Precision sedation with novel single syringe multimodal opioid or non-opioid 6-2-2 mixtures

The purpose of this study is to determine the efficacy and safety of sedation/analgesia using mixtures of propofol, opioids or non-opioid sedatives, and lidocaine or etomidate in one single syringe.

A retrospective case review was undertaken.

University outpatient surgical center.

1,376 adult patients undergoing ophthalmic surgery with ocular blocks and monitored anesthesia care were studied.

The 6 opioid-based mixtures contained 6 portions of propofol, 2 portions of opioid (alfentanil, fentanyl, a combination of alfentanil and fentanyl, or alfentanil and hydromorphone), and 2 portions of lidocaine or ketamine in a single syringe, in a 6:2:2 volume ratio. The non-opioid mixture contained 6 portions of propofol, 2 portions of ketamine, and 2 portions of etomidate. A bolus dose for all mixtures was calculated based on the patient's age and weight: < 40 yr, 1.2 mL/10 kg; 40-59 yr, 1 mL/10 kg; 60-69 yr, 0.8 mL/10 kg; 70-84 yr, 0.6 mL/10 kg; ≥85 yr, 0.5 mL/10 kg, and delivered by hand push or infusion pump intravenously (IV). For patients with a body mass index (BMI) >25, the adjusted weight for dosing (AWFD) was used: AWFD = ideal body weight (IBW) + 0.3 x (Actual weight [AW] - IBW). Ocular blocks were performed when patients reached a moderate level of sedation. Blood pressure (BP), heart rate (HR), oxygen saturation, clinical signs of sedation, responses to blocks, apnea and need for airway support, and recall were recorded.

91 %-98 % of all patients had no pain during ocular blocks and 98-99 % had no head movement, except in the KE6-2-2 without K10 (bolus only) group. The readiness time was 46-51 s for the opioid groups and 36- 43 s for the non-opioid groups. In the opioid groups, 97 %-99 % had no apnea and 88 %-94 % had no oxygen desaturation, while 99 % had no apnea and 96 % had no oxygen desaturation in the non-opioid groups. Heart rate and blood pressure decreased <10 % in the opioid groups while there was nearly no change in the non-opioid groups.

Adjusted for age and weight, the bolus dose of the 6-2-2 mixture met the sedation requirements for ocular blocks in most patients with favorable outcomes and minimal airway or hemodynamic compromise regardless of which mixture was used.