Clinical trial NCT05881395: Assessment of Sensory Block During Labour Epidural Analgesia in Patients Experiencing Pain During First Stage of Labour.
Official title: Assessment of Sensory Block During Labour Epidural Analgesia: a Prospective Cohort Study to Investigate the Upper and Lower Sensory Block Levels (USBL and LSBL) to Ice and Pinprick in Patients Experiencing Pain During First Stage of Labour.
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Labor Pain
Keywords: epidural analgesia
sensory block
programmed intermittent epidural bolus
Lead sponsor: Samuel Lunenfeld Research Institute, Mount Sinai Hospital
Sponsor class: OTHER
First posted: 2023-05-31
Enrollment: 30
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients admitted to the Labor and Delivery unit at Mount Sinai Hospital that receive epidural analgesia for labour and experience pain that is addressed by the anesthesiologist.

Brief summary: Epidural analgesia is the gold standard for pain control during labour and an essential component of delivering effective and safe epidural analgesia is the assessment of the epidural sensory block. There is significant literature on the assessment of sensory block during spinal anesthesia for cesarean section but limited studies exploring the assessment of sensory blockade in labour analgesia.

Prior studies have documented two thresholds of sensory block to both ice and pinprick: one defined as the lower sensory block level (LSBL) where the patient is able to notice a cold or sharp sensation but perceives that is not as sharp or cold as a control area and the other the upper sensory block level (USBL) where the patient perceives the cold or sharp sensation is at the same temperature or sharpness as the control area.

The goal of this study is to contribute to the standardization of the assessment of sensory block levels during labour epidural analgesia by studying patients with labour epidurals who are experiencing pain and determining the LSBL and USBL and how these change as the patients become comfortable following the administration of manual epidural top ups.

Detailed description: The pain pathways involved in the process of labour and delivery have been well established. Nociceptive stimuli during first stage of labour are transmitted via the T10 to L1 posterior nerve root ganglia, while the nociceptive stimuli during second stage of labour are transmitted via the L1 and S2 to S4 (pudendal nerve) posterior nerve root ganglia. Although these pain pathways are well established, there is no information in the literature as to what level or depth of sensory block, assessed by current clinical practices, is required for effective labour analgesia. This information is critical for planning and safety of epidural analgesia during labour.

The investigators hypothesize that the LSBL to either cold or pinprick would be below dermatome T10 in patients receiving labour epidural analgesia during first stage of labour and who are experiencing pain. The investigators also hypothesize that upon receiving a top-up and re-establishment of effective analgesia, (a) the LSBL would be at or above dermatome T10 or (b) USBL would increase to T10 or above T10 if USBL was below T10 before receiving a top-up.

Eligibility criteria: Inclusion Criteria:

* ASA (American Society of Anesthesiologists) Physical Status Classification II or III
* Patients admitted to labour and delivery unit at Mount Sinai Hospital in their first stage of labour
* Patients who have a labour epidural that has been initiated as an epidural, CSE (combined spinal epidural) or a dural puncture epidural (DPE).
* Patients who are experiencing pain, defined as Visual Numerical Rating Score of more than 1/10, despite our institution's standard epidural Programmed Intermittent Epidural Bolus maintenance regimen and request a manual epidural top-up for the first time
* Have capacity to consent to the study

Exclusion Criteria:

* Patients with a language barrier that may interfere with accurate response to sensory block assessment
* Patients with medical conditions that would compromise sensitivity to cold or pinprick assessments
* patients who sustained unintentional dural puncture, those requiring change in our standard epidural maintenance regimen or those who have had a failed epidural requiring replacement.

Primary outcomes:
measure: Lower sensory block level to ice when the patient is experiencing pain
timeFrame: 5 minutes
measure: Upper sensory block level to ice when the patient is experiencing pain
timeFrame: 5 minutes
measure: Lower sensory block level to pinprick when the patient is experiencing pain
timeFrame: 5 minutes
measure: Upper sensory block level to pinprick when the patient is experiencing pain
timeFrame: 5 minutes
Secondary outcomes:
measure: Verbal Numeric Rating Score (VNRS) at the time of request of assessment by anesthesiologist
timeFrame: 5 minutes
measure: Verbal Numeric Rating Score (VNRS) at 10 minutes after each epidural top-up administered.
timeFrame: 10 minutes
measure: Lower sensory block level to ice following epidural top-up
timeFrame: 5 minutes
measure: Upper sensory block level to ice following epidural top-up
timeFrame: 5 minutes
measure: Lower sensory block level to pinprick following epidural top-up
timeFrame: 5 minutes
measure: Upper sensory block level to pinprick following epidural top-up
timeFrame: 5 minutes
measure: Motor block score using Bromage score at the time of request of assessment by anesthesiologist
timeFrame: 5 minutes
measure: Motor block score using Bromage score following epidural top-up
timeFrame: 5 minutes
measure: Number of epidural top-ups required
timeFrame: 20 minutes
measure: Type of pain: questionnaire
timeFrame: 20 minutes
measure: Location of pain: questionnaire
timeFrame: 20 minutes
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Mount Sinai Hospital
state: Ontario
Study officials:
affiliation: MOUNT SINAI HOSPITAL
name: Jose Carvalho, MD
role: PRINCIPAL_INVESTIGATOR
References: