Search PubMed⌕ Search

Biomedical subjects

W J Kox

Publications and source records attributed to W J Kox.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Experimental results of using the "open lung concept"].

Several elements of the "open lung concept", like ventilation with small tidal volumes, were incorporated into various ventilatory strategies. Our study demonstrates how the whole concept can be applied in an animal model using a standardized protocol with the following possible results. Eighteen pigs weighing between 30 and 45 kg were anaesthetized, tracheotomized and ventilated. Acute lung injury was induced by surfactant washout. Blood gases were monitored via a continuous arterial sensor system (Trendcare system). After washout, the ventilatory pattern of the American "ARDS Network study" was applied (PEEP = 9 cmH2O, volume controlled mode with a tidal volume of 6 ml/kg body weight and a respiratory rate of 25 breaths per minute). Afterwards, the opening pressure and the pressure at which the lung collapses were titrated. Both levels were used as the basis for adjusting the recruitment pressure and PEEP, which was necessary to keep the lung open. The respiratory rate was chosen in such a way that at a low intrapulmonary pressure difference between inspiration and expiration as well as normocapnia was reached. After induction of an acute lung injury by surfactant washout, the oxygenation index (OI) dropped from 556 +/- 54 to 176 +/- 89 mmHg. In the "ARDS Network" mode, OI increased to 285 +/- 49 mmHg. After alveolar recruitment with a peak pressure of 53 +/- 7 cmH2O and application of a median PEEP of 17 +/- 3 cmH2O, oxygenation returned close to baseline. A pCO2 of 33 +/- 4 mmHg resulted after using a respiratory rate of 39 breaths per minute. The median tidal volume was 8 ml/kg body weight. Despite a short arterial systolic blood pressure drop of 23 +/- 11 mmHg during recruitment, no significant difference was detectable afterwards compared to the baseline. Using low tidal volumes alone, complete reopening was not achieved in an experimentally induced acute lung injury. After recruitment manoeuvres, it was possible to reopen the lung and keep it open by application of a sufficient PEEP.

Air Pressure↗
PubMed2002

Preoperative evaluation of chronic alcoholics assessed for surgery of the upper digestive tract.

BACKGROUND: Alcoholics are at risk of developing major complications in the postoperative period. Adequate prophylactic treatment, as well as preoperative abstinence, can significantly decrease the rate of complications. However, the preoperative diagnosis of alcoholism is difficult to establish. The purpose of this study was to assess whether three preoperative visits, an alcohol-related questionnaire (CAGE), and the laboratory markers carbohydrate-deficient transferrin (CDT) and gamma-glutamyltransferase (GGT) would increase the rate of detection of chronic alcoholics. METHODS: The study included the Departments of ENT, Facial and Maxillofacial Surgery, and General Surgery of a university hospital; 705 male patients were assessed for tumor surgery of the upper digestive tract and were allocated to 5 different groups. All patients were seen three times, and five different strategies were used to detect chronic alcoholics. The gold standard was the diagnosis of alcohol misuse made by an experienced (blinded) investigator according to the DSM-III-R. The main outcome measurements were the detection rates of the different test strategies. RESULTS: By clinical routine alone, only 16% were detected during the first visit and 34% after three visits. If the CAGE questionnaire was added, sensitivity increased to 64%. The further addition of GGT or CDT led to 80 and 85% detections, respectively. A combination of all tests had a sensitivity of 91%. CONCLUSIONS: To detect more alcoholic patients at risk for major complications, patients should be seen more often, and additional diagnostic tools such as the CAGE, CDT, and GGT should be used before surgery.

Adult↗
PubMed2002

[Focal surgery, antibiotic therapy--and then? The role of rhAPC in sepsis].

Severe sepsis and septic shock are still the leading causes of death in the surgical ICU. The only curative therapies of sepsis are still surgery as well as antibiotic therapy to cure the focus. In addition a supportive therapy (analgesia and sedation, mechanical ventilation, titrated volume substitution and positive inotropes/vasopressor support, parenteral and enteral neutron, renal replacement therapies) should be started as early as possible. A new promising approach in sepsis therapy is the application of rhAPC. The PROWESS study revealed a significantly lower 28 day mortality in patients with severe sepsis who received drotrecogin alfa (activated) compared to patients not treated with drotrecogin alfa (activated). Guidelines for the use in severe sepsis and septic shock in surgical patients (risk of bleeding, costs) are strongly recommended.

