PT  - JOURNAL ARTICLE
AU  - Araújo, Indianara
AU  - Vieira, Vanessa
AU  - Valois, Marco
AU  - Albuquerque, Claudio
AU  - Ferrari, Francimar
TI  - Effect of hyperoxygenation on measurement of the maximum inspiratory pressure (MIP) in critical patients
DP  - 2011 Sep 01
TA  - European Respiratory Journal
PG  - p1287
VI  - 38
IP  - Suppl 55
4099  - http://erj.ersjournals.com/content/38/Suppl_55/p1287.short
4100  - http://erj.ersjournals.com/content/38/Suppl_55/p1287.full
SO  - Eur Respir J2011 Sep 01; 38
AB  - The assessment of the maximum inspiratory pressure (MIP) is used as an indicator of inspiratory muscle strength and may be useful in evaluating the success of weaning from mechanical ventilation. During this procedure it is common that a fall of saturation peripheral O2 (SpO2) occurs, leading to discontinuation of the maneuver, which can underestimate the value of MIP.The objective of this study is to verify whether the implementation of hyperoxygenation prior to the assessment can mitigate this decline of SpO2, increasing the measurement support time (to) and generating a more reliable MIP.The evaluation of the MIP, occlusion time (OT), SpO2, respiratory rate (RR) and heart rate (HR) was carried out randomly on 26 patients, with or without hyperoxygenation prior, maintaining the duration of occlusion of unidirectional valve for an indefinite period. Hyperoxigenation was defined as the use of inspired oxygen fraction (FiO2) to 100%, two minutes before the maneuver. The measurement was performed with the patient in the supine position and elevated head with an angle of 60 °.The value of MIP and OT were higher with previous hyperoxygenation (53.77±22.37 cmH2O vs 43.38±20.11 cmH2O/p<0.001; and 58.69±26.09 sec vs 37.04±15.07 sec/p< 0.001; respectively). In addition, there was a smaller drop in SpO2 after the measurement when the method was performed with hyperoxygenation (93.15±7.24% vs 84.58±9.73%/p<0.001). There was increase in RR and HR independently of the hiperoxynation.Implementation of hyperoxygenation prior to the assessment of MIP increase the values obtained, generating a more reliable MIP.