A "closed" medical intensive care unit (MICU) improves resource utilization when compared with an "open" MICU.

We hypothesized that a "closed" intensive care unit (ICU) was more efficient that an "open" one. ICU admissions were retrospectively analyzed before and after ICU closure at one hospital; prospective analysis in that ICU with an open ICU nearby was done. Illness severity was gauged by the Mortality Prediction Model (MPM0). Outcomes included mortality, ICU length of stay (LOS), hospital LOS, and mechanical ventilation (MV). There were no differences in age, MPM0, and use of MV. ICU and hospital LOS were lower when "closed" (ICU LOS: prospective 6.1 versus 12.6 d, p < 0.0001; retrospective 6.1 versus 9.3 d, p < 0.05; hospital LOS: prospective 19.2 versus 33.2 d, p < 0.008; retrospective 22.2 versus 31.2 d, p < 0.02). Days on MV were lower when "closed" (prospective 2.3 versus 8.5 d, p < 0.0005; retrospective 3.3 versus 6.4 d, p < 0.05). Pooled data revealed the following: MV predicted ICU LOS; ICU organization and MPM0 predicted days on MV; MV and ICU organization predicted hospital LOS; mortality predictors were open ICU (odds ratio [OR] 1.5, p < 0.04), MPM0 (OR 1.16 for MPM0 increase 0.1, p < 0.002), and MV (OR 2.43, p < 0.0001). We conclude that patient care is more efficient with a closed ICU, and that mortality is not adversely affected.

Primary pulmonary hypertension in a patient with CD8/T-cell large granulocyte leukemia: amelioration by cladribine therapy.

We report a case of primary pulmonary hypertension in an adult man with CD8/T-cell large granulocyte leukemia. Successful treatment of his leukemia with cladribine resulted in dramatic and sustained improvement of his pulmonary hypertension.

Pulmonary and critical care medicine.

Although it is still unknown how much CPAP use is sufficient to prevent daytime hypersomnolence in obstructive sleep apnea syndrome, sleeping without CPAP for one night reversed the beneficial effects of 1 month of CPAP use. The assessment of tissue pH is relatively easy in hollow organs by means of tonometry.

Effects of dobutamine on oxygen transport and consumption in the adult respiratory distress syndrome.

OBJECTIVE: To determine if oxygen consumption (VO2) in patients with adult respiratory distress syndrome (ARDS) is dependent on, and thus limited by, oxygen transport (TO2) rather than O2 demand. DESIGN: Prospective study. SETTING: Intensive care unit of a tertiary referral center. PATIENTS: 12 patients with ARDS and sepsis syndrome. INTERVENTIONS: Routine intensive care unit monitoring including pulmonary and radial artery catheters. MEASUREMENTS: Dobutamine was used to increase cardiac output, thereby directly varying TO2 under conditions of constant O2 demand. After baseline measurements of TO2 and VO2, dobutamine was infused intravenously at progressively increasing doses of 5, 10, 15 and 20 micrograms/kg/min and measurements of TO2 and VO2 were repeated after 30 min at each dose. RESULTS: Dobutamine increased TO2 in 8 of the 12 patients, by 29% at 5 micrograms/kg/min and by 45% (net) at 10 micrograms/kg/min, but not at higher doses. In these 8 patients dobutamine also increased VO2 by 15% at 5 micrograms/kg/min, but did not further increase VO2 at higher doses. There was no correlation between baseline blood lactate concentration and the response of either TO2 or VO2 to dobutamine. CONCLUSIONS: In some but not all patients with ARDS and sepsis syndrome, short-term infusion of low-dose dobutamine can increase both TO2 and VO2. Achievement of a TO2-independent level of VO2 could not be convincingly demonstrated in any individual patient. The response of TO2 and VO2 to dobutamine could not be predicted from baseline blood lactate concentration. Determination of the impact on patient outcome of a more prolonged infusion of dobutamine requires further study.

Inclusion body myositis as a cause of respiratory failure.

Inclusion body myositis (IBM) is a slowly progressive myopathy that has not been reported to affect respiratory muscles. It is often refractory to treatment and a muscle biopsy specimen is necessary for the diagnosis. This is a report of a patient with IBM who quickly progressed to respiratory muscle failure requiring intubation.

Intensive one-week orientation for foreign medical graduates entering an internal medicine residency program.

The authors describe an intensive week-long introduction to hospital-based medical practice for foreign medical graduates (FMGs) entering an internal medicine residency program. The intensive orientation helps the FMGs function more effectively in the American hospital environment and reduces the frequency of personal and professional adjustment problems. The program is easily adaptable to other hospitals with large numbers of FMG residents.

Adequacy of tissue oxygenation.

OBJECTIVE: This paper reviews presently available techniques for monitoring the adequacy of tissue oxygenation, emphasizing the practical and theoretical problems that exist with presently used measurements. DATA SOURCES: The data are based on a review of the literature. DATA SYNTHESIS: Most of the presently available techniques focus on global measurements of oxygen transport and utilization that may be insensitive to changes occurring in vital tissues critically important to overall homeostasis. As a result, they are often insensitive, nonspecific, and become abnormal only at a very late stage of disease. CONCLUSIONS: In attempting to develop tools to assess adequate tissue oxygenation, emphasis should be placed on the monitoring of individual tissues that are felt to be highly susceptible to reduced oxygen delivery and key to overall survival. Preliminary data involving measurements of the interstitial pH of the gastrointestinal tract suggest that this measurement may be one approach to pursue.

