2005 OPEN FORUM Abstracts
In-Hospital Transport USING THE VIASYS AVEA IN A Critically ill Patient With Severe ARDS.
Kevin Jacques, RRT, John Salyer RRT, Respiratory Care Department, Jerry Zimmerman, MD. Pediatric Critical Care Service Children's Hospital and Regional Medical Center, University of Washington, Seattle WA.
Introduction: Intra-hospital transport of the critically ill can be very challenging. In many cases, patients are manually ventilated during these short transports. We describe a case where hand ventilation was deemed unacceptable and the critical care ventilator was used as a transport ventilator to take a very ill patient to interventional radiology.
Case Study: A 10 year old, 37 kg male with a closed head injury developed severe ARDS. Upon admission, HFOV with a Sensormedic 3100A failed due to SpO2 < 70%. Conventional ventilation was initiated using ARDSNET lung-protective strategies to minimize ventilator induced lung injury (VILI). Ventilator = Viasys Avea, mode = PRVC-SIMV, FIO2 from 0.90 to 1.00, f = 20/m, VT = 6 mL/ kg, PEEP = 12 cmH20. Inhaled nitric oxide (INO) at 10 ppm was started because of profound oxygenation failure. Neuromuscular blockade was necessary to maintain SpO2 > 87%. Permissive hypercapnea was used, to minimize the risk of further VILI. Over the next 10 days modest stabilization was achieved. On day ten, pneumothorax developed, requiring two chest tubes. In light of the patient's modest stabilization and in an attempt to minimize further lung injury, HFOV was tried again, this time with a Sensormedic 3100B. FIO2 = 0.90 to 1.00, MAP = 24 cmH20, Hz = 6, Amp = 80 cmH20. Following the transition to HFOV, ABG's were basically unchanged from conventional ventilation: pH = 7.33, PaCO2 = 99 mmHg, PaO2 = 60 mmHg, NaHCO3 = 53, BE = 28. Later that day, swelling of the right leg prompted ultrasonography which revealed a large deep-vein thrombosis. The decision was made to transport the patient to the Interventional Radiology (IR) laboratory, for placement of a filter above the thrombosis to prevent embolization to the lungs. Because the oscillator had no battery capability and to maintain ventilation according to the ARDSNET protocol during transport, the patient was changed back to AVEA on FIO2 0.90 to 1.00, SIMV with f = 20/min, VT = 6 mL/kg, PEEP = 12 cmH20. ABG pH = 7.38, PaCO2 = 91 mmHg, PO2 = 61 mmHg, NaHCO3 = 54 mEq/L, BE = 29. Using the AVEA on battery power with self-contained gas source, we transported the patient to IR, without interrupting or changing ventilation, while still on INO without any episodes of cardiovascular compromise and no apparent increase in VILI. Eight days after this transport, the patient remained on essentially the same ventilator settings, except that the FIO2 had â to @ 0.80 and PaCO2 had â @ 75 mmHg. Pt was successfully extubated on the 39th day after injury.
Discussion: It is well known that manual ventilation during intrahospital transport leads to derangement in blood gases (Respir Care 1992 Jul;37(7):775-93) and that manual ventilation can leads to inconsistent ventilation in infants and children (Respir Care 1999;44:1252 & Respir Care 1999;44:1253). This patient's critical condition and profound VILI made us very concerned about the changes in ventilation that would be associated with hand bagging, especially over-inflation. By using a state of the art critical care ventilator (Viasys Avea) to ensure uninterrupted and consistent ventilation and implementing best practice as per the ARDSNET protocol, we were able to provide a safe transport and minimize the risk further VILI during an extremely risky transport. The Avea is equipped with an internal battery rated at 30 minutes, but may last a shorter time when the compressor is operating. We provided a 50 psi oxygen source for the ventilator with an E-cylinder. This gave us sufficient battery life and oxygen supply for the short transport to our imaging department, which takes 5-10 minutes to move the patient there and get hooked up to wall power and gas. Anticipated time of transport must be carefully considered before transporting a critical patient away from an ICU using the technology we describe.