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Effects of graded upper airway obstruction on pulmonary mechanics during transtracheal jet ventilation
RESEARCH FORUM ABSTRACTS
Interventions: The first group (EPI) initially received a single subcutaneous dose of 0.3 mL of 1:1,000 epinephrine combined with an aerosolized updraft of 2.5 m g of albuterol in 2.5 mL of normal saline. The second group (CTR) received a single subcutaneous injection of 0.3 mL of normal saline combined with 2.5 mg of alhuterol in an aerosolized updraft. Both groups received additional doses of aerosolized albuterol at 20 and 40 minutes after the initial treatment, if clinically indmated. The FEV 1 spirometry and vital signs were measured with initial treatment and then every 30 minutes. Measurements and main results: There was no statistically significant difference in mean patient ages (26 versus 28.5 years, P = .3772), duration of asthma attack (23.4 versus 29.3 hours, P > .5), pretreatment FEV t (1.5 versus 1.4 L, P = .6229), 30-minute FEV l (2.3 versus 2.0 L, P = .1770), or 60-minute FEV I (2.7 versus 2.3 L, P = .1734) for the EPI or CTR groups, respectively. Conclttsion: Subcutaneous epinephrine provided no additional benefit to use of a ~]2-agonist by nebulization in mildly to moderately ill adult asthma patients. The simultaneous use of subcutaneous and inhaled [~2-agonist in severe acute asthma patients warrants investigation.
Relapse Following Emergency Department Treatment for Asthma 3 I--1e~ Acute RK Cydulka/MetroHealthMedical Center,CaseWestern Reserve CL Emerrnan, University, Cleveland,Ohio
Study objective: Previous studies have demonstrated that recovery of pulmonary function after emergency department treatment for acute asthma takes a number of days and that many patients relapse soon after- ED discharge. The purpose of this study was to establish the characteristics of patients who relapse after ED therapy. Design: Pulmonary function rests were obtained belore and after ED treatment. Patients were discharged with albuterol inhalers and short courses of prednisone. Patients werc contacted two, seven, and 21 days after discharge. In addition, hospital charts were reviewed for patients who could not be contacted by telephone. Setting: Urban, university-affiliated, county-owned ED. Type of participants: One hundred four adults discharged after treatment for asthma. Interventions: None. Measurements: Frequency of relapse after ED discharge. Main results: Follow-up was available on 91 of the patients (88%). There was no difference in the posttreatment FEV~ between those who relapsed (55.2%) and those who did not (57.8%; NS). There was no difference in the percentage improvement in the FEV~ before to after treatment between those who relapsed (76.6%) versus those who did not (59.1%; NS). Twentytwo of the patients (24%) relapsed within three weeks after discharge; 91% of the relapses occurred before the patient saw their primary care physician, and eight of the relapses (35%) occurred within ten days after steroid taper. Most patients failed to see a primary care physician after ED discharge. Conclusion: ED discharge planning should include consideration of the high relapse rate after steroid taper and failure of patients to obtain follow-up. Inhaled anti-inflammatory agents should be part of the discharge regimen.
Effects of Graded Upper Airway Obstruction on Pulmonary During Transtracheal Jet Ventilation 3 1,0,e~ Mechanics KJ Rhee,ES Schelegle,JF Green/Divisionof EmergencyMedicine and ML Carl, Department of Human Physiology,School of Medicine, Universityof California, Davis; Section of EmergencyMedicine, Universityof Nebraska, Omaha
Study objective: To quantify the effects of proximal graded upper airway obstruction on the delivered tidal volume and other selected parameters of pulmonary mechamcs during low-frequency transtracheal jet ventilation
616
(TTJV) in a dog model, with comparison to spontaneous breathing (SB) and unobstructed controls (TTJV-c). Design and methods: Laboratory study in which seven dogs were anesthetized, paralyzed, and placed within a volume plethysmograph that allowed for the head and neck to be externalized. Ventilation was performed using TTJV at 45 psi and a frequency of 15 bpm. The trachea above the TTJV catheter was progressively occluded with a Foley catheter at levels of approximately 150%, 200%, 250%, and 300% of the tracheal pressure (PT) obtained during TTJV-c. Main results: Mean levels of obstruction obtained were 130%, 190%, 220%, and 230% of the mean PT during TTJV-c (10.9 _+ 2.0 cm H20). As PT exceeded 200% (21.8 cm H20), it became difficult to regulate between subtotal and total upper airway obstruction. Tidal volume significantly increased with each level of obstruction except between 220% and 230% (SB, 506 -+ 72 mL; TTJV-c, 446 _+ 69 mL; TTJV-130%, 663 -+ 139 mL; TTJV-190%, 780 +_ 140 mL; TTJV-220%, 931 + 181 mL; and T'l'JV-230%, 944 + 135 mL). Transpulmonary pressure was not significantly higher than SB or TTJV-c when 130% obstruction was applied, but it significantly increased during higher levels of obstruction. Mean Pco 2 significantly decreased as all levels of obstruction were applied, secondary to significantly increased minute ventilation during all levels of obstruction (Pco 2 range of SB, 38.8 + 7.0 m m Hg; TTJV-230%, 16.2 + 6.5 mm Hg). There was no significant difference seen in the quasistatic compliance of the lungs among SB, TTJV-c, or any level of TTIV with upper airway obstruction Conclusion: Partial upper airway obstruction signfllcantly increases the delivered tidal volume, minute ventilation, and transpulmonary pressure of thc lungs during ~ITJV, with consequent significant decreases in Pco 2 as the level of obstruction increases. However, no significant changes are seen in the quasistatic compliance of the lungs, lending support to the position that T1]V is a safe technique of ventilation, even when ~vere partial upper airway obstruction is present.
