Genome-wide association study identifies candidate loci associated with postoperative fentanyl requirements after laparoscopic-assisted colectomy.

AIMS: Opioids are widely used as effective analgesics, but opioid sensitivity is well known to vary widely among individuals and the underlying genetic factors are not fully understood, thus hampering efficient pain treatment. We explored the genetic factors that contribute to individual differences in opioid sensitivity by performing a genome-wide association study. METHODS: We conducted a multistage genome-wide association study in subjects who underwent laparoscopic-assisted colectomy (LAC). RESULTS: A nonsynonymous SNP in the LAMB3 gene region, rs2076222, was strongly associated with postoperative opioid requirements. The C allele of this best-candidate SNP was associated with lower opioid sensitivity and/or higher pain sensitivity in the patient subjects. CONCLUSION: Our findings provide valuable information for personalized pain treatment after LAC, in which the C allele of the rs2076222 SNP is associated with lower opioid sensitivity and requires more opioid analgesic after LAC.

[Suspected case of postoperative malignant hyperthermia treated with dantrolene one week after neurosurgery].

We report the case of a 16-year-old man who presented with hyperthermia (>40°C), an elevated creatine kinase level (>64,000 IU · l-1), and myoglobinuria one week after undergoing two successive neurosurgeries for a brain hemorrhage under sevoflurane anesthesia. After having been diagnosed with suspicious atypical postoperative malignant hyperthermia, he was treated with dantrolene and his symptoms disappeared on the day of dantrolene administration. Central hyperthermia is defined as hyperthermia associated with thermoregulatory dysfunction after brainstem injury. Postoperative malignant hyperthermia can sometimes be difficult to distinguish from central hyperthermia, especially after neurosurgery. We could not eliminate the possibility of central hyperthermia as a cause of hyperthermia in the present patient If marked postoperative hyperthermia must be addressed immediately and managed appropriately in neurosurgical patients and dantrolene having few serious side effects, we were able to control his symptoms immediately after the infusion of dantrolene. Therefore, the administration of dantrolene should be considered when treating unidentified postoperative hyperthermia after a neurosurgical procedure.