Continuous vs Intermittent Nebulized Albuterol for Emergency Management of Asthma Hnin Khine, MD, Susan M. Fuchs, MD, Alan L.

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1 Subcutaneous Lidocaine and IV Access, Sacchefti, Curruccio Selby IR. Bowles BJ. Analgesia for venous cannulation: a comparison of EMLA (5 minutes application), lignocaine. ethyl chloride, and nothing. J R Soc Med. 1995; 88~ Soliman IE. Broadman LM. Hannallah RS. McGill WA. Comparison of the analgesic effects of EMLA (eutectic mixture of local anesthetics) to ineadennal lidocaine infiltration prior to venous cannulation in unpremeditated children. Anesthesiology 1988; 68: Litman RS. Recent trends in the management of pain during medical procedures in children. Pedian Ann. 1995; 24: Halperin DL, Koren G. Attias D, Pellegrini E. Greenberg M. Wyss M. Topical skin anesthesia for venous, subcutaneous drug reservoir and lumbar punctures in children. Pediatrics. 1989; 84: Klein El, Shugcrman RP, Leigh-Taylor K, Schneider C. Portscheller D. Koepsell T. Buffered lidocaine: analgesia for intravenous line placement in children. Pediatrics. 1995; 95: Armstrong P. Young C. McKcown D. Ethyl chloride and venipuncture pain: a comparison with intradermal lidocaine. Can J Aneesth. 1990; 37: Dennis AR. Leeson-Payne CG. Langham BT. Aitkenhead AR. Local anaesthesia for cannulation. Has practice changed? Anaesthesia. 1995; 50: Bartfield JM. Raccio-Robak N. Sallw RF. Does topical lidocaine attenuate the pain of infiltration of buffered lidocaine? Acad Emerg Med. 1995; 2~ Richtsmeier AJ. Hatcher JW. Buffered lidocaine for skin infiltration prior to hemodialysis. J Pain Symptom Manage. 1995; Nott MR. Peacock L. Relief of injection pain in adults. EMLA cream for 5 minutes before venipuncture. Anaesthesia. 1990; 45: Quinn M. Carraccio C. Sacchetti AD. Pain punctures and pediatricians. Pediatr Emerg Care. 1993; 9: Continuous vs Intermittent Nebulized Albuterol for Emergency Management of Asthma Hnin Khine, MD, Susan M. Fuchs, MD, Alan L. Saville, RRT I... ABSTRACT Objective: To compare the efficacy and safety of continuous nebulized (CN) albuterol therapy with those of intermittent nebulized (IN) albuterol therapy in the ED treatment of children with moderate to severe asthma exacerbations. Methods: A prospective, randomized, single-blind study was conducted at a children's hospital ED. Patients aged 2 to 18 years with a moderate to severe asthma exacerbation (asthma score 2 8) were enrolled. Patients were randomized to receive either IN albuterol (0.15 mg/kg/dose every 30 min) or CN albuterol (0.3 mg/kg/ hr) for a maximum of 2 hours. All patients received prednisone at entry. All released patients were evaluated by telephone, 48 hours after the ED visit. Estimates of respiratory therapist (RT) time commitments for the 2 delivery systems were calculated. Results: There were 35 patients assigned to IN therapy and 35 to CN therapy. Nine of the 35 patients (26%) in the IN group and 8 of the 35 patients (22%) in the CN group were hospitalized (p = NS). Although the durations of ED therapy were comparable in the 2 groups, the time spent by the RTs in delivering asthma therapy was significantly less for the CN group than it was for the IN group (30.3 min vs 51.9 min per patient; p c 0.001). There was no major adverse effect in either study group. Conclusion: There was no difference in efficacy or safety between CN therapy and IN therapy in the ED management of moderate to severe asthma exacerbations in children. Moreover, CN therapy provided a significant time savings in the delivery of asthma therapy to patients in a busy ED. Key words: asthma; nebulization; albuterol; inhaled therapy; peak expiratory flow; children. Acud. Emerg. Med. 1996; 3: From Albert Einstein College of Medicine, Bronx, NX Department of Pediatrics, Division of General Pediatrics (Emergency Medicine), Jacobi Medical Center (HK); University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh, Pittsburgh, PA, Department of Pediatrics, Division of General Academic Pediatrics and Emergency Medicine (SMF): and Children's Hospital of Pinsburgh. Pinsburgh. PA -(m). Received: November ; revision received: March 7. 19%; ac- cepted: March 15, 19%: updated: April %. Prior presentation: American Academy of Pediatrics annul meeting,. Dallas, m, October for cornsponderne and reprints: Hnin Khine, MD, I-w-20J Jacobi Medical Center, Pelham Parkway & Eastchester Road, Bronr, NY Fax: ,

2 ACADEMIC EMERGENCY MEDICINE NOV 1996 VOL 3/NO 11 I Nebulized albuterol is the first-line agent for the management of acute asthma exacerbations in children in the ED. However, the optimal dosage and method of administration have not been agreed upon. In 1991, the National Asthma Education Program recommended an albuterol dose of 0.15 mg/kg/dose (maximum of 5 mg) every 20 minutes by nebulization. This regimen is difficult to adhere to in a busy ED and it is quite labor-intensive. Often, there are long delays between treatments due to the large volume of patients being cared for. Continuous nebulization (CN) therapy, which provides an attractive alternative, has been studied in children with impending respiratory failure in the pediatric intensive care unit (PICU) with favorable re~ults.~-~ We undertook this study to compare the effectiveness of CN therapy with that of standard. intermittent nebulization (IN) therapy in the ED for patients with moderate to severe asthma exacerbations. I METHODS Study Design: A prospective, randomized, single-blind trial of CN vs IN albuterol therapy for asthma was performed with comparison of adverse events. levels of need for hospitalization and, respiratory therapist (RT) time commitments. The study was approved by the Institutional Review Board (Human Rights Committee) at the Children s Hospital of Pittsburgh. Setting and Patient Population: From June 1993 to June 1994, children 2-18 years of age with at least 1 episode of prior wheezing who presented to the pediatric ED at the Children s Hospital of Pittsburgh with an asthma exacerbation were eligible for the study. The hospital sees approximately 48,000 total ED visits per year and 3,500 visits for asthma per year. Exclusion criteria included known hypersensitivity to albuterol, a preexisting diagnosis of congenital heart disease, bronchopulmonary dysplasia, cystic fibrosis, or sickle-cell disease, possible foreign body aspiration, corticosteroid therapy initiated in the preceding 6 hours, or the use of subcutaneous epinephrine in the 20 minutes prior to enrollment. Children with concurrent stridor and wheeze also were excluded. To avoid the inclusion of children with bronchiolitis, the minimum age was set at 2 years. At the discretion of the treating physician, patients just over the minimum age underwent nasopharyngeal culture for respiratory syncytial virus (RSV) and were excluded at a later date if the enzyme-linked immunosorbent assay (ELISA) or culture was positive for RSV. Chest radiographs were obtained at the discretion of the treating physician. Patients were excluded if the chest x-ray revealed a lobar infiltrate consistent with bacterial pneumonia. Patients with streaky atelectasis on chest x-ray were included. Treatment and Study Protocol: Once the patient was determined to be eligible for the study, the primary investigator measured the severity of the patient s asthma using a clinical asthma score (Table 1).6 Patients with a score 2 8 were enrolled after written informed consent was obtained. Baseline vital signs and asthma score were recorded prior to treatment. All patients received corticosteroids at the time of enrollment, either oral prednisone 2 mgkg (60 mg maximum) or IV methylprednisolone 2 mg/kg (80 mg maximum). IV methylprednisolone was reserved for patients who either vomited the prednisone or were unable to take oral medication. The decision to use theophylline was at the discretion of the treating resident and attending emergency physician. Study patients were then randomly assigned to receive either CN albuterol at a dose of 0.3 mg/kg/hr, with a minimum of 5 mg/hr and maximum of 15 mg/hr, or IN albuterol at a dose of 0.15 mg/kg/dose, with a minimum of 2.5 mg/dose and maximum of 7.5 mg/dose every 30 minutes. The total dose of medication received per hour was equivalent in the 2 groups. Block randomization was used to maintain similar numbers in the 2 study groups. The RT in the ED was responsible for the administration of the treatments behind a curtain so that the treating physician and the study investigator were blinded to study group assignments. Continuous nebulization was achieved using the HEART nebulizer (B&B Medical Technologies Inc., Orangevale, CA). This nebulizer contains a large reservoir and was attached to a short piece of respiratory tubing I TABLE 1 Clinical Asthma Score*... Respiratory Rate (breathdmin) Accessory 0 2 Score Age 1-6 yr Age >6 yr Wheeze I:E Muscle Use Saturation 0 I30 I20 None 2: 1 None % End expiratory 1:l % Entire expiratory 1: % Inspiratorylexpiratory 1: % ~~ ~ ~~ ~~ ~ ~~~ *Severity based on total score range: mild, 0-7; moderate, 8-11; severe, IE = inspiratory to expiratory ratio. Adapted by permission of Pediatrics. vol. 92. p copyright