Comparison of gastric intramucosal pH with measures of oxygen transport and consumption in critically ill patients.

OBJECTIVE: To determine the relationship of tonometrically measured gastric intramucosal pH to clinically accepted indices of systemic oxygenation. DESIGN: Prospective, nonintervention study. SETTING: Medical and surgical ICUs of a university hospital. PATIENTS: Critically ill patients (n = 22) with pulmonary artery catheters in place who also required nasogastric suctioning. MEASUREMENTS AND MAIN RESULTS: Tonometric measurements of gastric intramucosal pH were compared with concurrently obtained systemic indices of tissue oxygenation. These variables included oxygen delivery (DO2), oxygen consumption (VO2), oxygen extraction ratio, arterial lactate concentrations, mixed venous PO2, and mixed venous pH. The study period ranged from the time of insertion of the pulmonary artery catheter to the time of its removal. We classified patients who were alive by the end of the study as survivors and those patients who died with the pulmonary artery catheter in place as nonsurvivors. Both groups had similar levels of DO2 during the study period, but nonsurvivors had greater levels of VO2, oxygen extraction ratio, and serum lactate concentrations than survivors. Gastric intramucosal pH, mixed venous pH, and mixed venous PO2 values were lower in nonsurvivors. Both groups demonstrated the phenomenon of oxygen supply dependency. When the final measurements taken before the removal of the pulmonary artery catheter or death were compared, only gastric intramucosal pH and mixed venous pH showed differences between the groups, being lower in nonsurvivors. All the patients who died, except for one, had final gastric intramucosal pH values of less than 7.32. CONCLUSIONS: In this group of patients, death was associated with increased tissue needs for oxygen that were not adequately satisfied by the available levels of oxygen supply. We also conclude that tonometrically measured gastric intramucosal pH is a useful noninvasive adjunct to current methods of monitoring systemic oxygenation.

Reversible brain death. A manifestation of amitriptyline overdose.

Tricyclic antidepressants are known to cause central nervous system depression. However, a generalized depression of brainstem functions is rarely reported. We report a patient in deep coma with complete absence of brain-stem reflexes after she had taken a large quantity of amitriptyline. With continuous supportive treatment, she eventually regained all neurologic function and made a full recovery.

Oxygen supply and utilization relationships. A reevaluation.

The relationship between oxygen transport (TO2) and oxygen consumption (VO2) has been studied in patients with a number of acute and chronic disorders. Many of these patients have been shown to have a linear relationship between these two variables over a wide range of TO2, which has been considered as evidence of pathologic supply dependency. This supply dependency contrasts with animal studies that have clearly demonstrated a biphasic relationship between TO2 and VO2. This review of the available data concerning the relationship between oxygen transport and supply under conditions of increased oxygen requirements and reduced oxygen transport suggests the possibility that the observed interaction in patients may, in many cases, represent the normal physiologic behavior of the system rather than an abnormal manifestation of impaired oxygen extraction.

Oxygen delivery and utilization.

Under normal circumstances, O 2 transport (TO 2 = cardiac output x arterial O 2 content) is regulated to provide sufficient O 2 to meet the demands of oxidative phosphorylation, quantified as the O 2 consumption (VO 2). When metabolic demands increase, TO 2 is augmented and in addition, the fractional extraction of the delivered O 2 by the tissues, the O 2ER, also increases, to levels as high as 0.80 at maximum VO 2. If TO 2 is decreased, at least in the experimental animal, VO 2 can be maintained initially by an increase in O 2ER, but eventually this mechanism is exhausted, VO 2 begins to fall, and the body invokes anaerobic means of energy generation to maintain cell integrity. In normal man, this critical level of TO 2 (TO 2crit) has not been determined, but in experimental animals it has been found once the O 2ER exceeds 0.50. Patients with sepsis and the adult respiratory distress syndrome have a very high mortality and usually die as a result of multiple organ failure. They have in addition, an apparent abnormality in their ability to extract and utilize the delivered O 2. Despite a TO 2 which is often higher than normal, patients with sepsis commonly have a lactic acidosis and when TO 2 is reduced, both groups of patients are usually unable to increase their O 2ER above the normal resting value of 0.33.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxygen transport and utilization in ARDS.

The process of tissue O2 transport and utilization is complex and incompletely understood. It depends on the successful interaction of the respiratory and cardiovascular system in order to deliver O2 in sufficient amounts and at a high enough capillary partial pressure to allow for adequate diffusion into the cell. Normally, adequate amounts of O2 are available and the system can easily augment transport to meet increased metabolic demands. Under these circumstances O2 utilization is the independent variable. In adult respiratory distress syndrome (ARDS) it appears that O2 transport is not sufficient to provide for the aerobic production of all the required energy and O2 utilization becomes limited by O2 transport. The mechanism of this supply dependency is unknown, but has been shown to be associated with a poor clinical outcome.