Ventilação mecânica não invasiva em uma paciente com pancreatite aguda e insuficiência respiratória

Abstract

Respiratory failure in acute pancreatitis is one of the prognostic factors for mortality and can lead to death in the first week of treatment. Therefore, much attention has been devoted to the respiratory complications of this condition. The most common pleuropulmonary complications of acute pancreatitis are inflammatory response syndrome, atelectasis, alveolar consolidation, and diaphragmatic dysfunction. (1,2) Noninvasive mechanical ventilation (NIMV) is an advance in intensive care in specific cases of acute respiratory failure, such as in COPD exacerbation and in cardiogenic pulmonary edema.(3) In such cases, NIMV is used in order to reduce the work of breathing and improve pulmonary gas exchange, as well as to avoid tracheal intubation. In the Adult ICU of the State University at Campinas Hospital de Clínicas, located in the city of Campinas, Brazil, we had the opportunity to treat a 35-year-old female patient who had been admitted with a diagnosis of acute biliary pancreatitis and signs of respiratory failure. The scores obtained were as follows: Simplified Acute Physiology Score II = 30; Ranson scoring system (48 h) = 5.8; and Balthazar CT score = B-C 3, D-E 12. At admission, the patient presented with severe abdominal pain, sweating, dyspnea (RR = 35 breaths/min), contraction of accessory respiratory muscles, nasal flaring, and paradoxical breathing.The patient received ventilatory support by NIMV for three consecutive days, requiring no endotracheal intubation or invasive mechanical ventilation. She was started on NIMV at 7:30 a.m. on postadmission day 2, NIMV being delivered via a face mask connected to a ventilator (BiPAP Vision; Respironics Inc., Murrysville, PA, USA) set in spontaneous mode. Initially, expiratory positive airway pressure (EPAP) was set at 25 cmH 2 O and inspiratory positive airway pressure (IPAP) was set at 12 cmH 2 O, oxygen being delivered at 7 L/min via a catheter connected to the ventilator circuit. After the patient's adaptation to the ventilator, the EPAP levels were periodically adjusted to obtain an SaO 2 greater than 94% and the IPAP levels were adjusted to obtain a tidal volume of 5-8 mL/kg and an RR below 30 breaths/min. Weaning from NIMV was achieved after three consecutive days by gradually reducing the EPAP and IPAP levels in order not to increase the RR and reduce the tidal volume and SaO 2 . On the fifth day of treatment, the patient received oxygen at 7 L/min via a nebulizer mask, showing no signs of respiratory distress. There was no need for NIMV for the remainder of her hospital stay.Before starting the treatment with NIMV, the patient was dyspneic because of the presence of bilateral alveolar infiltrates in the lung bases, microatelectasis, and abdominal distension. The last of the three led to a restrictive ventilatory pattern, with a reduction in diaphragmatic strength and mobility, which was due to cephalic displacement of the diaphragm. After the initiation of NIMV, her arterial pO 2 increased and her RR stabilized. On the first day of NIMV, there was clearl...