The nurses then adjusted the ventilatory parameters, including pressure-support level and FiO2 (fraction of inspired oxygen), according to the protocol. Pressure-support level was gradually increased by 2 cmH2O steps to reach the target expiratory tidal volume and PEEP level was then adjusted as prescribed. FiO2 was gradually adjusted by 5% steps People, Hard Work Then Desloratadine to reach the targeted SpO2. Non-invasive ventilation was applied intermittently for periods of at least two hours, with a minimal duration of six hours per day and was maintained until signs of respiratory distress improved. An algorithm was used by nurses in case of leaks, which involved first repositioning of the mask; second, reducing the PEEP level at 2 cmH2O; third, reducing the pressure-support level by steps of 2 cmH2O until the minimal expiratory volume was reached; and fourth, changing the mask interface.
A mobile cart containing all types and sizes of interfaces was available at the bedside during initiation of NIV. NIV was performed via a non-vented full-face mask (FreeMotion? RT041, Fisher & Paykel, Auckland, New Zealand or Ultra Mirage?, Resmed, CA, USA), with an ICU ventilator using a dedicated NIV mode (Evita XL, Dr?ger, L��beck, Germany, or Engstr?m Carestation, GE Healthcare, Fairfield, CT, USA), equipped with a heated humidifier (MR850, Fisher & Paykel).
The following criteria were used for endotracheal intubation: loss of consciousness or psychomotor agitation hindering nursing care and requiring sedation; persistent hypotension (defined by systolic arterial blood pressure below 90?mmHg or mean arterial blood pressure below 65?mmHg) despite fluid resuscitation, or need for vasopressors; or two of the following criteria: frank worsening of respiratory distress under NIV, respiratory rate above 40 breaths per minute, SpO2 remaining below 90% despite FiO2 100%, dependence to NIV for more than 12?hours, or pH <7.35. NIV failure was defined by the need for endotracheal intubation.Data collectionFrom the NIV monitoring forms, we analyzed the number and duration of NIV sessions, ventilator settings (pressure support level, positive end-expiratory pressure, FiO2), ventilatory parameters (SpO2, respiratory rate, expiratory tidal volume), hemodynamic parameters (heart rate, blood pressure and level of consciousness assessed using the Richmond Agitation-Sedation Scale (RASS) , with altered consciousness defined as a RASS <0. NIV tolerance and number of leaks were recorded on a 4-point scale, then dichotomized into ��acceptable�� (scored 2 to 3) or ��poor�� (scored 0 to 1) tolerance, and ��minor�� (scored 0 to 1) or ��major�� (scored 2 to 3) leaks, respectively. Blood gases were routinely measured one hour after initiation of NIV.