H. M. Oudemans-van Straaten

Outcome of critically ill patients treated with intermittent high-volume haemofiltration: a prospective cohort analysis.

Objective: To evaluate intervention and outcome in critically ill patients treated with high-volume haemofiltration (HV-HF). Design: Prospective cohort analysis. Setting: 18-bed closed format general intensive care unit (ICU) of a teaching hospital. Patients: 30-month cohort of ICU patients treated with HV-HF. Interventions: Intermittent high-volume venovenous haemofiltration. Endpoints: Observed and predicted mortality in prospectively stratified prognostic groups. Measurements and results: Clinical and filtration data, Acute Physiology and Chronic Health Evaluation (APACHE) II, Simplified Acute Physiology Score (SAPS) II and the Madrid Acute Renal Failure (ARF) score and predicted mortality. A total of 306 patients were haemofiltrated (140 medical, 166 surgical), 52 % were oliguric. Mean APACHE II score was 31 (SD 8) and mean SAPS II score 60 (SD 16). Mean ultrafiltrate rate was 63 ml/min (SD 20). A median total of 160 litres (90 % range 49 to 453) were filtrated per patient, material costs were 565 ECU (90 % range 199 to 1514). ICU mortality was 33 %, hospital mortality 40 % [95 % confidence interval (CI) 34 to 45], predicted mortality by the ARF score 67 % (CI 66 to 69). Non-cardiac surgery mortality was 47 % (CI 39 to 54), 73 % (CI 70 to 76) predicted by APACHE II and 67 % (CI 64 to 70) by SAPS II. Observed mortality was significantly lower than predicted in all prognostic groups. The standardised mortality ratio (SMR) was no higher than the SMR in the overall ICU population. Conclusions: Mortality in HV-HF patients was lower than that predicted by illness severity scores, as was the case in all patients in our ICU. Treatment with HV-HF appears to be safe and feasible. The efficacy of HV-HF should be tested in randomised, controlled trials of suitable power.

Intestinal permeability, circulating endotoxin, and postoperative systemic responses in cardiac surgery patients

OBJECTIVES To determine whether intestinal permeability increases during cardiac operations, and whether the degree of endotoxemia is related to this increase. Furthermore, to determine whether intestinal permeability is related to the hemodynamic state during operation and to postoperative systemic responses. DESIGN Prospective study. SETTING University hospital. PARTICIPANTS Twenty-three male patients undergoing elective coronary artery bypass surgery. INTERVENTIONS Before surgery and during the fifth postoperative day, 100 mL of a solution containing L-rhamnose and cellobiose were administered orally. MEASUREMENTS AND MAIN RESULTS Intestinal permeability was assessed by measuring the urinary excretion of L-rhamnose and cellobiose. Endotoxin concentrations in blood and prime fluid, hemodynamics, oxygen consumption, gas exchange, fluid balance, and the dose of vasoactive drugs were measured. Systemic responses were assessed by measuring hypermetabolism, circulatory support, and gas exchange. Intestinal permeation of cellobiose, reflecting paracellular transport, significantly increased during operation (p < 0.01), and correlated with the amount of circulating endotoxin (r2 = 0.46; p < 0.01). A high dose of ephedrine administered during operation, low baseline central venous pressure, and a less positive fluid balance during operation were associated with high intestinal permeability (r2 = 0.7; p < 0.01). Intestinal permeability was related to postoperative systemic responses (r2 = 0.49; p < 0.01). CONCLUSIONS This study shows that during elective coronary artery bypass operations intestinal permeability between cells may increase. The degree of endotoxemia is related to this increase. Increased intestinal permeability is related to the use of ephedrine, especially during hypovolemia, and to postoperative systemic responses. Although a causative relation is not shown, these results might indicate that hypovolemia and vasoconstriction should be avoided during the operation.

Disseminated tuberculosis, pulmonary aspergillosis and cutaneous herpes simplex infection in a patient with infliximab and methotrexate

Case presentationDespite chemoprophylaxis with isoniazid a 58-year-old Creole patient with mild rheumatoid arthritis developed disseminated tuberculosis, pulmonary aspergillosis and cutaneous herpes simplex infection during treatment with infliximab and methotrexate.TreatmentThe patient received antituberculous drugs (ethambutol, isoniazid, pyrazinamide, rifampicin), amphotericin B, flucytosine, and valaciclovir, along with prolonged intensive care treatment and mechanical ventilation.ConclusionsThe present case confirms that isoniazid prophylaxis (300 mg once daily, during 6 months) does not protect against the reactivation and dissemination of latent tuberculosis. It also shows that combined treatment with infliximab and methotrexate may induce severe immunosuppression with prolonged leukocytopenia and depressed cellular immunity, leading to multiple opportunistic infections. Extensive diagnostic testing, early start of antimicrobial therapy and enteral immunonutrition, and further infection prevention with selective decontamination of the digestive tract may have been the key to a good clinical outcome.

