The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts


Troy A. Whitacre1, Dexter Burns1, Stevan Whitt2

Introduction: We describe a recruitment maneuver (RM) in a critically ill, hypoxemic, morbidly obese (MO) patient with sepsis and respiratory failure post surgical drainage of perirectal abscess.

Case Summary: A 51 year old male with BMI > 75 k/m2 presented with shock requiring resuscitation, endotracheal intubation, and mechanical ventilation (Siemens Servo I). Initial settings of pressure control (PC) pressure = 30cmH2O, Rate = 12 breaths/min, PEEP = 8cmH2O, and FIO2 = 1.0. Arterial blood gas (ABG) results: pH = 7.188, PCO2 = 42torr, PaO2 = 320torr, HCO3- = 15.3mEq. FIO2 and inspiratory pressure were titrated to keep SpO2 > 95% and expired tidal volumes (Vt) ~ 600 ml. Over the next few days, multiple episodes of desaturation were reversed by a RM of 40 cmH2O PEEP for 40 seconds. An ABG, drawn concurrently with a drop in SpO2, revealed pH 6.903, PCO2 107, PaO2 46, HCO3 20, on 100% FIO2. Vt's had fallen to 150-200 mls. We performed recruitment with 55cmH2O PEEP for 40 seconds. No changes in heart rate or mean arterial pressure were observed. The SpO2 rose from 80% to 95%. After the recruitment maneuver PEEP was titrated for optimal compliance = PEEP @ 48 cmH2O(Open Lung Tool®, Maquet Critical Care AB). ABG's drawn 38 minutes post maneuvers revealed; pH 7.063, PaCO2 64, PaO2 65, HCO3 17.4. Over the next 24 hours, the patient continued to stabilize with reduced FIO2 and inspiratory pressure requirements while remaining on 48cmH2O PEEP.

Discussion: Lung recruitment remains one of the primary goals in the management of acute lung injury and adult respiratory distress syndrome, and many institutions have incorporated recruitment and optimal peep maneuvers into their ventilator guidelines and protocols1. Although RM's remain controversial2, when used in combination with a low tidal volume strategy they have been shown to be safe and to improve secondary end points related to hypoxemia3. Sprung et al, reports using higher than customary pressures for recruitment in MO perioperative patients8.

Conclusion: Lung recruitment in combination with optimal PEEP maneuvers should be considered in the bariatric population. Since MO patients tend to have lower respiratory system compliance4 - 7, higher than traditional levels of PEEP may be needed for both recruitment and maintenance of functioning respiratory units than in the general population.