Nosocomial infections during extracorporeal membrane oxygenation

OBJECTIVE: To examine trends in nosocomial infection associated with Extracorporeal Membrane Oxygenation (ECMO). DESIGN: Retrospective review of all patients who underwent ECMO over a 4-year period at our institution; specifically, examining reasons for placement and duration of time on ECMO, as well as nosocomial infections incurred while on or shortly after discontinuation of support. Infections were considered ECMO-related if the organism was recovered on support or within 7 days from decannulation. Analyses were performed utilizing Pearson's chi-square for dichotomous factors and t-tests for continuous factors. RESULTS: Of 141 patients requiring ECMO support, 90 (64%) survived to hospital discharge. Indication for support included circulatory failure (53%) and non-cardiac (47%). Twenty-six percent of patients developed infections on ECMO. Organisms isolated included: bacterial 20 (54%), fungal 10 (27%), mixed five (14%) and viral two (5%). Infection sites included: blood 13 (35%), urine nine (24%), mixed eight (22%), wound five (14%) and lung two (5%). Seventy-eight percent of infections noted occurred in cardiac patients. Patients with nosocomial infections were supported for a median of 169 h (range, 84-936 h), versus those without nosocomial infection [146 h (range, 50-886 h); P<0.001]. Procedures on ECMO were associated with an increased risk of infection (P<0.001) as was the presence of an open chest (P<0.025). CONCLUSIONS: The incidence of infection in ECMO patients at our institution has not increased significantly since our previous study. Cardiac patients have increased risk for nosocomial infection while on ECMO, which may be in part due to longer cannulation times, as well as increased likelihood of undergoing major procedures or having an open chest.     

Effects of continuous positive airway pressure/positive end-expiratory pressure and pressure-support ventilation on work of breathing,using an animal model

OBJECTIVE: Evaluate the effects of continuous positive airway pressure (CPAP)/positive end-expiratory pressure (PEEP) and pressure support ventilation (PSV) on work of breathing (WOB). METHODS: With 13 anesthetized lambs we measured WOB with an esophageal balloon and flow signals. All the animals were sedated, intubated, and ventilated, using 2 pediatric ventilators (Servo 300 and VIP Bird). Ventilator settings were CPAP of 0, 5, and 10 cm H(2)O and PSV of 5 and 10 cm H(2)O with PEEP of 0, 5, and 10 cm H(2)O. Data were analyzed with 2-way analysis of variance. RESULTS: With the Servo 300 the total WOB (WOB(T)) increased between CPAP/PEEP of 0 and 10 cm H(2)O (p 相似文献   

Febrile infants less than 3 months old: value of chest radiography

In the febrile infant less than 3 months old, a chest radiograph is commonly obtained to identify the cause of the fever. The purpose of this study was to evaluate the necessity of obtaining chest radiographs in this population. The clinical records and chest radiographs of 192 febrile infants (greater than 100.5 degrees F, rectal) were reviewed. Nineteen patients had signs of respiratory distress; seven had positive findings on chest radiographs. Of the 173 patients without signs of respiratory distress, five had positive findings on chest radiographs. When chest radiography was considered the gold standard for the presence or absence of pneumonia, findings of respiratory distress on physical examination had a sensitivity of 58% and a specificity of 93% for the detection of pneumonia. The prevalence of positive findings on chest radiographs in febrile infants less than 3 months old was 6%. A chest radiograph should be obtained in febrile infants only when signs of respiratory distress are present.     

Evaluation of work of breathing in spontaneously breathing animals during partial liquid ventilation.

BACKGROUND: Partial liquid ventilation improves lung mechanics and gas exchange in paralyzed mechanically ventilated animals. OBJECTIVE: Examine the work of breathing (WOB) in a spontaneously breathing animal model during partial liquid ventilation with and without the use of pressure-support ventilation (PSV). METHODS: This was a prospective study including 6 lambs (mean weight 10.9 +/- 1.3 kg). Baseline measurements, including total work of breathing (WOB(T)), elastic work of breathing (WOB(E)), and resistive work of breathing (WOB(R)), were obtained using pressure-controlled synchronized intermittent mandatory ventilation with positive end-expiratory pressure of 5 cm H(2)O at PSV levels of 0, 5, and 10 cm H(2)O. The animals' lungs were filled with perflubron through an endotracheal tube, in 10-20 mL aliquots, until filled, approximately 30 mL/kg or functional residual capacity. Repeat measurements were obtained at 10 mL/kg, 20 mL/kg, and full. Perflubron was then allowed to evaporate from the lungs and repeat measurements were obtained 3 additional times, with at least a 1 hour separation between phases, for up to 7 hours after the lungs were filled. RESULTS: No differences were detected in WOB(T), WOB(R), or WOB(E) between the gas-filled lung and the lung filled to functional residual capacity with perflubron. However, compared to the gas-filled lung, WOB(T) and WOB(R) were higher during the filling (p < 0.05) and evaporative phases (p < 0.05). The PSV level affected WOB. Work of breathing was least at PSV 10 cm H(2)O. CONCLUSION: In this pilot study of healthy animals breathing spontaneously with perflubron-filled lungs, there was an acceptable amount of WOB, which decreased with the addition of PSV. However, WOB increased when the perflubron level was not maintained at functional residual capacity.