Neuropsychological sequelae and impaired health status in survivors of severe acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) is a disease of acute respiratory failure manifested by severe hypoxemia with a high mortality rate. Previous outcome studies of ARDS have assessed survival and/or pulmonary function as the primary outcome variables. Cognitive or psychological outcomes following ARDS have not been described, despite the possibility that ARDS patients are at risk for brain injury through hypoxemia or other mechanisms. In the current study 55 consecutive ARDS survivors completed a battery of neuropsychological tests and questionnaires regarding health status, cognitive and psychological outcomes at the time of hospital discharge and 1 yr after onset of ARDS. At hospital discharge, 100% (55 of 55) of survivors exhibited cognitive and affective impairments, as well as problems with health status which affected their quality of life. At 1 yr after ARDS, 17 of 55 (30%) patients still exhibited generalized cognitive decline. Forty-three of 55 (78%) patients had all or at least one of the following: impaired memory, attention, concentration and/or decreased mental processing speed. One year after ARDS a substantial portion of ARDS survivors exhibit impaired health status and cognitive sequelae which may be due to hypoxemia, emboli, inflammation, drug toxicity, and/or other etiologies.

Calf-thigh sequential pneumatic compression compared with plantar venous pneumatic compression to prevent deep-vein thrombosis after non-lower extremity trauma.

OBJECTIVE: To compare the effectiveness of calf-thigh sequential pneumatic compression devices with the effectiveness of plantar venous intermittent pneumatic compression devices in prevention of venous thrombosis after major trauma. SUBJECTS AND METHODS: We evaluated 181 consecutive patients after major trauma without lower extremity injuries that precluded the use of pneumatic compression devices. We randomly assigned 149 patients to either calf-thigh sequential pneumatic compression or plantar venous pneumatic compression. After blinding the observers to the method of prophylaxis against deep-vein thrombosis, we performed bilateral compression ultrasonography on or before day 8 after randomization. RESULTS: Among 149 randomized patients, 62 who received calf-thigh sequential pneumatic compression and 62 who received plantar venous intermittent pneumatic compression devices completed the trial. Thirteen patients randomized to plantar venous intermittent pneumatic compression (21.0%) and 4 patients randomized to calf-thigh sequential pneumatic compression (6.5%) had deep-vein thrombosis (p = 0.009). Seven of 13 patients with deep-vein thrombosis after prophylaxis with plantar venous intermittent pneumatic compression had bilateral deep-vein thromboses, whereas all 4 patients with deep-vein thrombosis after prophylaxis with calf-thigh sequential pneumatic compression had unilateral deep-vein thrombosis. CONCLUSION: Calf-thigh sequential pneumatic compression prevents deep-vein thrombosis more effectively than plantar venous intermittent pneumatic compression after major trauma without lower extremity injuries.

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 computer-assisted management program for antibiotics and other antiinfective agents.

BACKGROUND AND METHODS: Optimal decisions about the use of antibiotics and other antiinfective agents in critically ill patients require access to a large amount of complex information. We have developed a computerized decision-support program linked to computer-based patient records that can assist physicians in the use of antiinfective agents and improve the quality of care. This program presents epidemiologic information, along with detailed recommendations and warnings. The program recommends antiinfective regimens and courses of therapy for particular patients and provides immediate feedback. We prospectively studied the use of the computerized antiinfectives-management program for one year in a 12-bed intensive care unit. RESULTS: During the intervention period, all 545 patients admitted were cared for with the aid of the antiinfectives-management program. Measures of processes and outcomes were compared with those for the 1136 patients admitted to the same unit during the two years before the intervention period. The use of the program led to significant reductions in orders for drugs to which the patients had reported allergies (35, vs. 146 during the preintervention period; P<0.01), excess drug dosages (87 vs. 405, P<0.01), and antibiotic-susceptibility mismatches (12 vs. 206, P<0.01). There were also marked reductions in the mean number of days of excessive drug dosage (2.7 vs. 5.9, P<0.002) and in adverse events caused by antiinfective agents (4 vs. 28, P<0.02). In analyses of patients who received antiinfective agents, those treated during the intervention period who always received the regimens recommended by the computer program (n=203) had significant reductions, as compared with those who did not always receive the recommended regimens (n= 195) and those in the preintervention cohort (n = 766), in the cost of antiinfective agents (adjusted mean, $102 vs. $427 and $340, respectively; P<0.001), in total hospital costs (adjusted mean, $26,315 vs. $44,865 and $35,283; P<0.001), and in the length of the hospital stay days (adjusted mean, 10.0 vs. 16.7 and 12.9; P<0.001). CONCLUSIONS; A computerized antiinfectives-management program can improve the quality of patient care and reduce costs.

