograft loss by hyperacute rejection (HAR), in the pig-to-primate combination, have been recently delineated. There are now several proposed therapies that deal with the problem of complement activation and xenoreactive natural antibody (XNA) binding to the vasculature that have been shown to prevent HAR. However, vascularized xenografts are still lost, typically within days, by delayed xenograft rejection (DXR), alternatively known as acute vascular rejection (AVR). This process is characterized by endothelial cell (EC) perturbation, localization of XNA within the graft vasculature, host NK cell and monocyte activation with platelet sequestration and vascular thrombosis. Alternative immunosuppressive strategies, additive anti-complement therapies with the control of any resulting EC activation processes and induction of protective responses have been proposed to ameliorate this pathological process. In addition, several potentially important molecular incompatibilities between activated human coagulation factors and the natural anticoagulants expressed on porcine EC have been noted. Such incompatibilities may be analogous to cross-species alterations in the function of complement regulatory proteins important in HAR. Disordered thromboregulation is potentially relevant to the progression of inflammatory events in DXR and the disseminated intravascular coagulation seen in primate recipients of porcine renal xenografts. We have recently demonstrated the inability of porcine tissue factor pathway inhibitor (TFPI) to adequately neutralize human factor Xa (FXa), the aberrant activation of both human prothrombin and FXa by porcine EC and the failure of the porcine natural anticoagulant, thrombomodulin to bind human thrombin and hence activate human protein C. The enhanced potential of porcine von Willebrand factor to associate with human platelet GPIb has been demonstrated to be dependent upon the isolated A1 domain of von Willebrand factor. In addition, the loss of TFPI and vascular ATPDase/CD39 activity following EC activation responses would potentiate any procoagulant changes within the xenograft. These developments could exacerbate vascular damage from whatever cause and enhance the activation of platelets and coagulation pathways within xenografts resulting in graft infarction and loss. Analysis of these and the other putative factors underlying DXR should lead to the development and testing of genetic approaches that, in conjunction with selected pharmacological means, may further prolong xenograft survival to a clinically relevant extent.

Respiratory depression under long-term sedation with sufentanil, midazolam and clonidine has no clinical significance.

OBJECTIVE: Assessment of respiratory depression caused by long-term sedation with sufentanil, midazolam and clonidine. DESIGN: Retrospective assessment using data from a patient data management system. SETTING: University hospital anaesthesiological ICU. PATIENTS: Three hundred ninety-five surgical and trauma patients with an ICU stay of more than 48 h. INTERVENTION: None. MEASUREMENTS AND RESULTS: Arterial blood partial pressure of carbon dioxide (PCO2) was evaluated during mechanically assisted spontaneous ventilation (continuous positive airway pressure, synchronised intermittent mandatory ventilation, mandatory minute ventilation, bilevel positive airway pressure). Continuous sedation with sufentanil, midazolam or clonidine or a combination of those drugs was administered to achieve a Ramsay score between 2 and 4. Spontaneously breathing patients without continuous sedation and patients on controlled mechanical ventilation (and sedation) served as control groups. Mean arterial PCO2 from spontaneously breathing patients without continuous sedation was 39.5 +/- 7.3 torr compared with 42.7 +/- 6.8 torr under sufentanil (median 0.44 microg x kg(-1) x h(-1), 98 % of observations between 0.1 and 2.1 microg x kg(-1) x h(-1)), 41.5 +/- 6.1 torr under sufentanil (median 0.90 microg x kg(-1) x h(-1) (0.1-2.8)) plus midazolam (median 45 microg x kg(-1) x h(-1) (7-170)) and 39.8 +/- 5.6 torr under a combination of sufentanil (median 1.15 microg x kg(-1) x h(-1) (0.2-3.6)), midazolam (median 45 microg x kg(-1) x h(-1) (11-216)) and clonidine (median 1.3 microg x kg(-1) x h(-1) (0.2-2.5)). Mean arterial PCO2 from patients on controlled mechanical ventilation was 39.9 +/- 6.1 torr. CONCLUSION: Patients under continuous sedation with sufentanil exhibit a statistically significant rise in arterial PCO2, however this respiratory depression is only slight and has no clinical significance. Mechanically assisted spontaneous ventilation modes can safely be used under continuous sedation with sufentanil, midazolam or clonidine.

Haemodynamic changes and skeletal muscle oxygen tension during complete blood exchange with ultrapurified polymerized bovine haemoglobin.

OBJECTIVE: The study investigates the effect of continuous blood exchange with ultrapurified, polymerized bovine haemoglobin (UPBH) in comparison to hetastarch on haemodynamics, oxygen transport and skeletal muscle oxygen tension in a canine model. DESIGN: Sixteen anaesthetized beagle dogs underwent haemodilution with lactated Ringer's to a starting haematocrit of 20% followed by progressive blood exchange with 6% hetastarch 200,000/0.5 (HES, group 1) or UPBH (haemoglobin 13 +/- 1 g.dl-1, molecular weight (MW) 32-500,000, group 2) to haematocrit target levels of 15%, 10% and 5% or less. MEASUREMENTS AND RESULTS: Besides haemodynamics, skeletal muscle tissue oxygen tension (tPO2) was measured using a polarographic needle probe. In HES-treated animals, heart rate, cardiac output and blood flow were higher while systemic vascular resistance, systemic and regional arterio-venous oxygen difference (avDO2) and oxygen extraction ratios were lower when compared to the UPBH group. In spite of a higher final haematocrit of 5% in group 1, in comparison to group 2 with 2%, final muscular oxygen uptake (4.7 +/- 4 vs 10.1 +/- 2 ml.min-1) and mean tPO2 (11.8 +/- 2.3 vs 51.1 +/- 2.9 mm Hg) were lower in group 1 than in group 2. While tPO2 histograms were continuously shifted to lower oxygen tensions during progressive haemodilution with HES, UPBH-exchanged animals showed tPO2 histograms shifted to higher values than baseline. CONCLUSION: In spite of vasoconstriction, UPBH provided more haemodynamic stability and enhanced skeletal muscle tPO2 during progressive blood exchange when compared to HES.

Fulminant malignant hyperthermia associated with ketoacidotic diabetic coma.

Malignant hyperthermia (MH) in humans is usually triggered by volatile anaesthetics and depolarizing muscle relaxants. However, other factors or drugs (e.g. cresol) are thought to induce MH. We report a case of fulminant MH associated with a ketoacidotic diabetic coma. After therapy for diabetic coma with insulin (containing the preservative cresol) and electrolyte solutions was started, the patient complained of increasing myalgia, developed a high fever and respiratory and metabolic acidosis and lost consciousness. MH was treated immediately with dantrolene; the patient recovered within 14 days. Five months later the patient was diagnosed as MH-susceptible by the in vitro caffeine and halothane contracture test. This case supports the assessment that MH and diabetes are associated diseases and that cresol could possibly trigger MH. Furthermore, therapy with dantrolene has been demonstrated to be beneficial in the treatment of MH associated with diabetic coma.

Cortical arousal in critically ill patients: an evoked response study.

OBJECTIVE: Assessing the level of sedation in critically ill patients remains a challenge for the intensivist in order to avoid over or under-sedation. Clinical scoring systems may fail in patients with concomitant neurological disorders or requiring muscle relaxants. We evaluated auditory (AER) and median nerve somatosensory evoked responses (MnSSER) in critically ill patients sedated with sufentanil and propofol, in order to quantify the level of sedation during therapeutic interventions. DESIGN: Prospective clinical study. SETTING: Anaesthesiological intensive care unit (ICU) in a university hospital. PATIENTS AND PARTICIPANTS: Thirty-two patients following major abdominal or thoracic surgery requiring sedation during their stay on the ICU. INTERVENTIONS: During physiotherapy and following nursing care (tracheal suctioning) AER and MnSSER were recorded. The level of sedation was evaluated clinically in relation to vital parameters. Data were analysed by multivariate analyses of variance (Hotellings T2), Friedman test. MEASUREMENTS AND RESULTS: In comparison to baseline levels the AER latency Nb decreased, while the amplitude NaPa increased during physiotherapy and after tracheal suctioning (p < 0.001). In contrast, the MnSSER latency P25 decreased and the amplitude P25N35 increased after tracheal suctioning only (p < or = 0.001). Clinical sedation scores decreased and mean arterial blood pressure increased during physiotherapy and nursing care. CONCLUSIONS: Changes of AER or MnSSER waves indicated cortical arousal in ICU patients during nursing care and physiotherapy. Further studies with evoked responses are recommended to evaluate whether bolus injections of sedatives and/or analgesics reduce cortical arousal and thereby minimise the patient's stress during nursing care.

