- Poster presentation
- Open Access
Bilevel plus PSV and nitric oxide as an alternative ventilatory strategy in acute respiratory distress syndrome patients
© BioMed Central Ltd 2007
- Published: 19 June 2007
- Nitric Oxide
- Pulmonary Hypertension
- Acute Respiratory Distress Syndrome
- Pulmonary Artery Pressure
- Inspiratory Pressure
The protective ventilatory strategy provided by usual ventilatory modes is a cornerstone factor to determine prognosis in acute respiratory distress syndrome (ARDS). However, there are situations where alternative strategies must be used.
We describe three patients, all females with a mean age of 76 ± 6 years, admitted to the ICU presenting ARDS related to community-acquired pneumonia (two patients) and pneumonia secondary to gastric aspiration (one patient). The mean APACHE II score was 25 ± 2. The ventilator used was the Puritan-Bennet 840. The mean static compliance (Cst), paCO2 and PaO2/FiO2 ratio after orotracheal intubation in the VCV mode and a PEEP level of 10 cmH2O were 24.3 ± 3.1, 48 ± 4 mmHg and 120.6 ± 46, respectively. All patients presented septic shock and were monitored with a Swan–Ganz catheter. The initial mean pulmonary artery pressure was 56 ± 4 mmHg on vasopressors to maintain a mean systemic arterial pressure above 65 mmHg. The patients were submitted to a recruitment maneuver using a pressure gradient between the PEEP and inspiratory pressure of 15 cmH2O during 2 minutes each step to a limit of 60 cmH2O, and after that the mean level of PEEP used was 20 ± 3 cmH2O and the ventilatory mode was switched to Bilevel plus PSV (derived mode from APRV). The mean Vt/kg used was 5.6 ± 0.8 ml/kg, with an inspiratory pressure level of 30 ± 2 cmH2O and I:E ratio of 1:1. The mean PaO2/FiO2 ratio was raised to 153 ± 25 (26.8%). Nitric oxide (NO) was started and the mean concentration used was 37 ± 3 ppm. After 4 hours, the mean pulmonary artery pressure and PaCO2 decreased to 40 ± 4 mmHg (28.6%) and 42 ± 2 mmHg (12.5%), respectively, and the PaO2/FiO2 ratio increased to 268 ± 22 (122.2%). After 24 hours NO was decreased to 18 ± 4 ppm, and was discontinued 12 hours after. Two patients were successfully weaned from mechanical ventilation after 8 and 10 days, respectively, and discharged home afterwards. One patient died.
This series of cases was the first that depicted the Bilevel plus PSV mode wholly with NO to control pulmonary hypertension and ARDS. These interventions seems to be beneficial and feasible to support critically ill patients, mainly those who failed to respond to recruitment maneuver and conventional ventilatory modality.