4 New-Onset Atrial Fibrillation: Is Admission Necessary?
M Mulcahy, PL Henneman,W Coates, R Lewis/Department of EmergencyMedicine, Harbor-UCLAMedical Center,Torrance, California Study o~qjectivc:To determine if all patients with new-onset atrial fibrillation (NOAF) require admission and if the need for admission is clinically obvious in the emergency department. Design: Retrospective chart review. Setting: Urban, county hospital. Statistical analysis: Descriptive. Variables were analyzed using the Wilcoxon rank-sum test. Significance was defined as P < 01. Patients were believed to require admissmn if they would have been admitted even if they did not have NOAF or if they had a significant complication during hospitalization. Participants: Two hundred twenty-eight consecuuve emergency department patients with. NOAF seen between September 1986 and December 1992. There were 112 women and 116 men (median age, 61 years; range, 16 to 101 years). Results: The etiology of NOAF was unknown in 38%, valvular in 19%, congestive heart failure in 13%, ethanol related in 11%, hyperthyroidism in 6%, myocardial infarction (MI) in 5%, coronary artery disease (CAD) in 4%, and other in 4%. Two hundred fifteen patients were admitted to our hospital, seven were transferred, five were discharged home, and one left against medical advice. Sixty-six percent (141 of 215) of the patients admitted to our hospital required admission because of additional problems; congesuve heart failure (CHF, 43), history suggestive of MI (42), infection (11), hypotension (five), cerebrovascular accident (four), uncontrolled diabetes (four), and other (32). The need for admission was clinically obvious in the ED in 98% (138 of 141) of those who required admission. Three patients (2%) who required admission were not clinically obvious in the ED: a 72-year-old developed chest pain on hospital day 6 (MI ruled out); an 86-year-old died
ANNALS OF EMERGENCYMEDICINE 23:3 MARCH 1994
Interventions: The first group (EPI) initially received a single subcutaneous dose of 0.3 mL of 1:1,000 epinephrine combined with an aerosolized updraft of 2.5 m g of albuterol in 2.5 mL of normal saline. The second group (CTR) received a single subcutaneous injection of 0.3 mL of normal saline combined with 2.5 mg of alhuterol in an aerosolized updraft. Both groups received additional doses of aerosolized albuterol at 20 and 40 minutes after the initial treatment, if clinically indmated. The FEV 1 spirometry and vital signs were measured with initial treatment and then every 30 minutes. Measurements and main results: There was no statistically significant difference in mean patient ages (26 versus 28.5 years, P = .3772), duration of asthma attack (23.4 versus 29.3 hours, P > .5), pretreatment FEV t (1.5 versus 1.4 L, P = .6229), 30-minute FEV l (2.3 versus 2.0 L, P = .1770), or 60-minute FEV I (2.7 versus 2.3 L, P = .1734) for the EPI or CTR groups, respectively. Conclttsion: Subcutaneous epinephrine provided no additional benefit to use of a ~]2-agonist by nebulization in mildly to moderately ill adult asthma patients. The simultaneous use of subcutaneous and inhaled [~2-agonist in severe acute asthma patients warrants investigation.
Relapse Following Emergency Department Treatment for Asthma 3 I--1e~ Acute RK Cydulka/MetroHealthMedical Center,CaseWestern Reserve CL Emerrnan, University, Cleveland,Ohio
Study objective: Previous studies have demonstrated that recovery of pulmonary function after emergency department treatment for acute asthma takes a number of days and that many patients relapse soon after- ED discharge. The purpose of this study was to establish the characteristics of patients who relapse after ED therapy. Design: Pulmonary function rests were obtained belore and after ED treatment. Patients were discharged with albuterol inhalers and short courses of prednisone. Patients werc contacted two, seven, and 21 days after discharge. In addition, hospital charts were reviewed for patients who could not be contacted by telephone. Setting: Urban, university-affiliated, county-owned ED. Type of participants: One hundred four adults discharged after treatment for asthma. Interventions: None. Measurements: Frequency of relapse after ED discharge. Main results: Follow-up was available on 91 of the patients (88%). There was no difference in the posttreatment FEV~ between those who relapsed (55.2%) and those who did not (57.8%; NS). There was no difference in the percentage improvement in the FEV~ before to after treatment between those who relapsed (76.6%) versus those who did not (59.1%; NS). Twentytwo of the patients (24%) relapsed within three weeks after discharge; 91% of the relapses occurred before the patient saw their primary care physician, and eight of the relapses (35%) occurred within ten days after steroid taper. Most patients failed to see a primary care physician after ED discharge. Conclusion: ED discharge planning should include consideration of the high relapse rate after steroid taper and failure of patients to obtain follow-up. Inhaled anti-inflammatory agents should be part of the discharge regimen.