Anti-Bacterial Agents↗
PubMed2001

Participation of the Ca(2+)-calmodulin-activated Kinase II in the control of metaphase-anaphase transition in human cells.

Treatment of HeLa S3 cells growing in suspension, and of endothelial cells ECV 304 growing as a monolayer, with the inhibitor of the Ca(2+)-calmodulin activated Kinase II KN-93, blocks cells at metaphase for 15 min (HeLa cells) and 30 min (ECV cells). Thereafter cells resume mitosis and enter anaphase. The inactive isomer KN-92 does not show such effects. The results show the involvement of the CaM K II system in the regulation of the metaphase-anaphase transition whereby the activation of the Kinase II, in particular by calmodulin appears to be affected, the residual autophosphorylation of the CaM K II system apparently sufficing after 15 to 30 min to release the cells into anaphase. The results are compared with the metaphase-blocking effects of the noble gas xenon, where the xenon-induced block can be overcome by small intracellular increases of Ca(2+), thus indicating the CaM K II system as a possible target for xenon.

Anaphase↗
PubMed2001

[Anesthesia in extreme obesity].

BACKGROUND: Approximately 1-2% of all anesthetized patients are morbidly obese (body mass index > 35 kg/m2). The perioperative mortality is significantly elevated (up to 20%) compared with lean patients. Morbidly obese patients are at high risk for cardiopulmonary dysfunction. Difficult airway management is reported in 13-20% of obese patients. Hypoxia is often observed due to faster desaturation during induction of anesthesia. After surgery, patients are endangered by a high incidence of obstructive sleep apnea syndrome (50%), pulmonary atelectasis (5%) and acute pulmonary embolism (5-12%). ANESTHESIA: Individualized perioperative management is required based on preoperative history and physical examination. Modern anesthetic drugs (desfluran, sevoflurane or propofol, and remifentanil, respectively) allow rapid recovery and early postoperative mobilization. Adequate monitoring, e.g. by an intraarterial blood pressure monitoring and repetitive blood gas analyses, improves patient safety prior the onset of complications. POSTOPERATIVE MANAGEMENT: Postoperative admission on an intensive care unit of morbidly obese patients is based upon concomitant diseases and surgical requirements. The main reason for admission is an inadequate pulmonary gas exchange. This interdisciplinary approach will reduce the risk of anesthesia and avoid complications in morbidly obese patients.

Anesthesia, General↗
PubMed2001

Reduction in intestinal leukocyte adherence in rat experimental endotoxemia by treatment with the 21-aminosteroid U-74389G.

OBJECTIVES: To investigate leukocyte adherence in intestinal venules in experimental endotoxemia after treatment with the 21-aminosteroid U-74389G. DESIGN AND SETTING: Prospective, randomized, controlled animal study in an experimental laboratory. SUBJECTS: Twenty-one male Wistar rats weighing 190 +/- 40 g. INTERVENTIONS: The rats were divided equally into three groups: (a) control group, (b) endotoxemia (5 mg/kg lipopolysacharide from Escherichia coli O55:B5), and (c) endotoxemia and U-74389G administration 30 min before (3 mg/kg) and 60 min after endotoxin challenge (1.5 mg/ kg). MEASUREMENTS AND MAIN RESULTS: The distal small intestine of the animals was examined using intravital fluorescence videomicroscopy 2 h after endotoxin challenge. Leukocytes were stained in vivo by means of rhodamine 6G. In the endotoxemic animals we observed a fourfold increase in the count of firmly adherent leukocytes in submucosal post-capillary and collecting venules. Treatment with the 21-aminosteroid U-74389G significantly attenuated the count of sticking leukocytes in the collecting venules (control, 61 +/- 10 cells/mm2; lipopolysaccharide, 237 +/- 42 cells/mm2; U-74389G 125 +/- 9 cells/mm2; p < 0.05). In these venules leukocyte rolling behavior was comparable to that in the control group without endotoxin challenge. CONCLUSIONS: Administration of U-74389G, which has radical scavenging properties, attenuates leukocyte adherence in selected populations of intestinal venules which is found increased during endotoxemia. Thus, 21-aminosteroids may have an impact in the treatment of endotoxin-induced intestinal injury.

