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The effect of bretylium tosylate on ECG-guided pericardiocentesis
RESEARCH FORUM A B S T R A C T S
period--56 (903%) resulting in a fatality and 6 (9.7%) resulting in serious injure'. Fifty-five (89%) of the victims were drivers. The frequency of head and neck injure' did not differ for victims wearing and not wearing seatbelts (57% versus 45%, Z 2 P=.378). The AV did not differ for victims with and without head and neck injure either (12.3 m p h versus 1 2 6 mph, t test P= 795). Passengers were more likely to suffer head and neck injury than drivers (100% versus 42.9%, Fisher's exact test P=.0048). Conclusion: Passengers in serious or fatal ear crashes in which an air bag deplo)'s are more likely than drivers to suffer head and neck injuries Seatbeh usage and the kV do not appear to be related to the occurrence of head and neck injure' in such crashes.
113
The Effect of Bretylium Tosylate on ECG-Guided Pericardioeentesis
Muhammad A, Hse CK/Beth Israel Medical Center, University Hospital, Manhattan Campus of the Albert Einstein College of Medicine, New York. NY Emergency ECG-guided pericardiocentesis is an important diagnostic and therapeutic maneuver when cardiac tamponade is suspected. It may be complicated by ventricular fibrillation and cardiac arrest. With ECG-guided pencardiocentesis, a current of injure' or ectopy is evidence that the tip of the advancing needle has irritated the myocardium This ECG clue allows the operator to slightly withdraw the needle from the myocardium back into the pericardium. Bretylium may be used when life-threatening arrhythmias artrefractory to treatment with lidocaine. The effect of bretylium on the current of injury or ectopy induced by the ECG-guided pericardiocentesis is unknown. Study objectives: To investigate the effect of bretylium on the current of injure" or ectopy induced during ECG-guided pericardiocentesis. Methods: A convenience sample of Yorkshire-Vermont pigs were used in both control and study groups. All pigs were intubated and anesthetized with inhaled isoflurane. An 18-gauge spinal needle was inserted into the pericardium and advanced toward the myocardium in controls The development of a current of injure" ectopy, or blood aspirated from the ventricle into the needle was recorded. In the study" group, hretylium 5 mg/kg IV followed by a 10-mg/kg dose was administered before the ECGguided pericardiocentesis. Results: Thirty-eight (92%) of the 41 controls developed either a current of injury or ectopy when myocardium was irritated. Two (4.8%) of 41 showed no change in cardiac rhythm when the needle aspirated ventricular blood. One animal developed irreversible vemricular fibrillation. In the study group, 2 (33%) of 6 developed either a current of injury or ectopy when the myocardium was imtated; 4 (66%) of 6 showed no change in the cardiac rhythm when the needle aspirated ventricular blood. Conclusion: Bretylium suppresses the current of injure" and associated ectopy during ECG-guided pericardiocentesis in swine pretreated with bretylium. Limitations of this study are that work was completed in swine in a small study sample.
114
Review of the Compliance With Advanced Trauma Life Support Protocol Among Patients Referred to a Level I Trauma Centre
Lewell M, McCauley W, Anderson S, Lee A/London Health Sciences Centre, University of Western Ontario, London, Ontario. Canada Study objective: The purpose of this study was to review the compliance with Advanced Trauma Life Support (ATLS) protocol among trauma patients referred to the London Health Science Centre (LHSC) and to recommend strategies for improvement of trauma care. The study was conducted at a Level 1 regional trauma centre teaching hospital with university affiliation. Methods: This was a retrospective chart review of all trauma patients with an Injure" Severity Score (1SS) >12 referred to LHSC between May 1995 and April 1996 Results: A total of 170 patients were reviewed; complete data were available for 129 in the trauma team activated (1-i-A) group and 29 in the trauma team not activated group (TTNA). Deviations from ATLS protocol were defined as follows: minor (no effect on morbidity or mortality), moderate (possible but no immediate effect on morbidity and mortality), and severe (life- or limb-threatening consequences). In the TTA group, there were a total of 217 deviations (136 minor, 55 moderate, and 26 severe). In the T1NA group, there were a total of 69 de~'iations (48 minor, 16 moderate, and 5 severe). The mean number of deviations from protocol per patient was 1.5 in the T1-A group versus 2.4 in the T1-NA group (P=.002). The mean ISSs were 283 for "FIA and 196 for TTNA (P=.02). Conclusion: In our population of referred patients with an ISS >12, 17% do not have TTA. In the TTA group, there was a mean of 1.5 deviations from ATLS protocol per patient and 2.4 in the TTNA group. This occurred despite the fact that the mean 1SS was significantly lower in the TTNA group. ATLS education among referring hos-
OCTOBER 1999, PART 2 34:4 ANNALS OF EMERGENCY MEDICINE
pitals should be enhanced in an effort to lower the total number of deviations from protocol Earl}" trauma team activation must be emphasized
115
The Utility of the Lateral Chest Radiograph in Trauma Patients
ChangAK, LegomeEL, Bell IV, LawrasonJN, Rap P/MassachusettsGeneralHospital, Boston, MA Stud)' ob/ective: We hypothesized that the addition of the lateral chest radiograph docs not add clinically important information about chest pathology" to the posterioranterior (PAY chest radiograph in trauma patients. Methods: The radiology" database of an urban Level I trauma center was queried for all trauma patients who sustained potential chest injury' from January 1, 1996, through December 31, 1998 Seventy-four pairs of PA and lateral chest radiographs that were identified as abnormal because of trauma were randomly mixed with 74 radiographs front the same database that had been formally interpreted as not having an)" acute abnomaality A dedicated emergency radiologist 0NL) and a fellow in emergency radiology (TVB). who were blinded to the previous readings~ prospectively reviewed the films While reading the randomized stud) and control films, the)' ",,.'ereasked if the lateral radiograph added an) information not seen on the PA radiograph. The data were then reviewed for clinical significance Results: A total of 148 film pairs (74 study, 74 control) were independently reviewed by each radiologist Of the stud)" group, differences in interpretations among the radiologists were tound in 18 (24%) of 74 (K:=0.37) Eight (11%) of 74 (95% confidence imerval ICI] 3% to 19%) had subtle findings missed by both radiologasts. JNL found 25 lateral radiographs, whereas TVB found 10 lateral radiographs to have additional information not seen on the PA radiograph Combined, 27 (36%) of 74 (95% C[ 25% to 47%) films had lateral radiographs that provided additional information not available on the PA radiograph alone. Of these 27 films, 15 (56%, 95% C1 37% to 75%) had abnol~nafities related to trauma. Nine (60%) of 15 were thoracic or lumbar spinal fractures, 3 [20%) of 15 were rib fvaclures, 2 (13~ of 15 were sternal fractures, and l (.4%) shov,'ed better [ocafization of a bullet. None of the remaining 12 films that had abnormalities related to medical conditions tie. atelectasis, pectus) had significant clinical importance Conclusion: The lateral chest radiograph rarely adds clinically significant pathologic findings to the PA chest radiograph in trauma patients. Surprisingly, it was common to find additional information, but rarely did this change clinical management or disposition Although vertebral fractures on the lateral radiograph were commonly found. physical examination findings or mechanism of injury should lead one to order spinal films to specifically exclude vertebral fractures in this relatively stable group of patients who are able to undergo PA and lateral radiographs. When clinically indicated, a lateral radiograph should be obtained to rule out a sternal fracture. Nondisplaced rib fractures ,,,,'ere uncommonly (1 l%) revealed on the lateral chest radiograph when not seen on the PA radiograph
1
U
Efficacy of Anterior Versus Lateral Chest Compressions: A Cadaver Study
Allegra PC, Allegra JR. Schock RB. LucasJ/Morristown Memorial Residencyin Emergency Medicine, Morristown. NJ; Data Scope Corp. Fairfield, NJ The thoracic pump theory" is a popular theory of blood flow dunng cardiopulmonary' resuscitation (CPR) In this mc~el, peripheral blood flow during CPR is thought to result from intrarhoracic pressure changes generated dunng chest compressions. The pressure changes are believed to be a result of changes in the volume of the chest cavity. It seems reasonable that a compression technique that has the potential to maximize cross-sectional area changes of the chest would result in greater reduction of chest volume and hence greater blood flov." Stud)' objective: Our goal was to determine whether lateral chest compressions would produce greater cross-sectional area changes than anterior chest compressions. Methods: Chest compressions were performed on a 4-hour postmortem cadaver by displacing the anterior chest wall 1.5 in and displacing each lateral side 0.75 in for a total of 1.5 in laterally Malleable metal stripping was attached to the chest cavity while the body was compressed and uncompressed to capture the axial cross-sectional areas. We then measured the percent changes in cross-sectional area tor anterior and lateral chest compressions by measunng the area enclosed by the malleable strips. Results: Anterior compressions produce a cross-sectional area change 17 times larger than the lateral compressions The percent decrease in cross-sectional area for standard CPR was IO7%, whereas lateral compressions produced a decrease of 6.2% Conclusion: Greater axial cross-sectional area changes occurred with anterior chest
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period--56 (903%) resulting in a fatality and 6 (9.7%) resulting in serious injure'. Fifty-five (89%) of the victims were drivers. The frequency of head and neck injure' did not differ for victims wearing and not wearing seatbelts (57% versus 45%, Z 2 P=.378). The AV did not differ for victims with and without head and neck injure either (12.3 m p h versus 1 2 6 mph, t test P= 795). Passengers were more likely to suffer head and neck injury than drivers (100% versus 42.9%, Fisher's exact test P=.0048). Conclusion: Passengers in serious or fatal ear crashes in which an air bag deplo)'s are more likely than drivers to suffer head and neck injuries Seatbeh usage and the kV do not appear to be related to the occurrence of head and neck injure' in such crashes.
113
The Effect of Bretylium Tosylate on ECG-Guided Pericardioeentesis
Muhammad A, Hse CK/Beth Israel Medical Center, University Hospital, Manhattan Campus of the Albert Einstein College of Medicine, New York. NY Emergency ECG-guided pericardiocentesis is an important diagnostic and therapeutic maneuver when cardiac tamponade is suspected. It may be complicated by ventricular fibrillation and cardiac arrest. With ECG-guided pencardiocentesis, a current of injure' or ectopy is evidence that the tip of the advancing needle has irritated the myocardium This ECG clue allows the operator to slightly withdraw the needle from the myocardium back into the pericardium. Bretylium may be used when life-threatening arrhythmias artrefractory to treatment with lidocaine. The effect of bretylium on the current of injury or ectopy induced by the ECG-guided pericardiocentesis is unknown. Study objectives: To investigate the effect of bretylium on the current of injure" or ectopy induced during ECG-guided pericardiocentesis. Methods: A convenience sample of Yorkshire-Vermont pigs were used in both control and study groups. All pigs were intubated and anesthetized with inhaled isoflurane. An 18-gauge spinal needle was inserted into the pericardium and advanced toward the myocardium in controls The development of a current of injure" ectopy, or blood aspirated from the ventricle into the needle was recorded. In the study" group, hretylium 5 mg/kg IV followed by a 10-mg/kg dose was administered before the ECGguided pericardiocentesis. Results: Thirty-eight (92%) of the 41 controls developed either a current of injury or ectopy when myocardium was irritated. Two (4.8%) of 41 showed no change in cardiac rhythm when the needle aspirated ventricular blood. One animal developed irreversible vemricular fibrillation. In the study group, 2 (33%) of 6 developed either a current of injury or ectopy when the myocardium was imtated; 4 (66%) of 6 showed no change in the cardiac rhythm when the needle aspirated ventricular blood. Conclusion: Bretylium suppresses the current of injure" and associated ectopy during ECG-guided pericardiocentesis in swine pretreated with bretylium. Limitations of this study are that work was completed in swine in a small study sample.
114
Review of the Compliance With Advanced Trauma Life Support Protocol Among Patients Referred to a Level I Trauma Centre
Lewell M, McCauley W, Anderson S, Lee A/London Health Sciences Centre, University of Western Ontario, London, Ontario. Canada Study objective: The purpose of this study was to review the compliance with Advanced Trauma Life Support (ATLS) protocol among trauma patients referred to the London Health Science Centre (LHSC) and to recommend strategies for improvement of trauma care. The study was conducted at a Level 1 regional trauma centre teaching hospital with university affiliation. Methods: This was a retrospective chart review of all trauma patients with an Injure" Severity Score (1SS) >12 referred to LHSC between May 1995 and April 1996 Results: A total of 170 patients were reviewed; complete data were available for 129 in the trauma team activated (1-i-A) group and 29 in the trauma team not activated group (TTNA). Deviations from ATLS protocol were defined as follows: minor (no effect on morbidity or mortality), moderate (possible but no immediate effect on morbidity and mortality), and severe (life- or limb-threatening consequences). In the TTA group, there were a total of 217 deviations (136 minor, 55 moderate, and 26 severe). In the T1NA group, there were a total of 69 de~'iations (48 minor, 16 moderate, and 5 severe). The mean number of deviations from protocol per patient was 1.5 in the T1-A group versus 2.4 in the T1-NA group (P=.002). The mean ISSs were 283 for "FIA and 196 for TTNA (P=.02). Conclusion: In our population of referred patients with an ISS >12, 17% do not have TTA. In the TTA group, there was a mean of 1.5 deviations from ATLS protocol per patient and 2.4 in the TTNA group. This occurred despite the fact that the mean 1SS was significantly lower in the TTNA group. ATLS education among referring hos-
OCTOBER 1999, PART 2 34:4 ANNALS OF EMERGENCY MEDICINE
pitals should be enhanced in an effort to lower the total number of deviations from protocol Earl}" trauma team activation must be emphasized
115
The Utility of the Lateral Chest Radiograph in Trauma Patients
