2005 OPEN FORUM Abstracts
AN ACUTE AIRWAY OBSTRUCTION DURING ARDSNET VENTILATORY STRATEGY WHILE UTILIZING A PASSIVE HUMIDIFICATION SYSTEM.
Kenneth Miller, MEd, RRT-NPS, Joseph Groller, RRT, Dr Robert Barraco, Linda Cornman, BS, RRT-NPS. Lehigh Valley Hospital, Allentown, PA 18105-1556
Introduction: Humidification during mechanical ventilation is essential to prevent ventilator induced mucus obstruction. Many different humidification systems are available to provide adequate humidification. The decision to utilize either an active or passive system is based on clinical judgement, protocols and current practice guidelines. In certain patient populations there exist a possibility of increased mucus production and the potential of airway obstruction. When ARDSnet ventilatory strategy is employed often a high respiratory rate is set with a corresponding short inspiration. We present a case study where an acute airway obstruction occurred using a passive humidification system during the ARDSnet ventilatory protocol.
Case study: A 46 year-old male admitted for multi trauma, including a left pulmonary contusion was placed on conventional ventilation on admission. Mechanical humidification was provided via a passive Heat Moisture Exchange Filter (HMEF) system. Upon the fifth day of mechanical ventilation the patient was diagnosed with acute lung injury. At this point, the ventilatory strategy was changed to the ARDSnet protocol. The ventilation settings were TV 380cc, respiratory rate 28 breaths per minute, FI02 50% and PEEP 10cmh2O. Over the next several days, the clinical end-points were maintained within the ARDSnet ventilatory protocol. During the seventh day of the ARDSnet ventilatory strategy the patient required an operative procedure for an abdominal washing and debridment. Post operatively the patient required several liters of fluid. Four hours later an acute upper airway obstruction occurred. Oxygen saturation drop to 75% and the decision was made to extubate and re-intubate. Upon examination of the removed endotracheal tube, it was noted that the endotracheal tube was completely obstructed by thick dried up mucus. The patient was re-intubated, subsequently received a tracheotomy and later liberated from mechanical ventilation.
Conclusion: Patients who are susceptible to mucus plugging and require a high minute ventilation associated with a short inpiratory time may benefit from an active humidification system. Often patients who are diagnosed with acute lung injury have increased mucus production. In conjunction with a large fluid resuscitation any dried secretion may become hydrophilic and cause an acute airway obstruction. Airway patency must be monitored very closely in this patient population and may benefit from an active humidification system.