Relation of echocardiographic preload indices to stroke volume in critically ill patients with normal and low cardiac index.

OBJECTIVE: To examine the usefulness of preload indices obtained by transoesophageal echocardiography (TOE) for estimating stroke volume at various levels of cardiac index. DESIGN: Prospective clinical study. SETTING: Intensive care unit with surgical patients. PATIENTS: 16 ventilated patients monitored via Swan-Ganz catheterization and TOE. INTERVENTIONS: Echocardiographic images of left ventricular cross-sectional short-axis areas were analysed for the preload indices end-diastolic area (EDA), stroke area and end-diastolic wall stress. The relation between these indices and stroke volume, calculated from thermodilution cardiac output, was analysed in all patients and in nine patient groups discriminated by various ranges in heart rate (< or = 70 to > 110 beats/min), pulmonary artery occlusion pressure (< or = 8 to > 12 mmHg) and cardiac index (< or = 3.0 to > 4.2 l/min per m2). MEASUREMENTS AND RESULTS: Overall stroke volume (n = 155) correlated significantly (p < 0.0001) with EDA (r = 0.89) and stroke area (r = 0.80). The correlation with end-diastolic wall stress was non-significant (r = 0.51). Linearity in the relation between stroke volume and EDA or stroke area was independent of variations in heart rate and pulmonary artery occlusion pressure. Stroke volume correlated well with EDA and stroke area, when cardiac index was normal or high, but the relation slightly deteriorated (r = 0.63 to < or = 0.72) when the cardiac index was low. Changes in EDA and stroke area by more than 1, 2 or 3 cm2 were weak predictors for changes in stroke volume greater than 20%. CONCLUSIONS: Stability of the relation between echocardiographic preload indices and stroke volume emphasize the potential of TOE for continuous preload monitoring in the critically ill.

Bovine hemoglobin increases skeletal muscle oxygenation during 95% artificial arterial stenosis.

BACKGROUND: This study investigates the effect of a stroma-free ultrapurified bovine hemoglobin solution (HBOC) on skeletal muscle tissue oxygenation in comparison with hetastarch during nearly complete arterial stenosis. METHODS: Fourteen foxhounds were intravenously anesthetized and mechanically ventilated with 30% oxygen in air. Catheters were inserted into the right femoral artery and vein for measurements of hemodynamic parameters and blood gas sampling. Arterial blood flow of the left popliteal artery was measured by means of an electromagnetic flow probe. Skeletal muscle tissue oxygen tension (tpO2) was measured in the left gastrocnemius muscle by using a stepwise driven polarographic needle probe creating histograms from 200 single tpO2 measurements. After isovolemic hemodilution with Ringer's lactate solution to a hematocrit of 25%, a 95% artificial stenosis of the popliteal artery was established. The animals then randomly received two applications of either 50 ml HBOC (molecular weight, 32,000 to 500,000; hemoglobin, 13 +/- 1 gm/dl-1) or 200 ml 6% hetastarch 200,000/0.5. Variables were measured at baseline, after hemodilution, 30 minutes after stenosis, and 15 minutes after two applications of the respective compound. RESULTS: Demographic data, muscle temperature, and arterial blood gases did not differ between groups. With the exception of higher mean arterial and mean pulmonary artery pressures in HBOC-treated animals, hemodynamics did not differ between groups. In both groups oxygen delivery and oxygen consumption of the muscle decreased in parallel to the decreasing blood flow during arterial stenosis. In contrast, oxygen extraction ratio increased after infusion of HBOC and was higher after the second application when compared with hetastarch-treated animals (p < 0.05). During stenosis tpO2 was decreased in both groups when compared with baseline (p < 0.001). Mean tpO2 remained at decreased levels after administration of hetastarch but increased to nearly baseline values after HBOC treatment (p < 0.001). CONCLUSIONS: The data suggest that increased oxygen extraction in the HBOC group is associated with improved skeletal muscle tissue oxygenation during severe arterial stenosis.