The OBstetric Lidocaine Patch (OBLido) Trial

This study will be a single-center, single blind, randomized controlled trial. The study will be conducted at UnityPoint-Health Meriter Hospital under investigators from the University of Wisconsin-Madison. Obstetric patients with prepregnancy obesity undergoing a Cesarean delivery at UnityPoint-Health Meriter will be eligible.

The purpose of this study is to determine whether transdermal lidocaine administered at the time of Cesarean delivery and for 12 hours postoperatively will reduce the total dose of opioids received. Our hypothesis is that a lidocaine patch will reduce the total dose of opioids received in the immediate 24 hours post-delivery. Secondary outcomes will include patient self-reported pain scores, patient-reported incidence of side effects, such as pruritis, development of objective complications, such as serious skin reactions (examples are acute generalized exanthematous pustolosis, Stevens-Johnson syndrome, and toxic epidermal necrolysis), hypersensitivity, nausea, and nervousness. Other outcomes collected will include length of stay, time to first rescue analgesic medication, total dose of opioids in 48 hours, use of supplemental oxygen during hospitalization, total dose of opioids during hospitalization, breastfeeding rates, both exclusive and in combination with formula use, amount of opioid prescribed at discharge and whether refills were requested or administered, rates of chronic pain at six weeks postpartum, and six week Edinburgh Depression Screen scores. Neonatal outcomes such as five-minute Apgar scores and development of adverse outcomes will also be collected.

Eligibility Criteria:
Inclusion Criteria:

* Maternal age greater than or equal to 18
* Prepregnancy body mass index greater than or equal to 30 kg/m2 or ≥35 kg/m2 at delivery if no prepregnancy/ early pregnancy weight available
* Singleton or multifetal pregnancy
* Able to receive neuraxial analgesia
* Planned/ scheduled Cesarean delivery OR non-urgent Cesarean delivery with adequate time to consider and consent to the study
* Gestational age greater or equal to 32 weeks

Exclusion Criteria:

* Known hypersensitivity to lidocaine or colloid patch (defined as a history of a reaction or allergy to lidocaine (injectable, intravenous, or transdermal) or hydrocolloid patch reported by patient or documented in the medical record) or patient report
* Contraindication to regional analgesia
* Positive urine drug screen at admission to the hospital, if ordered for clinical purposes.
* Current opioid use or opioid use disorder per patient report or documented in the medical record or the ePDMP (reviewed by PI 1-14 days prior to surgery)
* Chronic opioid use or opioid use disorder, either patient reported or documented in the medical record or the ePDMP (reviewed by PI 1-14 days prior to surgery), defined as opioid use on most days for \>3 months
* Planned Cesarean hysterectomy (excluded due to anticipated blood loss and alternative pain control measures, possible prolonged intubation)
* Planned vertical midline incision
* Presence of renal dysfunction precluding the use of NSAIDs
* Ischemic heart disease, congestive heart failure, or cardiomyopathy of pregnancy
* Coagulopathy
* Planned discharge from the hospital less than 24 hours postpartum