Differential Sensory Block During Labor Epidural Analgesia: a Prospective Observational Study to Investigate the Relationship of Lower and Upper Sensory Block Levels to Cold With Sensory Block to Pinprick and Light Touch

Study Overview
=================
Brief Summary
-----------------
Epidural analgesia remains the gold standard for pain control during labor and delivery. Proper assessment of an epidural's level of blockade is important for providing safe and effective analgesia. Previous studies have established that the most commonly tested modality for adequacy of epidural blockade is a patient's sensory blockade to cold temperature. In a study performed at our institution, Soares et. al. (publication pending) documented two thresholds of sensory block to ice: one defined as the lower sensory block level, in which the patient is able to notice the cold sensation but perceives that it is not as cold as a control dermatome; the other defined as the upper sensory block level, in which the patient perceives that the cold sensation is at approximately the same temperature as if it were applied to a non-anesthetized area such as the neck or face. Although this a known finding to nurses and physicians assessing the sensory block to ice, this phenomenon and its magnitude has not been previously reported in epidural anesthesia. The goal of this study is to examine patients with labour epidurals and to determine the dermatomal relationship between the lower and upper sensory block levels to cold when compared with sensory blockade to both pinprick and light touch.

Official Title
-----------------
Differential Sensory Block During Labor Epidural Analgesia: a Prospective Observational Study to Investigate the Relationship of Lower and Upper Sensory Block Levels to Cold With Sensory Block to Pinprick and Light Touch

Conditions
-----------------
Labor Pain

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: ASA Physical Status Classification II and III parturients Requested and received a labour epidural Capable of consenting to the study Have no language barrier which may obfuscate the sensory block assessment Are receiving programmed intermittent epidural boluses (PIEB) for maintenance analgesia, which is the Mount Sinai Hospital default maintenance regimen Exclusion Criteria: Medical comorbidities that could compromise the body's sensitivity to cold, pinprick, or touch Epidurals performed under a combined spinal-epidural (CSE) or dural puncture epidural (DPE) technique Epidurals with a documented unintentional dural puncture Inadequate epidural analgesia requiring either manually administered epidural boluses, an increase in the concentration of their maintenance local anesthetic, or a repeat of their epidural

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
-----------------
Female

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Women receiving epidural analgesia for labor<br>Sensory block level check Patients will have their sensory block level checked using 3 modalities: ice, pin prick and soft touch (cotton ball). | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lower sensory block level: ice test | The lower sensory block level to ice, defined as the dermatome at which there is a complete loss of cold perception. | 5 minutes | 
| Upper sensory block level: ice test | The upper sensory block level to ice is defined as the dermatome at which there is an altered cold perception without complete sensitivity loss. | 5 minutes | 
| Lower sensory block level: pinprick test | The lower sensory block level to pinprick, defined as the dermatome at which there is a complete loss of sharp sensation. | 5 minutes | 
| Upper sensory block level: pinprick test | The upper sensory block level to pinprick is defined as the dermatome at which there is an altered sharp sensation without complete sensitivity loss. | 5 minutes | 
| Sensory block level: soft touch test | The sensory block level using soft touch is defined as the dermatome below which the patient can feel a light touch. | 5 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Motor block score using Bromage score | Motor block will be assessed with the Bromage score: 0 = able to raise the extended leg; 1 = unable to raise the extended leg but able to flex knees; 2 = unable to flex knees, but able to flex ankle; 3 = unable to flex ankle. | 5 minutes | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
sensory block, epidural analgesia, programmed intermittent epidural bolus