Dexmedetomidine and Propofol in Mechanically Ventilated Patients by Using Salivary Alpha-amylase as a Stress Marker

Critically ill patients receiving mechanical ventilation (MV) in the Intensive Care Unit (ICU) have been reported to suffer due to their sense of dependency on technical medical equipment and from severe emotional responses such as hopelessness, anxiety, high levels of frustration and stress. The administration of sedatives is intended to reduce and/or prevent these negative experiences and to facilitate nursing care.

Dexmedetomidine is a highly selective α2 receptor agonist with 1600-fold affinity to α1 receptor. The use of dexmedetomidine before anesthesia has a positive effect on hemodynamic stability, which has been associated with reduced postoperative mortality and reduction of unpleasant postoperative complications . Dexmedetomidine has been shown to provide good patient comfort during MV; it also has a satisfactory safety profile and reduces time to extubating.

Salivary alpha amylase (SAA) will be considered as a suitable biomarker of sympathetic nervous system activity in recent years. SAA is locally produced by the highly differentiated epithelial acinar cells of the exocrine salivary glands, mostly of the parotid glands and plays an important role in carbohydrate hydrolysis.

Inclusion criteria

• Age 18 to 65 years old.
• Both sexes.
• Newly mechanically ventilated.

Exclusion criteria

• Patients who used inhaled steroids.
• Patients who used any medication that could affect salivary glands (such as antihypertensive, antidepressants or antipsychotic drugs).
• Those with smoking and drinking habits.
• Patients on adrenoreceptor agonist or antagonist therapy.
• Pregnant female.
• Known hypersensitivity to the study drugs.
• Women using oral contraceptive or were in their menstrual cycle.