Benjamin W. Dart

A randomized prospective trial of airway pressure release ventilation and low tidal volume ventilation in adult trauma patients with acute respiratory failure

BACKGROUND Airway pressure release ventilation (APRV) is a mode of mechanical ventilation, which has demonstrated potential benefits in trauma patients. We therefore sought to compare relevant pulmonary data and safety outcomes of this modality to the recommendations of the Adult Respiratory Distress Syndrome Network. METHODS Patients admitted after traumatic injury requiring mechanical ventilation were randomized under a 72-hour waiver of consent to a respiratory protocol for APRV or low tidal volume ventilation (LOVT). Data were collected regarding demographics, Injury Severity Score, oxygenation, ventilation, airway pressure, failure of modality, tracheostomy, ventilator-associated pneumonia, ventilator days, length of stay (LOS), pneumothorax, and mortality. RESULTS Sixty-three patients were enrolled during a 21-month period ending in February 2006. Thirty-one patients were assigned to APRV and 32 to LOVT. Patients were well matched for demographic variables with no differences between groups. Mean Acute Physiology and Chronic Health Evaluation II score was higher for APRV than LOVT (20.5 ± 5.35 vs. 16.9 ± 7.17) with a p value = 0.027. Outcome variables showed no differences between APRV and LOVT for ventilator days (10.49 days ± 7.23 days vs. 8.00 days ± 4.01 days), ICU LOS (16.47 days ± 12.83 days vs. 14.18 days ± 13.26 days), pneumothorax (0% vs. 3.1%), ventilator-associated pneumonia per patient (1.00 ± 0.86 vs. 0.56 ± 0.67), percent receiving tracheostomy (61.3% vs. 65.6%), percent failure of modality (12.9% vs. 15.6%), or percent mortality (6.45% vs. 6.25%). CONCLUSIONS For patients sustaining significant trauma requiring mechanical ventilation for greater than 72 hours, APRV seems to have a similar safety profile as the LOVT. Trends for APRV patients to have increased ventilator days, ICU LOS, and ventilator-associated pneumonia may be explained by initial worse physiologic derangement demonstrated by higher Acute Physiology and Chronic Health Evaluation II scores.

Preliminary experience with airway pressure release ventilation in a trauma/surgical intensive care unit.

BACKGROUND Airway pressure-release ventilation (APRV) is a pressure-limited, time-cycled mode of mechanical ventilation. The purpose of this study was to evaluate our initial experience with the use of APRV in acutely injured, ventilated patients. METHODS Since March 2003, APRV has been used selectively in adult trauma patients with or at risk for acute lung injury/acute respiratory distress syndrome. Data were obtained before and during the 72 hours after switching to APRV. A retrospective analysis of these data was then performed. RESULTS Complete data were available on 46 of 60 patients (77%) for the first 72 hours of APRV. Before APRV, the average Pao2/Fio2 ratio was 243 and the average peak airway pressure was 28 cm H2O. Peak airway pressure decreased 19% (p = 0.001), Pao2/Fio2 improved by 23% (p = 0.017) and release tidal volumes improved by 13% (p = 0.020) over the course of the analysis. CONCLUSION APRV significantly improved oxygenation by alveolar recruitment and allowed for a reduction in peak airway pressures. This relatively new modality had favorable results and appears to be an effective alternative for lung recruitment in traumatically injured patients at risk for acute lung injury/acute respiratory distress syndrome.

Split down the middle: A functional survivor of complete traumatic hemipelvectomy

A 38-year-old male was transferred to a Level I trauma facility after a high-speed motorcycle collision. Manual pressure was used to prevent exsanguination from a large open pelvic wound. His left leg and hemipelvis were delivered on a second stretcher. Blood pressure was 95/60 mm Hg, heart rate was 110 beats per minute, and temperature was 33.2°C. He was emergently transported to the operating room where the complete transection of his common iliac artery and vein were isolated and ligated. Destructive injuries to the penis, rectum, and anus were also identified. The prostatic urethra was noted to be transected. A suprapubic cystostomy tube was placed. The wound was then packed and the skin was closed over laparotomy pads. He was transported to the intensive care unit for further resuscitation, active rewarming, and stabilization. A pelvic X-ray was obtained demonstrating absence of the left hemipelvis (Fig. 1). Over the next several weeks, reconstruction consisted of penectomy, scrotectomy, loop sigmoid colostomy, multiple soft tissue debridements, and a contralateral posterior thigh muscle flap with skin graft. He was discharged from the hospital to a rehabilitation facility 29 days after the initial injury. All wounds have now healed and he ambulates with a prosthesis.