Ian L. Cohen

Endotracheal tube occlusion associated with the use of heat and moisture exchangers in the intensive care unit

A heat moisture exchanger (HME) with bacterial filtering capabilities was evaluated over an 8-month period in a total of 170 ICU patients. During this time there were 15 endotracheal tube (ETT) occlusions in 15 patients. Over the ensuing 4 months, cascade humidification was used for 81 patients and only one ETT occlusion occurred (p less than .01). The HMEs were replaced frequently with cascade humidifiers during the evaluation period because of inadequate airway humidification. The increase in ETT occlusion was associated with an increased incidence of pneumonia (p less than .001) and atelectasis (p less than .01). Most patients with ETT occlusion required minute volumes greater than 10 L and F10(2) greater than 0.4. We conclude that HMEs do not provide sufficient airway humidification for generalized ICU use. Their role outside of the operating room remains to be determined.

Guidelines on admission and discharge for adult intermediate care units

OBJECTIVE To present guidelines for writing admission and discharge policies for adult intermediate care units. DATA SOURCES Opinion of practitioners with experience and expertise in managing critical and intermediate care units. DATA SYNTHESIS Consensus was reached regarding the characteristics of patients best suited for management in an intermediate care unit, as supported by a literature review. CONCLUSION Criteria were developed that define patients who are optimal candidates for management in an intermediate care unit.

Reduction of duration and cost of mechanical ventilation in an intensive care unit by use of a ventilatory management team

ObjectiveTo test the hypothesis that a formal interdisciplinary team approach to managing ICU patients requiring mechanical ventilation enhances ICU efficiency. DesignRetrospective review with cost-effectiveness analysis. SettingA 20-bed medical-surgical ICU in a 450-bed community referral teaching hospital with a critical care fellowship training program. PatientsAll patients requiring mechanical ventilation in the ICU were included, comparing patients admitted 1 yr before the inception of the ventilatory management team (group 1) with those patients admitted for 1 yr after the inception of the team (group 2). Group 1 included 198 patients with 206 episodes of mechanical ventilation and group 2 included 165 patients with 183 episodes of mechanical ventilation. InterventionA team consisting of an ICU attending physician, nurse, and respiratory therapist was formed to conduct rounds regularly and supervise the ventilatory management of ICU patients who were referred to the critical care service. Measurements and Main ResultsThe two study groups were demographically comparable. However, there were significant reductions in resource use in group 2. The number of days on mechanical ventilation decreased (3.9 days per episode of mechanical ventilation [95% confidence interval 0.3 to 7.5 days]), as did days in the ICU (3.3 days per episode of mechanical ventilation [90% confidence interval 0.3 to 6.3 days]), numbers of arterial blood gases (23.2 per episode of mechanical ventilation; p < .001), and number of indwelling arterial catheters (1 per episode of mechanical ventilation; p < .001). The estimated cost savings from these reductions was

Clinical and economic outcome of patients undergoing tracheostomy for prolonged mechanical ventilation in New York state during 1993 : Analysis of 6,353 cases under diagnosis-related group 483

1,303 per episode of mechanical ventilation. ConclusionWe conclude that a ventilatory management team, or some component thereof, can significantly and safely expedite the process of “weaning” patients from mechanical ventilatory support in the ICU.

Management of the agitated intensive care unit patient

OBJECTIVE To examine and describe the relation between age and disposition in patients undergoing tracheostomy. DESIGN Retrospective analysis of a statewide database. SETTING All acute care hospitals in New York state. PATIENTS All patients (n = 6,353) > or = 18 yrs of age who were discharged from the hospital during 1993 with a final diagnosis-related groups code of 483. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS The final disposition, according to six disposition codes (other acute care facility, residential healthcare facility, other healthcare facility, home, home healthcare services, and death) was examined for the entire population. Cost per case was assumed to equal the average statewide Medicaid rate. An inverse relation between survival rate and age was observed, which resulted in an age-related increased cost per survivor. Also, survivors in older age groups had an increased rate of discharge to residential healthcare facilities. There was a negative, albeit less marked, effect of older age on the rates of survivors discharged to home and to other healthcare facilities. CONCLUSIONS Care of patients who undergo tracheostomy for prolonged mechanical ventilation is expensive. The older the patient, the less satisfactory the outcome from an economic, clinical, and possibly social perspective.

Patterns in costs and outcomes for patients with prolonged mechanical ventilation undergoing tracheostomy: an analysis of discharges under diagnosis-related group 483 in New York State from 1992 to 1996.