3 ~ ~ Continuous vs Intermittent Albuterol, Khine et al with a mask. The mask was worn by the patient during the entire treatment. IN was provided using the Air Life nebulizer (Baxter Healthcare Cop, Valencia, CA). Between treatments, patients in the IN group wore the mask with tubing attached to the HEART nebulizer, which contained 1/2 normal saline solution for mist therapy. That is, both groups wore the mask attached to the nebulizer setup throughout the study, with the CN group receiving the active agent continuously and the IN group getting saline mist therapy between active drug treatments. All children who were identified as hypoxic by pulse oximetry (ie., ~94% on room air) received O2 via either nebulization system. Patients were withdrawn from the study if they did not tolerate the mask andor prescribed medication could not be given as per the protocol, or if at any point their conditions deteriorated. Patients were treated in the ED for a maximum of 2 hours, followed by an additional 30-minute observation period. Patients were independently reassessed by the investigator and the treating physician every 30 minutes. Patient assessments were done with the patient receiving nebulization as above. Treatment was discontinued before 2 hours if the patient met clinical criteria for release home. These criteria included an asthma score 55 and an 0, saturation >94% on room air. The 30- minute waiting period was included to check for immediate relapse. Measurements: To eliminate interobserver variation, all patients were enrolled and monitored by the primary investigator. Peak expiratory flow rate (PEFR) measurements were obtained pretreatment and prior to release or admission for children 16 years of age. Predicted PEFRs were calculated using the height of the patient and used to compare pretreatment asthma severities. To identify the anticipated clinical adverse effects of treatment, heart rate, blood pressure, and respiratory rate were measured every 30 minutes. During the same assessment periods, hand tremor was assessed subjectively by the investigator as absent, mild, moderate, or severe. Any episodes of vomiting were recorded. Admission rates and relapse rates were compared fot the 2 groups. All patients released from the ED were contacted by telephone at 48 hours following treatment to determine whether a relapse had occurred. A relapse was defined as an admission to a hospital or an unscheduled office or ED visit. During the initial treatment, those patients who failed to improve adequately after 2 hours were admitted. The admission criteria were: persistent asthma score 28 andor O2 saturation ~ 94% on room air. The treating physician and investigator independently assessed whether the patient met admission criteria; there was complete concordance during the study. The investigator recorded the patient s total time in the ED. An estimate of the time spent by the RT on each I TABLE 2 Patient Characteristics and Baseline Measurements Age -mean Gender - male Race-black ( 2 SD) Initial 0, saturation < 94% Initial asthma score Albuterol use 6 hr prior 24 hr prior Prior cromolyn use* Prior theophylline use* Intermittent (n = 35) 97 (50) months No. prior admissions 3.2 (3.8) -mean (ksd) ~~~ *In previous 48 hours. 4 Continuous (n = 35) U-value 86 (46) months (4.1) oo 0.63 patient was calculated by multiplying the number of setups for the patients by the mean setup interval based on previous experience with CN and IN nebulization systems. Twenty minutes was allocated to the setup of either CN or IN treatment. Thereafter, 15-minute increments were added for each treatment required in the IN group and 5 minutes was added for the RT to assess each CN patient at 30-minute intervals. Data Analysis: Categorical group data were compared using chi-square or Fisher s exact test. Interval and continuous data were compared using the unpaired t-test (2- tailed). The asthma scores were compared using the Mann-Whitney U test. A p-value of 4-05 was considered significant. I RESULTS Initially, 73 patients were enrolled. Three were subsequently excluded: 2 children refused to keep the mask on during the study period and another child was diagnosed as having psychogenic wheeze. Of the remaining 70 patients, 35 were randomized to receive CN therapy and 35 to receive IN therapy. Baseiine Measurements: The patients in the 2 groups were similar with respect to age, sex, race, initial O2 saturation, and initial asthma score (Table 2). The patterns of recep, albuterol, cromolyn, and theophylline use also were similar in-the 2 groups. Only 15 patients in the CN

