The Science Journal of the American Association for Respiratory Care

2000 OPEN FORUM Abstracts


Kenneth Miller, RRT, MEd; Stephen Matchett, MD; Frederick Wieand, RRT, BA; Phillip Huffman, MD; Wanda Perich, RN. Lehigh Valley Hospital. Allentown, PA, USA, 18105-1556

Introduction: Turning patients from the supine to the prone position has been proposed as a useful supportive therapy that can improve oxygenation in many patients in ARDS. Clinical studies in ARDS patients have reported that changing to the prone position improves oxygenation in 60-70% of patients and has no deleterious effect on hemodynamics1. Almost 50% of these patients maintained their improvement when returned supine2. Theoretically, a beneficial response to prone positioning would be most likely during the early, edematous phase of ARDS, when lung edema and atelectasis predominate. However, clinical feedback has been lacking to define the optimal time to institute prone positioning during the clinical course of ARDS. Case Summary: A forty-one year-old female was admitted with Diabetic Ketoacidosis and possible sepsis. Post admission the patient suffered a cardiac arrest. The patient was successfully resuscitated following ACLS guidelines, however prior to intubation, gastric aspiration occurred. Post resuscitation x-ray revealed clear lungs. Initial ventilator setting were 600ccx12x50% with a PIP of 38cm/H20, EIP of 24cm/H20 and P/F ratio 255. Several hours later, pulmonary compliance deteriorated, P/F ratio decreased to 100. and a repeat x-ray demonstrated bilateral infiltrates consistent with ARDS. Despite aggressive ventilatory management, pharmological paralysis, kinetic bed therapy, and tracheostomy the P/F ratio remained around 100 and compliance (Clt) below 20cc/cm/H20. During the early course of pulmonary compromise the decision to utilize prone ventilation was discussed but not instituted secondary to hemodynamic instability which was maintained by titration of Levophed and Dopamine. Over the next several days the patient's oxygenation status remained critical with an average P/F ratio of 120 on a range of FIO2 between 60-90% and PEEP levels greater than 12cm/H20. Pulmonary compliance remained less than 20cc/cm/h20. On the nineteen day, after the diagnosis of ARDS, the decision was made to attempt prone positioning. Prior to beginning prone positioning the P/F ratio was 60 and Clt 18cc/cm/H20. After 12 hours of prone positioning the P/F ratio improved to 120 and FIO2 was titrated below 60% for the first time during the patient's clinical course. A chest X-ray twenty-fours after starting prone positioning demonstrated a decrease in interstitial edema. Prone positioning was maintained for a total of forty-eight hours without any hemodynamic compromise. The patient was returned to the supine position without any deterioration in pulmonary status. Subsequently the FI02 was reduced and pressure support was initiated to start the weaning process. days Conclusion: It has been theorized that the maximum benefit from prone positioning would occur early in the clinical course of ARDS. Our case presentation demonstrates that prone positioning can improve oxygenation later in the clinical course of ARDS. The therapeutic utilization of prone positioning should not be limited to the early phase of ARDS.
1. Langer M, Mascheroni D, Gattinoni L. The Prone Position in ARDS patients. Chest 1988;94:103-107
2. Lamm W, Graham M, Albert R. Mechanism By Which The Prone Position Improves Oxygenation In Acute Lung Injury. Am J Resp Crit Care Med 1994; 150:184-193.