2002 OPEN FORUM Abstracts
HFOV AND HFPV IN THE MANAGEMENT OF SEVERE UNILATERAL BLUNT CHEST TRAUMA
Jennifer De La Garza
RRT, Jason Higgins RRT, Dean Holland RRT, Grant O?Keefe MD MPH
Departments of Respiratory Care and
Surgery, Parkland Health and Hospital System, Dallas, TX
Introduction: High Frequency Oscillatory Ventilation (HFOV) and High Frequency Percussive Ventilation (HFPV) are specialized modes of ventilation. HFOV is often used as a rescue mode of ventilation when conventional ventilation fails to provide adequate oxygenation (or lung recruitment). HFPV was developed to facilitate the removal of secretions and sloughing from injured lung tissue. We present a case study in which both these modes of ventilation were utilized with success.
Case Summary: A 30 year-old Hispanic male, unrestrained driver involved in a high-speed motor vehicle collision resulting in major blunt chest and abdominal trauma was initially transported to an outside hospital and intubated. Six hours later the patient was transferred to our facility. Shortly after arrival, the patient was taken to the OR for hemoperitoneum with hemodynamic instability. Postoperative diagnoses included a grade IV splenic laceration, multiple grade I-II liver lacerations, left pulmonary contusion, and left pneumothorax. The patient left the OR with two chest tubes on the left side and an open abdomen. Post surgery, the patient?s PaO2 was 52mmHg on the following ventilator settings: PC (AC), PIP 45cmH2O, PEEP 10cmH2O, RR 20, FIO2 of 100%. The patient?s WBC was 7.2. A PEEP inflection curve was performed. Results were inconclusive secondary to air leaks at chest tube sites. The patient continued to deteriorate over the next 3-4 hours in spite of all efforts to overcome an increasing volume loss at the chest tube sites. The patient was placed on HFOV with initial settings of MAP 28, Amplitude 55, Hertz 5, Power 7.4, Bias Flow 30, FIO2 100%. During the first 24 hours of HFOV, the patient?s P/F ratio improved from 52 to 224 and the patient?s chest x-ray showed improved lung expansion. By hospital day four, the air leaks had resolved and the patient was placed on PC (AC), PIP 30cmH2O, PEEP 7cmH2O, RR 20, FIO2 60%. On day 5 the chest tubes were placed to water seal and the patient was placed on AC, RR 14, VT 750, PEEP 5cmH2O, FIO2 50%. The patient?s WBC count increased on day 5 to 19.2. On day 6, one chest tube was removed. A pneumothorax was identified on day 7 and the remaining chest tube was placed to suction. Over the next nine days, his WBC count increased to 64 in spite of aggressive treatment with antibiotics and anti-fungal agents. A chest CT on day 16 identified a left lower lobe consolidation and a pulmonary abscess that required a CT guided drain placement. On day 18, the patient was diagnosed with a necrotizing pneumonia. Thoracic surgery was consulted to perform a left pneumonectomy or lobectomy. Surgery was postponed due to patient instability. HFPV was initiated to facilitate secretion removal and recruit collapsed lung segments. Immediately prior to initiation the patient?s ABG was pH 7.22, PCO2 72mmHg, PaO2 91mmHg on an FIO2 of 100%. HFPV initial settings on the Volumetric Diffusive Respirator (VDR) were PIP 40, oscillatory PEEP of 11cmH2O, demand PEEP of 4cmH2O, respiratory rate 10, pulsatile frequency of 400, I:E 1.5:1, FIO2 100%. Within one hour of placement on the VDR, copious amounts of thin milky secretions were noted with suctioning. Twenty-four hours after HFPV placement, the patient?s ABG was pH 7.34, PCO2 57mmHg, PaO2 93mmHg on an FIO2 of 70%. Over the next 11 days, the pulmonary abscess and necrotizing pneumonia resolved. On ICU day thirty, the patient was successfully placed back on AC, RR 10, VT 750, PEEP 7, and FIO2 50%. The patient was weaned to a 40% trach collar and remained in the ICU for 11 more days. He was transferred to the general care area and FIO2 weaned to room air. Placement in a rehabilitation facility was obtained 10 days later.
Discussion: To our knowledge there have been no similar cases reported in the literature. This case demonstrates the importance of having and utilizing multiple options for a patient?s ventilatory requirements. We believe that due to the extent of the injuries reported neither HFOV nor HFPV alone would have provided the patient with a positive outcome.