Age, chronic disease, sepsis, organ system failure, and mortality in a medical intensive care unit

We retrospectively studied relations between age, pre-existing chronic disease, sepsis, organ system failure, and mortality in 487 patients from a medical ICU. Single organ system failure (SOSF) occurred in 136 (28%) and multiple (greater than or equal to 2) organ system failure (MOSF) in 187 (38%) patients. Cardiovascular and pulmonary failure predominated. Overall mortality was 27%. SOSF mortality was 16% and for MOSF 58%. Eighty-three percent of nonsurvivors had MOSF. Hence, MOSF is common and a major cause of death in critically ill medical patients. Advancing age and prior chronic disease may diminish physiologic reserve and predispose to sepsis and MOSF. Although sepsis is a major risk factor for MOSF, a nonspecific host response to critical illness may contribute to the syndrome in 35% of patients. Advancing age, chronic disease, and the number of failing organs, particularly failure of cardiovascular, pulmonary, renal, and neurologic systems, are major determinants of overall mortality, but sepsis is not an independent contributor.     

The influence of in vitro nitroimidazole resistance on the efficacy of nitroimidazole-containing anti-Helicobacter pylori regimens: a meta-analysis

OBJECTIVE: The aim of this study was to determine the influence of nitroimidazole resistance (NIR) on the efficacy of treatment for Helicobacter pylori (H. pylori) infections by meta-analysis of the world literature. METHODS: A MEDLINE search, a manual search of all major gastroenterological journals from 1993 to 1997, and abstracts of gastroenterological and H. pylori meetings from 1993 to 1997 were performed. All treatment studies using a nitroimidazole and providing data about the medication used, dose frequency, total daily dose, duration of treatment, and eradication results in relation to NIR were included. Eradication had to be assessed by two biopsy-based tests or a urea breath test > or = 4 wk after treatment. Individual studies were pooled into groups according to the medication used and the duration of treatment. The pooled estimate of the odds ratio (OR) of NIR for treatment failure and its 95% confidence interval (95% CI) were calculated for each group using the logit method. To detect any possible bias, funnel plots (plots of effect estimates against sample size) were constructed. RESULTS: A total of 91 treatment arms, including a total of 4823 patients, were evaluated. The pooled ORs of NIR for treatment failure (95% CI) of proton pump inhibitors, bismuth, and quadruple regimens were 5.2 (3.8-7.1), 5.9 (4.1-8.3), and 7.0 (3.1-16.0), respectively. Eradication rates were 90% in susceptible strains but <75% in resistant strains. In susceptible strains, neither treatment duration nor the choice of the second antibiotic influenced efficacy. In resistant strains, tetracycline was more effective than amoxicillin (bismuth regimens), and the longer the duration of regimens (bismuth-amoxicillin regimens) the more effective they were. Only quadruple regimens given for > or = 1 wk were effective in resistant strains. CONCLUSIONS: NIR decreases treatment efficacy. Treatment duration and choice of other drugs influence the impact of NIR on treatment efficacy. If NIR is present, a nitroimidazole-containing regimen should be avoided or a quadruple regimen should be given for > 1 wk.     

Gut luminal endotoxin reduces ischemia-reperfusion injury of the small gut in germ-free pigs.

Translocation of luminal bacteria and their products through the intestinal mucosa during ischemia-reperfusion (I/R) may modify I/R injury. To test this hypothesis, 16 germ-free pigs were studied prior to and after clamping the superior mesenteric artery (SMA) and 12 pigs served as controls. Nine pigs in the I/R and 5 in the control group received endotoxin intragastrically, 60 min before baseline. Gut absorption of an inert indicator (polyethyleneglycol [PEG] 3350), gut intraluminal PCO2 (tonometry), and systemic and regional hemodynamic variables were measured up to 4 h after baseline. Gut blood flow was stopped during clamping, some reactive hyperemia occurred up to 30 min after declamping in the I/R groups, independently of prior endotoxin administration. Gut intraluminal-arterial PCO2 gradients were elevated in I/R versus control groups during I and for some time during R, prior endotoxin had no effect. However, in controls without and with luminal endotoxin, PEG urinary excretion, as percentage of the dose administered, was 0.12 +/- 0.12 and 0.17 +/- 0.07, respectively, while it measured 1.82 +/- 0.70 in the I/R group and 0.55 +/- 0.37% in the I/R and endotoxin groups, respectively (P< 0.001). The data suggest that gut luminal endotoxin ameliorates I/R injury of the gut wall in germ-free pigs, without altering changes in gut perfusion adequacy and systemic hemodynamics.     

