The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts


Matt McNally1,2, Robert Darnall1; 1Respiratory Care, Dartmouth Hitchcock Medical Center, Lebanon, NH; 2Neonatology, Children’s Hospital at Dartmouth, Lebanon, NH

Background: False triggering of the mechanical ventilator can often be problematic when a variable airway leak is present. When determining the appropriate triggering sensitivity it is often difficult to determine the difference between a false breath and a true patient triggered breath. Electrical activity of the diaphragm (Edi) could be used to help determine the sensitivity and level of support that the patient actually needs by giving the care provider to see the patient’s true neural respiratory rate and work of breathing. Case: The patient is a 33 week GA male baby with trisomy 21 and extreme laryngeal / tracheal malacia requiring a tracheostomy tube and ventilator dependency. It was determined after a lengthy ICU stay that the patient was going to require long term mechanical ventilation after discharge. The patient was weaned to minimal settings on the Servo I (Solna, Sweden), Pressure Support ventilation with a Pressure Support 14 cmH2O, PEEP 5 and FiO2 .25. a flow trigger was set at 5. The patient was then transitioned to the Pulmonetics LTV 1150. The same settings were used as were used on the Servo I with the exception of the triggering sensitivity, which was placed at 1L. Twenty four hour trials often resulted in the patient becoming irritable, restless and desaturating during the night. It was decided to place a catheter to measure the patient’s electrical activity of the diaphragm (Edi). An 8fr naso gastric Edi catheter was placed. It was noted that the patient’s Edi was 6 to 10 mv. When the patient was asleep, the ventilator was delivering 60 breaths/min but the patient’s neural respiratory rate was only 42. The trigger was adjusted so that the the neural and ventilator RRs matched and the patient’s Edi remained stable at 6 to 12. Once the patient was placed on the LTV with a set respiratory rate of 15 breaths/min. he was able to tolerate the LTV 1150 through the night. Discussion: There is limited data to support the use of Edi to titrate mechanical ventilation in infants. In this case we were able to successfully obtain an Edi measurement in an infant having difficulty transitioning to the home mechanical ventilator. Using the Edi monitoring capabilities of the Servo I we were able to titrate the triggering sensitivity on the Servo I such that the patient was no longer being over-supported via false triggering of the Servo I and also determine settings needed for the patient to tolerate the LTV 1200. Sponsored Research - None