4 ~~ 1022 ACADEMIC EMERGENCY MEDICINE NOV 1996 VOL 3/NO 1 1 group and 21 patients in the IN group were able to provide PEFR measurements. The pretreatment-predicted PEFR measurements in the CN and IN group were comparable, with means of 44% and 39% predicted, respectively (p = NS). Outcome Measurements: Overall, 22% (95% CI 10-58%) of patients in the CN group and 26% (95% CI 9-54%) of patients in the IN group required hospitalization (p = NS; Table 3). Among those patients with initial asthma scores 212, 6 of 9 (67%; 95% CI 31-97%) in the IN group and 6 of 13 (46%; 95% CI 16-94%) in the CN group were admitted (p = NS). No patient deteriorated during the study period. ED management times for the CN and IN groups were comparable, with mean times of 123 and 124 minutes, respectively (p = NS). Mean changes in predicted PEFR measures in the CN and IN groups were 34% and 32%, respectively (p = NS). Although the 2 groups were comparable in terms of asthma scores at baseline and at the end of therapy, the CN group had a greater mean improvement in asthma score (7 points CN vs 5 points IN; p = 0.014). All the released patients had asthma scores 55, while the admitted patients had scores All the released patients were contacted by phone within 48 hours of the visit. No patient relapsed during the 30-minute observation period or prior to the 48-hour follow-up phone call. There was no major adverse effect among the study patients. Among the minor effects, the mean increase in heart rate for the CN group was beats/min compared with t 13.8 beats/min for the IN group (p = 0.001). There was no significant difference in increase in mean arterial pressure between the 2 groups ( mm Hg in the CN group vs 6.1 +: 9.1 mm Hg in the IN group; p = NS). Two patients in the IN and none in the CN group vomited (p = NS). Nine patients (26%) in the IN group and 5 patients (14%) in the CN groups had tremors (p = NS). The estimated mean per-patient RT time commitment was 30.3 minutes for the CN group, compared with 51.9 minutes for the IN group (p < 0.001). 1 DISCUSSION Several PICU studies have shown the superiority of CN P-agonist therapy over standard IN therapy for pediatric patients with impending respiratory failure. A 1987 study by Moler et al. showed that CN therapy with terbutaline in PICU patients led to more rapid improvement, compared with the standard hourly intermittent therapy. In 1992, Pap0 et al. performed a prospective randomized study of children with severe asthma in a PICU and showed that the CN therapy group required less time to reach an asthma score (Wood-Down s score) 55 for 4 consecutive hours and had a shorter PICU stay. No ad- verse side effect was noted in either of these studies, and the PICU patients were exposed to medication for a longer period than in our study. The current study suggests that the CN and IN systems are comparable in effectiveness for treating patients who have moderate to severe asthma exacerbations in terms of total ED management time and admission rate. However, subgroup analysis of patients with more severe exacerbations (asthma score 212) suggests a lower admission rate in the CN group (46%) compared with the admission rate in the IN group (67%). However, this difference is not statistically significant. Further, these findings are consistent with results reported for adult patients treated with CN therapy in the ED.. A 1993 study by Rudnitsky et al.* showed that the 2 systems were comparable when all patients were considered, whereas when patients with initial PEFRs < 200 Umin were evaluated separately, the admission rate was lower in the CN therapy group. Unlike other studies of CN therapy, in this study, both the investigator and the treating physician were blinded to the delivery mode used, thus reducing investigator bias. Since the effect of steroids is time-dependent: all the study patients received corticosteroids at entry into the study to minimize any confounding effects. Theophylline use was at the discretion of the treating physician. However, no patient received a theophylline bolus in the ED, so its use should not have affected our results. The results from our study were reassuring in terms of relapse after therapy. No patient had worsening of symptoms within a half hour after the treatment period, nor relapse within 48 hours of release. The IN patients experienced a significantly greater mean increase in heart rate than did the CN patients. This finding may nof be clinically significant in a young child whose tolerance for tachycardia is high, but it can be important in older children and adolescents who often express apprehension secondary to palpitations. Dysrhythmias have not been noted in any of the studies of CN the rap^.