Arterial and mixed venous blood acid-base balance during hypoperfusion with incremental positive end-expiratory pressure in the pig

The authors sought to determine how hypoperfusion influences acid-base balance in arterial and mixed venous blood. In anesthetized, ventilated pigs (n = 12), we determined hemodynamics, O2 uptake, CO2 output, dead-space ventilation, arterial and mixed venous blood acid-base balances, and lactate concentrations during graded reductions in cardiac output by incremental positive end-expiratory pressure (PEEP, 0-20 cm H2O). Cardiac output decreased from 3.2 +/- 0.2 (mean +/- SEM) to 1.2 +/- 0.1 L/min at 20 cm H2O PEEP. Oxygen delivery declined more than O2 uptake did by 60% +/- 2% and 27% +/- 2%, respectively. The decrease in CO2 output (by 21% +/- 2%) was less than that in O2 uptake. Fractional dead-space ventilation increased. At a slight increase in carbon dioxide tension (PCO2) of 4 +/- 1 mm Hg, pH decreased in arterial blood from 7.54 +/- 0.01 to 7.47 +/- 0.02 mmol/L, and standard bicarbonate decreased from 30.3 +/- 0.5 to 27.5 +/- 0.6 mmol/L. The decrease in standard bicarbonate exceeded the increase in blood lactate concentrations. At a similar decrease in standard bicarbonate, the decrease in pH was larger (P less than 0.005) in mixed venous blood than in arterial blood owing to a larger increase in PCO2 (from 40 +/- 2 to 50 +/- 2 mm Hg, P less than 0.005). The changes were reversed after discontinuing PEEP. The authors conclude that ischemia after incremental PEEP results in tissue metabolic acidosis with superimposed respiratory acidosis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Correlation between predicted and actual consequences of capsule endoscopy on patient management

BACKGROUND: Capsule endoscopy (CE) is a relatively new diagnostic modality in the evaluation of patients with suspected small bowel pathology. It is unclear to what extent physicians are able to predict the clinical consequences of CE on patient management. METHODS: In this prospective study, 180 consecutive CE examinations were analysed. Prior to CE, referring physicians were asked to indicate the consequences of CE according to potential different CE outcomes. The influence of CE on patient management was determined with at least 1 year follow-up. Management consequences were defined as major (surgical or endoscopic intervention, or medical therapy) or minor (nonspecific therapy, including iron supplementation, or no further diagnostic tests). RESULTS: CE led to major management consequences in 32% of cases. Of patients with obscure gastrointestinal bleeding and normal CE findings, 91% were independent of blood transfusions and experienced no further bleeding episodes during a mean follow-up of 33 months. In 78% of 118 cases that were evaluated, the actual consequences of CE matched the consequences predicted by the referring physicians. CONCLUSION: CE had a major impact on patient management in about one third of investigations. In the majority of cases, physicians adequately predicted the clinical consequences of CE.     

A closed-chest model for the study of electromechanical dissociation of the heart in dogs

A closed chest model in mechanically ventilated dogs is presented for the study of electromechanical dissociation (EMD) after defibrillation for ventricular fibrillation (VF). In seven dogs VF was induced by internal application of an AC current in the right ventricle. Precordial compression was not performed. When VF was continued for either 30 s or 60 s defibrillation typically resulted in complete restoration of electrical and mechanical cardiac activity. Immediately after defibrillation, the mean arterial blood pressure, pulmonary artery pressure, right ventricular filling pressure and cardiac output were markedly elevated; these elevations were accompanied by a slight increase in lactate and a decline in pH of the arterial blood. When VF was continued for 120 s EMD was observed in each instance after defibrillation in association with a regular rhythm. After 5-20 min, the ventricular fibrillation reappeared. The constancy of EMD in this model provides an experimental basis for study of clinical options, by which EMD may be prevented and/or mechanical competence of the heart may be restored.     

