Postoperative ShiveringNCT06996977
Menstrual Cycle and Postanesthetic Shivering
An observational study of Postoperative Shivering, run by Bozyaka Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
The goal of this observational study is to learn about the effect of menstrual cycle on postoperative shivering in women of fertile age. The main question it aims to answer is: Do women in the luteal phase have less postoperative shivering? Participants will have their intraoperative body temperature recorded and will… Read more about this study
- Who is it for?
- Ages 18 to 45 years, women only
- Conditions the study is for
- Postoperative Shivering
- How many people
- 100 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Jun 2025to 15 Aug 2025
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- Women only
- No healthy volunteers
- Adult
Study population: Female patients scheduled for elective nose surgery
Who may be able to join
- Female patients undergoing elective open technical septoplasty or rhinoplasty
- 18-45 years of age
- ASA score I-II
Who cannot join
- Patient-legal representative does not want to be included in the study
- Emergency surgery
- Use of drugs that affect cardiovascular function, heat balance and hormone levels (e.g. combined oral contraceptives)
- Menstrual irregularity
- Polycystic ovary syndrome
- Thyroid disease
Show all 13Show fewer
- Autonomic disease
- Reyno disease
- Uncontrolled diabetes mellitus
- Uncontrolled hypertension
- Surgeries where the duration of anesthesia is less than 1 hour
- Patients with NRS pain score above 7 in the recovery unit after anesthesia
- Core body temperature below 36°C before induction of general anesthesia
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site
Izmir City Hospital
Izmir, Bayraklı, 35540
Halide Şahinkaya, MD, +905058892157, drhhande@yahoo.com
Gözde Gürsoy Çirkinoğlu, MD, +905544071757, dr.gozde.gursoy@gmail.com
About this study
Official title: The Effect of Menstrual Cycle on Postanesthetic Shivering; Prospective Observational Study
The goal of this observational study is to learn about the effect of menstrual cycle on postoperative shivering in women of fertile age. The main question it aims to answer is:
- Do women in the luteal phase have less postoperative shivering? Participants will have their intraoperative body temperature recorded and will be observed for postanesthetic shivering, depending on whether they are in the luteal phase or follicular phase.
Read the detailed description
Postoperative shivering is a protective mechanism that the body uses to raise body temperature by rhythmic muscle contractions during hypothermia. Peroperative hypothermia is the most important cause of shivering after recovery. Shivering not only causes a decrease in patient comfort and discomfort but also increases metabolic demand by increasing oxygen consumption. This is an undesirable situation.
Women's hormonal status affects body temperature control. During the luteal phase, progesterone levels increase and this results in a 0.4 °C increase in core body temperature. The threshold for vasodilation also increases during this phase. Therefore, thermoregulation also changes during the luteal phase. Core body temperature in the follicular and luteal phase does not change with exposure to cold. However, under general anesthesia, core temperature is significantly reduced in both the luteal and follicular phase. Thermoregulatory vasoconstriction is less inhibited during luteal phase anesthesia.
The primary aim of our study was to determine the relationship between different phases of the menstrual cycle and the frequency of postoperative shivering. The secondary aim was to evaluate the incidence of intraoperative hypothermia and the duration of onset of intraoperative hypothermia in different phases of the menstrual cycle.
The study is planned as a prospective cross-sectional observational study. Female patients aged 18-45 years with ASA (American Society of Anesthesiology) score I-II who will undergo elective surgery for open technique septoplasty or rhinoplasty will be included in the study. They will be recorded in two groups as follicular group (F) and luteal group (L).
Patients data will be recorded;
- Demographic data
- Primary disease
- Comorbidities
- American Society of Anesthesiologists (ASA) Physical Status Classification
- The phase of the menstrual cycle (luteal or follicular phase) according to the patient's medical history
- Core body temperatures will be noted in the preoperative waiting area, before induction of general anesthesia, 1st hour under general anesthesia, 2nd hour under general anesthesia, 3rd hour under general anesthesia and in the postanesthetic recovery unit.
- Anesthesia and duration of surgery
- Infusion fluid quantity
- Pain level in the postoperative recovery unit (numerical rating scale-NRS)
- Postoperative tremors
- PAS (postanesthetic shivering scale) value SPSS statistical program for Windows will be used for statistical analysis of the results. Considering the number of surgeries performed in previous periods, it was predicted that approximately 100 patients could be included in the study within this period. This period, which was determined to ensure homogeneous distribution of the groups, will be extended if necessary and more patients will be included in the study. Parametric descriptive values will be given as mean and standard deviation, and non-parametric values will be given as n (%) and median and IQR (interquartile range). The conformity of the data to normal distribution will be evaluated by one sample Kolmogorov-Smirnov test. Comparisons of quantitative data conforming to normal distribution will be made with Student T test and comparisons of data not conforming to normal distribution will be made with Mann Whitney U test. Chi-Square test will be used to compare qualitative data. For the analyses, the significance level will be accepted as p<0.05 at 95% confidence interval.
- Conditions
- Postoperative Shivering
- Keywords
- menstrual cycle, core temperature
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Group follicular | Follicular phase of menstrual cycle | |
| Group luteal | Luteal phase of menstrual cycle |
What is being measured
The primary outcome is the main question the study is designed to answer.
Postoperative Shivering
Postanesthetic shivering will be evaluated in the postanesthesia care unit by Postanesthetic Shivering Scale. The scale is a 5-points scale. 0= no shivering
1= no visible muscle activity but piloerection, peripheral vasoconstriction, or both are present (other causes excluded); 2 = muscular activity in only one muscle group; 3 = moderate muscular activity in more than one muscle group but no generalized shaking; 4 = violent muscular activity that involves the whole body. 3 and 4 mean worse outcome as the patient needs medication to treat shivering.
Measured: First 15 minutes after surgery
Number of patients who require meperidine
The need for intravenous meperidine administration when the postanesthetic shivering scale (PAS) of the patient is above 3.
Measured: first 15 minutes after surgery
Secondary outcomes (2)
Number of patients whose core body temperature is below 36 °C
Intraoperative hypothermia is defined as a core body temperature below 36°C under anesthesia.
Measured: perioperative
The time when intraoperative core body temperature is detected below 36 °C
The time when the core body temperature is below 36°C during general anesthesia.
Measured: perioperative
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 May 2025
- Study start1 Jun 2025 (estimated)
- Primary completion1 Aug 2025 (estimated)
- Study completion15 Aug 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Postoperative ShiveringStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Bozyaka Training and Research Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Halide Hande Şahinkaya, Bozyaka Training and Research Hospital
- Investigators
- Halide Hande ŞAHİNKAYA, MD, Principal investigator, Izmir City HospitalGözde GÜRSOY ÇİRKİNOĞLU, MD, Study chair, Izmir City HospitalTuba KUVVET YOLDAŞ, MD, Study chair, Izmir City HospitalVolkan HANCI, MD, Study chair, 9 Eylul University Faculty of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06996977
- Sponsor's protocol ID
- menstrual cycle
- Status last verified
- May 2025
- First submitted
- 7 May 2025
- Last updated
- 30 May 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Simegn GD, Bayable SD, Fetene MB. Prevention and management of perioperative hypothermia in adult elective surgical patients: A systematic review. Ann Med Surg (Lond). 2021 Nov 14;72:103059. doi: 10.1016/j.amsu.2021.103059. eCollection 2021 Dec.
PubMed 34840773Tatsumi T, Sampei M, Saito K, Honda Y, Okazaki Y, Arata N, Narumi K, Morisaki N, Ishikawa T, Narumi S. Age-Dependent and Seasonal Changes in Menstrual Cycle Length and Body Temperature Based on Big Data. Obstet Gynecol. 2020 Oct;136(4):666-674. doi: 10.1097/AOG.0000000000003910.
PubMed 329256081. V. Erden, C. Güler, H. Bulut, N. Özsoy Toprak, and N. Uslu, "Menstrual cycle phase may effect the thermoregulation during anesthesia," International Journal of Anesthesia, vol. 5, 2018.
Study at a glance
From the registry record, last updated by the sponsor on 30 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Menstrual Cycle on Postanesthetic Shivering; Prospective Observational Study
- ClinicalTrials.gov ID
- NCT06996977
- Acronym / sponsor ID
- menstrual cycle
- Conditions
- Postoperative Shivering
- Keywords
- menstrual cycle, core temperature
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Bozyaka Training and Research HospitalUniversity, hospital or other
- Study start
- 1 Jun 2025 (estimated)
- Primary completion
- 1 Aug 2025 (estimated)
- Study completion
- 15 Aug 2025 (estimated)
- First posted
- 30 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this observational study is to learn about the effect of menstrual cycle on postoperative shivering in women of fertile age. The main question it aims to answer is:
- Do women in the luteal phase have less postoperative shivering? Participants will have their intraoperative body temperature recorded and will be observed for postanesthetic shivering, depending on whether they are in the luteal phase or follicular phase.
Detailed description
Postoperative shivering is a protective mechanism that the body uses to raise body temperature by rhythmic muscle contractions during hypothermia. Peroperative hypothermia is the most important cause of shivering after recovery. Shivering not only causes a decrease in patient comfort and discomfort but also increases metabolic demand by increasing oxygen consumption. This is an undesirable situation.
Women's hormonal status affects body temperature control. During the luteal phase, progesterone levels increase and this results in a 0.4 °C increase in core body temperature. The threshold for vasodilation also increases during this phase. Therefore, thermoregulation also changes during the luteal phase. Core body temperature in the follicular and luteal phase does not change with exposure to cold. However, under general anesthesia, core temperature is significantly reduced in both the luteal and follicular phase. Thermoregulatory vasoconstriction is less inhibited during luteal phase anesthesia.
