The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts


Patrick Williams1, Matthew McNally1, Timothy J. Quill2; 1Respiratory Care, Dartmouth Hitchcock Medical Center, Lebanon, NH; 2Anesthesia and Critical Care, Dartmouth Hitchcock Medical Center, Lebanon, NH

Introduction: Dynamic hyperinflation caused by COPD exacerbation often causes dys-synchrony between the patient and the mechanical ventilator, making it difficult for the patient to trigger and cycle each breath. Common strategies used to compensate for these problems include continuous bronchodilator therapy, administration of helium-oxygen mixtures (Heliox), and chemical paralysis of the patient. Neurally Adjusted Ventilatory Assist (NAVA) may be used in conjunction with continuous bronchodilator therapy and Heliox, without the need for chemical paralysis, eliminating the associated morbidity. Case Summary: A 58 year old female patient was admitted from an outside hospital, intubated and chemically paralyzed with cisatracurium due to a severe COPD exacerbation associated with pneumonia. The initial ventilator settings were SIMV (vol)/PS, VT 500ml x 10 bpm PS 10 cm H2O PEEP 5 cm H2O FIO2 0.5. The cisatracurium was held, but the patient decompensated demonstrating a prolonged forced expiratory phase with audible wheeze and increased ventilating pressures (PIP > 60 cm H2O, Plateau 39 cm H2O, Total PEEP 23 cm H2O). Cisatracurium was resumed; the PEEP was decreased to 0, with no improvement to PEEPAuto. Continuous Albuterol nebulizer (20 mg/hr) and Heliox was initiated with minimal improvement in bronchospasm and ventilation. Multiple attempts were made to discontinue the paralytic agent. Many empirical changes were made to ventilator settings to minimize hyperinflation. All failed until the patient was placed in NAVA. At that point, the breathing pattern had changed to a respiratory rate of 1-4 bpm, VT 800 - 1400 ml with an extremely prolonged expiratory phase. Five days after extubation, patient did well with short periods of BiPAP at night. The patient was discharged to an outside hospital for rehabilitation. Discussion: With the use of NAVA, the patient was able to control her breathing pattern and respiratory rate spontaneously, regardless of the flow she could generate. Triggering the ventilator with the electrical activity of the diaphragm made it possible to dramatically reduce air trapping and improve ventilator synchrony, eliminating the need for chemical paralysis. This allowed the patient to breath at a comfortable low rate with a very long expiratory phase while maintaining reasonable blood gas values. This eventually lead to successful extubation without the morbidity associated with the prolonged use of muscle relaxants. Sponsored Research - None