Feasibility and Postoperative Opioid Sparing Effect of an Opioid-free Anaesthesia in Adult Cardiac Surgery

A Retrospective Study

Clément Aguerreche; Gaspard Cadier; Antoine Beurton; Julien Imbault; Sébastien Leuillet; Alain Remy; Cédrick Zaouter; Alexandre Ouattara


BMC Anesthesiol. 2021;21(166) 

In This Article


Characteristics of the Population

During the study period, 80 patients were included, and were divided in two groups: the OFA group (n = 40) and the OBA group (n = 40). In our study, patients in the OFA-group were sicker and underwent more often non-elective surgery (Table 1). During the recruitment period matching between the groups was not possible. However, patients' inclusion in the study occurred during the same time frame and pace. The surgical procedure and length of surgery were similar (Table 2). The incidence of preoperative chronic pain (7% vs 4%, p = 0.33) or opioid consumption (3% vs 1%, p = 0.30) were similar between the OFA-group and the OBA-group.

Intraoperative Period

In the OFA group, the median loading dose of dexmedetomidine received before induction of anesthesia was 0.6 [0.4–0.6] μg.kg− 1 while the median maintenance dose was 0.11 μg.kg− 1.h− 1 [0.05–0.20]. In 10 (25%) patients, dexmedetomidine was discontinued for a drop of mean arterial pressure below 55 mmHg. The median maximal target effect-site concentration of remifentanil for the induction of anesthesia was 4.0 [3.0–4.0] ng.ml− 1. A larger number of patients in the OBA-group required intraoperatively ephedrine (Table 2).

Perioperative Analgesia and Outcomes

A large proportion of patients received paracetamol and nefopam with no difference between groups. A comparable proportion of patients received a morphine titration (58% versus 70%, p = 0.24) and received rescue analgesia during the first 48 postoperative hours in both groups (Table 3). The primary outcome defined as the total amount of opioid consumed in its equivalent of intravenous morphine during the first 48 postoperative hours was significantly lower in the OFA-group compared to the OBA group (15.0 mg [IQR 8.5–23.5] versus 30.0 mg [IQR 17.3–44.3], p < 0.001) (Figure 1). Maximal pain scores at rest were similar between the two groups (2.0 [0.0–3.0] in the OFA group versus 0.5 [0.0–5.0] in the OBA group, p = 0.60) but was lower in the OFA-group during coughing (3.5 [2.0–5.0] vs 5.5 [3.0–7.0], p = 0.04). No patient developed neither stroke nor seizure postoperatively. Patients in the OFA group presented a lower incidence of atrial fibrillation and required less frequently non-invasive ventilation (Table 4). We could observe a trend toward a reduction of new onset of postoperative delirium in patients receiving OFA but it did not reach a statistical significance. One patient in the OFA-group died (after a month due to a cessation of care because of a metastatic cancer discovered postoperatively during its ICU stay).

Figure 1.

Box-plot showing the total postoperative morphine consumption during the first 48 hours in the OFA and OBA groups. The line inside the box represents the median, box edges represent 25th and 75th percentile and the whiskers represent the minimum and maximum values