William T. Peruzzi

Clinical practice guidelines for the maintenance of patient physical safety in the intensive care unit: Use of restraining therapies— American College of Critical Care Medicine Task Force 2001-2002

ObjectiveTo develop clinical practice guidelines for the use of restraining therapies to maintain physical and psychological safety of adult and pediatric patients in the intensive care unit. ParticipantsA multidisciplinary, multispecialty task force of experts in critical care practice was convened from the membership of the American College of Critical Care Medicine (ACCM), the Society of Critical Care Medicine (SCCM), and the American Association of Critical Care Nurses (AACN). EvidenceThe task force members reviewed the published literature (MEDLINE articles, textbooks, etc.) and provided expert opinion from which consensus was derived. Relevant published articles were reviewed individually for validity using the Cochrane methodology (http://hiru.mcmaster.ca/cochrane/ or www.cochrane.org). Consensus ProcessThe task force met as a group and by teleconference to identify the pertinent literature and derive consensus recommendations. Consideration was given to both the weight of scientific information within the literature and expert opinion. Draft documents were composed by a task force steering committee and debated by the task force members until consensus was reached by nominal group process. The task force draft then was reviewed, assessed, and edited by the Board of Regents of the ACCM. After steering committee approval, the draft document was reviewed and approved by the SCCM Council. ConclusionsThe task force developed nine recommendations with regard to the use of physical restraints and pharmacologic therapies to maintain patient safety in the intensive care unit.

Diaphragm Pacing with a Quadripolar Phrenic Nerve Electrode: An International Study

We sought to determine the international experience with the quadripolar diaphragm pacer system and to test two hypotheses: the incidence of pacer complications would be (1) increased among pediatric as compared to adult patients; and (2) highest among active pediatric patients with idiopathic congenital central hypoventilation syndrome (CCHS). Data were collected via a questionnaire coupled with the Atrotech Registry data for a total of 64 patients (35 children and 29 adults) from 14 countries. Thoracic implantation of electrodes and bilateral pacer use each occurred in 94% of all subjects. Tetraplegic (vs pediatric CCHS) patients were more typically paced 24 hours/day (P = 0.001). Pacing duration averaged 2.0 ± 1.0 years among children and 2.2 ± 1.1 years among adults. Infections occurred among 2.9% of surgical procedures, all in pediatric CCHS patients (vs pediatric tetraplegic patients, P = 0.01). The incidence of mechanical trauma was 3.8%, without significant differences among patient groups. The incidence of presumed electrode and receiver failure were 3.1% and 5.9%, respectively, with internal component failure greater among pediatric CCHS than pediatric tetraplegic patients (P < 0.01). Intermittent or absent function of 0–4 electrode combinations occurred among 19% of all patients, with increased frequency among pediatric CCHS than pediatric tetraplegic patients (P < 0.03). Complication‐ free successful pacing occurred in 60% of pediatric and 52% of adult patients. In all, 94 % of the pediatric and 86% of the adult patients paced successfully after the necessary intervention. Although pacer complications were not increased among pediatric as compared to adult patients, the incidence of complications was highest among the active pediatric patients with CCHS. Longitudinal study of these patients will provide invaluable information for modification and improvement of the quadripolar system.

A clinical evaluation of a blood conservation device in medical intensive care unit patients

