the investigators conducted a randomized controlled trial in respiratory intensive care unit (RICU) of Assiut University Hospital. COPD patients admitted to RICU were included. Exclusion criteria include: Marked renal impairment, Liver cell failure, neurological disorders, age <18 or >70 and pregnancy.

Patients were randomly allocated to two groups. Midazolam was used for sedation in both groups. Richmond agitation-sedation score (RASS) was used to monitor level of sedation or agitation. Control group received daily interruption of sedation. intervention group managed by no-sedation strategy.

Primary outcome measure: changes in PaCO2 Secondary outcome measures include: changes in PH, heart rate, mean arterial blood pressure, respiratory rate, P0.1 and NIF.

The researchers conducted a randomized controlled trial in respiratory intensive care unit (RICU) of Assiut University Hospital. COPD patients admitted to RICU were included. Exclusion Criteria include: Marked renal impairment (creatinine > 2mg/dl), Liver cell failure (Bilirubin> 3mg/dl), neurological disorders, age <18 or >70 and pregnancy.

Patients were randomly allocated to two groups. Midazolam was used for sedation in both groups. Richmond agitation-sedation score (RASS) was used to monitor level of sedation or agitation. Control group received daily interruption of sedation. After intubation, patients received IV infusion of midazolam, gradually increasing dose till RASS reached -4 or -5. Infusion stopped at 7:00 AM. If the patient is awake no need for resuming infusion. If signs of discomfort occurred, infusion resumed at half of the prior dose, targeting conscious sedation (RASS 0: -3) Intervention group were managed by no-sedation strategy. Patients received bolus doses of midazolam only when needed, after atrial to control agitation by correcting the underlying cause. If the patient needed more than 3 bolus doses , IV infusion of midazolam was given by the daily interruption protocol as in the control group. No crossover was allowed between groups. Analysis was done by intension-to-treat principle.

Follow up arterial blood gas sampling was done baseline at intubation. 1hr., 2hrs., 12hrs., 24hrs. and 48hrs. after intubation. Recording of clinical monitoring parameters (hear rate, mean arterial blood pressure, respiratory rate) was done at the same intervals. Airway occlusion pressure (P0.1) and negative inspiratory force (NIF) were measured 48 hours after intubation to test affection of respiratory muscles in both groups.

Primary outcome measure: changes in PaCO2 Secondary outcome measures include: changes in PH, heart rate, mean arterial blood pressure, respiratory rate, P0.1 and NIF.

Inclusion Criteria:

Critically ill patients diagnosed as COPD, admitted to the respiratory intensive care unit (RICU) of Assiut University Hospital.

Exclusion Criteria:

Marked renal impairment (creatinine > 2mg/dl), Liver cell failure (Bilirubin> 3mg/dl), neurological disorders, age <18 or >70 and pregnancy.