Acute effect of passive cycle-ergometry and functional electrical stimulation on nitrosative stress and inflammatory cytokines in mechanically ventilated critically ill patients: a randomized controlled trial

Early mobilization is beneficial for critically ill patients because it reduces muscle weakness acquired in intensive care units. The objective of this study was to assess the effect of functional electrical stimulation (FES) and passive cycle ergometry (PCE) on the nitrous stress and inflammatory cytometry in critically ill patients. This was a controlled, randomized, open clinical trial carried out in a 16-bed intensive care unit. The patients were randomized into four groups: Control group (n=10), did not undergo any therapeutic intervention during the study; PCE group (n=9), lower-limb PCE for 30 cycles/min for 20 min; FES group (n=9), electrical stimulation of quadriceps muscle for 20 min; and FES with PCE group (n=7), patients underwent PCE and FES, with their order determined randomly. The serum levels of nitric oxide, tumor necrosis factor alpha, interferon gamma, and interleukins 6 and 10 were analyzed before and after the intervention. There were no differences in clinical or demographic characteristics between the groups. The results revealed reduced nitric oxide concentrations one hour after using PCE (P<0.001) and FES (P<0.05), thereby indicating that these therapies may reduce cellular nitrosative stress when applied separately. Tumor necrosis factor alpha levels were reduced after the PCE intervention (P=0.049). PCE and FES reduced nitric oxide levels, demonstrating beneficial effects on the reduction of nitrosative stress. PCE was the only treatment that reduced the tumor necrosis factor alpha concentration.

Estudo comparativo entre os sistemas de umidificação aquoso aquecido e trocador de calor e de umidade na via aérea artificial de pacientes em ventilação mecânica invasiva / Comparative study between heated water humidifiers and hygroscopic heat and moisture exchangers in artificial airways for patients undergoing invasive mechanical ventilation

CONTEXTO: Nos pacientes recebendo suporte ventilatório invasivo através de tubos endotraqueais é essencial o uso de umidificadores. OBJETIVO: avaliar os níveis de temperatura (TºC) e de umidade relativa (UR) do gás administrado ao paciente em ventilação mecânica através da umidificação aquosa aquecida (UAA) e do filtro trocador de calor e de umidade (FTCU). MÉTODO: Este foi um estudo prospectivo, randomizado, onde foram estudados 20 pacientes divididos em dois grupos: um grupo usou a UAA (n=10) e o outro grupo (n=10) usou FTCU Hygrobac "S", marca Mallinckrodt®. As variáveis analisadas foram: níveis de temperatura (T) e umidade relativa (UR) do gás, volume minuto (VM), volume corrente (VC) e volume de condensação. RESULTADOS: Verificou-se que o sistema de umidificação aquosa aquecida atingiu temperaturas mais baixas que o filtro trocador (29,01 ± 1,33 ºC, versus 30,14 ± 1,24 ºC; p<0,001). A umidade relativa foi maior na UAA do que no FTCU (97,45 ± 5,22 por cento, versus 89,87 ± 11.04 por cento, p < 0,021). O volume de condensação do circuito do grupo usando UAA foi maior que o do grupo usando o FTCU (p < 0,05). CONCLUSÃO: Os resultados demonstram que ambos os sistemas, UAA e o FTCU forneceram umidades absolutas abaixo do valor recomendado, sendo que o sistema de UAA ofereceu uma umidade relativa maior, enquanto que o aquecimento do gás com o FTCU obteve um melhor desempenho.

BACKGROUND: In patients receiving invasive mechanical ventilation through endotracheal tubes, the use of humidifiers is essential. OBJECTIVE: To evaluate temperature and relative humidity levels in the gas administered to patients undergoing mechanical ventilation by means of heated water humidifiers (HWH) and hygroscopic heat and moisture exchangers (HHME). METHOD: This was a prospective randomized study on 20 patients divided into two groups: one group using HWH (n=10) and the other using the Hygrobac "S" model of HHME, made by Mallinckrodt® (n=10). The variables analyzed were: temperature and relative humidity levels of the gas, minute volume (MV), tidal volume (V T) and condensation volume. RESULTS: It was found that HWH attained lower temperatures than did HHME (29.01 ± 1.33 ºC versus 30.14 ± 1.24 ºC; p<0.001). The relative humidity was higher in HWH than in HHME (97.45 ± 5.22 percent versus 89.87 ± 11.04 percent; p<0.021). The condensation volume in the ventilator circuit for the group using HWH was greater than for the HHME group (p<0.05). CONCLUSION: The results demonstrate that both systems (HWH and HHME) supplied absolute humidity that was below recommended values, while the HWH offered higher relative humidity. On the other hand, HHME produced better performance regarding gas heating.