Agitation: 1. Violent motion. 2. Strong or tumultuous emotion. Management of the agitated patient is fast becoming an area of major breakthroughs for critical care medicine. To illustrate, Figure 1 shows the total number of articles found on MEDLINE using a combination of search words related to sedation and critical care. This crude survey demonstrates an exponential rise in activity surrounding this topic and helps support the view that study of agitation in the critically ill patient is of rapidly expanding importance. Moreover, management of the agitated patient has developed into an economically powerful subject, both for pharmaceutical companies and for caregivers interested in improving the efficient use of intensive care unit (ICU) resources. It is increasingly apparent that outcomes are significantly influenced by the manner in which agitation is managed. The quantity of articles being published is only part of the picture. Investigations related to agitation in critical care are yielding a variety of intriguing observations including post-traumatic stress disorder and post-ICU depression, diagnosis of delirium, objective monitoring technology, sleep pattern changes, process/management strategies to enhance clinical and economic outcomes, scoring systems, tailorability of therapeutic approaches, and bronchodilatory, antioxidant, and immunosuppressive properties of sedative agents. Rather than simply discussing strategies for sedation, it is the deliberate intent of this continuing education program to focus on the specific topic of agitation (in the ICU patient). It is noteworthy that, although it is one of the most common issues facing critical care practitioners, agitation in the ICU has no clear and concise definition. The simple definition stated at the beginning of this article is from Funk and Wagnall’s 1982. This explanation of “agitation” has merit because it encompasses both physical and emotional distress. Under this characterization, either the nonsedated paralyzed patient or the comatose patient with patient-ventilator asynchrony can be considered agitated, even though the two may represent opposite ends of a spectrum. Accurate diagnosis of the cause of agitation frequently requires a careful analysis of the patient’s history and physical examination, review of laboratory and other diagnostic data, knowledge of the effectiveness of concomitant therapies, collaboration among members of the team and family, and a good deal of experience. The cause of agitation is often multifactorial (e.g., pain and confusion or delirium and withdrawal), and even with successful management it is difficult to be certain about precipitating factors in any single case. Anecdotes from patients and clinicians can serve as powerful tools for the critical care team’s armamentarium and help increase understanding from both sympathetic and empathetic perspectives. Pharmacologic management strategies for agitation include both prevention and treatment. Prevention commonly guides the hand of the critical care clinician when a patient is being stabilized and drips are ordered for analgesia and sedation in anticipation of agitation. Fine-tuning the therapy using agitation scales, daily awakening, and other strategies take on more of a treatment quality, as do pro re nata (PRN) agitation orders. Nonpharmacological approaches include a variety of environmental adjustments that are frequently underutilized. Yet, as obvious as these concepts for definition, diagnosis, and management may seem, it is difficult to consistently apply them to the literature (with the exception of short-term usage). There are a number of well-designed and wellexecuted studies in longer-duration agitation management but, excluding those in very focused populations (e.g., neurologic injury), most studies lump patients into groups for the purpose of assessing differing sedative regimens. Comparative pharmaceutical trials have been extraordinarily important to clinicians who deal regularly with agitation. These studies, as well as trials using innovative management techniques, are becoming increasingly sophisticated in the area of pharmacoeconomic assessment. There is still, however, a paucity of comprehensive studies evaluating the integration of economic, clinical, and humanistic outcomes of agitated ICU patients. Existing economic analyses include variables such as drug acquisition costs, ventilator duration, and ICU length of stay (LOS) to determine the “cost effectiveness” of one drug regimen over another; these are often only partial in their scope. Assigning or assuming costs for time in ICU or on a ventilator is fraught with the problems of evaluating the fixed and variable components. Opportunity costs are usually ignored, as they are exceedingly difficult to determine. And, failure to include post-ICU cost and outcome information ignores the post-ICU morbidity that appears linked to ICU sedation usage. These types of problems with economic analyses are widespread in the critically ill population and are not unique to the topic of agitation management. Notwithstanding, it can be said with a reasonable degree of confidence that the drug acquisition cost of various regimens is only one—often small—piece of the larger economic puzzle. Given the current tide of activity, it is conceivable that the approach to managing agitation in the critically ill patient will rise (or is rising) to a new level of sophistication. At this new level, pharmacologic and nonpharmacologic approaches will be highly selective and finetuned to more precisely address the Copyright

Effect of hemorrhagic shock and reperfusion on the respiratory quotient in swine.

OBJECTIVE To analyze the costs and discharge status for patients with prolonged mechanical ventilation undergoing tracheostomy. DESIGN Retrospective analysis of a statewide database. PATIENTS All patients (n = 37,573) >18 yrs of age who had prolonged mechanical ventilation (procedure code 96.72) and were discharged from the hospital between 1992 and 1996 with a final DRG code of 483. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Rates of change in discharges and hospital reimbursements and the cost per survivor were examined by case payment groups and discharge year. A direct relation between volume and reimbursement rate was seen over time, although the patient age distributions remained relatively stable. The greatest increase in volume was from 1995 to 1996. For most years, there was a consistent inverse relation between age and survival, with older survivors being more likely to be discharged to residential healthcare facilities and younger patients more likely to be discharged home. There was a consistent direct relation between age and cost per survivor, mainly the result of improved survival rather than decreased reimbursements in later years. CONCLUSIONS More controlled reimbursements and improved overall survival rates for DRG 483 have contributed to the improved cost per survivor among all age groups over the period. Given the greater proportion of elderly that do not survive or who are placed into residential healthcare facilities, more scrutiny is needed concerning the use of DRG 483 resources so that care is better coordinated for these patients in the inpatient and postacute care settings.

