Background and aims Although failed regional anesthesia is mostly attributed to technical issues, we report a case of local anesthetic (LA) resistance possibly due to voltage-gated sodium channellopathy.
Methods A 26-year-old redhead gravida 2, para 1 (15 weeks of gestation) presented for elective placement of cervical cerclage. A single-shot spinal in the left lateral position was decided at L3-4 interspace. Noticeably, the patient failed to achieve adequate skin anaesthesia despite repetitive doses of lidocaine 2%. Free flow of cerebrospinal fluid without aspiration was obtained on first attempt and a spinal injection of 2.3 ml of 0.75% ropivacaine with 15 mcg of fentanyl was ultimately performed. Twenty minutes later, she reported no sensory or motor blockade. A second attempt of the same technique and dose was performed at L2-3 interspace, taking into consideration the possibility of a high sensory block along with hemodynamic instability. Ten minutes after the second attempt, the patient was asked if she felt any difference compared to before; warmth in her feet was reported but no sensory or motor block. The decision was made to proceed with general anesthesia. On questioning, she described repeated failures of LAs during her previous caeserean delivery, while she and her mother reported having insufficient anaesthesia during dental procedures.
Results Inherited channelopathies due to genetic variations in voltage-gated sodium channels, the main site of action of LAs, should not be ruled out when confronting a failed regional technique.
Conclusions Our red-haired parturient may be more resistant to LAs due to various mutations of melanocortin receptors as literature suggests.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.