2005 OPEN FORUM Abstracts
The Utilization of High Frequency Percussive Ventilation as a Rescue Therapy in Toxic ShockSyndrome.
Kenneth Miller, MEd, RRT-NPS, Matthew McCambridge, MD, Laura Williams, RRT, Denise Shank, RRT-NPS. Lehigh Valley Hospital, Allentown, PA 18105-1556
Introduction: Toxic Shock Syndrome (TSS) is often manifested by multi-system organ failure. Included in that failure is the development of Acute Lung Injury (ALI) secondary to an inflammatory response and large fluid resuscitation. ARDSnet ventilatory strategy is the gold standard as a lung protective strategy for any patient who develops ALI. However in the face of rapid fluid administration and profound metabolic acidosis ARDSnet strategy may not be able to achieve the desired clinical end-points. Our case study demonstrates that when clinical end-points can not be reached with conventional ventilatory strategies High Frequency Percussive Ventilation (HFPV) may be an alternative form of rescue ventilation.
Case study: A seventeen year old female was admitted to the ICU with profound hypotension and moderate hypoxemia. Clinical interventions included fluid administration, mechanical ventilation, and inotropic support. The diagnosis of TSS was made and appropriate anti-biotic therapy was instituted. Volume target ventilation was changed to ARDSnet ventilatory strategy based on PF ratio< 200 torr and bilateral infiltrates, and an alveolar distending pressure was above 35 cm/h20. Initial Sp02 on ASRDSnet was 88% but over next six hours dropped below 75% despite an FIO2 of 90% and PEEP of 16cm/h20. Tidal volume was increased to 7cc/kg to combat a pH< 7.15. Based on the metabolic acidosis and hypoxia the decision was made to utilize HFPV as a rescue ventilatory strategy. Initial HFPV ventilatory parameters included a PIP of 50cm/h20, a PEEP of 20cm/h20, and a pressure limited set rate of 15 bpm and an oscillatory rate of 500 bpm. FIO2 was set at 70% and quickly reduced to 50% secondary to Sp02 > 95%. Over the course of the next few hours the pH increased to 7.15 and the PIP/PEEP were reduced to 36/16cm/h20 respectively and PF improved to 315 torr. Over the course of the day the patient was returned to ARDSnet ventilatory strategy but required reinstitution of HFPV secondary to high alveolar distending pressures and a SPO2< 88%. The patient clinical end-points were maintained via HFPV over the next forty-eight hours. The patient was returned to conventional ventilation and subsequently weaned from mechanical ventilation.
Conclusion: HPFV provides a pressure limited breath with bi-phasic oscillatory breaths. Historically this ventilatory strategy has been utilized in major Burn Centers and in some isolated other clinical scenarios. HFPV provides alveolar recruitment and a more stable mean airway pressure than other conventional ventilatory options. Airway patency is maintained during expiratory oscillations. As our case study demonstrates HFPV is an alternative ventilatory strategy when conventional strategies fail to obtain desired clinical end-points. Similar case studies support it's use as a rescue therapy and a valuable ventilatory option in any major medical center.