AAOMS Conference Coverage

Combining Dexmedetomidine and Ketamine Improves Sedation Safety in Patients With Obesity

Miranda Manier, BA

Key Highlights

  • Dexmedetomidine alone was more frequently associated with reduced oxygen saturation compared with dexmedetomidine plus ketamine.
  • Ketamine’s sympathomimetic effects may mitigate dexmedetomidine-induced bradycardia and hypotension.
  • Combining dexmedetomidine with ketamine may improve sedation safety in patients with obesity.

In a study presented by Marwa Hatem, DDS, MD, and colleagues at the American Association of Oral and Maxillofacial Surgeons (AAOMS) 2025 Annual Meeting in Washington, D.C., dexmedetomidine alone was associated with higher rates of oxygen desaturation in patients with obesity undergoing procedural sedation, whereas combining dexmedetomidine with ketamine appeared to reduce this decline.

Obesity, defined as a BMI of 30 kg/m² or over, is rising globally and poses serious public health concerns. Patients with obesity face increased perioperative risks due to airway obstruction and rapid oxygen desaturation under sedation, a consequence of respiratory depressant effects. The altered pharmacokinetics and pharmacodynamics of lipophilic agents in adipose tissue may also complicate drug metabolism and distribution.

To investigate these sedation complications in patients with obesity, researchers conducted a retrospective review of patients aged 12 years and older who underwent elective dental procedures at the Oral and Maxillofacial Surgery department at LSU Health Shreveport. Patients were stratified by BMI class: Class I (<35 kg/m²), Class II (35–39.9 kg/m²), and Class III (>40 kg/m²). The primary outcome was determining which sedative regimen best maintained oxygen saturation throughout the procedure.

The review included 368 patient records, of which 114 patients had obesity. Within this subset, 27 were classified as severely obese and 25 as morbidly obese. Sedation regimens commonly included midazolam, fentanyl, and propofol in combination with either dexmedetomidine alone or dexmedetomidine plus ketamine. Thirteen patients (11.4%) experienced oxygen desaturation to below 95% during sedation. Of these, 6 patients (46.2%) had received dexmedetomidine alone, while 3 patients (23.1%) had received dexmedetomidine with ketamine.

Dexmedetomidine is known to cause bradycardia and hypotension, and the findings showed that patients given dexmedetomidine alone were more likely to experience oxygen desaturation. In contrast, ketamine’s sympathomimetic effects—transiently increasing blood pressure, heart rate, and cardiac output—appeared to counteract these effects when used in combination with dexmedetomidine.

“Our results suggest that dexmedetomidine be complemented with ketamine for use in obese patients,” Hatem and colleagues concluded.

Reference:
Hatem M, Sunavala Dossabhoy G, Kim DD, Allen S. Dexmedetomidine with ketamine in procedural sedation of obese patients suppresses the decline in oxygen saturation. Presented at: American Association of Oral and Maxillofacial Surgeons Annual Meeting; Sept 15-20, 2025; Washington D.C. https://aaoms-annual-meeting-2025.eventscribe.net/