ITM + Bupivacaine QLB vs. ITM + Sham Saline QLB for Cesarean Delivery Pain

Study Overview
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Brief Summary
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Comparison of standard post-operative cesarean surgery pain management with regional post-op pain control.

Detailed Description
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The purpose of this trial is to determine the efficacy of a postoperative analgesia strategy that incorporates quadratus lumborum block (QLB) in conjunction with a multi-modal post-cesarean analgesia strategy. The investigators hypothesize that QLB will provide superior post-cesarean analgesia compared to the current standard of care, multi-modal analgesia. Thus, analgesia following cesarean section using QLB compared to the current standard of care alone will be further investigated. Current practice for cesarean surgical intervention consists of multi-modal analgesia (i.e., Intrathecal morphine (ITM) and scheduled post-operative non-opioid oral analgesics, with oral opioid analgesics reserved for breakthrough pain). Investigators will measure side-effects associated with each strategy: Standard of care methods consisting of intrathecal morphine (ITM) plus scheduled non-opioid analgesics in conjunction with prn opioid analgesics for breakthrough pain will be utilized for both. The experimental treatment arm will entail standard of care in addition to QLB. The sham comparator will entail standard of care in addition to QLB with saline. For each strategy, we will measure and model associated economic ramifications; such factors will include drug costs, procedure costs, and costs associated with length of stay and re-admissions. The quadratus lumborum block (QLB) is similar to the transversus abdominis plane (TAP) block, but differs slightly in regards to the anatomical region where local anesthetic is injected. Since the quadratus lumborum (QL) is more posteriorly located, it theoretically confers greater safety due to enhanced visualization. The TAP block has been studied extensively for post-cesarean delivery pain, consistently showing that it is not superior to ITM for post-operative analgesia; however, it may prove to be helpful in patients with breakthrough pain despite the use of ITM, or in patients who were unable to receive ITM (e.g. general anesthesia for cesarean, contraindications to neuraxial morphine). Thus, ITM is superior to TAP alone for post-cesarean analgesia, but it is associated with a dose-dependent increased risk for opioid related side effects. In 2015, Blanco et. al. published a study specifically using the QLB for postoperative pain after cesarean delivery. In this study, they compared a true QLB to a sham QLB all in patients who did not receive ITM, and found that the QLB provided improved pain control and decreased the need for post-operative opioids. Another study in 2016 demonstrated that the QLB is superior to the TAP block in regards to decreasing post-operative pain following c-section. Unfortunately, neither study compared the QLB to ITM (part of the current gold standard for post-cesarean delivery pain, multimodal analgesia). The gap in knowledge regarding the utility of QLB as part of a multimodal analgesic approach including ITM for cesarean section warrants further investigation. Clinicians are constantly searching for methods to provide patients with the most effective medical interventions that provide maximal benefit and minimal harm. Post-operative pain control following cesarean delivery is an area that is important to patients and to providers, and the introduction of the QLB for this purpose has the potential to improve analgesic benefit.

Official Title
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QL Block for Post-cesarean Delivery Pain

Conditions
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Pain, Postoperative

Intervention / Treatment
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* Drug: ITM + Sham QLB
* Drug: ITM + Bupivacaine QLB


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Elective cesarean planned under spinal anesthesia Singleton pregnancy American Society of Anesthesiologists (ASA) classification score of 2 (or less) Gestational age of at least 37 weeks Intention to breastfeed infant Exclusion Criteria: Contraindications to neuraxial blockade (such as clinically relevant coagulopathy, recent anticoagulant use, patient refusal, or localized skin infection overlying the site of needle entry) Anatomical abnormalities contraindicating spinal or QLB placement Received/Conversion to general anesthesia Received supplemental parenteral anesthesia (sedation) for any reason (e.g. unanticipated prolonged surgical procedure) History of chronic pain History of chronic opioid use/abuse History of Subutex, methadone, other maintenance therapy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: ITM + Sham QLB<br>Standard spinal with intrathecal morphine for surgical anesthetic with sham saline block. Saline will be administered as a quadratus lumborum block prior to cesarean section. | Drug: ITM + Sham QLB<br>* Sham subcutaneous non-anesthetic infiltration with saline<br>* Other names: Saline;|
| Experimental: ITM + Bupivacaine QLB<br>Standard spinal with intrathecal morphine for surgical anesthetic with ql block with bupivacaine local anesthetic. Interventional drug will be administered prior to cesarean section. | Drug: ITM + Bupivacaine QLB<br>* QL plane block with local anesthesia<br>* Other names: Bupivacaine;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| VAS pain score with movement | Post-operative pain accompanied with patient movement will be measured using a 10 point pain scale (VAS) | 24 hours after surgical procedure (cesarean delivery) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Breast feeding success/quality | Limited breastfeeding resulting from pain or opioid side effects | 12, 24 and 36 hours post-operatively | 
| VAS pain score at rest | VAS pain score reported by the patient at rest post-operatively using a 10 point pain scale (VAS) | At baseline (PACU entry) and 1, 4, 24 and 48 hours after intervention | 
| First request for pain medication | Time to first request for as desired (PRN) oral or parenteral opioid medication will be assessed | From post-operative until the patient is either withdrawn from the study or requests analgesic medication up until 72 hours | 
| Sedation | Presence or absence will be noted | From post-operative until the patient is either withdrawn from study or experiences this event up until 72 hours | 
| Pruritis | Presence or absence will be noted | From post-operative until the patient is either withdrawn from study or experiences this event up until 72 hours | 
| Nausea | Presence or absence will be noted | From post-operative until the patient is either withdrawn from study or experiences this event up until 72 hours | 
| Emesis | Presence or absence will be noted | From post-operative until the patient is either withdrawn from study or experiences this event up until 72 hours | 
| Heart Rate | Will be measured in beats/minute (BPM) per standard of care and documented by study staff | From post-operative every 24 hours until the patient is either withdrawn from or completes the study, on average 72 hours | 
| Anesthetic toxicity | symptoms indicating this event such as perioral numbness, ringing in the ears or metallic taste in the mouth will be noted | 15 min, 30 min, 45 min, 1 hour, and 4 hours post-operatively | 
| Blood pressure | Will be measured in mmHG per standard of care and documented by study staff | From post-operative every 24 hours until the patient is either withdrawn from or completes the study, on average 72 hours | 
| Respiratory Rate | Will be measured in rate/min per standard of care and documented by study staff | From post-operative every 24 hours until the patient is either withdrawn from or completes the study, on average 72 hours | 
| Oxygen Saturation | Will be measured in % per standard of care and documented by study staff | From post-operative every 24 hours until the patient is either withdrawn from or completes the study, on average 72 hours | 
| 36-Item Short Form Survey (SF-36) | Quality of life measures will be assessed using the SF-36 | 48-hours post-operatively | 
| Brief Pain Inventory (BPI) - Short Form | Severity of pain and its impact on functioning using BPI Short Form | 6-weeks post operatively | 
| Edinburgh Postnatal Depression Scale (EPDS) | Possible symptoms of depression in the postnatal period will be assessed via EPDS | 6-weeks post operatively | 
| Dynamic Pain Visual Analogue scale | Pain score reported by the patient at rest using the VAS scale | 6-weeks postoperatively | 
| Opioid use | Total opioid consumption post-operative | From post-operative until 36 hours and at 6-weeks postoperatively or until the patient is discharged or withdrawn from study | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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quadratus lumborum block, post-operative pain, cesarean section pain, analgesia, nerve block