ObjectivesThis study was designed to a) document the efficacy of a device intended to conserve blood in critically ill patients; b) determine the effect of this blood conservation on hemoglobin concentration and the need for blood transfusions; c) determine if the blood conservation device resulted in interference with arterial pressure waveforms; d) determine if use of the blood conservation device resulted in a difference in the number of accidental needle punctures suffered by healthcare workers. DesignProspective, randomized, controlled trial. A clinical trial using prospective, random allocation of consecutive eligible patients. SettingThe medical intensive care unit (ICU) of a university hospital located in a large metropolitan area. PatientsA total of 100 patients who were admitted to the medical ICU, required arterial line monitoring for clinical purposes, and were managed by the ICU medical service. Exclusion criteria included active bleeding or chronic renal failure at the time of ICU admission. InterventionsPatients in the experimental group had a blood conservation device incorporated into the arterial pressure monitoring system, while patients in the control group received a conventional arterial pressure monitoring system. Measurements and Main ResultsData gathered included: age; gender; ICU discharge status; the duration of ICU stay; time in the study; volume of all blood drawn, discarded, or lost due to leakage; hemoglobin concentrations; blood transfusions; and accidental needle injuries. Arterial pressure waveforms were recorded and inspected for dampening or other deformation. Mean hemoglobin concentrations were compared on ICU admission and at 12-hr intervals. Demographic and clinical characteristics of the two groups were not significantly different. The volume of blood drawn and discarded from arterial catheters was significantly lower in the blood conservation group (blood conservation device: 5.7 ± 7.5 mL; control: 96.4 ± 88.5 mL; p < .0001), as was the total volume of blood discarded (blood conservation device: 19.4 ± 47.4 mL; control: 103.5 ± 99.9 mL; p < .0001). Mean hemoglobin concentration on admission was similar in the two groups (blood conservation device group: 11.8 ± 2.5 g/dL; control group: 12.6 ± 2.3 g/dL). In both groups, the mean hemoglobin concentration declined most rapidly in the first 24 hrs of ICU care and, thereafter, declined more slowly. Although the mean hemoglobin concentration was higher in the blood conservation group after 6 days, statistical significance was not reached until 9.5 days of ICU care. The mean change in hemoglobin concentration (overall: 1.2 ± 2.2 g/dL) during the study represents a statistically significant (p < .0001) decrease of 9.7%. Hemoglobin concentration during the study decreased by 1.4 ± 2.2 g/dL in the control group and 1.0 ± 2.3 g/dL in the blood conservation group (p = nonsignificant). Univariate and multiple regression analysis demonstrated discarded blood volume to be a significant and independent predictor of the decline in hemoglobin concentration. Transfusion requirements were similar in both groups. The blood conservation system did not alter or interfere with pressure waveforms. There were no accidental needle injuries noted.

Preliminary evaluation of an intra-arterial blood gas system in dogs and humans

The reliability and accuracy of an intra-arterial fluorescent optode system to measure continuously pHa, PaCO2, and PaO2 were evaluated in a dog model and in a group of critically ill patients. Six hundred sixty-three arterial blood gas (ABG) samples were analyzed for pHa, PaCO2, and PaO2 in the dog studies. The intra-arterial blood gas system (IBGS) indicated a steady state in 420 instances for pH, 359 instances for PaCO2, and 256 instances for PaO2. Comparison of these ABG and IBGS values by linear regression analysis revealed r = .97 for pHa, .95 for PaCO2, and .96 for PaO2. The mean +/- SD of the difference between ABG and IBGS was -0.02 +/- 0.03 for pHa, 1.05 +/- 3.8 for PaCO2, and -17 +/- 13 for PaO2. Nonsteady states were correctly identified by the IBGS in every instance. Comparisons between 79 temporally matched ABG and IBGS values, exclusive of in vivo calibration samples, in 12 critically ill patients revealed r = .97 for pHa, .96 for PaCO2, and .99 for PaO2. The difference was 0.002 +/- 0.02 for pHa, 0.44 +/- 2.97 for PaCO2, and -1.22 +/- 9.34 for PaO2. We conclude that it is possible to measure continuously pHa, PaCO2, and PaO2 with the IBGS in critically ill patients for periods from 3 to 25.5 h while maintaining the ability to monitor BP and withdraw blood samples from the arterial cannula. Agreement between the two techniques is within clinically acceptable ranges for pHa and PaCO2, whereas PaO2 measurement by the IBGS requires further refinement.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyponatremia in acute spinal cord injury

