Abstract 1773

Introduction: BAL is currently utilized in Neonatal Intensive Care to obtain material from the lower airways (Epithelial Lung Fluid, ELF) in subjects affected by pulmonary diseases. This procedure can be performed either with a diagnostic aim (identification of infectious agents and/or inflammatory mediators), or as a therapeutic procedure in the presence of atelectasis and/or severe airway obstruction. The aim of our study was to assess the effects of diagnostic and therapeutic BAL on lung mechanics in intubated and mechanically ventilated newborns.

Subjects: We studied 28 subjects with a mean birthweight (BW) of 1710 gr (range 490-3780), a mean gestational age (GA) of 31.3 wks (range 24-40) at 1 to 42 days of life. Diagnostic BALs were performed in 16 subjects with RDS with a mean BW of 1380 gr (range 490-2750), a mean GA of 30.4 wks (range 25-36). Therapeutic BALs were performed in 12 subjects with: pneumonia (n=3), atelectasis (n=4), Meconium Aspiration Syndrome (n=3), BPD (n=1), Mediastinic mass (n=1). These subjects had a mean BW of 2160 gr (range 490-3780), a mean GA of 32.4 wks (range 24-40).

Methods: BALs were performed following the method already published by Laurenti et al. (Pediatrics, 1995), administrating endotracheally 1.5 ml/kg of saline heated at 37°C. Lung mechanics was assessed with a Bicore CP100 (Sensor Medics) monitoring the following variables: tidal volume (Vt, ml/kg), minute ventilation (VE, l/min/kg), dynamic compliance (Cdyn, ml/cmH2O/Kg), airway resistance (Raw, cmH2O/l/sec). Heart rate (HR), respiratory rate (RR), transcutaneous oxygen saturation (SaO2) and arterial blood pressure (BP) were also monitored continuously. Lung mechanics was assessed 10 minutes before and 10 minutes after the BAL procedure. The differences between the values recorded before and after BAL were expressed as means (() (Standard Deviation (SD), with the relative 95% Confidence Intervals (C.I.). Their statistical significance was evaluated by the pair test.

Results: In all subjects HR, RR, SaO2 and BP did not change significantly following the BAL procedure.

Diagnostic BAL: The ventilatory pattern (Vt and VE) did not change significantly after the procedure: (Vt 0.43 ml/kg (1.18; (CI: -0.21/+ 0.99); (VE 0.03 l/min/Kg (0.07 (CI -0.01/+ 0.07). Raw decreased slightly but significantly while Cdyn did not change; (Raw -37.25 cmH2O/l/sec (62.81 (CI: -70.7/+ 3.8; p < 0.05); (Cdyn 0.04 ml/cmH2O/kg (0.08 (CI 0.00/+ 0.08).

Therapeutic BAL: In this group all variables, with the exception of Vt, improved significantly, after the procedure: (Vt 0.73 ml/kg (1.61 (CI -0.20/+ 1.76); (VE 0.06 l/min/kg (0.09 (CI 0.00/+ 0.12; p < 0.05); (Raw -41.50 (64.0 cmH2O/l/sec (CI -82.2/+ 0.9; p < 0.05); (Cdyn 0.13 (0.17 ml/cmH2O/kg (CI 0.02/0.23; p < 0.02).

Conclusions: Our study shows that broncho-alveolar lavage is a safe technique which could be helpful for different purposes. In some cases the collection of ELF could be useful for diagnostic studies and BAL can be performed without any major cardiorespiratory complication in mechanically ventilated neonates even with very low birthweight. In the presence of pulmonary atelectasis or severe airway obstruction BAL is not only a safe procedure, but can also improve lung mechanics and decrease oxygen requirements.

(Supported by a Grant of Italian Ministry of Health)