Dex as Analgesic Adjuvant in OSA Patients

BACKGROUND/STUDY SIGNIFICANCE

Patients with OSA undergoing surgery have increased surgical risk compared to patients that
do not have OSA . Perioperative medication such as benzodiazepines and opioids can decrease
upper airway tone, inhibit central respiratory drive and inhibit upper airway reflexes. The
supine position may also worsen the severity of the OSA. Additionally, this group of patients
is more likely to have a higher incidence of complications, particularly post operative
hypoxemia , difficult intubation , and complicated extubation course .

Uvulopalatopharyngoplasty (UPPP) along with other tongue base procedures are commonly
performed surgical procedures used to help alleviate the symptoms of obstructive sleep apnea
(OSA). Postoperative management of oropharyngeal pain is challenging since narcotic
administration may compromise respiratory status in OSA patients. The Anesthesiology and
Otorhinolaryngology communities have begun to rethink acceptable narcotic use in OSA patients
especially following the recent FDA announcement highlighting serious adverse effects related
to codeine consumption in children who had undergone tonsillectomies.

Dexmedetomidine (Precedex) is a sedative with minimal respiratory depression. Its mechanism
is via alpha 2 agonism and has 8 times the affinity for the alpha 2 adrenoreceptor than
clonidine. It has been shown to have sedative, analgesic, and anxiolytic effects. It produces
a predictable and dose dependent decrease in heart rate and blood pressure. Dexmedetomidine
undergoes extensive metabolism in the liver and is then eliminated as methyl and glucuronide
conjugates mostly via the renal system. The pharmacokinetics are markedly affected by hepatic
insufficiency .

Inclusion Criteria:

- Age 18 or older

- Patients scheduled for UPPP

- Patients with diagnosis of OSA via polysomnography

- American Society of Anesthesiology (ASA) classification 3 or lower

Exclusion Criteria:

- Bradycardia as defined as resting heart rate <60 Beats per min (BPM) or symptomatic

- Any degree of heart block diagnosed by ECG

- Hypotension as defined as <20% from baseline or symptomatic

- Liver failure, (two fold rise in liver enzymes)

- Chronic Kidney Disease (CKD) III or greater

- History of allergy to opioids or dexmedetomidine

- ASA classification 4 or higher

- ICU or Step down admission

- Difficult airway as defined by previous history of difficult intubation or requiring a
fiberoptic intubation.