W. M. Stahl

Limitations of the TRISS method for interhospital comparisons : A multihospital study

The value of the TRISS method for interhospital comparisons of trauma care was studied using data for 5,616 consecutive patients from three trauma centers and five community hospitals. Z-scores were used to compare mortality rates. Three limitations of the method were documented: 1) the lack of homogeneity within the patient subcategory of penetrating injuries, specifically between patients with gunshot versus stab wounds; 2) the inability of the TRISS method to predict the survival rate of patients suffering low falls; and 3) the inability of the TRISS method to account for multiple severe injuries to a single body part. Remedies to the first two of these limitations can be addressed within the present TRISS method. A remedy for the third requires a new method.

Basic life support versus advanced life support for injured patients with an injury severity score of 10 or more

To study the value of advanced life support (ALS) compared with basic life support (BLS) for penetrating and motor vehicle crash (MVC) patients, data were collected from eight hospitals over 24 months on 781 consecutive patients with Injury Severity Scores > or = 10 as well as on a subset of 219 hypotensive patients. Initial prehospital Revised Trauma Scores (RTSs) were compared with initial emergency department RTSs. Scene times, total prehospital times, and the use of a pneumatic antishock garment (PASG), intravenous fluids, and endotracheal intubation were also documented. A modified TRISS method was used to compare mortality rates. The MVC ALS patients showed improvement in mean RTSs between prehospital and the emergency department while MVC BLS patients did not. Mean changes in blood pressure (BP) and the percentage of patients with improved BP were significantly higher among patients who received ALS; ALS was associated with increased use of PASGs and IV fluids. There were no differences between groups with respect to observed versus predicted mortality. Similar results were found in the hypotensive subset of patients. No benefit from the use of ALS for trauma patients with total prehospital times of less than 35 minutes was documented.

Controlling for the severity of injuries in emergency medicine research

The injury severity score (ISS) and age have been used retrospectively to control for trauma severity. Other control variables such as the revised trauma score (RTS) and the TRISS method (which estimates the probability of survival for each patient) additionally require that values of blood pressure, Glasgow coma scale, and respiratory rate, be recorded in the emergency department. The authors question when the RTS, ISS, the ISS and age, or the probability of survival calculated using the TRISS method should be used to control for severity of injuries in trauma research. Relations between predictor variables and (1) survival to hospital discharge, (2) hospital length of stay for survivors, and (3) length of ICU stay were compared by cause of injury: penetrating, motor vehicle accident, low fall, or other blunt. Data were collected over 12 months for 2,914 consecutive adult patients who died or stayed in five nontrauma and three trauma centers for 48 hours or more. For survival, the false-negative rates of probability of survival calculated using the TRISS method were approximately half that of the ISS and age; no variable adequately explained survival among those with low falls. Combinations of ISS, RTS, and age explained the most variation in lengths of hospital stay among survivors, while ISS explained the most variation in lengths of intensive care unit (ICU) stay. Researchers should consider the ISS with RTS and age to control for severity when lengths of hospital or ICU stay are studied. The TRISS method should be used in studies of survival. In both cases, the RTS which requires data collection in the emergency department must be calculated.

Dual response runs in prehospital trauma care

The effects of dual responses [Basic Life Support (BLS) and Advanced Life Support (ALS)] on the outcomes of trauma patients were evaluated. Outcomes included changes in physiologic measurements between the scene and the emergency department (ED), and survival to hospital discharge. Data for 2394 patients with penetrating, motor vehicle crash (MVC), or other blunt injuries were included. Changes in physiologic measurements (Revised Trauma Scores) between the prehospital and ED settings were positively associated with documented ALS or dual response care. Survival to hospital discharge among penetrating injury patients was negatively related to dual responses, whereas that among MVC patients was positively associated with dual responses. Parallel results were found for a subset of more severely injured patients. Future research should confirm and refine these results so that protocols for the appropriate use of dual response runs can be developed.

Depressed myocardial function after transurethral resection of prostate.

Cardiovascular physiologic monitoring was undertaken in 12 patients undergoing transurethral resection of the prostate with the aid of flow-directed Swan-Ganz catheter and the Automated Physiologic Profile. Cardiac and pulmonary pressures and physiologic parameters were derived pre- and postoperatively. Resecting time, body temperature, intravenous fluid administered, serum hemoglobin, and sodium also were recorded. Of the 12 patients studied, 66 per cent experienced a drop in their cardiac index as well as their left ventricular function after surgery. Myocardial function curves revealed that 7 patients (58 per cent) had decreased cardiac function, 2 had no change, and 3 had increased function. Four patients with preoperative pulmonary wedge pressures (PAW) over 9 mm. Hg experienced depressed cardiac function. Three patients were resected for over sixty minutes, and all experienced depressed cardiac function. Vital signs, serum hemoglobin, or serum sodium did not reflect this change. We believe that relative hypervolemia, undetected elevation of pulmonary wedge pressure. We believe that relative hypervolemia, undetected elevation of pulmonary wedge pressure, and prolonged resection are factors that depress cardiac function and increase the risk of cardiovascular complication in transurethral surgery.

A comparison of diagnostic related group length of stay outliers: motor vehicle crash versus penetrating injuries.

The incidence and degree to which patients injured by motor vehicle crashes (MVCs) and penetrating wounds remain in the hospital beyond the diagnostic related group (DRG) mean length of stay (LOS) are compared. During a 12-month period, records for consecutive patients admitted to eight hospitals (including three trauma centers) were studied. Patients aged 13 or younger, staying less than 48 hours, or with major burns or only distal fractures were excluded. In that time, 2,914 patients were eligible. Twenty percent of injuries were penetrating; 27% were MVC injuries; and, 53% were blunt injuries from other causes. Patients injured in MVCs and with penetrating injuries were compared with respect to mean LOS, incidence of DRG outliers, number of hospital days beyond the DRG mean LOS, and demographic variables. Patients injured in MVCs had a greater proportion of DRG LOS outliers and higher mean numbers of DRG excess days than did patients with penetrating wounds (p less than 0.01, for both). Injuries were distributed among relatively more DRGs for MVC patients. The DRG scheme may lack sufficient attention to factors more likely to affect MVC patients, such as multiplicity of injuries, incidence of CNS injuries, ICU requirements, and older age. In structuring more appropriate reimbursement for trauma care, special attention must be paid to patients injured in MVCs.