2002 OPEN FORUM Abstracts
ALVEOLAR RECRUITMENT MANEUVER POST CABG/MVR
Zack Frazier BS, RRT, Kelly Joplin RRT, Martin Rohrer, BS, RRT, and Terrence Coulter MD. Cox Health Systems; Springfield, MO.
Introduction: The alveolar recruitment maneuver (ARM) has been proven to be an effective procedure that improves oxygenation in patients with acute respiratory distress syndrome. Its application in post-operative cardiac patients has been limited due to concerns of compromising cardiac output as a consequence of high levels of peak end-expiratory pressure (PEEP). Herein, we describe a case of alveolar recruitment in a post-operative cardiac patient who tolerated high levels of PEEP without causing hemodynamic instability.
Case Summary: A 74 year old female with no underlying lung disease presented to the SICU after a 7 hour surgery for a three vessel CABG and a mitral valve replacement. Initial ventilator settings of PC 20 for a Vt 650 (10ml/kg IBW), rate 12, PEEP 10, FIO2 1.0 resulted in an ABG @ 1949 hours of pH 7.27, PaCO2 35, PaO2 68. Although comfortable with the ARM in ALI/ARDS patients, we were hesitant to incorporate this into our open-heart ventilator protocol. Thus, PEEP was increased to 12 and repeat ABG @ 2050 hours noted a pH of 7.15, PaCO2 49, PaO2 30. As a consequence of her clinical decline, the cardiothoracic surgeon administered 3 amps of NaHCO3-, told us to ?warm up? the 1010 jet ventilator, and consulted a pulmonologist. Thirty minutes after bicarbonate administration and increasing PEEP to 15cm, the ABG revealed a corrected pH , however, PaO2 was 32 (FIO2 1.0). The pulmonologist increased PEEP to 18. Follow-up ABG @ 2245 hours revealed a pH 7.31, PaCO2 49, and PaO2 50. After discussing with the cardiothoracic surgeon and assuring hemodynamic stability, the pulmonologist ordered a recruitment maneuver. The procedure began on PC 20, rate 10, PEEP 20, I:E 1:1 for 2 minutes. Observing good patient tolerance, a second recruitment maneuver was performed 15 minutes later, using a PEEP of 25. Finding this maneuver was also tolerated well, a third recruitment maneuver was done with a PEEP of 30 followed by an ABG 30 minutes later, resulting in a pH 7.36, PaCO2 46, PaO2 184. The ventilator settings at this point were PC 14 for a Vt of 450, rate 15, FIO2 1.0, PEEP 18. The patient?s P/F Ratio continued to improve and she was on an FIO2 .40 with a PaO2 of 100 the next day. Graphing the first eight post-op ABGs as related to Shunt %, PEEP, and P/F Ratio resulted in the following chart:
Discussion: This case demonstrates that the alveolar recruitment maneuver can be safe and effective in select post-operative cardiac patients. Further studies are needed to identify patients who would most likely benefit or be at high risk for complications from this procedure.