Animals↗
PubMed2001

Risk factors for prolonged ventilation after cardiac surgery using APACHE II, SAPS II, and TISS: comparison of three different models.

OBJECTIVE: To identify the risk for prolonged mechanical ventilation in cardiac surgical patients. DESIGN: Prospective study with retrospective combination of a second database. PATIENTS: Six hundred and eighty-seven patients after cardiac surgery over a period of 12 months. MEASUREMENTS: Demographic data were recorded preoperatively, and surgical procedures intraoperatively using a surgical database designed for quality control. Length of ICU and hospital stay, and hospital outcome were recorded. Severity of illness was assessed daily using APACHE II, SAPS II, and Organ Failure Score. Intensity of treatment and nursing care was monitored by means of the Therapeutic Intervention Scoring System (TISS). Univariate and multivariate analyses were performed using logistic regression. The predictive value of the identified variables was tested by the Wilcoxon test using the receiver operating characteristic curve. MAIN RESULTS: Sixty-two patients (9.0%) were ventilated for > 48 h and accounted for 42.8% of the total costs in the ICU. The pre- and intraoperatively collected data produced a model with weak predictive capacity for prolonged ventilation [area under curve (AUC) 73.22 and 71.08, respectively]. The use of TISS and SAPS postoperatively resulted in an effective model of prediction (AUC 93.76). Adding the occurrence of reoperation, reintubation, emergency transfusion, intraaortic balloon pumping, and need for total parenteral nutrition to the model further improved its predictive capacity (AUC 94.74). CONCLUSIONS: The present results strongly suggest that data collected postoperatively using established scoring systems as well as documented events of high clinical impact for risk assessment and quality control are reliable predictors of prolonged ventilation.

APACHE↗
PubMed2001

Hirudin versus heparin for anticoagulation in continuous renal replacement therapy.

OBJECTIVE: To compare the efficacy and safety of hirudin and heparin for anticoagulation during continuous renal replacement therapy (CRRT) in critically ill patients. DESIGN: Prospective, randomized controlled pilot study. SETTING: Single centre; interdisciplinary intensive care unit at a university hospital. PATIENTS: Seventeen patients receiving CRRT. INTERVENTIONS: Patients were randomly allocated to two groups. Heparin group (nine patients): continuous administration of 250 IU/h heparin; dose was adjusted in 125 IU/h steps with a targeted activated clotting time (ACT) of 180-210 s. Hirudin group (eight patients): continuous infusion of 10 micrograms/kg/h hirudin, dose was adjusted in 2 micrograms/kg/h steps with a targeted ecarin clotting time (ECT) of 80-100 s. Observation time was 96 h. MEASUREMENTS AND MAIN RESULTS: Measured filter run patency and haemofiltration efficacy did not significantly differ between the two groups. Three bleeding complications were observed in the hirudin group, none in the heparin group (P < 0.01). At the onset of bleeding, which occurred 60 or more hours after the start of therapy, only one patient was still under continuous hirudin administration but levels were either in therapeutic range or below. CONCLUSIONS: Hirudin can be used efficiently for anticoagulation in CRRT. Late bleeding complications may have been caused by possible hirudin accumulation, but this was not evident from hirudin plasma and ECT levels. Since bleeding complications were observed only in the presence of documented coagulation disorders, not only adequate drug monitoring but also the plasmatic and cellular coagulation status of the patient should be taken into consideration for adjusting hirudin dosage.

APACHE↗
PubMed2001

A randomized controlled double-blind trial comparing piritramide and morphine for analgesia after hysterectomy.

BACKGROUND AND OBJECTIVE: Efficacy and side-effects of piritramide (pirinitramide) and morphine, given intravenously for postoperative analgesia after hysterectomy, were compared in a randomized controlled double-blind trial in 92 ASA class I-III patients. METHODS: Administration was investigator-controlled during the first 90 min and subsequently via a patient-controlled device. Visual analogue scales for pain intensity and verbal rating scales for side-effects were taken repeatedly. RESULTS: Median visual analogue scores for pain intensity on a 100-mm scale 4, 8 and 24 h after surgery were 10, 8.5 and 5 mm in the piritramide group and 18, 10 and 8.5 mm in the morphine group. These differences are neither statistically nor clinically significant. Median values for nausea on a verbal rating scale from 0 to 3 were zero for both groups at all times with similar ranges. There was no difference in number of episodes of vomiting and retching and usage of antiemetics. The mean amount of piritramide used for initial titration was 15.2 mg; the respective amount of morphine was 15.4 mg. CONCLUSIONS: In this setting the two agents are equally effective and show a similar profile of side-effects.

