Search PubMed⌕ Search

Biomedical subjects

D F Zandstra

Publications and source records attributed to D F Zandstra.

At least 37 records · Page 2Linked to original sources
PubMed2000

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.

Aged↗
PubMed2000

Pathogenesis, risk factors, and incidence of upper gastrointestinal bleeding after cardiac surgery: is specific prophylaxis in routine bypass procedures needed?

OBJECTIVES: (1) To obtain a literature review concerning pathogenesis and incidence of stress ulceration (SU) in patients undergoing cardiac surgery. (2) To determine which methods are useful in the prevention of SU and to analyze whether SU prophylaxis by acid reduction is effective in patients undergoing cardiac surgery. DESIGN: Literature review from Medline and reference list of identified articles until 1999. MEASUREMENTS AND MAIN RESULTS: SU and upper gastrointestinal bleeding (UGIB) in patients after cardiac surgery have been reported since 1957. All articles were retrospective reports. Definitions of SU and UGIB were variable. Ischemia, reperfusion injury, and endotoxemia were the main pathogenetic mechanisms in SU formation. Valve replacement, aortic cross-clamping and bypass time, nonpulsatile flow during bypass, reoperation, and inflammatory state were risk factors for UGIB. Randomized, controlled clinical trials concerning SU prophylaxis have not been performed. The overall incidence of UGIB was 0.45% (638 bleeds in 141,887 patients). In patients with known use of SU prophylaxis with histamine2-receptor antagonists or antacids, the incidence of UGIB was 0.35%, and in patients without these medications, the incidence of UGIB was 0.45% (p = 0.16). CONCLUSIONS: Pathogenesis and risk factors for SU and UGIB are summarized. A review of the literature showed that the incidence of UGIB in patients after cardiac surgery was low. A randomized, controlled trial concerning pharmacologic stress ulcer prophylaxis has not been performed. The available retrospective reports concerning pharmacologic stress ulcer prophylaxis do not support the routine use of histamine2-receptor antagonists.

Cardiac Surgical Procedures↗
PubMed1999

Increased mortality associated with growth hormone treatment in critically ill adults.

BACKGROUND: The administration of growth hormone can attenuate the catabolic response to injury, surgery, and sepsis. However, the effect of high doses of growth hormone on the length of stay in intensive care and in the hospital, the duration of mechanical ventilation, and the outcome in critically ill adults who are hospitalized for long periods is not known. METHODS: We carried out two prospective, multicenter, double-blind, randomized, placebo-controlled trials in parallel involving 247 Finnish patients and 285 patients in other European countries who had been in an intensive care unit for 5 to 7 days and who were expected to require intensive care for at least 10 days. The patients had had cardiac surgery, abdominal surgery, multiple trauma, or acute respiratory failure. The patients received either growth hormone (mean [+/-SD] daily dose, 0.10 +/- 0.02 mg per kilogram of body weight) or placebo until discharge from intensive care or for a maximum of 21 days. RESULTS: The in-hospital mortality rate was higher in the patients who received growth hormone than in those who did not (P<0.001 for both studies). In the Finnish study, the mortality rate was 39 percent in the growth hormone group, as compared with 20 percent in the placebo group. The respective rates in the multinational study were 44 percent and 18 percent. The relative risk of death for patients receiving growth hormone was 1.9 (95 percent confidence interval, 1.3 to 2.9) in the Finnish study and 2.4 (95 percent confidence interval, 1.6 to 3.5) in the multinational study. Among the survivors, the length of stay in intensive care and in the hospital and the duration of mechanical ventilation were prolonged in the growth hormone group. CONCLUSIONS: In patients with prolonged critical illness, high doses of growth hormone are associated with increased morbidity and mortality.

Adolescent↗
PubMed1999

[Selective decontamination of the digestive tract reduces mortality in intensive care patients].

