Dexmedetomidine, Ketamine Show Similar Analgesia For Minimally Invasive Thoracic Surgery

Author: Chase Doyle

Anesthesiology News

A study comparing the opioid-sparing effects of dexmedetomidine and ketamine has demonstrated similar intraoperative analgesic effects when used as part of a multimodal approach in minimally invasive thoracic surgery.

In patients undergoing minimally invasive lung lobectomy, the retrospective analysis found comparable intraoperative opioid requirements and hemodynamic parameters. Although differences in pain and agitation scores on arrival to the PACU were statistically significant, these small differences were not considered clinically relevant. According to the researchers, these findings indicate that both ketamine and dexmedetomidine can be used as part of a multimodal regimen in enhanced recovery protocols in minimally invasive lung surgery.

“In the absence of contraindications, either drug can be used. In this era of multimodal analgesia, adjuvants improve the quality of postoperative pain control,” said Alessia Pedoto, MD, FASA, a thoracic anesthesiologist in the Department of Anesthesiology and Critical Care Medicine at Memorial Sloan Kettering Cancer Center, in New York City. “Minimally invasive procedures still cause pain in the postoperative period. It’s important to create an ‘analgesic cocktail’ with different medications to reduce opioid consumption in the perioperative period.”

“Patients who come for lung resection are often older and have multiple comorbidities,” said Dr. Pedoto. “Anecdotally, it seems that patients who are exposed for a long time to even low-dose ketamine wake up agitated.”

Many Clinical Similarities

As Dr. Pedoto reported at the 2018 annual meeting of the European Society of Anaesthesiology, patient characteristics and comorbidities were comparable between those receiving ketamine (n=67) and dexmedetomidine (n=74). More importantly, researchers observed no difference in intraoperative opioid requirements between the groups, and the use of acetaminophen, ketorolac and dexamethasone also was similar.

“When used as part of multimodal analgesia, dexmedetomidine and ketamine appear to have similar effects on intraoperative analgesia and hemodynamic parameters in patients undergoing minimally invasive thoracic surgery,” said Dr. Pedoto. “We observed no difference in surgical times, intraoperative fluids, estimated blood loss, pressor requirement, or length of stay in either the PACU or hospital.”

Although patients receiving ketamine had slightly lower sedation scores and higher pain scores on arrival in the PACU, investigators noted these differences were not clinically significant and resolved at four hours. “Ketamine may cause more sedation and higher pain scores at PACU arrival, but this effect is transient,” Dr. Pedoto said.

A prospective study is needed for more definitive analysis, Dr. Pedoto said, although dexmedetomidine can be considered an alternative in enhanced recovery pathways for minimally invasive thoracic surgery. But the field is still evolving, she added.

“As we continue to develop our [enhanced recovery] protocol, the adjuvants used for analgesia continue to change,” Dr. Pedoto said. “For a successful prospective trial, the only variable should be the continuous infusion used, maintaining the multimodal protocol constant. Furthermore, although standard doses of ketamine and dexmedetomidine were applied, they were sometimes changed by clinicians, depending on patient vital signs.”

In the meantime, the choice of analgesic comes down to provider preference.

“Some anesthesiologists prefer ketamine over dexmedetomidine,” said Dr. Pedoto, who noted a preference for ketamine in patients with chronic pain. “Dexmedetomidine is a good analgesic when used in combination with other medications and when combined with peripheral nerve blocks. Patients are very comfortable in the recovery period, with minimal amounts of opioids used as rescue in the intraoperative and postoperative period.”