Pulmonary artery catheter occlusion as an indication of pulmonary embolus.

Two patients with respiratory failure had consistently reproducible findings on insertion of flow directed pulmonary artery catheters which led to the subsequent diagnosis of pulmonary embolus. Occlusion of the catheter tip and development of a rising "overwedge" tracing on deflation of the balloon may mean the catheter tip has become embedded in clot. When combined with the inability to obtain a wedge tracing, the deflation "overwedge" tracing should alert the physician to the possibility of unsuspected pulmonary embolus.

The adult respiratory distress syndrome. A report of survival and modifying factors.

The adult respiratory distress syndrome (ARDS) is a form of acute lung injury characterized by arterial hypoxemia, reduced thoracic compliance, normal pulmonary capillary wedge pressure, and diffuse infiltrates on chest roentgenograms. Mortality remains high and has been associated with sepsis, organ failure, age, and predisposing factors. We prospectively identified 215 ARDS patients over 34 months to examine how these factors influence outcome. One hundred two (47 percent) of 215 patients survived. Age 65 years or older was associated with a survival of 34 percent, which was statistically different from the 53 percent survival of those patients younger than 65 years (p = 0.02). Aspiration pneumonia as a predisposing factor of ARDS was associated with a better survival (p = 0.04). Survivors had statistically less organ failure and sepsis than did nonsurvivors (p less than 0.05). Cause of death was determined using the criteria of Montgomery et al for irreversible organ dysfunction. Forty-five (40 percent) of our patients died of respiratory failure (not sepsis). We conclude the following: (1) survival in our ARDS patients is different from previous reports; (2) the cause of death in our ARDS patients is different from that reported by Montgomery et al in 1985; and (3) multisystem organ failure, sepsis, age, and some predisposing factors of ARDS continue to be associated with decreased survival of ARDS patients.

The financial impact of Medicare diagnosis-related groups. Effect upon hospitals receiving cardiac patients referred for tertiary care.

To evaluate the financial effects of diagnosis-related groups, we compared 128 Medicare and 183 non-Medicare cardiac patients aeromedically evacuated to a major referral center for critical care. A significant difference (p less than 0.05) was found between Medicare patients vs non-Medicare patients for age (71 +/- 7 vs 51 +/- 9 years) and mortality (13 percent vs 6 percent). No significant difference was found for admissions to the intensive care unit (95 percent vs 95 percent), mean length of stay in intensive care (4.7 +/- 5.3 vs 3.9 +/- 5.4 days), mean length of hospitalization (9.6 +/- 7.5 vs 7.9 +/- 7.0 days), mean number of International Classification Diagnoses (ICD-9) surgical operations (0.8 +/- 1.3 vs 0.6 +/- 1.2), and mean number of ICD procedures (3.0 +/- 2.3 vs 3.3 +/- 2.1). The average cost of care ($13,427 +/- $12,700 per patient) for Medicare patients was higher but not statistically different from non-Medicare patients ($10,474 +/- $10,114 per patient). Prior cost-based Medicare payments ($10,594 +/- $9,861 per patient) have been significantly (p less than 0.01) reduced by 24 percent under the Medicare diagnosis-related group (DRG) prospective payment system ($8,024 +/- $4,824). The DRG payments are significantly less than (p less than 0.001) and provide only 60 percent of the true hospital cost required to care for Medicare cardiac patients referred for tertiary care ($13,427 +/- $12,700 per patient). A Medicare DRG system adopted by third-party payers would reduce present hospital revenues from $9,524 +/- $8,422 per patient to $7,968 +/- $4,800 per patient and would provide only 68 percent of the cost required in the care of all cardiac patients referred for tertiary care ($11,690 +/- $11,344). The results of this study indicate that hospitals that receive large numbers of seriously ill cardiac patients, especially Medicare patients, referred for critical care are at a significant financial disadvantage under the Medicare DRG system. Future economic pressures may prohibit critical care treatment centers from accepting large numbers of cardiac patients referred for intensive care and reimbursed under the current Medicare DRG payment policy.

Increased survival of ARDS patients with severe hypoxemia (ECMO criteria).

The adult respiratory distress syndrome (ARDS) is a form of diffuse lung injury associated with multiple risk factors. Patients with severe hypoxemia who meet blood gas criteria defined by the extracorporeal membrane oxygenation trial (ECMO) of 1974 to 1977 have a reported survival of 11 percent. The reported survival has remained unchanged for 15 years despite numerous technologic advances. We prospectively studied ARDS patients who met ECMO blood gas criteria. One hundred seventy-eight ARDS patients were prospectively screened over a 30-month period. Fifty-one of these patients met ECMO blood gas criteria and 23 (45 percent) survived (p less than 0.001 vs ECMO trial). No obvious differences in etiology, APACHE II score, organ system failure, or the incidence of sepsis was found between survivors and nonsurvivors. We conclude that survival of ARDS patients who met ECMO blood gas criteria in our institution is higher than that previously reported from both other centers and our own hospital.