Increased oxygen consumption after cardiac surgery is associated with the inflammatory response to endotoxemia.

ObjectiveThe aim of this study was to determine whether the increase in post-operative oxygen consumption (ΔVO2) in cardiac surgery patients in related to endotoxemia and subsequent cytokine release and whether ΔVO2 can be used as a parameter of post-perfusion syndrome.DesignProspective study.SettingOperating room and intensive care unit of a university hospital.PatientsTwenty-one consecutive male patients undergoing elective coronary artery bypass surgery without major organ dysfunction and not receiving corticosteroids.Measurements and resultsPlasma levels of endotoxin, tumor necrosis factor (TNF) and interleukin-6 (IL-6) were measured before, during and for 18 h after cardiac surgery. Oxygen consumption, haemodynamics, the use of IV fluids and dopamine, body temperature and the time of extubation were also measured. Measurements from patients with high ΔVO2 (≥median value of the entire group) were compared with measurements from patients with low ΔVO2 (<median). Patients with high ΔVO2 had higher levels of circulating endotoxin (P=0.004), TNF (P=0.04) and IL-6 (P=0.009) received more IV fluids and dopamine while in the ICU, and were extubated later than patients with low ΔVO2. Several hours after ΔVO2 the patients body temperature rose, Forward stepwise regression analysis showed that circulating endotoxin and TNF explained 50% of the variability of ΔVO2.ConclusionsThis study demonstrates that patients with high post operative oxygen comsumption after elective cardiac surgery have higher circulating levels of endotoxin, TNF and IL-6 and also have more symptoms of post-perfusion syndrome. Early detection of high VO2 might be used as a clinical signal to improve circulation in order to meet the high oxygen demand of inflammation. In addition, continuous measurement of VO2 provides us with a clinical parameter of inflammation in interventional studies aiming at a reduction of endotoxemia or circulating cytokines.

Nadroparin versus dalteparin anticoagulation in high-volume, continuous venovenous hemofiltration: a double-blind, randomized, crossover study.

Objectives: To compare filter survival times during high‐volume, continuous venovenous hemofiltration in patients with normal coagulation variables, using anti‐factor Xa bioequivalent doses of nadroparin and dalteparin. To evaluate which other factors influence filter survival time. Design: Randomized, prospective, double‐blind, crossover study. Setting: An 18‐bed intensive care unit in a 530‐bed teaching hospital. Patients: Thirty‐two critically ill patients with renal failure, treated with high‐volume, continuous venovenous hemofiltration. Interventions: High‐volume, postdilutional continuous venovenous hemofiltration, with a standard blood flow rate of 200 mL/min and an ultrafiltrate volume of 100 L in 24 hrs, was performed with a highly permeable, large‐surface cellulose triacetate membrane. Anticoagulation with anti‐Xa bioequivalent doses of nadroparin and dalteparin was administered in the extracorporeal line before the filter. Blood was sampled for determination of coagulation variables before hemofiltration, 0.5, 2, 4, 6, and 12 hrs after starting the treatment, and at the end of the hemofiltration run. Measurements and Main Results: Anti‐Xa peak activity, time of anti‐Xa peak activity, area under the curve for 0‐3 hrs and filter survival time were not significantly different using nadroparin or dalteparin. When analyzing the patients according to the length of filter survival time, no relationship among anti‐Xa peak activity, area under the curve for 0‐3 hrs, and filter survival time was found. However, there was a strong trend toward a negative correlation between baseline platelet count and filter survival time (r2 = .11; p = .07). Mean blood urea nitrogen decreased from 81.0 ± 31.9 to 41.1 ± 21.2 mg/dL (p < .01) and mean creatinine decreased from 3.4 ± 1.8 to 1.9 ± 1.2 mg/dL (p < .01). There were no clinically important bleeding complications. Conclusions: Nadroparin and dalteparin are bioequivalent with respect to their anti‐Xa activities. Using either drug, we did not find a difference in filter survival time during high‐volume, continuous venovenous hemofiltration. No relationship between anti‐Xa activity and filter survival time could be found. However, there is a strong trend toward a negative correlation between baseline platelet count and filter survival time. This suggests that during high‐volume, continuous venovenous hemofiltration, patients with a higher baseline platelet count might need a different anticoagulation regimen to obtain longer filter survival times.

