The use of etched, chemically modified, rectangular capillaries as a separation medium for open tubular capillary electrochromatography.

The use of etched, chemically modified, capillaries with a rectangular inner channel for open tubular electrochromatography is investigated. Comparisons of separation capabilities are made between circular and rectangular capillaries undergoing the same etching and chemical modification processes. With the long dimension of the rectangular column aligned in the direction of the optical light path, the relative sensitivities of the two capillary geometries are evaluated.

Urinary creatinine excretion in the ICU: low excretion does not mean inadequate collection.

Background: It has been assumed that a urinary creatinine excretion rate of less than 10 mg/kg per day means an inadequately collected urine sample.

Objective: To determine the frequency of a urinary creatinine excretion rate of less than 10 mg/kg per day in intensive care unit patients with an adequately collected urine sample.

Method: In a prospective study of creatinine excretion rates, 24-hour urine samples were evaluated for urinary creatinine in 209 critically ill patients with indwelling Foley catheters.

The effects of midazolam on the EEG during sedation of critically ill patients.

Patients who require mechanical ventilation are often sedated with midazolam. As clinical signs of sedation are often confusing or nonexistent, and there are few adverse side effects when large doses are infused over a period of days, substantial drug accumulation can result in these critically ill patients, despite the short half-life of midazolam. An objective monitor of sedation would help maintain sedation at a constant level despite changing pharmacokinetic values in patients.

Cost-effectiveness of monoclonal antibodies to gram-negative endotoxin in the treatment of gram-negative sepsis in ICU patients.

Objective: To evaluate the fiscal impact and the cost-effectiveness of monoclonal antibodies against gram-negative endotoxin (MAbGNE) in the treatment of presumed gram-negative sepsis.

Design: A decision analysis model was developed from (1) data from two phase III trials that studied the E5 or HA-1A MAbGNE, and (2) financial data from 1405 septic patients who required intensive care at a large tertiary hospital.

Setting: Intensive care unit (ICU) patients with presumed gram-negative sepsis.

Prediction equation estimates of creatinine clearance in the intensive care unit.

Objective: To assess the accuracy of 4 mathematical equations used to estimate creatinine clearance versus the 24-h creatinine clearance in ICU patients.

Design: Prospective study of renal function prediction.

Setting: The general adult ICUs of 3 metropolitan hospitals.

Ventilatory support during magnetic resonance imaging.

Ventilatory support during magnetic resonance imaging is difficult because metallic objects on ventilatory support devices can interfere with the imaging field and/or become magnetized and move inside the patient or become flying projectiles. We report the successful MRI examination of an intubated respirator-dependent pediatric patient. Ventilatory support was carried out with a plastic ambu bag, exhalation valve circuit, and tubing.

Room-temperature thermodilution cardiac output: central venous vs right ventricular port.

Objective: To assess the accuracy of room-temperature thermodilution cardiac output measurements from the right ventricular port. In addition, waveform patterns were evaluated to determine the actual location of the right ventricular port.

Design: Central venous port cardiac output measurements were compared with right ventricular port cardiac output measurements using the same right-heart catheter.

Successful management of CMV pneumonia in a mechanically ventilated patient.

We report a case of severe respiratory failure due to cytomegalovirus pneumonitis in a patient who underwent an allogeneic bone marrow transplant, who was successfully treated with the combination of ganciclovir and high-dose intravenous immune globulin. We also reviewed the rationale for the use of combination therapy with an antiviral agent and immunotherapy. Because of the bone marrow toxicity of ganciclovir, an aggressive diagnostic approach, including bronchoalveolar lavage and open lung biopsy, may be necessary to establish a definitive diagnosis prior to institution of therapy.

Use of neural network analysis to classify electroencephalographic patterns against depth of midazolam sedation in intensive care unit patients.

The electroencephalographic (EEG) analog signal is complex and cannot easily be described by univariate variables. Clear visual changes in the EEG power spectrum can be present with little or no change in univariate variable values. A method that could produce a single value based on the total data available in the EEG power spectrum would be very useful in monitoring EEG changes.

Thermodilution cardiac output: proximal lumen versus right ventricular port.

Objective: To assess the accuracy of thermodilution cardiac output measurements from the right ventricular port vs. the central venous port. In addition, waveform patterns were evaluated in 50 right-heart catheters to determine the actual location of the right ventricular port.

Tension pneumocephalus: treatment with controlled decompression via a closed water-seal drainage system. Case report.

The successful treatment of a patient with tension pneumocephalus by controlled decompression via external drainage is described. The advantage of the technique includes the immediate release of high pressure and the capability of maintaining constant low pressure to enable and facilitate sealing of dural tears. The method has been used in three other patients, leading to resolution of the tension pneumocephalus without recurrence or other complications.

Hypertonic nasogastric tube feedings: do they cause diarrhea?

Hypertonic NG tube feeding in hospitalized patients, whether on the hospital ward or in the ICU, is considered a common etiology of diarrhea. To evaluate the accuracy of this assumption, five normal volunteers, ten hospitalized postoperative patients with head and neck cancer, and 24 ICU patients were given hypertonic (690 mosm), low residue, lactose-free tube feedings starting at 30 kcal/kg.day.

Age and utilization of intensive care unit resources of critically ill cancer patients.

Older patients, patients with malignancies, and those admitted to ICUs utilize a disproportionate amount of hospital resources. To evaluate the combined impact of age and a diagnosis of malignancy on ICU utilization and outcome, we reviewed the care provided to all 1,212 patients admitted to a medical/surgical ICU in a hospital specializing in the treatment of cancer between January 1, 1986 and December 31, 1987. Patients between 19 and 64 yr (young) were compared with those between 65 and 74 yr (young-old) and with those greater than or equal to 75 yr (old-old) with respect to utilization of nutritional support (total parenteral nutrition [TPN]), mechanical ventilation (MV), pulmonary artery (PA) catheterization, dialysis (D), and blood products (B).

Intravenous glycerol infusions: effect on free fatty acid metabolism.

The plasma-free fatty acid response to intravenous glycerol infused at 250 and 500 mumol/min was determined in five normal volunteers in the postabsorptive state. There was a drop in free fatty acid concentration in all five subjects (one-way ANOVA, p less than 0.01) after the glycerol infusion with no change in insulin concentration compared to the post-absorptive state.

Frequency response of the peripheral sampling sites of a clinical mass spectrometer.

Mass spectrometers are used in ICUs and ORs to measure the concentration of medical and anesthetic gases gathered from multiple sites. This investigation was designed to determine the accuracy of a clinical system, which included 12 ICU bedside stations monitored by a medical mass spectrometer (Perkin-Elmer RMS III, Pomona, CA). Each site station was connected to the analyzing unit via two Teflon tubes, one permanently installed, 30-m long, and the second disposable, 2.

Isotonic nasogastric tube feedings: do they cause diarrhea?

NG tube feedings in hospitalized patients, whether in a ward or ICU, are considered a common etiology of diarrhea. To evaluate the accuracy of this assumption, 13 hospitalized postoperative patients with head and neck cancer, 11 ICU patients, and five healthy volunteers were given isotonic, low-residue, lactose-free tube feedings starting at 30 kcal/kg.day.