^'^' The attractiveness of the CN system includes its efficacy and reduced workload. While the 2 delivery modes were comparable in terms of hospitalization rate and mean ED stay, CN therapy significantly reduced the workload of the RT by requiring less time with each patient. This benefit can be extrapolated to other personnel responsible for the delivery of medication to asthma patients. CN therapy potentially may increase the likelihood that patients receive recommended doses on time since less frequent setup is required. Hence, CN therapy provides an efficient delivery system with a high patient-to-staff ratio potential. One disadvantage to the use of CN therapy is that it requires patient cooperation to keep the face mask on during treatment. It may be difficult for younger children to use this technique since they may be afraid or annoyed by the mask. Another potential disadvantage is that pa-

5 Continuous vs Intermittent Albuterol, Khine et al I TABLE 3 Results... Intermittent Continuous p-value Asthma score at 2 hr-mean Change in asthma score-mean Hospitalization rates All patients With baseline asthma score /35 (26%) 6/9 (67%) 8/35 (22%) 6/13 (46%) 1.OOo Duration of ED stay-mean (ZSD) 124 (29.2) min 123 (23.9) min Respiratory therapist time-mean (ZSD) 52 (14) min 30 (4) min <0.001 tients may be left without physician involvement for a long period since no intervention is needed for continuation of therapy when CN is used. However, typically, a trained RT or a nurse can evaluate these patients on a regular basis and can alert the physician to womsome signs and symptoms. Though continuous nebulization using a HEART nebulizer is more expensive than intermittent nebulization with an Air Life nebulizer ($17.91 vs $2.50), it is possible to use the HEART nebulizer on multiple patients. The apparatus is separated from the patient by respiratory tubing and there is a 1-way air flow system, and contamination between patients is not expected. When ED respiratory care charges in our hospital were compared, CN therapy was less expensive per patient ($ for CN therapy vs $ for IN therapy). Estimates of actual differential hospital costs are not available. I LIMITATIONS AND FUTURE QUESTIONS This study has a number of limitations. First, a relatively small sample of patients (n = 35) were enrolled in each of the 2 delivery system groups. The requirement that patient enrollment take place only while the principal investigator was available to do independent, blinded measurements limited patient enrollment. Although block randomization was used, the small sample size may have allowed group differences in asthma severity or other parameters to occur. Given the small sample size, statistical demonstration of baseline differences may not have been possible. However, post-hoc review of the intergroup demographics and baseline asthma seventy measures suggests that any such selection bias was minimal. Nonetheless, small sample size also limits the ability to discern differences in outcome measures (e.g.. hospitalization rates). Second, we estimated the time devoted to setup for these delivery systems based on prior experience in our ED. These estimates may not be fully representative for the entire patient population studied or for other ED populations, which may use different treatment protocols. Third, some investigators have demonstrated a reduction in serum potassium with aggressive nebulization therapy. We did not measure this parameter since prior reports have found no hypokalemia in patients who were treated with equivalent doses of albuterol for longer periods.. Future larger studies might extend the current findings and address whether a true advantage of CN over IN exists for the more severely affected asthma patient or whether rare adverse effects not demonstrated in our total sample size of 70 patients may occur with these delivery systems. However, we anticipate that therapy using either of the 2 delivery systems will produce a positive response with few adverse effects. I CONCLUSIONS Overall, we found that CN therapy provides a convenient, safe, and potentially cost-effective alternative to traditional IN therapy for delivering asthma medication in a busy ED. Supported by Children s Hospital of Pittsburgh GCRC (General Clinical Research Center) Grant 5MOlRR The authors are grateful to the respiratory department, the ED nursing staff, and the housestaff at Children s Hospital of Pittsburgh for their cooperation and to Dr. Ellen Crain for her review of the manuscript. I REFERENCES 1. Sheffer AL. Guidelines for the Diagnosis and Management of Asthma. Bethesda. MD: National Institutes of Health, National Heart, Lung. and Blood Institute, Report Moler FW. Hurwitz ME, Custer JR. Improvement in clinical asthma score and PaCO, in children with severe asthma treated with continuously nebulized terbutaline. J Allergy Clin Immunol. 1988; 81: Portnoy J, Agganval J. Continuous terbutaline nebulization for the treatment of severe exacerbations of asthma in children. Ann Allergy. 1988; 60~ Portnoy J. Nadel G. Amado M. Willsie-Ediger S. Continuous nebulization for status asthmaticus. Ann Allergy. 1992; 69: Pap0 MC, Frank J. Thompson AE. A prospective randomized study of continuous vs intermittent albuterol for severe status asthmaticus in children. Crit Care Med. 1993; 21:

6 1024 ACADEMIC EMERGENCY MEDICINE NOV 1996 VOL 3/NO Scarfone RT. Fuchs SM, Nager AL, Shane SA. Controlled trial of oral prednisone in the emergency department treatment of children with acute asthma. Pediatrics. 1993; Schuh S. Reider MJ, Canny G. et al. Nebulized albuterol in acute childhood asthma: comparison of two doses. Pediatrics. 1990; 86: Rudnitsky GS. Eberlein RS, Schoffstall JM, Mazur JE, Spivey WH. Comparison of intermittent and continuously nebulized albuterol for treatment of asthma in an urban emergency department. Ann Emerg Med. 1993; 22: Lin RY, Sauter D, Newman T, Sirleaf J, Walters J, Tavakol M. Continuous versus intermittent albuterol nebulization in the treatment of acute asthma. Ann Emerg Med. 1993; 22: Olshaker J, Jerrard D. Barish RA, Brandt G, Hooper F. The efficacy and safety of a continuous albuterol protocol for the treatment of acute adult asthma attacks. Am J Emerg Med. 1993; 11: Computed Tomography Screens Stable Patients at Risk for Penetrating Cardiac Injury Kimberly K. Nagy, MD, Susan H. Gilkey, MD, Roxanne R. Roberts, MD, John J. Fildes, MD, John Barrett, MD I... ABSTRACT Objective: To determine the accuracy of CT of the chest in diagnosing the presence of cardiac injury in stable pitients with penetrating chest injuries. Methods: A retrospective chart review of a convenience sample of stable patients with penetrating thoracic wounds evaluated for hemopericardium using chest CT at an urban level I trauma center..results: 60 stable patients with penetrating wounds in proximity to the heart underwent CT. Three patients had radiographic evidence of pericardial fluid, and 1 had an equivocal study. These 4 patients underwent subxiphoid pericardial window exploration: 2 had only clear fluid present, the other 2 had hemopericardium. The latter patients had a total of 3 cardiac and 1 diaphragmatic injuries, which were repaired at subsequent sternotomy. None of the 56 patients who had negative CTs had further clinical evidence of cardiac injury. The sensitivity, specificity, and accuracy of CT in this setting for hemopericardium are 100% (95% CI %). 96.6% (95% CI %). and 96.7% (95% CI 89-loo%), respectively. Conclusion: Chest CT may be a useful test for diagnosing the presence of hemopericardium in the setting of penetrating thoracic injury. With the caveat that the patient must be removed from a closely monitored environment, the authors advocate the use of CT in stable patients with penetrating chest wounds whenever echocardiography is unavai1able.j Key words: wounds, penetrating; cardiac wounds; computed tomography; hemopericardium; thoracic trauma. Acad. Emerg. Med. 1996; 3: I The majority of patients who sustain penetrating cardiac injuries will present to the hospital with unstable vital signs or in extremis. However. a small group will be relatively asymptomatic. It is this group of patients with... From Cook County Hospital, Chicago, IL, Department of Trauma (KKN, RRR, JJF. JB) and Department of Radiology (SHG). Received: November 22, 1995; revision received: March ; accepted: April 8, 1996; updated: April 2 I, Prior presentation: 60th International Scientific Assembly of American College of Chest Physicians, Orlando, FL, October Aaiiress for correspondence and reprints: Kimberly K. Nagy, MD, Trauma M-3241, 1835 West Harrison, Chicago, IL Fax: 312- normal vital signs for whom early diagnosis and treatment of their cardiac wounds are essential to their survival. The preferred noninvasive method of diagnosing hemopericardium after penetrating cardiac injury is with bedside echocardiography (ECHO). Occasionally, ECHO has been unavailable and we have substituted CT of the chest in an effort to avoid unnecessary subxiphoid pericardial window (SPW). CT is a well-described method for diagnosing pericardial effusion, but has not been specifically studied in the trauma population. I METHODS Study Design: we perfomed a retrospective analysis of : kknagy@aol.com a case series of hemodynamically stable patients with pen-