Selective decontamination of the digestive tract (SDD) is a strategy designed to prevent or minimize the impact of infections by potentially pathogenic micro-organisms in critically ill patients requiring long-term mechanical ventilation. SDD is a four-component protocol to control the three types of infections occurring in intensive care patients: (a) a parenteral antibiotic, cefotaxime, for a few days to prevent primary endogenous infections that generally occur 'early'; (b) the topical antimicrobial drugs colistine (polymyxin E), tobramycin and amphotericin B (together: PTA) used throughout the stay in the intensive care unit (ICU) to prevent secondary endogenous infections developing in general 'late'; (c) a high standard of hygiene to prevent exogenous infections that may occur throughout the ICU stay; (d) surveillance samples of throat and rectum to distinguish between the three types of infection, to monitor compliance and efficacy of treatment and to detect emergence of resistance at an early stage. The most recent and rigorous meta-analysis examined 33 randomized SDD trials involving 5727 patients. It shows significant reductions, in overall mortality by 20% and in the incidence of lower airway infections by 65%. It failed to detect any report on the emergence of resistance and associated superinfections and/or out-breaks in the 33 studies covering a period of more than 10 years. Using the criterion of cost-per-survivor, four recent randomised trials showed that it is cheaper to produce a survivor using SDD than with the traditional approach.

Amphotericin B↗
PubMed1999

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.

APACHE↗
PubMed1998

The use of intensive care information systems alters outcome prediction.

OBJECTIVE: To study the effect of using an Intensive Care Information System (ICIS) on severity scores and prognostic indices: Acute Physiology and Chronic Health Evaluation II (APACHE II), Simplified Acute Physiology Score II (SAPS II), and Mortality Probability Models II (MPM II). DESIGN: Prospective pilot study. SETTING: A 20-bed medical-surgical intensive care unit (ICU) in a teaching hospital. PATIENTS: 50 consecutive adult patients admitted to the ICU on a bed equipped with an ICIS. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: In each patient all the physiologic variables, as required by the severity scores, were both manually charted and recorded by ICIS. ICIS registration resulted in the extraction of more abnormal values for all physiologic variables (except temperature): p < 0.05. Higher severity scores and mortality prediction were achieved by using ICIS charting: predicted mortality increased by 15% for APACHE II compared to manual charting, 25% for SAPS II, and 24% for MPM0. ICIS charting resulted in higher severity scores and mortality prediction for 29 of the 50 patients using APACHE II with a mean increase in mortality prediction in this subgroup of 27%. In the case of SAPS II, ICIS charting resulted in higher scores in 23 of the 50 patients and in the case of MPM0 in 13 patients, the mean increase in mortality in these subgroups being 64 and 148%, respectively. CONCLUSIONS: The use of ICIS charting to acquire the most abnormal physiologic values for severity scores and the derived prognostic indices results in a higher mortality prediction. Comparison of groups of patients and/or ICUs based on severity scores is impossible without standardization of data collection. The mortality prediction models have to be revalidated for the use of ICIS charting. While awaiting this, we suggest that every patient record in local regional, national, or international ICU databases should be marked as being recorded by manual or by ICIS charting.

Humans↗
PubMed1997

[Is the pulmonary artery catheter discredited because of ignorance?].

Recently in an observational study the use of a pulmonary artery catheter in critically ill patients was associated with an increase in both mortality and utilization of resources when compared with case-matched control patients. The authors corrected for selection bias by using a propensity score. The publication of this article elicited a flood of commentary in both medical journals and the lay press. Critical assessment of this study and other studies about pulmonary artery catheterization in our opinion supports the view that it is probably not the use of the catheter itself, but physicians' insufficient knowledge of right heart catheterization and the specific treatment resulting from its use that is at fault.

Cardiac Catheterization↗
PubMed1996

Endotoxaemia and postoperative hypermetabolism in coronary artery bypass surgery: the role of ketanserin.

In a randomized, double-blind clinical study in 29 patients undergoing elective coronary artery surgery, we assessed the role of ketanserin, an inhibitor of serotonin-induced vasoconstriction and weak alpha 1 sympathetic blocker, in reducing endotoxaemia and postoperative hypermetabolism. Male patients without major organ dysfunction were allocated randomly to receive either ketanserin or placebo. Hypermetabolism was defined as an increase in oxygen consumption in the early postoperative hours (delta Vo2). Circulating endotoxin (P = 0.04) and postoperative delta Vo2 (P = 0.03) were lower in the ketanserin patients. Endotoxaemia was associated also with low vascular filling. From these preliminary results we conclude that treatment with ketanserin during cardiac surgery may reduce but not abolish endotoxaemia and postoperative hypermetabolism.

Aged↗