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Completed

NCT Number: NCT05991141

Could Apnea Induce Hypoalgesia?

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.

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Key information

Conditions

Pain Apnea Neurologic Manifestations Pathological Conditions, Signs and Symptoms Respiration Disorders Respiratory Tract Diseases Signs and Symptoms Signs and Symptoms, Respiratory

Age range

18 year–30 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Centro Superior de Estudios La Salle

Madrid, 28023, Spain

About this study

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

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Apnea

Other

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.

Control intervention

Other

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.

Primary outcomes

  1. Pressure Pain Threshold

    Time frame: Before and immediately after the interventions

    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.

Secondary outcomes

  1. Conditioned pain modulation

    Time frame: Before and immediately after the interventions

    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.

  2. Heart Rate and Oxygen Saturation

    Time frame: During the intervention and for 2 minutes additionally after the end of the intervention

    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.

  3. Rated Perceived Exertion

    Time frame: This outcome was assessed immediately after having finished the intervention protocols

    Apnea and control interventions were explored in terms of Rated Perceived Exertion in with Borg's modified CR-10

Sponsors and collaborators

Lead sponsor

Centro Universitario La Salle

Other

Registry information

Official study title

Could Apnea Induce Hypoalgesia? An Explorative Randomized Controlled Trial

Important dates

Study start
2023
Primary completion
2023
Study completion
2023
First posted
Aug 14, 2023
Registry last updated
Aug 14, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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