Systematic review of perioperative selective decontamination of the digestive tract in elective gastrointestinal surgery

Studies on selective decontamination of the digestive tract (SDD) in elective gastrointestinal surgery have shown decreased rates of postoperative infection and anastomotic leakage. However, the prophylactic use of perioperative SDD in elective gastrointestinal surgery is not generally accepted.

Oxygen consumption after cardiopulmonary bypass — implications o of different measuring methods

ObjectiveTo determine whether intra-pulmonary oxygen consumption or whole body oxygen consumption is the main determinant of the hypermetabolic response after cardiopulmonary bypass. Secondly, which method of measuring oxygen consumption best quantifies this hyperdynamic response.DesignWe measured oxygen consumption by analysing respiratory gas (VO2-gas), carbon dioxide excretion (VCO2), and respiratory exchange ratio (RER = VCO2/VO2), and calculated oxygen consumption using the Fick-method (VO2-Fick) and intra-pulmonary oxygen consumption (VO2-gas — VO2-Fick) in patients at fixed times before and after elective cardiac surgery. Next, comparisons were made between methods and also between measurements at different times before and after bypass.SettingUniversity hospitalPatients10 elective cardiac surgical patientsInterventionsNoneMeasurements and resultsVO2-gas, VCO2 and RER were measured with an open circuit indirect calorimeter VO2-Fick was calculated: VO2-Fick=cardiac indexx(arterial — mixed venous oxygen content). Intrapulmonary oxygen consumption was calculated as the difference between VO2-gas and VO2-Fick. Both VO2-gas and VO2-Fick were about 20% higher after bypass than after induction of anaesthesia. Absolute values of VO2-gas were about 30% higher than VO2-Fick. Intra-pulmonary oxygen consumption accounted for 32% of whole body oxygen consumption after induction of anaesthesia and did not increase after bypass.ConclusionWhole body oxygen consumption and not intra-pulmonary oxygen consumption is the main determinant of the hypermetabolic response after bypass. Increased intra-pulmonary oxygen consumption is not related to bypass. VO2-gas best quantifies this hypermetabolic response directly after bypass, and not VO2-Fick, VCO2 or intra-pulmonary oxygen consumption, since VO2-Fick excludes intra-pulmonary oxygen consumption and VCO2 does not reflect metabolism directly after bypass.

Randomized clinical trial of perioperative selective decontamination of the digestive tract versus placebo in elective gastrointestinal surgery

This randomized clinical trial analysed the effect of perioperative selective decontamination of the digestive tract (SDD) in elective gastrointestinal surgery on postoperative infectious complications and leakage.

Cardiovascular effects of hyperoxia during and after cardiac surgery.

During and after cardiac surgery with cardiopulmonary bypass, high concentrations of oxygen are routinely administered, with the intention of preventing cellular hypoxia. We systematically reviewed the literature addressing the effects of arterial hyperoxia. Extensive evidence from pre‐clinical experiments and clinical studies in other patient groups suggests predominant harm, caused by oxidative stress, vasoconstriction, perfusion heterogeneity and myocardial injury. Whether these alterations are temporary and benign, or actually affect clinical outcome, remains to be demonstrated. In nine clinical cardiac surgical studies in low‐risk patients, higher oxygen targets tended to compromise cardiovascular function, but did not affect clinical outcome. No data about potential beneficial effects of hyperoxia, such as reduction of gas micro‐emboli or post‐cardiac surgery infections, were reported. Current evidence is insufficient to specify optimal oxygen targets. Nevertheless, the safety of supraphysiological oxygen suppletion is unproven. Randomised studies with a variety of oxygen targets and inclusion of high‐risk patients are needed to identify optimal oxygen targets during and after cardiac surgery.

Fulminant falciparum malaria.

A case of fulminant falciparum malaria with a 35% parasitaemia, shock and subcoma was treated successfully by using parenteral chemotherapy, exchange transfusion, dexamethasone, circulatory support and mechanical ventilation. Pathophysiology and complications of falciparum malaria are discussed. The treatment of severe malaria should aim for a fast reduction in parasitaemia and toxic products. An exchange transfusion can be additive to parenteral chemotherapy. Blocking the over-reacting cell-mediated immune response, aggressive shock treatment, prevention of secondary infections and maintaining normoglycaemia might reduce morbidity and mortality of fulminant falciparum malaria.