Effects of Graded Upper Airway Obstruction on Pulmonary During Transtracheal Jet Ventilation 3 1,0,e~ Mechanics KJ Rhee,ES Schelegle,JF Green/Divisionof EmergencyMedicine and ML Carl, Department of Human Physiology,School of Medicine, Universityof California, Davis; Section of EmergencyMedicine, Universityof Nebraska, Omaha
Study objective: To quantify the effects of proximal graded upper airway obstruction on the delivered tidal volume and other selected parameters of pulmonary mechamcs during low-frequency transtracheal jet ventilation
616
(TTJV) in a dog model, with comparison to spontaneous breathing (SB) and unobstructed controls (TTJV-c). Design and methods: Laboratory study in which seven dogs were anesthetized, paralyzed, and placed within a volume plethysmograph that allowed for the head and neck to be externalized. Ventilation was performed using TTJV at 45 psi and a frequency of 15 bpm. The trachea above the TTJV catheter was progressively occluded with a Foley catheter at levels of approximately 150%, 200%, 250%, and 300% of the tracheal pressure (PT) obtained during TTJV-c. Main results: Mean levels of obstruction obtained were 130%, 190%, 220%, and 230% of the mean PT during TTJV-c (10.9 _+ 2.0 cm H20). As PT exceeded 200% (21.8 cm H20), it became difficult to regulate between subtotal and total upper airway obstruction. Tidal volume significantly increased with each level of obstruction except between 220% and 230% (SB, 506 -+ 72 mL; TTJV-c, 446 _+ 69 mL; TTJV-130%, 663 -+ 139 mL; TTJV-190%, 780 +_ 140 mL; TTJV-220%, 931 + 181 mL; and T'l'JV-230%, 944 + 135 mL). Transpulmonary pressure was not significantly higher than SB or TTJV-c when 130% obstruction was applied, but it significantly increased during higher levels of obstruction. Mean Pco 2 significantly decreased as all levels of obstruction were applied, secondary to significantly increased minute ventilation during all levels of obstruction (Pco 2 range of SB, 38.8 + 7.0 m m Hg; TTJV-230%, 16.2 + 6.5 mm Hg). There was no significant difference seen in the quasistatic compliance of the lungs among SB, TTJV-c, or any level of TTIV with upper airway obstruction Conclusion: Partial upper airway obstruction signfllcantly increases the delivered tidal volume, minute ventilation, and transpulmonary pressure of thc lungs during ~ITJV, with consequent significant decreases in Pco 2 as the level of obstruction increases. However, no significant changes are seen in the quasistatic compliance of the lungs, lending support to the position that T1]V is a safe technique of ventilation, even when ~vere partial upper airway obstruction is present.
4 New-Onset Atrial Fibrillation: Is Admission Necessary?
M Mulcahy, PL Henneman,W Coates, R Lewis/Department of EmergencyMedicine, Harbor-UCLAMedical Center,Torrance, California Study o~qjectivc:To determine if all patients with new-onset atrial fibrillation (NOAF) require admission and if the need for admission is clinically obvious in the emergency department. Design: Retrospective chart review. Setting: Urban, county hospital. Statistical analysis: Descriptive. Variables were analyzed using the Wilcoxon rank-sum test. Significance was defined as P < 01. Patients were believed to require admissmn if they would have been admitted even if they did not have NOAF or if they had a significant complication during hospitalization. Participants: Two hundred twenty-eight consecuuve emergency department patients with. NOAF seen between September 1986 and December 1992. There were 112 women and 116 men (median age, 61 years; range, 16 to 101 years). Results: The etiology of NOAF was unknown in 38%, valvular in 19%, congestive heart failure in 13%, ethanol related in 11%, hyperthyroidism in 6%, myocardial infarction (MI) in 5%, coronary artery disease (CAD) in 4%, and other in 4%. Two hundred fifteen patients were admitted to our hospital, seven were transferred, five were discharged home, and one left against medical advice. Sixty-six percent (141 of 215) of the patients admitted to our hospital required admission because of additional problems; congesuve heart failure (CHF, 43), history suggestive of MI (42), infection (11), hypotension (five), cerebrovascular accident (four), uncontrolled diabetes (four), and other (32). The need for admission was clinically obvious in the ED in 98% (138 of 141) of those who required admission. Three patients (2%) who required admission were not clinically obvious in the ED: a 72-year-old developed chest pain on hospital day 6 (MI ruled out); an 86-year-old died
ANNALS OF EMERGENCYMEDICINE 23:3 MARCH 1994