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Biomedical subjects

J S Groeger

Publications and source records attributed to J S Groeger.

At least 19 recordsLinked to original sources

The intensive care unit medical director as manager. Impact on performance.

This article examines the impact of greater management involvement by the medical director on efficiency of bed allocation in the intensive care unit (ICU) or critical care unit. Managerial involvement is modeled using a principal components approach in terms of perceived supervision, conflict resolution regarding bed allocation at critical times, extent of control over treatment, and employment status. Using data from a 1991 survey of 2,879 ICUs in 1,706 hospitals conducted by the Society of Critical Care Medicine, two equations reflecting efficiency--the ICU occupancy rate and the presence of misallocated ICU patients--were estimated. It was found that greater involvement by medical directors in the day-to-day management of the ICU significantly reduces the average occupancy rate in ICUs and also the probability of patients misallocated to the ICU, suggesting superior resource allocation in ICUs as a result. These results also suggest that the managerial impact of the medical director is greater in ICUs in high-occupancy hospitals.

Bed Occupancy

A prospective analysis of vascular access device-related infections in children.

To identify significant predictors of device-related infections, we performed a prospective, nonrandomized analysis of our experience with vascular access devices over a 2-year period in a pediatric oncology population. Variables analyzed included: (1) age at placement, (2) sex, (3) underlying disease, (4) type of device used (catheter v port), and (5) total white blood cell count at placement. Quantitative microbiologic criteria were used for diagnosis of bacteremia while clinical and microbiologic criteria were used in diagnosis of tunnel/port/site infections. During the study period a total of 351 devices, comprising 78,159 days in situ, were placed and data for univariate and multivariate analysis were available on 271 (77%). The mean age at placement was 7.2 +/- 4.7 years for catheters and 9.5 +/- 4.8 years for implantable devices (P less than or equal to .01). Significant predictors of device-related infections in univariate analysis were type of device (P less than or equal to .0001) and age (P less than or equal to .002). External catheters and age less than or equal to 7 years were associated with increased risk of infection. Underlying disease had a marginal effect on the infection rate (P = .08). In multivariate analysis, device type (P less than or equal to .0001) and age (P less than or equal to .002) continued to affect infections, whereas underlying disease demonstrated only a borderline effect (P = .14). We conclude that device type and age significantly affect the rate of device-related infections. These data support increased use of implantable devices in pediatric oncology patients.

Catheters, Indwelling

Descriptive analysis of critical care units in the United States.

OBJECTIVE: To gather data about available technology, staffing, administrative policies, and bed capacities of ICUs in the United States. DESIGN AND SETTING: On January 15, 1991, survey instruments were mailed to the administrators of 4,233 hospitals to gather information from the medical director of the institutions' respective ICUs for the purpose of developing a database on ICUs in the United States. The sampling frame for this study was based on all American Hospital Association (AHA) hospitals that stated they have ICUs. MEASUREMENTS: Census questionnaires solicited information on types of hospitals, types of ICUs, number of ICU beds open and closed, technology available to the unit, organizational structure and management of the ICU, as well as the staffing and certification of unit personnel. MAIN RESULTS: Data were obtained on 32,850 ICU beds with 25,871 patients from 2,876 separate ICUs in 1,706 hospitals in the United States. Census responses came from units in all sizes of hospitals within all ten census regions in the country, all states, and all types of hospital sponsorship (federal, state, and local government, private nonprofit and private for profit). The census response rate was 40% of the AHA hospitals that stated that they have ICUs, with specific ICU data on 38.7% of the nation's ICUs. The number of ICUs per hospital increases with overall hospital size. The smallest hospitals (less than 100 beds) usually had only one ICU. As hospital size increased, the single, all inclusive medical/surgical/coronary care units diminished, and in hospitals with greater than 300 beds, specialization of units became prevalent. In absolute terms, hospitals had the following number of ICUs: 1.04 +/- 0.20 (less than or equal to 100 beds); 1.30 +/- 0.65 (101 to 300 beds); 2.37 +/- 1.58 (301 to 500 beds); and 3.34 +/- 2.21 (greater than 500 beds). ICU beds averaged, nationally, 8.09% of hospital-licensed beds with a median of 6.98%. Generally, medical units, pediatric units, coronary care units (CCUs), and medical/surgical/CCUs reported an average of 10 beds per unit. Neonatal units averaged 21 beds, and surgical units averaged 12 beds. The average ICU size, nationally, was 11.7 +/- 7.8 beds per unit. Available technology within hospitals and individual units was increased as hospital size increased; surgical units tended to have more available technology than other unit types. A wide range of organizational arrangements within hospitals determines where the ICU appears in an organizational chart and to whom unit management is accountable. Thirty-six percent of the units were located organizationally within the hospital's department of medicine, while 23% were considered "free standing," having no departmental affiliation. Although units must have a medical director, the perception as to whether this director supervises the day-to-day operation was different in larger vs. smaller hospitals. In hospitals with less than or equal to 100 beds, 72% of the units were perceived to be supervised by the medical director, whereas in larger hospitals (greater than 500 beds), 81% of units were supervised. Study results indicated that medical directors in pediatric, neonatal, and burn units most often were perceived to supervise the unit. Presently, 63% of all ICUs responding are directed by an internist. The next largest group to direct ICUs were surgeons, followed by pediatricians. Pediatrician involvement tended to be exclusive in pediatric and neonatal units. Surgeons directed most surgical and neurologic units and were involved in 21% of mixed medical/surgical units. Internists predominated in medical units and in CCUs, as well as in combined medical/surgical/CCUs. Direction by anesthesiologists, although relatively infrequent, predominated in the surgical unit. Critical care medicine certification of the medical director and attending staff of the ICU increased as hospital size increased, although only 44% of all units stated that thei

