Methadone-induced rigid-chest syndrome after substantial overdose

Fentanyl-induced muscle rigidity in a dog during weaning from mechanical ventilation after emergency abdominal surgery: A case report

A 22.5-kg, 8.4-year-old female mixed breed dog was presented for an emergency ovariohysterectomy for pyometra. No neurological abnormalities were observed on preoperative physical examination. Surgery was completed uneventfully under fentanyl- and sevoflurane-based anaesthesia. Cardiorespiratory indices remained stable under mechanical ventilation throughout the procedure. Approximately 23 min after the discontinuation of fentanyl infusion, the investigator noticed jaw closure and stiffness and thoraco-abdominal muscle rigidity. To rule out fentanyl-induced muscle rigidity, naloxone was administered. Following administration of naloxone, there was a return of spontaneous respiratory effort, indicated by capnogram and visible chest wall excursion. Based on the clinical signs and response to naloxone administration, the dog was diagnosed with suspected fentanyl-induced muscle rigidity. Six minutes after the return of spontaneous respiration, the dog was extubated uneventfully without additional naloxone administration. During 4 days of postoperative hospitalization, no recurrent muscle rigidity was observed, and the patient was discharged safely. The total dose of fentanyl administered was 0.61 mg (27 μg kg^-1 ).

Efficacy of dexmedetomidine during radiofrequency ablation of liver tumors

AIM

To evaluate the efficacy and safety of dexmedetomidine during radiofrequency ablation (RFA) of liver tumors.

METHODS

Sixty patients who would undergo RFA for liver tumors were randomly allocated to two groups to receive either dexmedetomidine (group D) or propofol (group P). Both groups received continuous infusion of remifentanil for pain control. The general clinical data of patients, intraoperative vital signs, operative time, total dose of intraoperative remifentanil, anesthesia effects, anesthesia awakening time and major adverse anesthesia events were recorded and compared between the two groups.

RESULTS

The general clinical data of patients, intraoperative vital signs, operative time, anesthesia effects and anesthesia awakening time showed no significant differences between the two groups (P > 0.05). Compared with group P, the total dose of intraoperative remifentanil and the incidence of respiratory depression were significantly reduced in group D (P < 0.05).

CONCLUSION

Compared with propofol, dexmedetomidine provides better respiratory stability and reduces opioid consumption and the incidence of adverse events in patients undergoing RFA for liver tumors.

Comparative Effects of Dexmedetomidine and Propofol on US-Guided Radiofrequency Ablation of Hepatic Neoplasm Under Monitored Anesthesia Care: A Randomized Controlled Study

Percutaneous radiofrequency ablation (RFA) is a useful and safe procedure for treating hepatic neoplasm. However, liver RFA causes severe pain, which thereby increases the demand for monitored anesthesia care (MAC). Here, we compared the efficacy and safety of propofol and dexmedetomidine, which are commonly administered during MAC when performing RFA to assess hepatic neoplasm.In this randomized controlled trial, 40 patients were randomly allocated to 2 groups for elective RFA. Patients received either dexmedetomidine (group D) or propofol (group P). Both groups received the continuous infusion of remifentanil for pain control. The primary outcomes were opioid consumption and differences in partial pressure of arterial carbon dioxide (PaCO2) between pre- and postprocedure RFA. In addition, hemodynamic parameters, patient satisfaction, and interventional radiologist satisfaction were determined.There were significant differences in opioid consumption (50.1 ± 16.8 ng/kg/min [group D] vs 71.2 ± 18.7 ng/kg/min [group P]; P = 0.001) and delta PaCO2 (10.4 ± 6.4 mm Hg vs 17.2 ± 9.2 mm Hg, respectively; P = 0.016). Moreover, respiratory rates were significantly different between groups during RFA (P < 0.001). However, blood pressure and heart rate did not significantly change during RFA. Neither patient nor interventional radiologist satisfaction was significantly different between groups.Dexmedetomidine provides better respiratory stability and reduces opioid consumption in comparison with propofol when administered under MAC when performing RFA for hepatic neoplasm.

Methadone toxicity and possible induction and enhanced elimination in a premature neonate

INTRODUCTION

Reports describing methadone overdose in adult and pediatric patient populations are not uncommon. Reports in the preterm neonate patient population, however, are infrequent even though the utilization of methadone in that population continues to increase. Significant age-related pharmacokinetic differences complicate the management of methadone overdose in neonates, and literature involving methadone toxicokinetics and toxicodynamics in pediatric and neonate populations is largely limited.

CASE REPORT

The clinical course and pharmacologic data of a massive methadone overdose in a 20-day-old male neonate is described, and a contemporary review of developmental pharmacology is presented.

DISCUSSION

As clinicians continue to use methadone in neonates, they should be aware of the many significant peculiarities regarding its toxicology and pharmacology in that patient population.