1998 OPEN FORUM Abstracts
TRANSPORTABLE ISOFLURANE SYSTEM FOR STATUS ASTHMATICUS USED BY RESPIRATORY CARE PRACTITIONERS: A CASE STUDY.
John Emberger BS RRT, Rick Ermak RRT, Pete Grossweiler AS RRT, Dean Bonsall BA RRT, Wendy Connor BS RRT, Billie Speakman RRT, Mark Jones MD, Christiana Care Health System, Newark, Delaware.
Introduction: Due to increased numbers of patients presenting to the emergency department (ED) with severe asthma exacerbations, our Respiratory Department obtained a ventilator equipped to deliver Isoflurane to patients with status asthmaticus. The portable system includes: Servo 900C, Isoflurane Vaporizer, scavenging system, Isoflurane Agent Monitor, battery, and a tank system. Respiratory staff was trained to use the Isoflurane system and the Respiratory Department helped to educate nursing about Isoflurane therapy in status asthmaticus. We developed the Isoflurane system as a mobile unit so we could receive the patient in the ED and safely transport the patient to the medical ICU (MICU) for care. Case Summary: A 40 year old black female presented to the ED with status asthmaticus, spontaneously breathing in severe distress (ABG: pH = 6.98, PaCO2 = 122, PaO2 = 87 on 100% mask). The patient was sedated, paralyzed, intubated, and mechanically ventilated. Breath sounds were very decreased bilaterally. Continuous Albuterol via nebulizer was started on arrival without significant response. Ventilator settings were: assist/control mode, 550cc tidal volume, 12 breaths/minute, 100 % FiO2 and +0 cmH2O PEEP (ABG: pH = 6.97, PaCO2 = 127, PaO2 = 396). Peak inspiratory pressure (PIP) = 70 cmH2O. Static plateau pressure = 24 cmH2O. Calculated inspiratory airway resistance (Ri) was 84 cmH20/L/sec. End expiratory hold revealed AutoPEEP of +20 cmH20. Isoflurane administration was initiated at 0.5% for 15 minutes and then increased to 1.0%. After 25 minutes of Isoflurane therapy, PIP decreased by 10 cmH20, FiO2 was decreased to 60% and ABG values improved (pH = 7.05, PaCO2 = 98, PaO2 = 115). The patient was transported on 1.0% Isoflurane from the ED to MICU. After 2 hours the ABG further improved (pH = 7.15, PaCO2 = 64, PaO2 = 275). PIP, Ri, and AutoPEEP trended downward dramatically over the next 12 hours and the ABG continued to improve (pH = 7.34, PaCO2 = 45, PaO2 = 78 on 35% FiO2). The Isoflurane was discontinued 24 hours from initiation. The patient was extubated 44 hours after intubation and transferred to a general floor bed. Discussion: Isoflurane (an anesthetic agent) has been documented as a bronchodilator (1,2). Literature supports its use in status asthmaticus (1,2). We had a positive outcome in this case of status asthmaticus, and we wanted to document the use of a portable Isoflurane delivery system maintained by Respiratory Care practitioners.
1. Parnass SM, Feld JM, Chamberlin WH, et al. Status asthmaticus treated with Isoflurane and Enflurane. Anesth Analg 1987;66:193-5.
2. Johnston RG, Noseworthy TW, Friesen EG, et al. Isoflurane therapy for Status Asthmaticus in children and adults. Chest 1990;97:698-701.
The 44th International Respiratory Congress Abstracts-On-Disk®, November 7 - 10, 1998, Atlanta, Georgia.