Allied Health Personnel

Long-term vascular access via the inferior vena cava.

A prospective evaluation of long-term venous access catheters placed via the inferior vena cava was performed to determine their efficacy as well as short- and long-term morbidity. From June 1987 to May 1989, 31 catheters were placed in 26 patients, for a total of 3,503 catheter use days. All catheters were placed via an infraumbilical approach when the more conventional supraumbilical route was technically difficult, dangerous, or impossible to be used. There were a total of 14 complications in 12 episodes (one in every 701 catheter use days), six episodes of catheter occlusion or vessel thrombosis (one in every 583 catheter use days), one catheter malfunction, one episode of cuff erosion through the skin, and one catheter that migrated through the inferior vena cava into the retroperitoneum. These results compared favorably with our experience with long-term catheters of a similar type placed via a supraumbilical approach into the superior vena cava. We conclude that the infraumbilical route for long-term central venous access is safe and technically easy and should be strongly considered in patients in whom venous access via the supraumbilical approach will be technically difficult or have a high likelihood of failure.

Adolescent

Haemodynamic effects of recombinant interleukin-2 administered by constant infusion.

Adoptive immunotherapy with recombinant interleukin-2 (rhIL-2) has been reported to induce tumour regression in some patients with refractory cancer. However, the cardiovascular toxicity of bolus therapy requires invasive monitoring of patients in the intensive care unit (ICU). In an effort to examine the haemodynamic alterations caused by a constant infusion of IL-2, as opposed to bolus therapy, we studied the haemodynamic variables of 10 patients, with no evidence of heart disease, receiving 3 x 10(6) IU/m2 per day of rhIL-2 as a continuous infusion for 5 days. Measured and derived haemodynamic variables were obtained immediately prior to, at 2, 24, and 48 h during, and upon termination of the infusion. There was no evidence of clinical haemodynamic instability in these patients. Except for development of fever and tachycardia, there were no clinically significant differences in any measured or derived haemodynamic parameter. Moreover, continuous electrocadiographic monitoring of these patients during the infusion did not reveal any abnormalities. Invasive haemodynamic monitoring in an ICU is not necessary in carefully selected patients receiving constant infusion rhIL-2, at the described dose and schedule.

Adult

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.

Adult

Assist control versus synchronized intermittent mandatory ventilation during acute respiratory failure.

Controversy persists as to the relative advantages and disadvantages of synchronized intermittent mandatory ventilation (SIMV) vs. assist/control ventilation (A/C) in the management of acute respiratory failure. In an effort to resolve these differences, we evaluated differences in hemodynamic, metabolic, ventilatory, and oxygenation variables during ventilation with both SIMV and A/C using a crossover protocol in critically ill patients without chronic obstructive pulmonary disease. Despite differences in ventilation, resting energy expenditure, and oxygen delivery in specific subgroups of patients, we found no evidence to support any clear-cut advantage of SIMV or A/C in the acute management of respiratory failure. Careful assessment of individual patients may indicate which patient might benefit from each modality of support.

Critical Care

Relationship between glucose oxidation and FFA concentration in septic cancer-bearing patients.

Glucose oxidation is inhibited in severely ill patients. The present investigation was designed to study the relationship between glucose tissue uptake, glucose oxidation, and FFA concentration in septic cancer-bearing patients. The influence of glucose infusion alone (3.9 mg x kg-1 x min-1), followed by a euglycemic clamp with the same glucose load, on oxidation of glucose, plasma FFA concentration, and lipid oxidation were measured in eight septic cancer-bearing patients. During infusion of 3.9 mg glucose x kg-1 x min-1 glucose tissue uptake was 4.6 +/- 0.3 mg x kg-1 x min-1, glucose oxidation 0.5 +/- 0.2 mg x kg-1 x min-1, FFA concentration 377 +/- 52 mumol x L-1, and lipid oxidation 2.0 +/- 0.2 mumol x kg-1 x min-1. During the euglycemic clamp glucose tissue uptake was 4.4 +/- 0.3 mg x kg-1 x min-1, glucose oxidation rose to 1.8 mg x kg-1 x min-1 (.001 less than P less than .01), FFA concentration dropped to 202 +/- 23 mumol x L-1 (P less than .001), and lipid oxidation to 1.2 +/- 0.2 mumol x kg-1 x min-1 (.001 less than P less than .01). Nonprotein respiratory quotient rose from 0.73 +/- 0.02 to 0.85 +/- 0.02 (.001 less than P less than .01); 11% +/- 5% of the total amount of glucose taken up by the tissues was oxidized during infusion of glucose alone and increased to 42% +/- 6% during the euglycemic glucose clamp. It is concluded that in septic cancer-bearing patients glucose oxidation is inhibited during infusion of 3.9 mg glucose x kg-1 x min-1, even when expressed as percentage of glucose tissue uptake. With insulin, glucose tissue uptake was not influenced, but glucose oxidation expressed as percentage of glucose tissue uptake was normalized.

