Francis Lytle, MD
MD
University Hospitals of Cleveland/Case Western, United States
Disclosure information not submitted.
Heather McFarland, MD, DO
MD
University Hospital Case Medical Center, United States
Disclosure information not submitted.
Title: Status Asthmaticus Breaks With Sevoflurane While On Veno-Venous Extra-corporeal Membrane Oxygenation
Case Report Body:
Introduction: Status asthmaticus (SA) is a life threatening exacerbation refractory to regular treatments. It may require intubation, mechanical ventilator support and veno-venous extracorporeal membrane oxygenation (VV ECMO). Inhaled anesthesia has been described as a rescue therapy.
We describe a rare case of SA that was resistant to multimodal bronchodilator therapy and required both VV ECMO and inhaled sevoflurane therapy for lung protection and successful treatment.
Case: A 50 year old female with asthma and chronic obstructive pulmonary disease present with hypercapnic respiratory failure due to an asthma exacerbation. She required intubation for worsening respiratory acidosis and despite optimal medical management, she was placed on VV-ECMO for further support and lung protection.
Acute respiratory acidosis was corrected rapidly following ECMO, her bronchospasm persisted despite additional medications and time. Therefore we transitioned her from our intensive care unit ventilator to an anesthesia machine and delivered inhaled sevoflurane. Her bronchospasm resolved over several days (Figure 1). She was decannulated 3 days following and was transferred to regular floor 10 days following.
Discussion: The pathophysiology of SA includes gas trapping with hyperinflation and generation of auto-PEEP.VV ECMO improves gas exchange, lowers peak inspiratory pressure and reduces ventilator induced lung injury. Volatile anesthetics cause relaxation of airway smooth muscle through various mechanisms.
VV ECMO and inhaled anesthetics remain non-conventional therapies for SA due to resources, potential side-effects, difficulty scavenging sevoflurane in the ICU, and lack of guidelines.
Our case illustrates the successful use of sevoflurane to break severe bronchospasm in a patient with refractory SA while VV ECMO allowed adequate gas exchange and lung protection.
Figure 1: Ventilator settings with initiation of VV ECMO and inhaled Sevoflurane therapy
| Timing | Initiation of ECMO | Post ECMO and with initiation of Sevoflurane | Day 2 post Sevoflurane | Day 4 post Sevoflurane |
| Peak Inspiratory Pressure | 65 | 48 | 34 | 23 |
| Plateau Pressure | 30 | 30 | 25 | 30 |
| Tidal Volume | 160 | 180 | 270 | 350 |
| Inspiratory Time | 0.8 | 8 | 1.3 | 1.5 |
| PEEP | 0 | 0 | 0 | 0 |
| Ph | 7.21 | 7.38 | 7.47 | 7.43 |
| PCO2 | 79 | 61 | 45 | 42 |