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Effect of Interscalene Block on Obstructive Sleep Apnea in Shoulder Surgery Patients

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02034370
Recruitment Status : Withdrawn (Inclusion criteria not met at preoperative clinic visit screening. No eligible participants.)
First Posted : January 13, 2014
Last Update Posted : November 30, 2016
Information provided by (Responsible Party):
Satya Krishna Ramachandran, University of Michigan

Brief Summary:

Obstructive Sleep Apnea (OSA) is when a person stops breathing repeatedly during sleep. Breathing stops because the airway collapses and prevents air from getting into the lungs.This airway closure results in a decrease in the amount of oxygen that is in the blood. Anesthetics given during surgery are known to increase the tendency for a patient's airway to close immediately after surgery in the recovery room and to reduce the amount of oxygen in a patient's blood immediately after surgery. These two factors combined could have a profound effect on a patient's well being after surgery.

Recent advances in general anesthesia, pain medications, and surgical techniques have made outpatient surgery more common. Due to the increase in outpatient surgeries, pain management techniques that will work efficiently and for longer periods of time are necessary. One of these techniques is a nerve block, which coats the nerve with a numbing medication and blocks all pain from that area. Nerve blocks are routinely used along with general anesthesia for outpatient surgeries and help reduce or eliminate the need for IV or oral pain medicine after the surgery. Nerve blocks can provide good pain relief with early recovery and fewer side effects (nausea, vomiting, etc.) related to narcotic pain medicines.

Unfortunately, there are no studies that look at the effect of anesthesia and nerve blocks on breathing patterns and oxygen saturation levels after discharge from outpatient surgery. We therefore propose to study the changes in lung function tests and blood oxygen levels after a nerve block and general anesthesia for outpatient shoulder surgery. We would like to conduct a home sleep study including measuring oxygen levels while subjects are sleeping, before, during and after surgery, and test lung function both before and after surgery to see if there are any differences.

We will recruit 10 subjects with eligibility based on clinically indicated shoulder surgery and a nerve block. The study will be non-interventional during surgery.

It is possible that future screening for out-patient shoulder surgery includes preoperative overnight oxygen saturation measurement to identify patients at high-risk of changes in oxygen levels. These patients may benefit from hospital admission after surgery for close observation. Thus, this study could have significant implications for patient safety and resource utilization.

Condition or disease Intervention/treatment
Obstructive Sleep Apnea Device: Lung-function spirometry test Device: Overnight sleep test

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Study Type : Observational [Patient Registry]
Actual Enrollment : 0 participants
Observational Model: Case-Control
Time Perspective: Prospective
Target Follow-Up Duration: 1 Week
Official Title: Influence of Inter-scalene Blockade on Postoperative Episodic Desaturation in Patients at High Risk of Obstructive Sleep Apnea (OSA)
Study Start Date : March 2014
Actual Primary Completion Date : August 2015
Actual Study Completion Date : August 2015

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Sleep Apnea

Group/Cohort Intervention/treatment
Included patients
All ten patients included in this cohort. Shoulder surgery patients that are getting a nerve block and are at high risk for OSA. They will receive a Lung-function spirometry test and an overnight sleep test.
Device: Lung-function spirometry test
5 minute lung function test performed once preoperatively and once postoperatively

Device: Overnight sleep test
Somte sleep monitor to be worn two nights before and the night of surgery.

Primary Outcome Measures :
  1. Incidence of postoperative sleep disordered breathing [ Time Frame: The night after surgery ]
    The incidence of postoperative sleep disordered breathing (apnea-hypopnea index) defined as ≥5 episodes per hour of >50% reduction of expiratory air flow associated with a ≥4% reduction in oxygen saturation (referred to as ODI4 or oxygen desaturation index > or = to 4 points drop in SpO2) that lasts for at least 10 seconds each as measured by the pulse oximeter.

Secondary Outcome Measures :
  1. Changes in lung function [ Time Frame: Once in Pre-op the day of surgery, and once in the Post Anesthesia Care Unit the day of surgery once the patient is sufficiently recovered from their procedure but before going home (all within 24 hours) ]
    As measured by spirometry test administered preoperatively and postoperatively

Other Outcome Measures:
  1. Lowest oxygen saturation levels during sleep [ Time Frame: two nights before and night of surgery ]
  2. Mean oxygen saturation levels during sleep [ Time Frame: Two nights before and the night of surgery ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Our study population consists of patients who are receiving an interscalene nerve block as an anesthetic for their scheduled shoulder surgery, and are at risk for OSA.

Inclusion Criteria:

  • Any adult 18 years of age or older
  • Six or more of the following risk factors (P-SAP score): age > 43, male gender, body mass index >30, diabetes, high blood pressure, snoring at night, neck circumference > 17 inches, reduced thyromental distance, and/or modified Mallampati class of 3 or 4
  • Scheduled for an outpatient elective shoulder surgery for which an interscalene nerve block is scheduled for postoperative pain control along with a general anesthetic per the surgeon

Exclusion Criteria:

  • Age <18 years old
  • Patients on home oxygen therapy, existing OSA that is treated with Continuous Positive Airway Pressure or Bilevel Positive Airway Pressure machine
  • Unable or unwilling to provide consent
  • Prisoners
  • Non-English speaking
  • Pregnant
  • Hearing impaired
  • Chronic pain present for 3 months or longer requiring >3 pills a day of opioid pain/pain modifying medications
  • Daily use of gabapentin, pregabalin, tricyclic antidepressant, serotonin-norepinephrine reuptake inhibitor, tramadol, corticosteroids, or clonidine.
  • Preexisting nerve damage/peripheral neuropathy
  • Significant respiratory, kidney, liver or cardiovascular impairment
  • Coagulation/bleeding disorders
  • Uncontrolled diabetes
  • Drug or alcohol abuse
  • Uncontrolled anxiety, schizophrenia or bipolar disorder
  • Hearing impairment
  • American Society of Anesthesiologists class IV or V

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02034370

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United States, Michigan
Domino's Farm's Preoperative Clinic
Ann Arbor, Michigan, United States, 48109
University of Michigan Hospitals
Ann Arbor, Michigan, United States, 48109
Sponsors and Collaborators
University of Michigan
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Principal Investigator: Satya Krishna Ramachandran, MD University of Michigan Anesthesiology Department
Additional Information:

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Responsible Party: Satya Krishna Ramachandran, Assistant Professor of Anesthesiology, University of Michigan Identifier: NCT02034370    
Other Study ID Numbers: 36398
First Posted: January 13, 2014    Key Record Dates
Last Update Posted: November 30, 2016
Last Verified: November 2016
Keywords provided by Satya Krishna Ramachandran, University of Michigan:
Interscalene nerve block
Shoulder surgery
Obstructive Sleep Apnea
Sleep Disordered Breathing
Additional relevant MeSH terms:
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Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases