Perioperative Opioids and the Anesthesiologist

Intraoperative Considerations

Opioid Administration During Anesthesia Care

Can anesthesia care modify susceptibility to opioid-related harm, including new chronic opioid use and opioid misuse? Some groups have suggested that "opioid-free anesthesia" should be standard of care, but the definition of this concept and the rationale for avoidance of intraoperative opioids remain unclear. Furthermore, opioid-free anesthesia practice may not be feasible for all case types, and the hemodynamic consequences of such an approach have not been evaluated (for example, some anesthesiologists utilize opioids to blunt the sympathetic response to direct laryngoscopy). Currently, there is no evidence that total avoidance of opioids during anesthesia improves outcomes other than postoperative nausea and vomiting. A meta-analysis comparing opioid-inclusive with opioid-free intraoperative anesthesia found no differences in pain scores or opioid consumption at 2, 12, or 24 h postoperatively.^[101] This meta-analysis did show, however, that opioids increase rates of nausea and vomiting. More recently, a multicenter randomized blinded trial of a standard balanced anesthesia technique plus remifentanil and morphine compared with the same balanced technique plus dexmedetomidine (opioid-free) was halted prematurely due to increased incidence of severe bradycardia in the opioid-free group. The primary outcome of postoperative hypoxemia, ileus, or cognitive dysfunction occurred more frequently in patients in the opioid-free group compared with the opioid-receiving group.^[102] In terms of postdischarge opioid-related metrics, two large-scale administrative claims studies found no relationship between nerve blockade and chronic postoperative opioid use after total knee arthroplasty^[103] and shoulder arthroplasty,^[104] thereby suggesting that simple regional anesthesia techniques alone cannot prevent poor outcomes.

There is evidence that regional anesthesia and multimodal analgesic techniques improve acute pain and reduce in-hospital opioid consumption.^[105] However, there are no available studies to suggest that perioperative anesthesia practices can affect long-term opioid outcomes, and there is evidence that opioid-free anesthetic strategies may increase risk for perioperative adverse events without influencing the likelihood of persistent postoperative opioid use or preventing postoperative opioid overprescription.^[106–108] While anesthesiologists should be judicious, opioids remain an important tool for anesthetic care. We do note that the overall level of evidence related to opioid-free anesthesia is low, and that further research regarding the impact of intraoperative opioid use on intermediate- and long-term outcomes is needed.

Table 1. Sample Preoperative Opioid Tapering Protocol for a Patient Taking 150 mg Daily Oral Morphine Equivalents of Oxycodone (Conversion to Oral Morphine 1:1.5)
Week	Oxycodone Dose (Daily mg)	Oral Morphine Equivalents (Daily mg)
1	100	150
2	90	135
3	80	120
4	70	105
5	60	90
6	50	75
7	40	60
8	30	45
9	25	37.5
10	20	30
11	15	22.5
12	10	15
13	5	7.5
14	0	0

We recommend a taper every week by 10% of original dose until 30% remains. Then, taper by roughly 10% weekly (as feasible with available pill sizes). Clonidine 0.1 to 0.2 mg orally three times daily as needed or 0.1 to 0.2 mg/24 h transdermally every 7 days as needed can be considered for withdrawal symptoms, with close attention paid to potential hypotension or anticholinergic effects. A pause in the weaning protocol may be appropriate based on patient response.⁹⁶