Estudo comparativo entre a pressão positiva intermitente (Reanimador de Müller) e contínua no pós-operatório de cirurgia de revascularização do miocárdio

Abstract

OBJECTIVETo compare the effect of the use of intermittent and continuous positive airway pressure in postoperative patients undergoing coronary artery bypass grafting. METHODSThis study included forty patients divided into two groups: one undergoing continuous positive airway pressure (CPAP Group), and the other undergoing intermittent pressure (Müller Resuscitator Group). The patients were evaluated in relation to the several study variables at the following time points: preoperative, 3rd, 24th, and 48th hours. RESULTSThe patient groups were homogeneous in relation to the several demographic and clinical variables. The values of pO 2 , pCO 2 and sO 2 were within normal limits and no signifi cant differences were found between the groups. Regarding respirometry, the groups showed signifi cant differences in the tidal volume and respiratory rate at the 48th postoperative hour. Dyspnea and use of accessory muscle in postoperative assessments were found with a signifi cantly higher frequency in patients undergoing CPAP. Patients undergoing Müller Resuscitator had a normal chest radiograph more frequently than did patients undergoing CPAP. CONCLUSIONBoth devices were shown to be able to keep pO 2 , pCO 2 , and sO 2 values within normal limits. However, when the objective was pulmonary reexpansion with less imposed workload, the Müller Resuscitator was more effective because of its prompter action and consequently lower levels of dyspnea, respiratory rate (RR) and use of accessory muscle were observed. KEY WORDSIPPB, continuous positive airway pressure, physical therapy.

Fisioterapia respiratória na disfunção pulmonar pós-cirurgia cardíaca

“…Positive effects were observed with the use of NIV, including improvements in BIPP [25,27], BIPP associated with PEP [30], CPAP [24][25][26] and BiPAP [24,26] in the first days after HS, when the breathing is characterized by low tidal volume, offset by increased respiratory rate [24]. The adoption of this pattern of breathing tends to favor the development and continuity of atelectasis and changes in gas exchange [25,26]. Compared to CPAP [25] and IS [27], BIPP was considered more effective in increasing tidal volume, providing pulmonary re-expansion with less ventilation function [25,27].…”

“…Among the studies included, incentive spirometry (IS) was performed in three of them [20,24,27], deep breathing exercises (DBE) were used in six [20,21,23,[28][29][30]; DBE associated with positive expiratory pressure (PEP) was used in four [21,22,28,29] and PEP associated with respiratory resistance (PEP-IR) was used in two [21.28]. Breathing with intermittent positive pressure (BIPP) was used in three studies [25,27,30]; continuous positive airway pressure (CPAP) was used in two [24 , 26], bi-level positive airway pressure (BiPAP) was used in three studies [24][25][26]. Two clinical trials used a control group that didn't receive respiratory physiotherapy [22.23].…”

“…In one study [24], IS was associated with less favorable results in the improvement of VC, FEV1 and PaO2 when compared to other techniques (CPAP and BiPAP). In another randomized clinical trial [20], the addition of IS to respiratory physiotherapy (DBE, early mobilization and techniques of [20] / 1997/ RCT Matte et al [24] / 2000/ RCT Westerdahl et al [21] / 2001/ RCT Brasher et al [23] / 2003/ RCT Westerdahl et al [28] / 2003/ RCT Pasquina et al [26] / 2004/ RCT Borghi-Silva et al [29] / 2005/ RCT Westerdahl et al [22] / 2005/ RCT Mendes et al [30] / 2006/ RCT Muller et al [25] bronchial hygiene) was not more effective than the respiratory physiotherapy alone in reducing the occurrence of pulmonary complications, the length of hospital stay, radiological pulmonary function or SatO 2 improvement. In the early days of PO HS, the use of such resources was associated with greater difficulty in lung expansion due to restrictive factors such as pain [27], with questionable potential to prevent subsequent damage in lung function [24].…”

“…Such methods of ventilation serve to reduce respiratory function and improve respiratory gas exchange [45,46]. Positive effects were observed with the use of NIV, including improvements in BIPP [25,27], BIPP associated with PEP [30], CPAP [24][25][26] and BiPAP [24,26] in the first days after HS, when the breathing is characterized by low tidal volume, offset by increased respiratory rate [24]. The adoption of this pattern of breathing tends to favor the development and continuity of atelectasis and changes in gas exchange [25,26].…”

“…The analyzed variables included pulmonary oxygenation (oxygen saturation -SatO 2 , partial pressure of oxygen in arterial blood -PaO 2 , oxygenation index -PaO 2 / FiO 2 ) [20,[22][23][24][25][26][27][28]; lung function measured by spirometry (forced expiratory volume in the first second -FEV1, vital capacity -VC, forced vital capacity -FVC, peak expiratory flow -PEF, forced expiratory flow between 25 and 75% of FVC -FEF 25-75%) [20][21][22]24,26,29,30]; chest x-rays, including signs of atelectasis [20,21,23,24,26]; time of hospital stay [20,23]; rates of lung infection [20.23], respiratory muscle strength (maximum inspiratory pressure -MIP, and maximal expiratory pressure -MEP) [27,29,30]. Two of the included studies analyzed the results of thoracic computed tomography (TCT) [22.28].…”