Coagulopathy following major liver resection: the effect of rBPI21 and the role of decreased synthesis of regulating proteins by the liver

This prospective study investigated the role of reduced hepatic synthesis of regulating proteins in coagulopathy after partial hepatectomy (PH) compared with major abdominal surgery (MAS) without involvement of the liver. Furthermore, we studied the effect of rBPI21, an endotoxin-neutralizing agent, on coagulopathy after PH was studied. Compared with MAS, PH resulted in significantly elevated levels of thrombin-antithrombin-III and plasmin-alpha2-antiplasmin complexes. Levels of antithrombin-3, alpha2-antiplasmin, fibrinogen, plasminogen, alpha2-macroglobulin (alpha2-M), and C1-inhibitor remained lower following PH. Treatment with rBPI21 led to significantly lower levels of tissue-type plasminogen activator (t-PA). Post-operative disseminated intravascular coagulation (DIC) was associated with significantly higher bilirubin and t-PA plasma levels and significantly lower levels of alpha2-M. This study indicates that PH induced hepatic failure results in decreased synthesis of hepatic regulating plasma proteins and subsequent activation of coagulation and fibrinolysis. Prevention of t-PA release by rBPI21 may have important clinical implications. Decreased availability of alpha2-M may be a factor in post-operative DIC.     

Outcome of ICU treatment in invasive aspergillosis

Objective To assess the outcome of intensive care treatment in invasive aspergillosis.Design Retrospective study.Setting University Hospital, Medical Intensive Care Unit (ICU).Patients Twenty-five patients with invasive aspergillosis who were admitted to the medical ICU in a 5 1/2 year period. Twenty-two had received high-dose chemotherapy for (mainly hematologic) malignancies, one had been treated with cyclosporine and prednisolone for systemic lupus erythematosus, one with high-dose methylprednisolone for polyarteritis nodosa and one had an ARDS after near-drowning.Measurements and results The medical records were reviewed for patient and disease characteristics, outcome, reasons for admission to the ICU, supportive care and antifungal therapy as well as for the results of cultures and autopsy. Out of 25 patients, a definite ante mortem diagnosis could be established in seven. When autopsied patients were included, a total of 15 suffered from proven invasive aspergillosis. Although standard antifungal treatment and maximal available supportive care were given, 23 of 25 patients (92%) died after a mean of 15 (1–51) days in the ICU. Both patients who recovered had received high-dose chemotherapy for hematologic malignancy and showed bone marrow recovery and/or had a localized pulmonary infection.Conclusions In patients with highly suspected or proven invasive aspergillosis, admission to an ICU and mechanical ventilation should be considered in cases of localized infection and obvious signs of hematologic recovery. In most other circumstances ICU admission for mechanical ventilation does not seem to improve survival.     

Plasma endothelin levels are increased during septic shock.

OBJECTIVE: To study whether serially measured plasma concentrations of endothelin (a novel, potent, endogenous vasoconstrictor derived from endothelium and macrophages) relate to the pathophysiology and severity of human septic shock. DESIGN: Prospective analysis. SETTING: Medical ICU of a university hospital. PATIENTS: Six patients with septic shock, studied for 8 days after ICU admission. MEASUREMENTS AND MAIN RESULTS: The initial plasma endothelin concentration was increased (14.2 +/- 5.2 [SD] vs. normal 4.2 +/- 0.7 pg/mL, p less than .05) and correlated with the Acute Physiology and Chronic Health Evaluation II score (r2 = .79, p less than .05). For pooled data, endothelin levels correlated poorly with leukocyte counts (r2 = .13), mean arterial pressure (MAP) (r2 = .16), and administered doses of dopamine (r2 = .26). In multiple regression analyses, plasma endothelin concentrations were predicted by dopamine doses and not by MAP. Plasma endothelin concentrations predicted the decrease in creatinine clearance, independently from MAP. The pooled value for correlations between endothelin levels and creatinine clearance, during the course of disease in individual patients, was statistically significant (r2 = .31). CONCLUSIONS: During septic shock, the release or production of endothelin may increase as a consequence of endothelial injury by activated leukocytes and the infusion of catecholamines, and this mechanism may relate to renal vasoconstriction and to the severity of disease.