BIPAP in the Management of Acute Respiratory Distress Syndrome

Biphasic Positive Airway Pressure in the Management of Acute Respiratory Distress Syndrome: A Comparative Study

Evaluation of biphasic positive airway pressure as a new mode of ventilation in management of acute respiratory failure constituted in ARDS as a category of hypoxaemic respiratory failure in comparison to conventional ventilation.

Biphasic positive airway pressure (BIPAP) is a mode of mechanical ventilation that allow unrestricted spontaneous breathing independent of ventilator cycling, using an active expiratory valve. BIPAP mode is pressure-limited and time-cycled, Ventilation occurs via the time-cycled switching between two set pressure levels. In the absence of spontaneous breathing, this mode resemble conventional pressure controlled ventilation. A proposed advantage of BIPAP compared to conventional pressure-controlled ventilation is the improved distribution of gas to dependent lung regions as the result of spontaneous breathing enabled during the inspiratory and expiratory time cycles, so prevents atelectasis and promotes alveolar recruitment resulting in an improved ventilation-perfusion matching. ARDS is an acute diffuse, inflammatory lung injury, leading to increased pulmonary vascular permeability, increased lung weight, and loss of aerated lung tissue with hypoxemia and bilateral radiographic opacities, associated with increased venous admixture, increased physiological dead space and decreased lung compliance. In patients with ARDS, BIPAP with spontaneous breathing contributes to improved pulmonary gas exchange, systemic blood flow and oxygen supply to the tissue. This is reflected by clinical improvement in the patient's condition, which is associated with significantly fewer days on ventilatory support, earlier extubation and a shorter stay in the intensive care unit.

Oxygen saturation of the participants will be measured from the arterial blood gases taken from the patient and according to the range of oxygen saturation from 90 to 98% will be compared

Base line oxygen saturation of BIPAP group and SIMV PC group patients will be taken from the arterial blood gases and recorded from the range of oxygen saturation from 90 to 98% and will be compared between both groups

Blood pressure in mm Hg of BIPAP group and SIMV PC group will be measured by the sphygmomanometer device

Blood pressure in mm Hg of BIPAP group and SIMV PC group will be measured by the sphygmomanometer device and will be compared between both groups according to the normal range of systolic blood pressure from 90mmHg to 130mmHg and diastolic blood pressure from the range of 60 mmHg to 90 mmHg

Lung mechanics including the tidal volume by ml per kg ideal body weight of BIPAP and SIMV PC groups will be taken from the ventilators and recorded

Lung mechanics including the tidal volume by ml per kg ideal body weight of BIPAP and SIMV PC groups will be taken from the ventilators and compared between both groups according to the range of tidal volume from 4 to 8 ml per kg ideal body weight

Inclusion Criteria: All intubated Adult ARDS patients ARDS is diagnosed according to berlin criteria. Exclusion Criteria: Age < 18 years. Cardiac or respiratory arrest on admission. Morbid obesity with BMI > 40. Acute exacerbation of IPF. Cerebrovascular or neuro muscular disorder. 6. Diabetic ketoacidosis. 7. Hepatic or renal disease. 8.Cardiac disease.

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Hormann C, Baum M, Putensen C, Mutz NJ, Benzer H. Biphasic positive airway pressure (BIPAP)--a new mode of ventilatory support. Eur J Anaesthesiol. 1994 Jan;11(1):37-42.