A Portable System For Continuous On Line Assessment Of Hemodynamics & Perfusion

OBJECTIVES Respiratory quotient, the ratio of CO2 production to oxygen consumption (VO2), is principally affected by the fuel source used for aerobic metabolism. Since the respiratory quotient, VO2, and CO2 production cannot be directly measured easily, indirect calorimetry is commonly used to determine the value of these variables at the airway level (i.e., airway respiratory quotient, airway VO2, and airway CO2 production). However, under nonsteady-state conditions, a variety of phenomena can alter the relationship between true metabolic activity and measurements determined by indirect calorimetry. During exercise, for example, airway respiratory quotient increases as anaerobic threshold is reached because of the disproportionate increase in airway CO2 production that results from the CO2 liberated through the buffering of excess hydrogen ions by bicarbonate. We hypothesized that hemorrhage and reinfusion might change airway respiratory quotient in a consistent manner as shock is produced and reversed. DESIGN Prospective laboratory study. SETTING University animal laboratory. SUBJECTS Eight pigs (25 +/- 2 [SD] kg), anesthetized with fentanyl and relaxed with pancuronium bromide, and mechanically ventilated on room air. INTERVENTIONS The animals were sequentially hemorrhaged and then autotransfused while metabolic and hemodynamic measurements were obtained, using continuous indirect calorimetry and continuous applications of the Fick principle. Hemoglobin, arterial lactate concentration, and blood gases for calibration were measured serially. Analysis of variance was used to compare various periods in time. MEASUREMENTS AND MAIN RESULTS Between baseline and peak hemorrhage, and between peak hemorrhage and postreinfusion, all of the following variables changed significantly (p < .05): airway VO2 (baseline 6.4 +/- 0.9 mL/min/kg, peak hemorrhage 3.9 +/- 0.6 mL/min/kg, postreinfusion 7.0 +/- 1.4 mL/min/kg); airway CO2 production (baseline 5.5 +/- 0.9 mL/min/kg, peak hemorrhage 4.5 +/- 0.9 mL/min/kg, postreinfusion 6.0 +/- 1.4 mL/min/kg); airway respiratory quotient (baseline 0.87 +/- 0.07, peak hemorrhage 1.16 +/- 0.07, postreinfusion 0.87 +/- 0.05); lactate concentration (baseline 2.4 +/- 1.2 mmol/L, peak hemorrhage 6.7 +/- 1.9 mmol/L, postreinfusion 5.1 +/- 2.0 mmol/L); and delta PCO2 (venous PCO2-PaCO2) (baseline 4.5 +/- 3.6 torr [0.6 +/- 0.5 kPa], peak hemorrhage 12.1 +/- 5.3 torr [1.6 +/- 0.7 kPa], postreinfusion 2.7 +/- 2.7 torr [0.4 +/- 0.4 kPa]). CONCLUSIONS Airway respiratory quotient increases in hemorrhagic shock and decreases again as shock is reversed during reinfusion. This phenomenon appears related to the buffering of excess of hydrogen ion during hemorrhagic shock.

clinical and economic issues of prolonged mechanical ventilation

We have developed a PC based system incorporating an indirect calorimeter, physiologic monitor, pulse oximeter, and fiberoptic pulmonary artery catheter and module. Hemodynamic and perfusion variables, through standard computations, are determined and displayed minute by minute. This system has been used both in the operating room and intensive care unit settings.

Mechanical Ventilation for the Elderly Patient in Intensive Care: Incremental Changes and Benefits

&NA; Mechanical ventilation is pervasive and appears to be growing in prevalence, incidence, and economic impact. Further, the process becomes increasingly complex for those requiring prolonged support. There has been an explosive proliferation of information in the area of weaning in recent years. Although widespread controversy exists about specifics, there is no doubt that the process can be improved in terms of decreased costs and better outcomes. Popular trends, such as intermediate care units and specialized respiratory care facilities, designed to deal with stable, ventilator‐dependent patients, offer clear advantages to economically burdened intensive care units. Nonetheless, there is sparse information to show that these strategies are economically advantageous, from a broader perspective. Increased standardization of care coupled with larger multicenter trials may help unravel much of the remaining controversy and confusion surrounding the topic.