Pressure-volume curves with and without muscle paralysis in acute respiratory distress syndrome

• Published in: Intensive care medicine 2006-09, Vol.32 (9), p.1322-1328
• Main Authors: DECAILLIOT, Francois, DEMOULE, Alexandre, MAURIZIO MAGGIORE, Salvatore, JONSON, Bjorn, DUVALDESTIN, Philippe, BROCHARD, Laurent
• Format: Article
• Language: English
• Subjects: Adult; Aged; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Atracurium - administration & dosage; Biological and medical sciences; Compliance; Conscious Sedation - methods; Cytokines; Emergency and intensive respiratory care; Feasibility Studies; Female; Fentanyl; Hemodynamics; Humans; Hypotheses; Injuries of the thorax. Foreign bodies. Diseases due to physical agents; Intensive care; Intensive care medicine; Lung Compliance; Lung Volume Measurements; Male; Medical sciences; Middle Aged; Neuromuscular Blockade - methods; Neuromuscular Nondepolarizing Agents - administration & dosage; Patients; Positive-Pressure Respiration; Prospective Studies; Respiratory distress syndrome; Respiratory Distress Syndrome, Adult - physiopathology; Respiratory Mechanics - drug effects; Respiratory system; Risk Factors; Tidal Volume; Traumas. Diseases due to physical agents
• ISSN: 0342-4642; 1432-1238
• DOI: 10.1007/s00134-006-0265-8

Pressure-volume (PV) curves are recorded after induction of complete muscle paralysis, which may limit their clinical use. The feasibility of recording PV curves without paralysis has not been tested. In 19 patients with acute respiratory distress syndrome (ARDS) and no hemodynamic instability we prospectively evaluated whether PV curves can be safely and reliably recorded under deep sedation without neuromuscular blockade. After standardized sedation (continuous infusion of midazolam and fentanyl) PV curves were recorded during apneic sedation, defined as absence of respiratory effort during a 6-s expiratory pause and during paralysis induced by cis-atracurium. Agreement between PV curve parameters in the two conditions was evaluated. Curves were obtained from 10 cmH2O and from zero end-expiratory pressure in all patients under apneic sedation. In five patients propofol was given in addition to midazolam and fentanyl, and in two of them fluid resuscitation was needed. A strong agreement was found for respiratory system compliance and the lower inflection point and for chest wall compliance in the five patients whose esophageal pressure was measured. The variability of the measurements, however, should be taken into account in clinical practice. Neuromuscular blockade can be dispensed with when recording PV curves in many ARDS patients. Reliable PV curves can be obtained under anesthesia alone, with no serious adverse effects.