Immunocompromised pediatric patients with acute respiratory failure: outcome and prognosis factors

Introduction

Acute respiratory failure (ARF) in immunocompromised patients is associated with a high mortality rate. The aim of this investigation is to study these patients' behavior patterns to collect data that can allow us to improve their survival rate.

Methods

A retrospective study (January 2004–July 2007) in a pediatric ICU. We analyse the morbimortality, the reasons for ARF and the critical care support required. We included medical inmunocompromised patients with ARF (Wilkinson criteria). Exclusion factors: postoperative mechanical ventilation; 15 were ruled out due to upper obstruction airway, pulmonary cardiogenic edema, pulmonary thromboembolism and limitation of therapeutic effort (LTE).

Results

Fifty-seven patients (64 admissions) were enrolled in the study. Median age was 66 months (1 month–17 years). Reason for inmunodepressed situation: haematological 41 (64.1%): postchemotherapy neutropenia 20, hematopoietic stem cell transplantation (HSCT) 21, primary immunodeficiencies 10 (15.6%); solid organ transplantation 7 (10.9%), miscellany 6 (9.4%). PRISM 24-hour score was 12 (0–40). Reason for ARF: infectious pulmonary disease 23 (36%), noninfectious pulmonary disease 8 (13%), secondary pulmonary injury 28 (43%), neurological disorders 5 (8%). Evolutive organ failures (% patients): hematopoietic (68.8%), cardiovascular (65.6%), renal (54.7%), hepatic (37.5%), neurologic (28.1%), gastrointestinal (6.3%). Multiorgan failure (MOF) in 70.3%. Critical care support: conventional mechanical ventilation (96.8%), noninvasive positive pressure ventilation (7.8%; exclusive 2), high frequency ventilation (HFV) (20.3%), extracorporeal life support with membrane oxygenator (1.5%) (positive end-expiratory pressure (PEEP) > 7 (62.5%), PaFiO₂ < 150 (57.8%), oxygenation index (OI) > 15 (42.2%), barotrauma: 18.8%), sympathomimetic drugs (64.1%), renal replacement therapy (25%). Length of stay was 10 days (1–47). Mortality was 51.6%; greater if PaFiO₂ < 150 (67.5%; p = 0.004), PEEP > 7 (65%; P = 0.006), OI > 15 (64%; P = 0.008), HSCT (71.4%; P = 0.024), MOF (60%; P = 0.035), HFV (76.9%; P = 0.039). Death with LTE was 91%, and by respiratory failure was 40%.

Conclusion

Immunocompromised patients with ARF have a high mortality rate, especially if they have undergone HSCT and present MOF. Assessing the kind of lung injury by a biopsy sample to begin an early direct treatment is necessary to improve their survival. Although the respiratory index associated with the risk of mortality is known, this does not allow one to predict these patients' prognosis with certainty.