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.

Randomized clinical trial of pressure-controlled inverse ratio ventilation and extracorporeal CO2 removal for adult respiratory distress syndrome.

The impact of a new therapy that includes pressure-controlled inverse ratio ventilation followed by extracorporeal CO2 removal on the survival of patients with severe ARDS was evaluated in a randomized controlled clinical trial. Computerized protocols generated around-the-clock instructions for management of arterial oxygenation to assure equivalent intensity of care for patients randomized to the new therapy limb and those randomized to the control, mechanical ventilation limb. We randomized 40 patients with severe ARDS who met the ECMO entry criteria. The main outcome measure was survival at 30 days after randomization. Survival was not significantly different in the 19 mechanical ventilation (42%) and 21 new therapy (extracorporeal) (33%) patients (p = 0.8). All deaths occurred within 30 days of randomization. Overall patient survival was 38% (15 of 40) and was about four times that expected from historical data (p = 0.0002). Extracorporeal treatment group survival was not significantly different from other published survival rates after extracorporeal CO2 removal. Mechanical ventilation patient group survival was significantly higher than the 12% derived from published data (p = 0.0001). Protocols controlled care 86% of the time. Average PaO2 was 59 mm Hg in both treatment groups. Intensity of care required to maintain arterial oxygenation was similar in both groups (2.6 and 2.6 PEEP changes/day; 4.3 and 5.0 FIO2 changes/day). We conclude that there was no significant difference in survival between the mechanical ventilation and the extracorporeal CO2 removal groups. We do not recommend extracorporeal support as a therapy for ARDS. Extracorporeal support for ARDS should be restricted to controlled clinical trials.

Clinical performance of a rule-based decision support system for mechanical ventilation of ARDS patients.

We developed a clinical decision support system--ventilation protocols--that managed tidal volume and ventilator rate settings during mechanical ventilation of patients with the Adult Respiratory Distress Syndrome (ARDS). We applied these protocols for a total of 10,903 hours in 40 ARDS patients. The clinical staff suspended the protocols for only 5% of the total application time due to medical procedures, surgeries, transient clinical problems not addressed by the protocols, or because of attending physician request. Of 3,148 instructions generated by the ventilation protocols, the clinical staff followed 2,932 (93%). The staff did not follow some instructions because of patient data errors, computer software and protocol logic errors, inability of the clinical staff to implement protocol instructions because of more pressing duties, and clinical staff objections to specific instructions. Sixty percent of the patients treated by the ventilation protocols survived. Our results demonstrate that the ventilation protocols provided a practical and safe decision support system for the mechanical ventilation of ARDS patients.

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.

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.

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.

A strategy for development of computerized critical care decision support systems.

It is not enough to merely manage medical information. It is difficult to justify the cost of hospital information systems (HIS) or intensive care unit (ICU) patient data management systems (PDMS) on this basis alone. The real benefit of an integrated HIS or PDMS is in decision support. Although there are a variety of HIS and ICU PDMS systems available there are few that provide ICU decision support. The HELP system at the LDS Hospital is an example of a HIS which provides decision support on many different levels. In the ICU there are decision support tools for antibiotic therapy, nutritional management, and management of mechanical ventilation. Computer protocols for the management of mechanical ventilation (respiratory evaluation, ventilation, oxygenation, weaning and extubation) in patients with adult respiratory distress syndrome ((ARDS) have already been developed and clinically validated at the LDS Hospital. These protocols utilize the bedside intensive care unit (ICU) computer terminal to prompt the clinical care team with therapeutic and diagnostic suggestions. The protocols (in paper flow diagram and computerized form) have been used for over 40,000 hours in more than 125 adult respiratory distress syndrome (ARDS) patients. The protocols controlled care for 94% of the time. The remainder of the time patient care was not protocol controlled was a result of the patient being in states not covered by current protocol logic (e.g. hemodynamic instability, or transport for X-Ray studies). 52 of these ARDS patients met extra corporal membrane oxygenation (ECMO) criteria. The survival of the ECMO criteria ARDS patients was 41%, four times that expected (9%) from historical data (p less than 0.0002).(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Effectiveness of the kinetic treatment table for preventing and treating pulmonary complications in severely head-injured patients.

