Impact of Paresthesia on Postoperative Neurological Symptoms

Effect of Paresthesia During Interscalene Block Procedure on the Incidence of Postoperative Neurological Symptoms: A Prospective Observational Clinical Study

In this study, the effect of paresthesia occurring during the interscalene block procedure on the incidence of postoperative neurological symptoms will be investigated. Paresthesia is defined as an abnormal sensation described as "tingling, pinprick, severe pain, or an electric feeling in the arm." The status of postoperative neurological symptoms in patients at the end of the block's effective duration will be assessed through phone interviews, evaluating symptoms such as arm numbness, tingling, abnormal sensations, pain, and weakness.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain; Interscalene Block
• Intervention / Treatment: Other: Paresthesia; Other: No paresthesia

Detailed Description

Our study includes patients aged 18-65 years with American Society of Anesthesiologists (ASA) physical status I or II who undergo interscalene nerve block prior to arthroscopic shoulder surgery under general anesthesia. All patients will be fasting according to standard protocol. During the preoperative period, patients' age, comorbidities, gender, body mass index (BMI), ASA scores, and preoperative Quality of Recovery-15 (QoR-15) scores will be recorded.

In the operating room, possible complications related to the block (paresthesia, Horner's syndrome, dyspnea, hoarseness) will be monitored in the preoperative area. During the intraoperative period, data such as pulse, blood pressure, infusion fluids, intraoperative remifentanil requirements, anesthesia duration, and surgical time will be recorded.

In the postoperative period, postoperative pain status, block duration, postoperative nausea and vomiting, need for rescue analgesics and antiemetics, and QoR-15 scores on the first day will be assessed in the recovery room and ward. Additionally, postoperative neurological symptoms and QoR-15 scores will be followed via telephone on the 3rd, 7th, 10th, and 30th days after discharge.

For patients developing postoperative pain, pain intensity will be evaluated using an 11-point numeric rating scale, where 0 indicates no symptoms and 10 represents maximum severity.

• Study Type: Observational
• Enrollment (Actual): 120

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Ankara, Çankaya
    • Ankara, Ankara, Çankaya, Turkey (Türkiye), 06800
      • Ankara Bilkent City Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

The study will include patients aged 18-65 years with ASA physical status I or II who are planned to undergo interscalene nerve block for analgesia prior to arthroscopic shoulder surgery in the beach chair position under general anesthesia.

Description

Inclusion Criteria:

• ASA physical status I to II
• Age range of 18-65 years
• Patients planned for interscalene nerve block for analgesia prior to arthroscopic shoulder surgery in the beach chair position under general anesthesia

Exclusion Criteria:

• body mass index >35 kg/m²)
• history of drug use
• Patient's refusal to participate in the study
• Psychiatric disorders
• Central nervous system diseases
• Vestibular disorders
• Presence of diabetes, neuropathy, and paralysis
• Pregnancy
• Open shoulder surgery
• Allergy to local anesthetics
• Coagulopathy
• Severe thrombocytopenia
• Infection at the puncture site
• Pre-existing neuropathy in the limb to be operated on
• Use of opioid and antiemetic medications before surgery
• Use of dexamethasone
• Lung disease
• Low baseline oxygen saturation
• Patients who cannot cooperate in the postoperative period (e.g., mental retardation, delirium, language acquisition deficiency, etc.)

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Paresthesia; Patients experiencing paresthesia during the interscalene nerve block	Other: Paresthesia; Patients experiencing paresthesia during the interscalene nerve block
No paresthesia; Patients not experiencing paresthesia during the interscalene nerve block	Other: No paresthesia; Patients not experiencing paresthesia during the interscalene nerve block

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Paresthesia incidence	Paresthesia is considered an abnormal sensation described as "tingling, pinprick, severe pain, or an electric feeling in the arm." When paresthesia occurs, the block procedure will be halted, and the needle will be redirected; local anesthetic will not be administered until the paresthesia resolves, and the occurrence of paresthesia will be recorded.	Perioperative time

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
intraoperative opioid requirement	To maintain the bispectral index (BIS) between 40-60, remifentanil will be initiated and titrated between 0.05-0.25 mcg/kg/min, taking into account a 20% increase in MAP (mean arterial pressure) compared to the initial value and a 15% increase in heart rate compared to the initial value.	intraoperative time
Horner's syndrome	Miosis and ptosis of the ipsilateral pupil during the perioperative period.	Perioperative/Periprocedural
Dyspnea	Breathing difficulty as described by the patient during the perioperative period.	Perioperative/Periprocedural
Incidence of postoperative neurological symptoms	the status of postoperative neurological symptoms will be assessed via telephone by a physician different from the one who performed the block. During the evaluation, symptoms such as arm numbness, tingling, abnormal sensations, pain, and weakness will be considered. Those responding "yes" to any of these symptoms will be classified as patients experiencing postoperative neurological symptoms.	30 days
Postoperative pain	In the postoperative period, patients will be assessed for pain using a 0-10 Numeric Rating Scale (NRS) at rest at 4, 6, 8, 12, 16, and 18 hours, and at both rest and during movement at 24 and 36 hours to record the highest pain scores. The NRS is a scale used for patients to express their pain levels, where 0 represents the absence of pain and 10 represents the most severe pain.	36 hours
Duration of block effectiveness	The time (in minutes) until the patient reports a significant increase in pain after the block	36 hours
Postoperative nausea and vomiting	Significant nausea, vomiting, and/or need for rescue antiemetics	36 hours
Rescue analgesic requirement	Number of additional analgesic applications	36 hours
Rescue antiemetic requirement	Number of additional antiemetic applications	36 hours
Duration of stay in the recovery room	The time from arrival in the recovery room until the discharge criteria are met	2 hours
Quality of Recovery-15 (QoR-15) scores	The QoR-15 questionnaire consists of 15 questions rated on a scale of 0 to 10, with a total score assessed out of 150. Results are classified as follows: above 135 is considered "excellent," 122-135 is "good," 90-121 is "fair," and below 90 is "poor.	30 days
Hoarseness	Voice changes described by the patient during the perioperative period	Perioperative/Periprocedural

Collaborators and Investigators

• Sponsor: Ankara City Hospital Bilkent

Study record dates

Study Major Dates

• Study Start (Actual): April 11, 2025
• Primary Completion (Actual): September 15, 2025
• Study Completion (Actual): October 20, 2025

Study Registration Dates

• First Submitted: March 25, 2025
• First Submitted That Met QC Criteria: March 31, 2025
• First Posted (Actual): April 2, 2025

Study Record Updates

• Last Update Posted (Actual): November 17, 2025
• Last Update Submitted That Met QC Criteria: November 14, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Interscalene block; Paresthesia; Postoperative neurological symptoms
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Postoperative Complications; Pathologic Processes; Sensation Disorders; Somatosensory Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Paresthesia
• Other Study ID Numbers: Paresthesia

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No