Evaluation of manual resuscitators used in ICUs in Brazil

OBJECTIVE: To evaluate the performance of manual resuscitators (MRs) used in Brazil in accordance with international standards. METHODS: Using a respiratory system simulator, four volunteer physiotherapists employed eight MRs (five produced in Brazil and three produced abroad), which were tested for inspiratory and expiratory resistance of the patient valve; functioning of the pressure-limiting valve; and tidal volume (V(T)) generated when the one-handed and two-handed techniques were used. The tests were performed and analyzed in accordance with the American Society for Testing and Materials (ASTM) F920-93 criteria. RESULTS: Expiratory resistance was greater than 6 cmH(2)O . L(−1) . s(−1) in only one MR. The pressure-limiting valve, a feature of five of the MRs, opened at low pressures (< 17 cmH(2)O), and the maximal pressure was 32.0-55.9 cmH(2)O. Mean V(T) varied greatly among the MRs tested. The mean V(T) values generated with the one-handed technique were lower than the 600 mL recommended by the ASTM. In the situations studied, mean V(T) was generally lower from the Brazilian-made MRs that had a pressure-limiting valve. CONCLUSIONS: The resistances imposed by the patient valve met the ASTM criteria in all but one of the MRs tested. The pressure-limiting valves of the Brazilian-made MRs usually opened at low pressures, providing lower V(T) values in the situations studied, especially when the one-handed technique was used, suggesting that both hands should be used and that the pressure-limiting valve should be closed whenever possible.