ChangAK, LegomeEL, Bell IV, LawrasonJN, Rap P/MassachusettsGeneralHospital, Boston, MA Stud)' ob/ective: We hypothesized that the addition of the lateral chest radiograph docs not add clinically important information about chest pathology" to the posterioranterior (PAY chest radiograph in trauma patients. Methods: The radiology" database of an urban Level I trauma center was queried for all trauma patients who sustained potential chest injury' from January 1, 1996, through December 31, 1998 Seventy-four pairs of PA and lateral chest radiographs that were identified as abnormal because of trauma were randomly mixed with 74 radiographs front the same database that had been formally interpreted as not having an)" acute abnomaality A dedicated emergency radiologist 0NL) and a fellow in emergency radiology (TVB). who were blinded to the previous readings~ prospectively reviewed the films While reading the randomized stud) and control films, the)' ",,.'ereasked if the lateral radiograph added an) information not seen on the PA radiograph. The data were then reviewed for clinical significance Results: A total of 148 film pairs (74 study, 74 control) were independently reviewed by each radiologist Of the stud)" group, differences in interpretations among the radiologists were tound in 18 (24%) of 74 (K:=0.37) Eight (11%) of 74 (95% confidence imerval ICI] 3% to 19%) had subtle findings missed by both radiologasts. JNL found 25 lateral radiographs, whereas TVB found 10 lateral radiographs to have additional information not seen on the PA radiograph Combined, 27 (36%) of 74 (95% C[ 25% to 47%) films had lateral radiographs that provided additional information not available on the PA radiograph alone. Of these 27 films, 15 (56%, 95% C1 37% to 75%) had abnol~nafities related to trauma. Nine (60%) of 15 were thoracic or lumbar spinal fractures, 3 [20%) of 15 were rib fvaclures, 2 (13~ of 15 were sternal fractures, and l (.4%) shov,'ed better [ocafization of a bullet. None of the remaining 12 films that had abnormalities related to medical conditions tie. atelectasis, pectus) had significant clinical importance Conclusion: The lateral chest radiograph rarely adds clinically significant pathologic findings to the PA chest radiograph in trauma patients. Surprisingly, it was common to find additional information, but rarely did this change clinical management or disposition Although vertebral fractures on the lateral radiograph were commonly found. physical examination findings or mechanism of injury should lead one to order spinal films to specifically exclude vertebral fractures in this relatively stable group of patients who are able to undergo PA and lateral radiographs. When clinically indicated, a lateral radiograph should be obtained to rule out a sternal fracture. Nondisplaced rib fractures ,,,,'ere uncommonly (1 l%) revealed on the lateral chest radiograph when not seen on the PA radiograph
1
U
Efficacy of Anterior Versus Lateral Chest Compressions: A Cadaver Study
Allegra PC, Allegra JR. Schock RB. LucasJ/Morristown Memorial Residencyin Emergency Medicine, Morristown. NJ; Data Scope Corp. Fairfield, NJ The thoracic pump theory" is a popular theory of blood flow dunng cardiopulmonary' resuscitation (CPR) In this mc~el, peripheral blood flow during CPR is thought to result from intrarhoracic pressure changes generated dunng chest compressions. The pressure changes are believed to be a result of changes in the volume of the chest cavity. It seems reasonable that a compression technique that has the potential to maximize cross-sectional area changes of the chest would result in greater reduction of chest volume and hence greater blood flov." Stud)' objective: Our goal was to determine whether lateral chest compressions would produce greater cross-sectional area changes than anterior chest compressions. Methods: Chest compressions were performed on a 4-hour postmortem cadaver by displacing the anterior chest wall 1.5 in and displacing each lateral side 0.75 in for a total of 1.5 in laterally Malleable metal stripping was attached to the chest cavity while the body was compressed and uncompressed to capture the axial cross-sectional areas. We then measured the percent changes in cross-sectional area tor anterior and lateral chest compressions by measunng the area enclosed by the malleable strips. Results: Anterior compressions produce a cross-sectional area change 17 times larger than the lateral compressions The percent decrease in cross-sectional area for standard CPR was IO7%, whereas lateral compressions produced a decrease of 6.2% Conclusion: Greater axial cross-sectional area changes occurred with anterior chest
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