Analgesia, Patient-Controlled↗
PubMed2001

Effects of sevoflurane and propofol on pulmonary shunt fraction during one-lung ventilation for thoracic surgery.

Forty patients requiring one-lung ventilation (OLV) for thoracic surgery were randomly assigned to receive propofol (4-6 mg kg(-1) h(-1)) or sevoflurane (1 MAC) for maintenance of anaesthesia. Three sets of measurements were taken: (i) after 30 min of two-lung ventilation (TLV), (ii) after 30 min of one-lung ventilation (OLV-1) in the supine position and (iii) during OLV in the lateral position (OLV-2) with the chest open and before surgical manipulation of the lung. There were no differences between groups in patient characteristics or preoperative condition. Increases in shunt fraction during OLV-1 were 17.4% and 17.2% (P=0.94), those during OLV-2 were 18.3% and 16.5% (P=0.59) for the propofol and sevoflurane group, respectively. Cardiac index and other haemodynamic and respiratory variables were similar for the two groups. We conclude that inhibition of hypoxic pulmonary vasoconstriction by sevoflurane may only account for small increases in shunt fraction and that much of the overall shunt fraction during OLV has other causes.

Adult↗
PubMed2001

Downward movement of syringe pumps reduces syringe output.

We studied how lowering a syringe pump and changing the outflow pressure could affect syringe pump output. We experimentally reduced the height of three different syringe pump systems by 80 cm (adult setting) or 130 cm (neonatal setting), as can happen clinically, using five flow rates. We measured the time of backward flow, no flow and the total time without flow. An exponential negative correlation was present between infusion rate and time without flow (r2=0.809 to 0.972, P<0.01). Minimum flow rates of 4.4 and 2.6 ml h(-1) respectively were calculated to give 60 and 120 s without infusion. The compliance of the different syringe pumps and their infusion systems was linearly correlated with the effective time without infusion (r2=0.863, P<0.05). We conclude that the height of the syringe pumps should not be changed during transportation. If vertical movement of the syringe pump is necessary, the drugs should be diluted so that the flow rate is at least 5 ml h(-1).

Adult↗
PubMed2001

Thoracic epidural anesthesia combined with general anesthesia: the preferred anesthetic technique for thoracic surgery.

UNLABELLED: Thoracic epidural anesthesia (TEA) combined with general anesthesia (GA) as well as total-IV anesthesia (TIVA) are both established anesthetic managements for thoracic surgery. We compared them with respect to hypoxic pulmonary vasoconstriction, shunt fraction and oxygenation during one-lung ventilation. Fifty patients, ASA physical status II-III undergoing pulmonary resection were randomly allocated to two groups. In the TIVA group, anesthesia was maintained with propofol and fentanyl. In the TEA group, anesthesia was maintained with TEA (bupivacaine 0.5%) combined with low-dose concentration 0.3-0.5 vol% of isoflurane (end-tidal). Changing from two-lung ventilation to one-lung ventilation caused a significant increase in cardiac output (CO) in the TIVA group, whereas no change was observed in the TEA group. One-lung ventilation caused significant increases in shunt fraction in both groups which was associated per definition with a significant decrease in PaO(2) in both groups but PaO(2) remained significantly increased in the TEA group (P < 0.05). We conclude that both anesthetic regimens are safe intraoperatively. However, TEA in combination with GA did not impair arterial oxygenation to the same extent as TIVA, which might be a result of the changes in CO. Therefore, patients with preexisting cardiopulmonary disease and impaired oxygenation before one-lung ventilation might benefit from TEA combined with GA. IMPLICATIONS: Fifty patients underwent lung surgery through the opened chest wall requiring ventilation of only one lung. Patients were randomly assigned to receive either general anesthesia alone or in combination with regional anesthesia via a catheter in the back. Oxygen content in the blood and blood pressure was better maintained in the group receiving the combination of general with regional anesthesia.

Adult↗
PubMed2001

Effects of iloprost, a stable prostacyclin analog, on intestinal leukocyte adherence and microvascular blood flow in rat experimental endotoxemia.