The efficacy of using the Kinetic Treatment Table (KTT) to prevent or reduce pulmonary complications in severely head-injured patients is unclear. This study is a prospective, randomized trial using the KTT vs. conventional bed care in severely head-injured patients. Outcome measures were hospital length of stay (LOS), mortality, CNS morbidity at hospital discharge, and rate of improvement of pulmonary status as gauged by chest radiograph, arterial/alveolar PO2 ratio, patient temperature, WBC count, suctioning frequency, sputum volume, and days on ventilator. The KTT group (n = 23) and conventional bed care group (n = 26) were well matched for age, sex, severity of injury, and pulmonary status. There was no significant difference in mortality, CNS morbidity, LOS in ICU or hospital, or rate of pulmonary improvement between the groups. The efficacy of the KTT in reducing pulmonary complications in head-injured patients remains unclear.

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.

Effectiveness of implementing a trauma triage system on outcome: a prospective evaluation.

A 9-month prospective study was conducted in Salt Lake County to evaluate the efficacy of a field trauma triage system using the CRAMS score. Before the triage system was implemented trauma victims were taken to the nearest appropriate hospital. Post-implementation, trauma victims with field CRAMS scores of 1 through 6 were triaged to the Level I Trauma Center. Of the 113 study patients, 53 were in the pre-implementation phase and 60 in the post-implementation phase. The study patients with CRAMS scores of 4 or less had lower mortality when cared for at the Level I Trauma Center (p = 0.013). We conclude that trauma patients who are severely injured (CRAMS less than or equal to 4) have a significantly higher rate of survival if taken to the Level I Trauma Center. The use of the CRAMS triage system appears to be an effective approach toward improving trauma care in Salt Lake County.

The economic impact of DRG payment policies on air-evacuated trauma patients.

This study assessed the injury severity, patient outcome, the cost of care, and the economic impact of Medicare DRG payment policies on patients referred to a Level I trauma center. Only 11 of 283 admitted traumatized patients were Medicare patients. Yet, these 11 Medicare patients left the trauma center with a deficit of $249,601. No significant differences were found between the Medicare and non-Medicare groups for Trauma Score, CRAMS Score, Glasgow Coma Score, Injury Severity Score, ICU or hospital length of stay, disability, or mortality. Under DRG's, Medicare payments ($4,237 +/- 2,351/patient) have fallen to 20% of prior cost-based Medicare reimbursements ($21,542 +/- 34,170/patient), are providing only 16% of hospital costs ($26,928 +/- 42,713/patient), and are significantly (p less than 0.0001) less than non-Medicare reimbursements ($15,288 +/- 17,111/patient). Despite the high financial losses occurring when the trauma center treats referred traumatized Medicare patients, when all referred Medicare and non-Medicare patient trauma reimbursements are combined, overall trauma revenues have declined by only 4.3% under DRG's. If Medicare DRG payments were to be adopted by all third-party payers, reimbursement ($5,058 +/- 4,090/patient) would be significantly (p less than 0.0001) less than current hospital reimbursements ($14,801 +/- 16,537/patient) and costs ($16,121 +/- 17,624/patient). These results indicate that although high financial losses result when caring for traumatized Medicare patients, DRG's have not had a major financial effect upon centers receiving referred trauma patients because of the low numbers of admitted traumatized Medicare patients. However, if third-party payers were to enact the Medicare payment system, devastating economic losses would be inflicted upon major trauma centers.

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.