Increased mortality of older patients with acute respiratory distress syndrome.

OBJECTIVE: To examine the relationship between age and mortality in ARDS patients and evaluate the importance of factors that increase the mortality of older ARDS patients. DESIGN: Prospective inception cohort study. SETTING: Community-based referral hospital. PATIENTS: Two hundred fifty-six ARDS patients identified from May 1987 to December 1990. ARDS was defined by the following: (1) PaO2/PAO2 < or = 0.2; (2) pulmonary capillary wedge pressure < or = 15 mm Hg; (3) total static thoracic compliance < or = 50 mL/cm H2O; (4) bilateral infiltrates on chest radiograph; and (5) an appropriate clinical setting for ARDS. MAIN OUTCOME MEASURES: Comparison of organ failure, incidence of sepsis, patient demographics, arterial oxygenation, and level of support in those 55 years and younger and those older than 55 years of age. Withdrawal of support in patients who died. RESULTS: Seventy-two of 112 patients older than 55 years (64%) died vs 65 of 144 patients 55 years and younger (45%) (p = 0.002). Examination of patient groups using age identified older than 55 years as a "cutpoint" above which mortality was greater (p = 0.002). Older nonsurvivors did not differ from nonsurvivors 55 years or younger with respect to gender, smoking history, ARDS risk factors, ARDS identifying characteristics, APACHE II (acute physiology and chronic health evaluation), number of organ failures, or the incidence of sepsis. In the 48 h prior to death, nonsurvivors 55 years and younger had more organ failure (3.4 +/- 0.2 vs 2.8 +/- 0.2; p = 0.03), higher fraction of inspired oxygen (0.82 +/- 0.03 vs 0.68 +/- 0.03; p = 0.008), and higher positive end-expiratory pressure levels (13 +/- 1 vs 8 +/- 1; p = 0.001) than older nonsurvivors. Despite more severe expression of disease, only 32 (50%) nonsurvivors 55 years and younger had support withdrawn. Significantly more nonsurvivors older than 55 years (73%) had support withdrawn (p = 0.009). Even in the absence of chronic disease states, withdrawal was more likely for patients older than 55 years (21/51) than in those 55 years and younger (3/32; p < 0.001). CONCLUSIONS: Mortality is significantly higher for patients with ARDS older than 55 years. Decisions to withdraw support are made more often in ARDS patients older than 55 years. These data suggest that age bias may influence decisions to withdraw support.

A successful computerized protocol for clinical management of pressure control inverse ratio ventilation in ARDS patients.

We have developed a computerized protocol that provides a systematic approach for management of pressure control-inverse ratio ventilation (PCIRV). The protocols were used for 1,466 h in ten around-the-clock PCIRV evaluations on seven patients with severe adult respiratory distress syndrome (ARDS). Patient therapy was controlled by protocol 95 percent of the time (1,396 of 1,466 h) and 90 percent of the protocol instructions (1,937 of 2,158) were followed by the clinical staff. Of the 221 protocol instructions, 88 (39 percent) not followed were due to invalid PEEPi measurements. Compared with preceding values during CPPV, the expired minute ventilation was reduced by 27 percent during PCIRV while maintaining a pH that was not clinically different (mean difference in pH = 0.02). There was no difference in the PaO2, PEEPi, or the FIO2 between PCIRV and CPPV. The PEEP setting was reduced by 33 percent from 9 +/- 0.05 to 6 +/- 0.6 and the I:E ratio increased from 0.64 +/- 0.04 to 2.3 +/- 0.10. Peak airway pressure was reduced by 24 percent (from 59 +/- 1.5 to 45 +/- 0.6) and mean airway pressure increased by 27 percent (from 22 +/- 0.8 to 28 +/- 0.6) in PCIRV. Right atrial and pulmonary artery pressures were higher and cardiac output lower in PCIRV but blood pressure was unchanged. The success of this protocol has demonstrated the feasibility of using PEEPi as a primary control variable for oxygenation. This computerized PCIRV protocol should make the future use of PCIRV less mystifying, simpler, and more systematic.

Nutrition in the critical care unit.