The primary aim of our study was to determine the relationship between different phases of the menstrual cycle and the frequency of postoperative shivering. The secondary aim was to evaluate the incidence of intraoperative hypothermia and the duration of onset of intraoperative hypothermia in different phases of the menstrual cycle.
The study is planned as a prospective cross-sectional observational study. Female patients aged 18-45 years with ASA (American Society of Anesthesiology) score I-II who will undergo elective surgery for open technique septoplasty or rhinoplasty will be included in the study. They will be recorded in two groups as follicular group (F) and luteal group (L).
Patients data will be recorded;
- Demographic data
- Primary disease
- Comorbidities
- American Society of Anesthesiologists (ASA) Physical Status Classification
- The phase of the menstrual cycle (luteal or follicular phase) according to the patient's medical history
- Core body temperatures will be noted in the preoperative waiting area, before induction of general anesthesia, 1st hour under general anesthesia, 2nd hour under general anesthesia, 3rd hour under general anesthesia and in the postanesthetic recovery unit.
- Anesthesia and duration of surgery
- Infusion fluid quantity
- Pain level in the postoperative recovery unit (numerical rating scale-NRS)
- Postoperative tremors
- PAS (postanesthetic shivering scale) value SPSS statistical program for Windows will be used for statistical analysis of the results. Considering the number of surgeries performed in previous periods, it was predicted that approximately 100 patients could be included in the study within this period. This period, which was determined to ensure homogeneous distribution of the groups, will be extended if necessary and more patients will be included in the study. Parametric descriptive values will be given as mean and standard deviation, and non-parametric values will be given as n (%) and median and IQR (interquartile range). The conformity of the data to normal distribution will be evaluated by one sample Kolmogorov-Smirnov test. Comparisons of quantitative data conforming to normal distribution will be made with Student T test and comparisons of data not conforming to normal distribution will be made with Mann Whitney U test. Chi-Square test will be used to compare qualitative data. For the analyses, the significance level will be accepted as p<0.05 at 95% confidence interval.
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group follicular | – | –Follicular phase of menstrual cycle |
| Group luteal | – | –Luteal phase of menstrual cycle |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Female patients scheduled for elective nose surgery
Key inclusion criteria (3 listed)
- Female patients undergoing elective open technical septoplasty or rhinoplasty
- 18-45 years of age
- ASA score I-II
Key exclusion criteria (13 listed)
- Patient-legal representative does not want to be included in the study
- Emergency surgery
- Use of drugs that affect cardiovascular function, heat balance and hormone levels (e.g. combined oral contraceptives)
- Menstrual irregularity
- Polycystic ovary syndrome
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Postoperative Shivering
Time frame: First 15 minutes after surgery
Postanesthetic shivering will be evaluated in the postanesthesia care unit by Postanesthetic Shivering Scale. The scale is a 5-points scale. 0= no shivering 1= no visible muscle activity but piloerection, peripheral vasoconstriction, or both are present (other causes excluded); 2 = muscular activity in only one muscle group; 3 = moderate muscular activity in more than one muscle group but no generalized shaking; 4 = violent muscular activity that involves the whole body. 3 and 4 mean worse outcome as the patient needs medication to treat shivering.
Number of patients who require meperidine
Time frame: first 15 minutes after surgery
The need for intravenous meperidine administration when the postanesthetic shivering scale (PAS) of the patient is above 3.
2 secondary outcomes
Number of patients whose core body temperature is below 36 °C
Time frame: perioperative
The time when intraoperative core body temperature is detected below 36 °C
Time frame: perioperative
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 May 2025.
- Background: PubMed 34840773Simegn GD, Bayable SD, Fetene MB. Prevention and management of perioperative hypothermia in adult elective surgical patients: A systematic review. Ann Med Surg (Lond). 2021 Nov 14;72:103059. doi: 10.1016/j.amsu.2021.103059. eCollection 2021 Dec.
- Background: PubMed 32925608Tatsumi T, Sampei M, Saito K, Honda Y, Okazaki Y, Arata N, Narumi K, Morisaki N, Ishikawa T, Narumi S. Age-Dependent and Seasonal Changes in Menstrual Cycle Length and Body Temperature Based on Big Data. Obstet Gynecol. 2020 Oct;136(4):666-674. doi: 10.1097/AOG.0000000000003910.
- Background1. V. Erden, C. Güler, H. Bulut, N. Özsoy Toprak, and N. Uslu, "Menstrual cycle phase may effect the thermoregulation during anesthesia," International Journal of Anesthesia, vol. 5, 2018.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Halide Hande ŞAHİNKAYA, MD principal investigator
Izmir City Hospital
Gözde GÜRSOY ÇİRKİNOĞLU, MD study chair
Izmir City Hospital
Tuba KUVVET YOLDAŞ, MD study chair
Izmir City Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Postoperative Shivering, run by Bozyaka Training and Research Hospital at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 30 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Halide Hande Şahinkaya, MD (+905058892157, drhhande@yahoo.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Postoperative Shivering (time frame: First 15 minutes after surgery). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06996977, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 May 2025.