Dissertation committee:
Στάικου Χρυσούλα, Αναπληρώτρια Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Θεοδωράκη Κασσιανή, Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Πανουλής Κωνσταντίνος, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Τσαρουχά -Δημητροπούλου Αθανασία, Αναπληρώτρια Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Παρασκευά Άντεια, Αναπληρώτρια Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Ελευθεριάδης Μακάριος, Αναπληρωτής Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Αραβαντινός Λέων, Επίκουρος Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Summary:
Background and aims: The management of acute postoperative pain as well as its transition to chronic postoperative pain (CPP) remains challenging and the research for adjuvants to reduce opioid use continues. The effect of intravenous dexmedetomidine and lidocaine on postoperative pain, opioid consumption and functional recovery as well as for their effectiveness on preventing CPP was studied.
Methods: In this double-blind study, 91 women, 30–70y, ASA I-II, scheduled for abdominal hysterectomy/myomectomy, were randomized to receive either dexmedetomidine (DEX-group) or lidocaine (LIDO-group) or placebo (CONTROL-group). Before anesthesia induction, a loading intravenous dose of one of the aforementioned drugs was given to all patients (0.9ml/kg/h for 10min), followed by 0.15ml/kg/h infusion until last suture. Identical 50ml-syringes containing dexmedetomidine 4mcg/ml (bolus: 0.6mcg/kg, infusion: 0.6mcg/kg/h), or lidocaine 10mg/ml (bolus: 1.5mg/kg, infusion: 1.5mg/kg/ h), or NaCl 0.9% were used. The main outcomes were cumulative morphine consumption and postoperative pain at rest and cough (Numerical rating scale, NRS: 0-10). Other measurements included anesthetic (sevoflurane) consumption, nausea/vomiting, postoperative sedation, time to first passage of flatus/stool, mobilization, sleep quality, satisfaction, discharge time, and drug side effects. Measurements were performed at Post-anesthesia Care Unit (PACU), 2h, 4h, 8h, 24h and 48h. We also evaluated the patients for CPP development at 3, 6 and 12 months.
Results: Data from 81 patients were analyzed for acute pain (DEX-group:26, LIDO-group:29, CONTROL-group:26). Cumulative morphine consumption (mg) was significantly lower in the LIDO versus CONTROL-group in the PACU (LIDO-group:8.41±1.45, CONTROL-group:10.4±3.29, p=0.017), at 24h (LIDO-goup:16.86±5.85, CONTROL-group:23.4±9.54, p=0.036) and 48h (LIDO-group:20.45±6.58, CONTROL-group:28.87±12.55, p=0.022). The DEX-group experienced significantly less nausea compared to CONTROL-group in the PACU (p=0.041). Finally, the use of vasoconstrictors was higher in the treatment groups, especially in DEX-group compared to CONTROL (p=0.012). The rest of the measurements regarding NRS scores, sevoflurane consumption, bowel function and other recovery characteristics, satisfaction, discharge time and drug side effects did not differ significantly among the groups. Regarding chronic pain, data from 74 women were analyzed. Higher NRS (numerical rating scale) cough scores at 48h led to statistically significant NRS and DN4 scores at 3, 6 and 12 months (p<0.02). At 6 months, a statistically significant effect was also found among NRS values and age of patient (p=0.020), where higher values of NRS are expected for older patients. Dexmedetomidine significantly reduced the NRS scores comparing to placebo at 3 months (p=0.018), while lidocaine, at six months, was found superior to placebo (p=0.02) in preventing neuropathic pain (DN4<4).
Conclusions: Dexmedetomidine and lidocaine could be useful adjuvants for analgesia after abdominal surgery. Lidocaine significantly reduced postoperative opioid consumption, while dexmedetomidine prevented early postoperative nausea. However, hypotension and need for vasopressors was common with both agents, especially with dexmedetomidine.
Dexmedetomidine reduced the duration and severity of CPP, while lidocaine exhibited a protective effect against neuropathic elements of CPP.
