Faculty Bibliography

We previously validated an expert computer program (Hemodyn) designed to assist in interpreting pulmonary artery catheterization data. The present multicentric study assessed the influence of Hemodyn on the therapeutic strategies of residents. Each resident made several diagnostic choices and suggested appropriate treatments based on pulmonary artery catheterization (PAC) data. After knowledge of the computer interpretation, the resident could either maintain or change his or her diagnosis and treatment under a senior supervision. Agreement between the residents' initial evaluation and the computer's was poor (kappa <0.6). After computer assistance, agreement improved dramatically (kappa >0.9). Computer assistance led the residents to change at least one suggested treatment in 63% of cases, and in 8% of cases the residents changed the initial suggestion to its opposite. Expert software capable of helping residents to interpret PAC data properly may improve the quality of care given to critically ill patients.

OBJECTIVE: Peripheral perfusion in critically ill patients frequently is assessed by use of clinical signs. Recently, the pulse oximetry signal has been suggested to reflect changes in peripheral perfusion. A peripheral perfusion index based on analysis of the pulse oximetry signal has been implemented in monitoring systems as an index of peripheral perfusion. No data on the variation of this index in the normal population are available, and clinical application of this variable in critically ill patients has not been reported. We therefore studied the variation of the peripheral perfusion index in healthy adults and related it to the central-to-toe temperature difference and capillary refill time in critically ill patients after changes in clinical signs of peripheral perfusion. DESIGN: Prospective study. SETTING: University-affiliated teaching hospital. PATIENTS: One hundred eight healthy adult volunteers and 37 adult critically ill patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Capillary refill time, peripheral perfusion index, and arterial oxygen saturation were measured in healthy adults (group 1). Capillary refill time, peripheral perfusion index, arterial oxygen saturation, central-to-toe temperature difference, and hemodynamic variables were measured in critically ill patients (group 2) during different peripheral perfusion profiles. Poor peripheral perfusion was defined as a capillary refill time >2 secs and central-to-toe temperature difference > or = 7 degrees C. Peripheral perfusion index and arterial oxygen saturation were measured by using the Philips Medical Systems Viridia/56S monitor. In group 1, measurements were made before and after a meal. In group 2, two measurements were made, with the second measurement taken when the peripheral perfusion profile had changed. A total of 216 measurements were carried out in group 1. The distribution of the peripheral perfusion index was skewed and values ranged from 0.3 to 10.0, median 1.4 (inner quartile range, 0.7-3.0). Seventy-four measurements were carried out in group 2. A significant correlation between the peripheral perfusion index and the core-to-toe temperature difference was found (R2=.52; p <.001). A cutoff peripheral perfusion index value of 1.4 (calculated by constructing a receiver operating characteristic curve) best reflected the presence of poor peripheral perfusion in critically ill patients. Changes in peripheral perfusion index and changes in core-to-toe temperature difference correlated significantly (R =.52, p <.001). CONCLUSIONS: The peripheral perfusion index distribution in the normal population is highly skewed. Changes in the peripheral perfusion index reflect changes in the core-to-toe temperature difference. Therefore, peripheral perfusion index measurements can be used to monitor peripheral perfusion in critically ill patients.

A married couple affected by necrotizing enterocolitis is described. Both had the same toxin-producing Staphylococcus aureus which was considered to be responsible for the necrotizing enterocolitis.