ObjectiveTo define the occurrence rate, time course, and potential etiologic factors of hyponatremia in patients with acute spinal cord injury. DesignAnalysis of data obtained from a retrospective review of medical records and from a systematized, prospective database pertaining to patients with spinal cord injury. SettingA university hospital with a federally funded regional spinal cord injury center and a dedicated spinal cord injury intensive care unit. PatientsTwo hundred eighty-two patients admitted between January 1, 1988 and December 31, 1989 with acute (<24-hr duration) spinal cord or vertebral column injury. InterventionsNone. Measurements and Main ResultsThe mean age of patients was 36.7 ± 17.6 (SD) yrs; 225 (80%) of the patients were male and 57 (20%) were female. Hyponatremia, when it occurred, developed at a mean time of 6.4 ± 6.7 days postadmission, reached its nadir at 8.7 ± 8.8 days, and occurred in 28% of those patients with cervical injuries, 34% with thoracic injuries, and 27% with lumbar injuries (p = NS). Logistic regression analysis demonstrated that the type of spinal cord injury (Frankel class: range is A = complete neurologic lesion to E = no neurologic lesion) was the strongest predictor of hyponatremia. The occurence rate of hyponatremia was as follows: Frankel class-A 62%; Frankel class-B 48%; Frankel class-C 41%; Frankel class-D 23%; Frankel class-E 16% (p < .0001). ConclusionsThe prevalence of hyponatremia in acute spinal cord injury is much higher than in the general medical or surgical patient population. This abnormality usually occurs within the first week postinjury. The most significant predictor of hyponatremia is the type rather than the level of spinal cord injury. The potential etiological factors are many and these factors are probably interrelated. The pathophysiologic mechanisms that result in hyponatremia must be explored so that this occurrence and its consequences can be prevented. (Crit Care Med 1994; 22:252–258)

Intensive care unit patients with acquired immunodeficiency syndrome and Pneumocystis carinii pneumonia: Suggested predictors of hospital outcome

ObjectiveTo define our ICU experience with AIDS patients, Pneumocystis carinii pneumonia, and respiratory failure, and to delineate factors predictive of hospital survival. DesignA retrospective study in which logistic regression analysis was applied to data obtained during the first 144 hrs of ICU admission. SettingA university hospital medical ICU associated with a national AIDS treatment center. PatientsTwenty-seven male patients with AIDS, P. carinii pneumonia, and respiratory failure who desired full supportive and resuscitative care. Measurements and Main ResultsOf 27 patients who met study criteria, 19 (70%) were nonsurvivors and eight (30%) were survivors. The relative risk of death was 2.2 times greater in patients who exhibited the combination of pH <7.35 and a base deficit >4 mEq/L, at any time in their ICU course, than in patients who did not (95% confidence interval = 1.01, 4.81). Furthermore, the relative risk of death was 3.7 times greater in patients who required positive end-expiratory pressure >10 cm H2O after 96 hrs of ICU care than in those patients who did not (95% confidence interval = 1.09,12.33). Indices of oxygen transfer, severity of chest radiograph abnormalities, concurrent lung infections, and most laboratory studies on hospital admission were not different between the two groups nor predictive of hospital survival. ConclusionsWhen dealing with AIDS/P. carinii pneumonia/ICU patients, it is not possible to distinguish who will survive to hospital discharge based on information routinely available before ICU admission. Those patients with the greatest chance of survival demonstrate a significant decrease in the required level of respiratory support within the first 4 days of ICU care. The presence of a metabolic acidemia (pH <7.35 and base deficit >4 mEq/L), at any time during the ICU course, is a poor prognostic sign. We suggest that such objective variables should be included in the development of any new outcome predictor model for this group of ICU patients. (Crit Care Med 1991; 19:892)

Sleep in the intensive care unit.

Adequate sleep, in terms of both quantity and quality, is an essential component of any overall health program. Sleep deprivation has serious deleterious effects on any subject, regardless of species. The most obvious and well‐documented adverse effects of sleep deprivation are focused on cognitive function, cardiopulmonary function, and the immune system. Despite these deleterious effects of sleep deprivation, even on healthy subjects, intensive care patients are rarely permitted sufficient natural sleep. The causes of sleep disturbance in the intensive care unit involve factors related to the underlying clinical condition, those due to the various drugs required to provide treatment and comfort, and those related to the environment and processes of care in the intensive care unit. Only through a comprehensive approach to intensive care can an environment that promotes sleep and revitalization be constructed and maintained.