Guidelines for the evaluation and management of the nutritional needs of the critically ill patient are outlined. Special emphasis is given to nutritional assessment, goal setting, administration of nutrients, and continuous reappraisal of nutritional status.

An integrated approach to the patient with acute respiratory failure.

Because of the complexity of the illness and the therapies administered, careful daily review of data with all members of the health care team is necessary. This must be done with all pertinent information known and must be organized in such a way that interrelationships are given expression and not obscured. In depth discussion of all the patient's problems among the team members accompanied by a clear communication of the plan of therapy to those involved in caring for the patient will result in organized and effective treatment.

Impact of Medicare prospective reimbursement system on nutritional support service patients: the importance of pass throughs.

The financial data of all patients (535) admitted to the Nutritional Support Service (NSS) during 1985, including charges, true care costs, and actual reimbursement including pass-through payments (which are Medicare funds given directly to hospitals for education and capital equipment, and vary significantly from hospital to hospital), were analyzed. The NSS Medicare patients fell into 98 diagnostic related groups (DRGs). All 3,939 Medicare patients admitted in 1985 with the same DRGs as the NSS patients were also identified and their financial data analyzed. The NSS patients lost $999,643 because of the 266 medicare reimbursed NSS patients sustained high losses which overwhelmed the modest profits of the 269 non-Medicare patients. When data from all Medicare patients (which includes both NSS and non-NSS patients) with the same DRGs are analyzed, large profits are realized. These profits are totally due to pass-through payments received. Without pass throughs the loss for all 3,939 Medicare patients in these 98 DRGs would have been $1,641,273. The impact of eliminating pass throughs in the next few years needs to be determined. NSS patients represent a group that generates high financial losses under the federal prospective reimbursement system. However, present Medicare reimbursement of other less seriously ill patients with similar DRGs more than compensate these losses if pass throughs are used in determining reimbursements.

Granulocyte aggregation in adult respiratory distress syndrome (ARDS)--serial histologic and physiologic observations.

Although a number of studies have suggested that granulocyte sequestration is an important pathophysiologic event in ARDS, histologic evidence of aggregated granulocytes in the pulmonary microvasculature is limited, and serial histologic data have not been reported with physiologic measurements. We report a patient with ARDS who demonstrated microvascular granulocyte aggregation and lung edema in sections of a lung biopsy obtained seven days after the onset of symptoms. Pulmonary vascular resistance and pulmonary capillary wedge pressure were normal immediately before the biopsy. A second biopsy performed 12 days later showed decreased lung edema and no evidence of intravascular leukostasis. This case provides histologic support for the hypothesis that granulocyte aggregates contribute to pulmonary edema associated with ARDS.

Evaluation of compliance with a computerized protocol: weaning from mechanical ventilator support using pressure support.

STUDY OBJECTIVES: To use a computerized consultation system to evaluate the feasibility of a mechanical ventilator weaning protocol which used the rapid shallow breathing index to guide adjustments in pressure support. A program to monitor user compliance and reasons for noncompliance was built into the computerized consultation system. METHODS: A total of nine critically ill patients (ten weaning episodes) were enrolled in the protocol. The respiratory therapists performed routine computer charting in the electronic database. They accepted or declined the explicit instructions generated by the computerized protocol and displayed on the bedside terminal. The consultation program monitored whether accepted instructions were implemented by the user. RESULTS: Patient's therapy was controlled by protocol for a total of 1075 h (mean 108 h, range 4 to 339 h) and 94.8% (1321/1394) of instructions were followed by the clinical staff. Of the 42 instructions clinical staff refused to follow, 23 (55%) were extubation instructions. There were 52 (3.7%) incorrect instructions generated with 24 software errors, 21 errors in underlying logic, and seven user misunderstanding errors. CONCLUSIONS: A high level of user compliance with this protocol was achieved. The methods described herein to monitor compliance and reasons for noncompliance within a protocol are reusable in the domain of mechanical ventilation and possibly in other domains.

A survey of advanced trauma life support procedures being performed by physicians and nurses used on hospital aeromedical evacuation services.

Traumatized patients may be transported by a variety of aeromedical transport teams. Frequently, the skills of physicians, nurses, and paramedical personnel overlap. This study was undertaken to determine if nurses used on hospital aeromedical evaluation services perform advanced trauma life support (ATLS) procedures usually reserved for physicians. Forty-seven hospital programs responded to our questionnaire. Flight nurses on programs (26) in which physicians were frequently used were significantly (p less than 0.05) less likely to perform cricothyreotomy, esophageal obturator airway placement, oral intubations, and pericardiocentesis than flight nurses of programs (21) not using flight physicians. Except for cervical tong placement (p less than 0.05), central line placement (p less than 0.05), and the performance of saphenous vein cutdown (p less than 0.05), no differences were found in procedures performed by flight nurses of programs not using physicians and those performed by flight physicians. We conclude that flight nurse abilities are expanding into areas traditionally set aside for physicians in providing advanced trauma life support procedures on hospital aeromedical services. Future studies need to be performed to determine their success and complication rates.