OBJECTIVE:To evaluate the safety and efficacy of the platelet-activating factor receptor antagonist BB-882 in the treatment of patients with sepsis. DESIGN/METHODS:Double-blind, placebo-controlled, randomized, multi-centered study. SETTING/METHODS:Thirty-four European intensive care units. PATIENTS/METHODS:One hundred fifty-two patients with clinical suspicion of infection and a mean APACHE II score between 15 and 35 in the 24 hrs before entry into the trial. INTERVENTIONS/METHODS:Patients received either a loading dose of 4 mg of BB-882 on the first day, followed by an intravenous infusion of 96 mg/24 hrs for up to 120 hrs, or placebo. MEASUREMENTS/METHODS:Hemodynamic, respiratory and oxygen transport variables, blood lactate concentrations, interleukin-6, interleukin-8, tumor necrosis factor (TNF)-alpha, soluble TNF receptor concentrations, organ failure score, 28-day mortality rate, Acute Physiology And Chronic Health Evaluation (APACHE) II score within 24 hrs of entry. RESULTS:Sixty-nine patients (42 male, 27 female) received placebo and 83 (59 male, 24 female) received BB-882. Patients ranged in age from 16 to 89 yrs (mean, 60 yrs). No important differences existed between the two groups in terms of gender distribution, age, or initial APACHE II score. Sepsis was identified as Gram-positive in 49 patients, Gram-negative in 40, mixed in 37, and unknown in 26. No important differences were shown in hemodynamic, respiratory, or oxygen transport variables between groups during the study. Organ failure scores were similar in the two groups throughout the study. Cytokine concentrations were not significantly different in the two groups. Within 28 days of entering the study, 75 patients died, including 31 (45%) in the placebo group and 44 (53%) in the treatment group, p = .32. The median time to death in the placebo group was 6.0 days, and in the treatment group, it was 4.5 days (p = .30). CONCLUSION/CONCLUSIONS:Treatment of sepsis with the platelet-activating factor antagonist BB-882 offers no advantage over placebo on survival, hemodynamic status, respiratory function, or organ failure scores.

STUDY OBJECTIVES/OBJECTIVE:To establish the value of electrical impedance tomography (EIT) in assessing pulmonary edema in noncardiogenic acute respiratory failure (ARF), as compared to the thermal dye double indicator dilution technique (TDD). DESIGN/METHODS:Prospective clinical study. SETTING/METHODS:ICU of a general hospital. PATIENTS/METHODS:Fourteen ARF patients. INTERVENTIONS/METHODS:In order to use the TDD to determine the amount of extravascular lung water (EVLW), a fiberoptic catheter was placed in the femoral artery. MEASUREMENTS AND MAIN RESULTS/RESULTS:Fourteen consecutive ARF patients receiving mechanical ventilation were measured by EIT and TDD. EIT visualizes the impedance changes caused by the ventilation in two-dimensional image planes. An impedance ratio (IR) of the ventilation-induced impedance changes of a posterior and an anterior part of the lungs was used to indicate the amount of EVLW. For the 29 measurements in 14 patients, a significant correlation between EIT and TDD (r = 0. 85; p < 0.001) was found. The EIT reproducibility was good. The diagnostic value of the method was tested by receiver operator characteristic analysis, with 10 mL/kg of EVLW considered as the upper limit of normal. At a cutoff level of the IR of 0.64, the IR had a sensitivity of 93%, a specificity of 87%, and a positive predictive value of 87% for a supranormal amount of EVLW. Follow-up measurements were performed in 11 patients. A significant correlation was found between the changes in EVLW measured with EIT and TDD (r = 0.85; p < 0.005). CONCLUSION/CONCLUSIONS:We conclude that EIT is a noninvasive technique for reasonably estimating the amount of EVLW in noncardiogenic ARF.

OBJECTIVE:To compare a recently introduced hand-held lactate analyser to a reference point of care analyser (POCI) and the hospital laboratory in a critical care setting. SETTING/METHODS:10-bed surgical/medical intensive care unit in a teaching hospital. PATIENTS AND METHODS/METHODS:In 39 critically ill patients, 50 convenience measurement cycles consisting of three paired measurements at 30-min intervals were carried out with a hand-held analyser, reference POCI and hospital laboratory using arterial blood samples. Duplicate measurements with the hand-held analyser were done in 129 blood samples. RESULTS:Lactate levels ranged from 1.1 to 21.0 mmol/l. Regression analysis of the hand-held analyser and laboratory showed a slope of 1.01, bias of -0.38 mmol/l, R(2) = 0.97 and mean error of 14.9 %. Reference POCI versus laboratory: slope = 1.07, bias = -0.29 mmol/l, R(2) = 0.98 and mean error of 6.4 %. Hand-held analyser versus reference POCI: slope = 0.90, bias = 0.09 mmol/l and R(2) = 0. 92. The hand-held analyser showed acceptable precision. CONCLUSION/CONCLUSIONS:The hand-held lactate analyser can reliably measure arterial blood lactate levels in critically ill patients.