OBJECTIVE: To investigate the effects of iloprost, a stable prostacyclin analog, on leukocyte adherence in intestinal venules and intestinal microvascular blood flow in experimental endotoxemia. DESIGN: Prospective, randomized, controlled animal study. SETTING: Experimental laboratory. SUBJECTS: Twenty-one male Wistar rats weighing 190 +/- 40 g. INTERVENTIONS: The rats were divided equally into three groups: the first was a control group; the second received endotoxin (20 mg/kg lipopolysaccharide from Escherichia coli O55:B5 intravenously); and the third received endotoxin and intravenous iloprost infusion (2 ng.kg-1.min-1). MEASUREMENTS AND MAIN RESULTS: The distal small intestine of the animals was examined by using intravital fluorescence videomicroscopy 2 hrs after endotoxin challenge. Leukocytes were stained in vivo by means of rhodamine 6G. Intestinal microvascular blood flow was measured by laser Doppler flowmetry in the terminal ileum. Iloprost treatment significantly attenuated the count of adherent leukocytes in collecting venules (control, 61 +/- 10 n/mm2; lipopolysaccharide, 364 +/- 60 n/mm2; iloprost, 232 +/- 29 n/mm2; p <.05) and in postcapillary venules (control, 96 +/- 14 n/mm2; lipopolysaccharide, 470 +/- 21 n/mm2; iloprost 390 +/- 41 n/mm2; p <.05). Intestinal microvascular blood flow was decreased significantly in the lipopolysaccharide group (-49%), whereas iloprost-treated animals showed no significant difference compared with the control group. CONCLUSIONS: The study demonstrated that administration of iloprost attenuated leukocyte adherence in postcapillary and collecting intestinal venules and improved intestinal microvascular blood flow. Thus, iloprost treatment may impact endotoxin-induced intestinal injury.

Analysis of Variance↗
PubMed2001

Enoximone in contrast to dobutamine improves hepatosplanchnic function in fluid-optimized septic shock patients.

OBJECTIVE: To investigate the impact of dobutamine and enoximone on hepatosplanchnic perfusion and function in fluid-optimized septic patients. DESIGN: Prospective, randomized, double-blinded interventional study. SETTING: Intensive care unit of a university hospital. PATIENTS: Forty-eight septic shock patients were examined within 12 hrs after onset of septic shock. Patients were conventionally resuscitated, achieving an optimal pulmonary artery occlusion pressure at which the left ventricular stroke work was on the maximal plateau. Liver blood flow was estimated by venous suprahepatic catheterization using the continuous indocyanine green infusion technique. Microsomal liver function was assessed by the plasma appearance of monoethylglycinexylidide, and release of hepatic tumor necrosis factor-alpha (TNF-alpha) was measured to estimate the severity of hepatic ischemia-reperfusion syndrome. INTERVENTIONS: Patients were randomly treated with dobutamine or enoximone. Within the first 10 hrs after baseline measurements, the dosage was increased until no further increase in the left ventricular stroke work index occurred. Then, positive inotropes were kept constant throughout the study. MEASUREMENTS AND MAIN RESULTS: Measurements were performed at baseline and after 12 and 48 hrs after baseline measurements. Cardiac index, systemic oxygen delivery, systemic oxygen consumption, and liver blood flow increased significantly in both groups during treatment (p <.01) without a significant difference between groups. Fractional liver blood flow (liver blood flow/cardiac index) did not change in the enoximone group and showed a significant but only minor (median, 10%) decrease in the dobutamine group (p <.05 after 12 hrs and p <.01 after 48 hrs vs. baseline). After 12 hrs of enoximone treatment, monoethylglycinexylidide kinetics and hepatosplanchnic oxygen consumption demonstrated a significant increase (p <.05). The release of hepatic TNF-alpha after 12 hrs of dobutamine treatment was twice as high (p <.05) as during enoximone. CONCLUSION: The increase in hepatosplanchnic oxygen consumption, together with an increased lignocaine metabolism and decreased release of hepatic TNF-alpha, indicates improved hepatosplanchnic function and antiinflammatory properties after 12 hrs of enoximone treatment. Therefore, if the inflammatory response should be attenuated in high-risk patients, administration of enoximone in fluid-optimized septic shock patients may be favorable compared with dobutamine.

APACHE↗