Adult

Free fatty acid turnover and lipolysis in septic mechanically ventilated cancer-bearing humans.

Loss of body fat and lean body mass are features of critical illness, and anabolism is difficult to achieve despite parenteral nutrition. Resting energy expenditure (REE), free fatty acid turnover (FFT) and glycerol turnover (glyTO) were measured in septic, mechanically ventilated cancer-bearing patients, both fasting and immediately following or during a glucose infusion providing 87% of REE. No patient was in septic shock nor required pressor support. In the fasting state, REE was greatly elevated compared with basal energy expenditure calculated using the Harris-Benedict equations. Fasting FFT (14.2 +/- 0.9 mumol/kg/min) and glyTO (4.7 +/- 0.5 mumol/kg/min) were elevated compared with normal humans. Fasting respiratory quotient (RQ) was 0.68 +/- 0.02 and did not rise significantly with glucose. Fat appears to be the preferred calorie source in septic, cancer-bearing humans even in the presence of glucose. As similar, but less pronounced, changes have been seen in septic and injured humans without cancer, it is likely that these changes are not cancer-specific.

Adolescent

Capnography in mechanically ventilated patients.

Capnography, the science of CO2 waveforms analysis, can play a role in the management of mechanically ventilated patients. Mass spectrometers are the devices most commonly used to collect sequentially and examine CO2 waveforms from multiple patients in the ICU or operating rooms. We present here a review of some clinical and technical problems, which may be resolved efficiently and expeditiously through the use of mass spectrometry and capnography. Mechanical failures, especially those that lead to rebreathing of exhaled gases, can be readily detected. The patient's progress during weaning and the consequences of changes in mechanical assistance can be virtually and noninvasively determined. An expanded role of capnography in mechanically ventilated patients can increase the use of mass spectrometers in the ICU.

Carbon Dioxide

Life-threatening fluid and electrolyte abnormalities associated with cancer.

This article reviews the life-threatening fluid and electrolyte abnormalities that develop in association with, or as a result of neoplasms or their therapy. Ectopic hormone secretion by tumors and their resultant electrolyte aberrancies are also discussed. The emphasis of this article is on clinical phenomena encountered in the ICU that are specific to cancers and their therapy rather than being a review of electrolyte abnormalities in general. Each topic includes a discussion of the management of the abnormality.

Antineoplastic Agents

Indirect calorimetry in the mechanically ventilated patient.

We used indirect calorimetry to measure oxygen consumption (VO2) and carbon dioxide production in 29 mechanically ventilated patients. These data were compared to VO2 measured simultaneously by a standard thermodilution technique. A good correlation was demonstrated between the methods, but VO2 measured by indirect calorimetry was 15% higher than VO2 measured by thermodilution.

Adolescent

High-dose naloxone: pharmacokinetics in patients in septic shock.

Naloxone, a commonly used narcotic antagonist, may be beneficial in reversing the hemodynamic alterations seen in septic shock. In normal subjects, naloxone pharmacokinetics are characterized by rapid distribution and elimination. We investigated the pharmacokinetics of high-dose naloxone in four patients with septic shock and multiorgan failure. The pharmacokinetics of naloxone in these patients can be described by a two-compartment model with a rapid alpha distribution similar to that observed in normal humans. However, in these critically ill patients there was virtually no drug elimination as levels were followed for 5 h post-termination of a 6-h infusion of 2.4 mg/kg X h. This dramatic accumulation of naloxone may explain why responses have been reported by others to small doses of naloxone in septic shock patients. No significant side-effects were seen in our patients with plasma naloxone levels as high as 3.78 micrograms/ml. Caution is warranted when one administers naloxone to patients whose ability to eliminate this drug is minimal.

Double-Blind Method

High-frequency jet ventilation: technical implications.

A variety of technical decisions are required for the proper selection and safe and efficacious application of high-frequency jet ventilation (HFJV). Criteria for analyzing the performance of an HFJV system are presented, along with discussions of some of the more common respiratory measurements and their applicability to HFJV.

Equipment Safety

Experimental evaluation of high-frequency jet ventilation.

The consensus of available studies indicates that high-frequency jet ventilation (HFJV) can adequately ventilate animals in respiratory failure, although a clear superiority to volume-cycled ventilation (VCV) cannot be established. HFJV is probably useful in the presence of airway disruption and in tracheal or pulmonary surgery. Clinical trials and additional bench and animal studies must be performed, to reach a full understanding of the potential benefits of this technique.

Animals