Could Apnea Induce Hypoalgesia?

Could Apnea Induce Hypoalgesia? An Explorative Randomized Controlled Trial

A randomized controlled trial (RCT) in healthy subjects will be conducted with the following aims: (1) Explore the effect of low pulmonary volume dynamic apnoea bouts on Pressure Pain Threshold (PPT) and conditioned pain modulation (CPM); (2) analyse whether CPM response correlates with apnoea induced hypoalgesia; (3) examine the association between apnoea bouts, Rate of Perceived Exertion, hypoxemia and Heart Rate changes in PPT.

Study Overview

• Status: Completed
• Conditions: Pain; Apnea
• Intervention / Treatment: Other: Apnea; Other: Control Intervention

Detailed Description

A randomized controlled trial (RCT) in healthy subjects will be conducted with the following aims: (1) Explore the effect of low pulmonary volume dynamic apnoea bouts on Pressure Pain Threshold (PPT) and conditioned pain modulation (CPM); (2) analyse whether CPM response correlates with apnoea induced hypoalgesia; (3) examine the association between apnoea bouts Rate of Perceived Exertion, hypoxemia and Heart Rate changes in PPT

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Madrid, Spain, 28023
    • Centro Superior de Estudios La Salle

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy participants
• 18-30 years
• Currently pain-free
• Basal SpO2 ≥95%

Exclusion Criteria:

• Diabetes diagnosis
• Hypertension or hypotension diagnosis
• Pharmacological treatment
• Frequent pain during last month
• Drug consumption
• Self-harming behaviours
• Pregnant or potentially pregnant
• Cardiac or respiratory pathology
• Splenectomy or spleen disease
• Having performed moderate or high intensity physical activity 24 hours prior to the study
• Not having slept the previous night
• Alcohol intake 24 hours prior to study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental Group	Other: Apnea; In both experimental and control groups participants walked on a treadmill at 5.5 km/h with 5º inclination for 6 minutes. The experimental group (EG) added throughout the 6 minutes intervention the following breathing pattern cyclically: 5 seconds breathing normally followed by 10 seconds of low volume apnoea, performing a total of 24 cycles of normal breathing continued by apnoea.
Sham Comparator: Control Group	Other: Control Intervention; In both experimental and control groups participants walked on a treadmill at 5.5 km/h with 5º inclination for 6 minutes. The Control group (CG) performed this protocol breathing normally.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pressure Pain Threshold	PPT refers to the minimal amount of pressure needed to cause the first sensation of pain. The mechanical pressure algometer (PAIN TEST™ FPX 25, Wagner Instruments, Greenwich, CT, USA) counted with a round rubber disc of 1 cm2, displaying values in Kg, hence, data was expressed in Kg/cm2. Two locations, in upper and lower limbs, were examined to examine systemic hypoalgesia effects. The dorsal distal-phalange base of the thumb and tibialis anterior muscle belly, both in the dominant limb, were tested. These regions were marked with a pen before assessments, to repeat the trials in the same place. Three trials were tested in each location, with 30 seconds rest between trials. Pressure speed was paced with a metronome applying a constant force of 0.5 Kg/cm2/s ± 0.1 Kg/cm2/s.	Before and immediately after the interventions

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Conditioned pain modulation	Conditioning stimulus was applied on the contralateral limb to test stimulus, since its arrangement does not influence CPM response. Only controversial CPM response have appeared when tests and conditioned stimuli were applied on the same body region. Ischemic pain was applied as conditioning stimulus and PPT as test stimulus. Ischemic pain was provoked inflating a sphygmomanometer at the proximal region of the non-dominant arm. When inflated up to 180-200 mmHg patients were asked to actively move fingers and wrist. They were asketd to report when a 7/10 pain in Numerical Pain Rating Scale (NPRS) scale was reached. In that moment, three trials of test stimuli were applied on the dorsal distal-phalange base of the thumb in the dominant arm, while maintaining the ischemic pain perception.	Before and immediately after the interventions
Heart Rate and Oxygen Saturation	We video-taped HR and SpO2 values during the 6 min interventions and 2 minutes afterwards to explore their changes during and after interventions. HR and SpO2 data were extracted in each second. These values would be graphically displayed. Peak %HRmax and minimum SpO2, and means of both variables, value would be extracted from the 6-minute interventions. HR zones or exercise-induced hypoxemia zones were also recorded.	During the intervention and for 2 minutes additionally after the end of the intervention
Rated Perceived Exertion	Apnea and control interventions were explored in terms of Rated Perceived Exertion in with Borg's modified CR-10	This outcome was assessed immediately after having finished the intervention protocols

Collaborators and Investigators

• Sponsor: Centro Universitario La Salle
• Investigators: Principal Investigator: José Fierro Marrero, CSEULaSalle

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2023
• Primary Completion (Actual): May 15, 2023
• Study Completion (Actual): May 15, 2023

Study Registration Dates

• First Submitted: July 26, 2023
• First Submitted That Met QC Criteria: August 11, 2023
• First Posted (Actual): August 14, 2023

Study Record Updates

• Last Update Posted (Actual): August 14, 2023
• Last Update Submitted That Met QC Criteria: August 11, 2023
• Last Verified: August 1, 2023

More Information

Terms related to this study

• Keywords: Pain; Apnea; Hypoalgesia; Apnoea
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Signs and Symptoms, Respiratory; Apnea
• Other Study ID Numbers: CSEULS-PI-029/2022

Drug and device information, study documents

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