Observational Study of Peripheral Skin Temperature Changes Following Spinal Anaesthesia for Category 4 Lower Segment Caesarean Section (LSCS)
Conditions: Anesthesia
Sponsor: Cambridge University Hospitals NHS Foundation Trust

Research protocol, version 8 dated 06/05/2021 
 
IRAS ID No: 263967 
 
 
 
 
 
Observational study of peripheral skin temperature changes  
following spinal anaesthesia  
for category 4 lower segment caesarean section (LSCS) 
 
IRAS ID number: 263967 
 
Research protocol Version 8 Dated 06/05/2021 

Research protocol, version 8 dated 06/05/2021 
 
IRAS ID No: 263967 
 
 
Research protocol 
 
Study Title: 
Observational study of peripheral skin temperature changes following spinal anaesthesia for 
category 4 lower segment caesarean section (LSCS). 
 
Chief Investigator:  
Dr Laura Kessack, Cambridge University Hospitals NHS Foundation Trust. 
 
Purpose: 
In the literature there is very little observational data for the changes in peripheral limb skin 
temperature following regional anaesthesia in the obstetric population. It has been documented 
previously in the non-pregnant population that the blockade of sympathetic nerve fibres by regional 
anaesthesia (including spinal, epidural and lumbar plexus anaesthesia) results in vasodilation of 
peripheral blood vessels and an increase in the blood flow to the skin, increasing the peripheral skin 
temperature1-7. Saito et al reviewed the thermoregulatory effects of spinal and epidural anaesthesia 
during caesarean delivery but did not review the changes in peripheral limb skin temperature 8. 
Griffin and Reynolds explored the correlation between sensory block asymmetry and a disparity in 
foot temperature following epidural bupivacaine administration in labour. Their findings indicated a 
clear association between sensory block asymmetry and the difference between the temperature of 
the feet. This difference can be detected simply by feeling the feet 9. However, they did not review 
findings following spinal anaesthesia. The hypothesis of this study is that peripheral skin 
temperature will increase following regional anaesthesia/analgesia due to sympathetic block and 
that this temperature change could potentially be used as an indicator of potential efficacy of 
regional anaesthesia/analgesia. Spinal anaesthesia should reliably produce a bilateral sympathetic 
block. Therefore if a sympathetic block produces an increase in peripheral temperature this effect 
should be observable in women who have successful spinal anaesthesia for caesarean section.  We 
propose measuring this peripheral foot temperature with Covidien Mon-a-Therm skin temperature 
probes and a Braun Welch Allyn tympanic membrane thermometer device. If this effect is found 
then this finding could be investigated in future studies to determine the value of using peripheral 
temperature measurement with a Braun Welch Allyn tympanic membrane thermometer device, as a 
marker and predictor of the efficacy of labour epidural analgesia. 
Primary research question: 
The hypothesis is that peripheral skin temperature of the dorsum of the feet will rise bilaterally 
following establishment of a spinal anaesthetic block and that the peripheral skin temperature will 
change with regression of the spinal anaesthetic block.    
Secondary research question: 
The secondary hypothesis is that an infrared tympanic thermometer could be as reliable a method of 
measuring temperature as a skin temperature probe and therefore be a practical accessible method 
for measuring peripheral skin temperature in delivery rooms. 

Research protocol, version 8 dated 06/05/2021 
 
IRAS ID No: 263967 
 
 
 
Methods: 
This is an observational study. We will obtain ethics committee approval for conducting the study. 
ASA 1 and 2 full term (37-42 weeks), parturients with singleton pregnancy, normal placental 
position, scheduled for category 4 LSCS under ‘single-shot’ spinal anaesthesia will be recruited. We 
intend to recruit 60 parturients. The parturients will undergo an informed consent process including 
an explanation of the methods and risks of the study. A patient information leaflet will be provided 
for the parturients. 
The data will be collected on a password protected spread-sheet with no patient identifiable 
information. A grant for funding will be applied for from the Obstetric Anaesthetists’ Association. 
Prior to establishment of spinal anaesthesia, the skin temperature of the women’s feet will be 
measured on the dorsum of the right and left feet above space between the 2nd and 3rd metatarsal 
bones while she is lying supine with left lateral tilt. The temperature will be measured by Covidien 
Mon-a-Therm skin temperature probes and a Braun Welch Allyn tympanic membrane thermometer 
device. Following spinal injection when the woman is lying supine with lateral tilt, the temperature 
will be re-measured by Covidien Mon-a-Therm skin temperature probes and a Braun Welch Allyn 
tympanic membrane thermometer device. The skin temperature of the women’s feet will be 
monitored continuously by the Covidien Mon-a-Therm skin temperature probes using the GE 
Healthcare monitor with readings transcribed every 1 minute by the research investigator until 
transfer onto the bed at the end of surgery. The skin temperature of the women’s feet will be 
measured and recorded every 1 minute using a Braun Welch Allyn tympanic membrane 
thermometer device until the sterile drapes are applied prior to commencing the operation and then 
again after removal of the drapes prior to transfer onto the bed. Following transfer to the post-
operative recovery area, the skin temperature of the women’s feet will be measured and recorded 
every 10 minutes using a Braun Welch Allyn tympanic membrane thermometer device until 
discharged to the ward from the recovery area (usually 2 hours from departmental guidelines). 
Theatre room temperature will be measured and recorded at the start of anaesthesia and at the end 
of surgery using a room thermometer. Surgical drapes will be applied over the parturient's lower 
limbs during the caesarean section procedure as per our routine practice. The ambient temperature 
under the surgical drapes will be measured and recorded at the start of anaesthesia and at the end 
of surgery using a room thermometer.  
Tympanic temperature will be measured by a Braun Welch Allyn tympanic membrane thermometer 
device before spinal anaesthesia and then every 30 minutes until the end of surgery as per NICE 
clinical guideline 65. 
Spinal anaesthesia will be conducted as per usual practice. All intravenous fluids will be given 
through a fluid warmer. 
Patient data to be recorded will include: Age, Weight, Height, BMI, total dose of intra-operative 
vasopressor given, highest estimated dermatome level of anaesthesia to cold (ethyl chloride spray) 
bilaterally prior to commencing surgery, level motor block using straight leg raise as per normal 

Research protocol, version 8 dated 06/05/2021 
 
IRAS ID No: 263967 
 
 
practice when anaesthesia ready for surgery, duration of surgery, estimated blood loss, total volume 
of intravenous fluids given (including any blood products).  
Dermatome level of anaesthesia will be measured to cold (ethyl chloride spray) level and motor 
block will be measured using straight leg raise as per normal practice, in recovery, every 30 minutes. 
6 parturients will be recruited as a control group. The skin temperature of these women’s feet will 
be measured on the dorsum of the right and left feet above space between the 2nd and 3rd 
metatarsal bones while she is lying supine with left lateral tilt in theatre. The temperature will be 
measured by Covidien Mon-a-Therm skin temperature probes and a Braun Welch Allyn tympanic 
membrane thermometer device. The sterile drapes will be applied and the skin temperature of the 
women’s feet will be monitored continuously by the Covidien Mon-a-Therm skin temperature 
probes using the GE Healthcare monitor with readings transcribed every 1 minute by the research 
investigator for 30 minutes. After 30 minutes, the skin temperature of the women’s feet will be 
measured and recorded every 1 minute using a Braun Welch Allyn tympanic membrane 
thermometer device for 5 minutes.  Theatre room temperature will be measured and recorded for 
this control group of parturients. The ambient temperature under the surgical drapes will be 
measured and recorded using a room thermometer.  
Inclusions / exclusions: 
Parturients will be excluded from the study if they refuse or if they have medical conditions that may 
affect their peripheral temperature and therefore the results of the study. Our exclusion criteria are: 
Parturients converted to other forms of anaesthesia (not just spinal anaesthesia); Parturients with a 
pyrexia / sepsis; Parturients with peripheral vascular disease (including Raynaud’s); Parturients with 
cardiovascular disease; Parturients with diabetes mellitus (gestational, type 1 or 2); Hypertensive 
disorders of pregnancy; ASA 3+ Parturients; BMI >40 or <18; Parturient refusal. 
Consent: 
We will assess the participants to check that they have capacity and therefore we will obtain valid 
consent from them. We will confirm that participants understand the purpose and nature of the 
research; understand what the research involves, the benefits (or lack of benefits), risks and 
burdens; understand the alternatives to taking part. We will also confirm that participants are able 
to retain the information long enough to make an effective decision, are able to make a free choice 
and are capable of making this particular decision at the time it needs to be made. 
Informed consent will be taken from participants themselves by anaesthetists who have completed 
good clinical practice. Informed consent will be taken on a written consent form after a patient 
information leaflet detailing the study has been provided and a discussion of the details of the study 
has taken place. 
Risks, burdens and benefits: 
We have chosen methods for measuring skin temperature that are safe for patient use and already 
easily available in our hospital. Therefore these methods could be readily used if the results of the 

Research protocol, version 8 dated 06/05/2021 
 
IRAS ID No: 263967 
 
 
trial mean that this method of temperature measurement to assess regional block can be extended 
to routine clinical practice. 
The main risk may be allergy or skin reaction to the adhesive used on the skin temperature probe. 
However the probes are used routinely already in the hospital to measure skin temperature and 
therefore the risk is low. 
Confidentiality:  
Person-identifiable information will not be used unless it is absolutely necessary.  If person-
identifiable information is used, the minimum necessary will be used. Access to person-identifiable 
information will be on a strict need-to-know basis. Everyone with access to person-identifiable 
information will be made aware of their responsibilities. The data will be collected on a password 
protected spread-sheet with no patient identifiable information. If any problems arise from the 
processing of identifiable data these will be handled in line with data protection laws.  
At the end of the study personal data will be kept for 6-12 months in case we need to check it, but 
anonymised research data will be kept for 10 years.  This data will be saved for the purposes of data 
verification in a separate key, on password protected Cambridge University Hospitals NHS 
Foundation Trust secure computers linked to the study data by a unique participant ID. 
Regulatory approval:  
Before the start of the study, the following approvals will be sought: 
 
Health Research Authority (HRA) Approval  
 
NHS Research Ethics Committee (REC) review 
 
Confirmation of Capacity and Capability from the NHS research site. 
An annual progress report (APR) will be submitted to the NHS REC within 30 days of the anniversary 
date on which the favourable opinion was given, and annually until the study is declared ended. It is 
the responsibility of the study team to produce the annual reports as required. 
The study team will notify the NHS REC of the end of the study. If the study is ended prematurely, 
the study team will notify the NHS REC, including the reasons for the premature termination 
Within one year after the end of the study, the study team will submit a final report with the results, 
including any publications/abstracts, to the NHS REC. 
Peer review: 
The study has received independent peer review from the CUH Research Advisory Committee. 
Indemnity: 
NHS indemnity will apply for the design, management and conduct of the study. 
Amendments: 
All amendments to the protocol will be discussed with the CUHNFT R&D department and submitted for 
HRA and REC review. Amendments submitted for regulatory review will not be implemented until the 
necessary regulatory approvals are received. 

Research protocol, version 8 dated 06/05/2021 
 
IRAS ID No: 263967 
 
 
 
 
References: 
1. Werdehausen R, Braun S, Hermanns H, Freynhagen R, Lipfert P, Stevens MF. Uniform Distribution of 
Skin-Temperature Increase After Different Regional-Anesthesia Techniques of the Lower Extremity. 
Regional Anesthesia and Pain Medicine 2007; 32(1): 73–78. 
2. Hermanns H, Werdehausen R, Hollmann MW, Stevens MF. Assessment of skin temperature during 
regional anaesthesia — What the anaesthesiologist should know. Acta Anaesthesiol Scand. 2018; 62: 
1280–1289. 
3. Park SY, Nahm FS, Kim YC, Lee SC, Sim SE and Lee SJ. The Cut-off Rate of Skin Temperature Change to 
Confirm Successful Lumbar Sympathetic Block. The Journal of International Medical Research 2010; 
38: 266 – 275. 
4. Bengtsson M. Changes in skin blood flow and temperature during spinal analgesia evaluated by laser 
Doppler flowmetry and infrared thermography. Acta Anaesthesiol Scand. 1984 Dec;28(6):625-30. doi: 
10.1111/j.1399-6576.1984.tb02134.x. 
5. Penno A, Arumugam M, Antweiler G, Laubert T, Habermann J, Bruch HP. [Increase in skin surface 
temperature in spinal anesthesia. Predictive value for probability of surgical tolerance]. 
[Article in German] Anaesthesist. 2012 Sep;61(9):770-6. doi: 10.1007/s00101-012-2076-3. Epub 2012 
Sep 8. 
6. Jetzek-Zader M, Hermanns H, Freynhagen R, Lipfert P, Stevens MF. Increase in skin temperature after 
spinal anesthesia in infants. Reg Anesth Pain Med. 2006 Nov-Dec;31(6):519-22. 
doi:10.1016/j.rapm.2006.07.007. 
7. Ehrlich PF(1), Vedulla G, Cottrell N, Seidman PA. Monitoring intraoperative effectiveness of caudal 
analgesia through skin temperature variation. J Pediatr Surg. 2003 Mar;38(3):386-9. 
doi:10.1053/jpsu.2003.50113. 
8. Saito T, Sessler DI, Fujita K, et al. Thermoregulatory effects of spinal and epidural anesthesia during 
cesarean delivery. Regional Anesthesia and Pain Medicine 1998; 23: 418–23. 
9. Griffin RP, Reynolds F. The association between foot temperature and asymmetrical epidural 
blockade. Int J Obstet Anesth. 1994 Jul;3(3):132-6. doi: 10.1016/0959-289x(94)90224-0. PMID: 
15636935.