2000 OPEN FORUM Abstracts
Case Summary: Use of Respironics NPPV-Heliox System For COPD Exacerbation
Frank Austan RRT, Michael Polise MD, Temple University Hospital, UMDNJ-Respiratory Care Program & West Jersey Hospital, Philadelphia, Pennsylvania & Cainden, New Jersey
A 63-year-old man with chronic obstructive pulmonary disease (COPD) was admitted to the Emergency Department (ED) complaining of severe dyspnea. The respiratory rate was 28 breaths/min, blood pressure 190/120 mm Hg, pulse 144 b/min and oral temperature 98.6° F. Laboratory results revealed a hemoglobin 16.5 g/dl, white blood cell count 15.2/cmm and serum theophylline 14.8 ug/ml. Chest auscultation revealed expiratory wheezes bilaterally. Severe accessory muscle use was observed. Arterial blood gas analysis (ABGA) on oxygen at 6 L/min by nasal cannula at 4:00 PM revealed pH 7.07, PaC02 86 torr, Pa02 52 torr. Pharmocologic intervention included intravenous aminophylline, solumedrol and three back-to-back Albuterol nebulized treatments without improvement. Repeated ABGA at 4:30 PM, pH 7.09, PaC02 82 torr, Pa02 56 torr. In view of this situation, noninvasive positive pressure ventilation (NPPV) using a Respironics S/T-D System (Murrysville, PA) was placed on the patient using a nasal mask. The settings were as follows, Inspiratory Positive Pressure (IPAP) 10 cm H20, Expiratory Positive Pressure (EPAP) 3 cm H20, rate 12 breaths/min, oxygen at 6 L/min. Repeated ABGA at 5:00 PM, pH 7.11, PaC02 78 torr, Pa02 63 torr. Patient observation revealed a rate of 22 breaths/min with moderate accessory muscle use. NPPV setting was increased to IPAP 12 cm H20, EPAP 6 cm H20, 02 remained at 6 L/min. Repeated ABGA at 5:30 PM, pH 7.20, PaC02 68 torr, Pa02 72 torr. Clinical observation revealed continued accessory muscle use and patient complaining of being "unable to catch my breath". In view of this situation, an H cylinder of 70% Helium-30% Oxygen (so-called heliox) was introduced into the treatment plan via the nasal mask. He continued on 6 L/min oxygen and 12 L/min of heliox. (We estimated that in a proportional relationship, 6 L/min equals 44% 02, diluting the helium to 56% but still providing a less dense mixture, reduction in turbulance, and lessened work of breathing.) Repeated ABGA at 6:00 PM, pH 7.38, PaC02 50 torr, Pa02 76 torr. Clinical observation presented a calmer patient, breathing a rate of 18/min and verbalized "breathing easier". He remained on NPPV until 7:00 PM and was changed to 02, 50% Venturi Mask. ABGA was repeated at 8:00 PM, pH 7.37, PaC02 45 torr, Pa02 91 torr. The patient was admitted to the hospital and discharged six days later without incident. Discussion: This case report describes a patient with COPD exacerbation and ventilatory failure who experienced greater tolerance of NPPV and improved ABGA with the introduction of heliox. On admission, he received aggressive treatment without timely response. In view of ventilatory failure, NPPV was used, moderately improving ABGA. In light of this, heliox was added as an adjunct to NPPV. Within 30 minutes of treatment the patient's clinical presentation improved. Lessened accessory muscle use was noted and patient verbalized a greater degree of comfort and tolerance for IPPV, as well as improving ABGA. It could be inferred that helium with 1/7th the density of nitrogen facilitated a reduction in the work of breathing, thus "buying" time for pharmacologic impact to occur. Conclusion: Though further study is needed to test the efficiency IPPV-Heliox method before widespread use can be seen, the outcome presented in this case is encouraging. Equipment and techniques that help reduce the risk of invasive ventilation are important if quality and cost outcomes are to be assured.