Microbial contamination of blood conservation devices during routine use in the critical care setting : Results of a prospective, randomized trial

OBJECTIVES To compare microbial contamination of two different blood conservation devices; to determine if there was an association between contamination of the blood conservation devices and clinical infections; to determine if there was a significant user preference for either of the two devices. DESIGN Prospective, randomized trial. SETTING Medical, neurosurgical, and spinal cord intensive care units of an urban, university hospital. PATIENTS Forty patients who required clinically indicated intrafierial catheters placed at new sites. INTERVENTIONS The two most widely available blood conservation devices at the time of the study (Venous Arterial blood Management Protection system [VAMP], Baxter Edwards Critical-Care, Irvine, CA; and Safe Draw, Ohmeda, Madison, WI) were chosen for comparison. After the normal 48 to 72 hrs of device use, the blood conservation systems were removed and semi-quantitative and quantitative cultures were taken from comparable sites of the two devices. Positive cultures from the patients were recorded and correlated with cultures obtained from the devices. In order to assess preference for either device, a survey tool was administered to the nursing staff who participated in the study. MEASUREMENTS AND MAIN RESULTS Quantitative cultures from all sites cultured in both groups demonstrated mean colony counts of < 10(3) colony-forming units (cfu)/mL. There were no statistically significant differences in the colony counts at any of the sites compared between the two groups. There were no statistically significant relationships between positive cultures and patient age, gender, duration of device utilization, frequency of device entry, or the intensive care unit in which the study was conducted. In no circumstance did positive cultures from any of the blood conservation devices correlate with positive culture results from any sites of clinical infection. The clinical survey demonstrated a statistically significant preference for the VAMP system, which persisted despite increased experience with the Safe Draw system. CONCLUSIONS The levels of microbial contamination noted in these devices were not consistent with clinical infection (defined as 10(3) cfu/mL on quantitative cultures). There was no significant difference in degree or pattern of contamination between the two devices. When utilized and changed according to the Centers for Disease Control guidelines, blood conservation devices are not harbors of infection in the critical care setting. Blood conservation devices can be used as part of a comprehensive blood conservation program in the critical care setting without undue concern for exacerbating infectious processes.

THE PREOPERATIVE ASSESSMENT CLINIC: Its Value and Function

The value of preoperative assessment is often assumed to be related to a reduction in morbidity and mortality during the perioperative period; but the paucity of evidence supporting this concept makes the benefit theoretical, at best. The documented value 5,6,13 of an organized approach to preoperative assessment includes cost-effective patient evaluation improved operating room efficiency improved patient safety through preoperative anticipation of intraoperative needs improved patient satisfaction because of clear communication and allayed anxiety regarding the risks and procedures associated with the administration of anesthesia If properly performed, therefore, the comprehensive preoperative assessment becomes a value-added service provided by the anesthesiologist. This serves to expand our role well beyond that of the physician-anesthetist to that of the perioperative physician. Such a role is vital to our function and survival in the future medicoeconomic environment. 17

Evaluation of an On-Demand, Ex Vivo Bedside Blood Gas Monitor on Pulmonary Artery Blood Gas Determinations

Critically ill patients often have cardiopulmonary perturbations that require rapid and frequent assessment for optimal care, including cardiac output determinations, measurement of cardiac filling pressures, and arterial and mixed venous blood gas determinations.We evaluated the performance of a rapid, on-demand bedside blood gas monitor to determine arterial and mixed venous blood gas values. The blood gas monitor uses fluorescent optode technology to directly measure PO2, PCO2, and pH. This measurement is accomplished by aspirating blood from the artery or vein into a sampling chamber where it interfaces with the fluorescent optode. After approximately 90 s of equilibration, the blood gas values are reported. Since the blood is drawn into the sampling chamber, it can be returned to the patient, thus eliminating the need for phlebotomy. We studied 15 critically ill patients requiring systemic and pulmonary arterial catheterization. Conventional blood gas analysis was performed simultaneously. The results obtained from the blood gas monitor were compared with those obtained via traditional blood gas analysis using Bland-Altman plots and examination of bias and precision. The results were well within the expected clinical variance. During the study period, there was no interference with patient care or adverse events related to the use of the monitoring system. In conclusion, the blood gas monitor can provide rapid, accurate determinations of arterial and mixed venous blood gases allowing optimal therapeutic interventions in critically ill patients. (Anesth Analg 1996;83:500-4)