A nationwide survey of civilian air ambulance services.

To identify and characterize civilian air ambulance services, a questionnaire was mailed nationwide to 583 prospective air ambulance services, with 154 responding. Our survey identified differences between hospital, hospital-affiliated, and private air ambulance services as to aircraft ownership, availability, types of aircraft, types of patients being transported, types of medical personnel and equipment, aircraft retrofit, and their feelings regarding air ambulance regulations. We found that hospital air ambulances are better suited for transporting critically ill patients while many private air ambulances appear better suited to transport nonemergency patients. Hospital-affiliated air ambulance services, although not as consistent in providing the specialized care of hospital air ambulances, appear better able to provide critical care than private air ambulance services. Based upon this data, we recommend that air ambulance regulations be directed at levels of patient care. Such regulations and guidelines will assist patient safety during aeromedical transports without jeopardizing currently operating air ambulance services.

Commitment to trauma in a low population density area.

Between January 1978 and March 1979, we conducted a prospective and retrospective study of 202 consecutive blunt trauma patients ages 11 to 92 years. All patients admitted through the trauma service to the intensive care units at LDS Hospital (Salt Lake City) from a low population density area were scored using the Injury Severity Score (ISS) and Glasgow Coma Score (GCS) and patients were categorized according to outcome. There were 30 deaths, for a mortality rate of 14.8%. Twenty-six patients had persistent morbidity, 12.9%. The mean ISS for death was 39; for morbidity, 36; and for patients who were successfully rehabilitated, 23. There were 119 patients with head injuries. The mean GCS was 7 for nonsurvivors, 10 for patients with morbidity, and 12 for rehabilitated patients. We conclude that commitment is a major factor in determining the effectiveness of any trauma system. We strongly encourage regionalization of trauma care and education of paramedics, emergency medical technicians, and physicians in the rapid triage of high-risk patients to a major trauma center.

Adult respiratory distress syndrome during pregnancy and immediately postpartum.

From 1976 to 1983, the adult respiratory distress syndrome occurred in 14 patients during pregnancy or within a month postpartum. There were 8 survivors, giving a 43% mortality. All but 2 patients had obstetric-related precipitating events--labor problems, infections, eclampsia-toxemia, and obstetric hemorrhages. During emergency cesarean sections, 3 patients had respiratory problems that may have caused their respiratory distress syndrome. The average duration of mechanical ventilatory support was 16 days. Six patients had barotrauma with 1 patient sustaining an irreversible anoxic central nervous system injury. Infections were documented in 8 patients, 6 of whom had obstetric foci. There is a lack of information regarding the adult respiratory distress syndrome in this patient group. Though uncommon, it can cause substantial mortality and morbidity.

Outcome, transport times, and costs of patients evacuated by helicopter versus fixed-wing aircraft.

We determined the differences in transport times and costs for patients transported by fixed-wing aircraft versus helicopter at ranges of 101 to 150 radial miles, where fixed-wing and helicopter in-hospital transports commonly overlap. Statistical analysis failed to show a significant difference between the trauma-care patients transported by helicopter (n = 109) and those transported by fixed-wing (n = 86) for age, injury severity score, hospital length of stay, hospital mortality, or discharge disability score. The times in returning patients to the receiving hospital by helicopter (n = 104) versus fixed-wing (n = 509) did not differ significantly. Helicopter transport costs per mile ($24), however, were 400% higher than those of fixed-wing aircraft with its associated ground ambulance transport costs ($6). Thus, helicopter transport is economically unjustified for interhospital transports exceeding 100 radial miles when an efficient fixed-wing service exists.

Outcome of critically injured patients treated at Level I trauma centers versus full-service community hospitals.

Critically injured patients were identified by a CRAMS (circulation, respiration, abdomen, motor, speech) score of 6 or less while still in the field. They were prospectively followed as they received their care at the nearest medical facility according to the then-existing district Emergency Medical Services protocols. Those cared for by Level I trauma centers had a significantly reduced mortality rate compared to those treated at the other large full-service community hospitals. The commitment to Level I trauma care improves outcome of the critically injured, and field triage of the critically injured patient to these centers is indicated.