Does continuous arterial blood pressure monitoring during surgery benefit patients who are high risk, particularly those who are older and living with frailty?

ISRCTN	ISRCTN12558538
DOI	https://doi.org/10.1186/ISRCTN12558538
ClinicalTrials.gov (NCT)	Nil known
Clinical Trials Information System (CTIS)	Nil known
Integrated Research Application System (IRAS)	351284
Protocol serial number	R&D 24/006, CPMS 65485
Sponsor	South Tees Hospitals NHS Foundation Trust
Funder	National Institute for Health and Care Research

Submission date: 10/07/2025
Registration date: 09/09/2025
Last edited: 07/10/2025

Recruitment status: Recruiting
Overall study status: Ongoing
Condition category: Surgery

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
Many people have low blood pressure during surgery, which can be harmful, especially for older or frail patients. This can affect important organs like the heart, kidneys, or brain. One way to help is by measuring blood pressure continuously during surgery using a drip in the wrist, instead of checking it every few minutes with a cuff. This might help doctors spot and treat low blood pressure more quickly. However, this method isn’t used often because there isn’t enough research to support it. This study aims to find out if continuous blood pressure monitoring during surgery helps high-risk patients, especially those having surgery for a broken hip.

Who can participate?
The study is for people aged 65 or older who are considered frail and need surgery for a broken hip.

What does the study involve?
Participants will be randomly placed into one of two groups. One group will have their blood pressure measured continuously during surgery using a drip in the wrist. The other group will have it measured at regular intervals using a cuff. Researchers will look at how well the study works, track blood pressure during surgery, check for any complications, and ask patients about their quality of life afterward.

What are the possible benefits and risks of participating?
The study may help improve care for future patients by showing whether continuous blood pressure monitoring is better. There may be some small risks from the drip used for monitoring, such as discomfort or infection, but these are rare and will be carefully managed.

Where is the study run from?
South Tees Hospitals NHS Foundation Trust (UK)

When is the study starting and how long is it expected to run for?
The study started in June 2025 and is expected to run until April 2028.

Who is funding the study?
National Institute for Health and Care Research (NIHR) (UK)

Who is the main contact?
Andrew Kane, andrew.kane@nhs.net

Contact information

Mr Andrew Kane
Public, Scientific, Principal investigator

South Tees Hospitals NHS Foundation Trust
James Cook University Hospital
Marton Road
Middlesbrough
TS4 3BW
United Kingdom

ORCID ID	0000-0001-9488-4086
Phone	+44 7709619017
Email	andrew.kane@nhs.net

Study information

Primary study design	Interventional
Study design	A feasibility study consisting of an external multi-centre two-arm parallel-group assessor-blinded randomized pilot trial with a nested qualitative study
Secondary study design	Randomised controlled trial
Study type	Participant information sheet
Scientific title	Continuous ARterial monitoring in Elderly and Frail patients for hip fractUre surgery to prevent Low blood pressure
Study acronym	CAREFUL
Study objectives	1. To undertake a systematic review and meta-analysis to understand what is currently known regarding the use of continuous blood pressure monitoring and its impact on intra-operative hypotension and associated morbidity. 2. To understand clinician attitudes towards continuous arterial monitoring in older frail patients presenting for trauma surgery through questionnaires and focus groups. 3. To undertake a feasibility study with embedded qualitative research to assess whether a full-scale randomised controlled trial (RCT) of continuous invasive arterial blood pressure monitoring versus standard care is feasible in the older, frail patient population presenting for hip fracture surgery.
Ethics approval(s)	Approved 15/09/2025, Wales REC 7 (Health and Care Research Wales, Castlebridge 4, 15-19 Cowbridge Road East, Cardiff, CF11 9AB, United Kingdom; +44 (0)2922 941107, 2922 940968; Wales.REC7@wales.nhs.uk), ref: 25/WA/0235
Health condition(s) or problem(s) studied	Continuous invasive arterial blood pressure monitoring during orthopaedic trauma surgery
Intervention	Study arms Participants will be randomly allocated in a 1:1 ratio using block randomisation, stratified by site to either: Continuous invasive arterial blood pressure monitoring • Up to three attempts to establish continuous invasive arterial blood pressure monitoring using local anaesthesia before general or neuraxial anaesthesia. • Continuous arterial blood pressure monitoring will be maintained until the patient reaches the recovery room, where it may be discontinued or continued at the discretion of the clinical team. OR Standard care • 3-to-5-minute cycles of blood pressure monitoring. Duration of treatment Start: From the start of anaesthesia care. End: The randomised treatment can be removed at a point the clinician feels is appropriate- normally in the recovery room. Follow-up period 120 days from the day of surgery. Randomisation The randomisation schedule will be stratified by site and formed of randomly permuted blocks of randomly varying size using a 1:1 allocation ratio. The allocation sequence will be generated by a statistician not involved in the study and uploaded to the REDCap platform. Following consent, randomisation will be performed immediately via the REDCap platform. Clinical teams will be informed as early as possible to allow planning of care.
Intervention type	Procedure/Surgery
Primary outcome measure(s)	Feasibility outcomes: 1. Site setup is measured using number of sites recruiting first participant at end of trial 2. Participant recruitment rate is measured using number of participants recruited per site per month at end of trial 3. Outcome follow-up data completeness is measured using proportion of participant-reported outcome data collected at 120 days 4. Intervention compliance is measured using proportion of participants receiving allocated treatment at end of trial 5. Treatment crossover is measured using proportion of patients not receiving allocated treatment at baseline and during hospital stay 6. Unblinding rate is measured using number of outcome assessors unblinded to trial allocation at 120 days
Key secondary outcome measure(s)	Feasibility of data collection of clinical and patient-reported outcome measures: 1. Pre-injury mobility is measured using patient or carer report at baseline 2. Pre-injury quality of life is measured using EuroQol EQ5D5L questionnaire at baseline 3. Pre-injury residential status is measured using patient or carer report at baseline 4. Delirium is measured using 4AT tool at baseline and on day 3 (+/-1 day) post-surgery 5. Comorbidities are measured using patient notes at baseline 6. Drug history is measured using patient notes at baseline 7. Routine blood test results are measured using full blood count, urea and electrolytes, clotting screen, CRP at baseline 8. Blood pressure is measured using standard clinical measurement on admission 9. ASA score is measured using anaesthetic chart at time of surgery 10. Type of anaesthetic is measured using anaesthetic chart at time of surgery 11. Volume of fluids administered is measured using anaesthetic chart during surgery 12. Units of blood products administered is measured using anaesthetic chart during surgery 13. Vasopressor and inotrope use is measured using anaesthetic chart during surgery 14. Estimated blood loss is measured using anaesthetic chart during surgery 15. Cardiac arrest is measured using anaesthetic chart during surgery 16. Death in theatre is measured using anaesthetic chart during surgery 17. Intra-operative blood pressure is measured using uploaded intra-operative measurements during surgery 18. First blood pressure in recovery is measured using standard clinical measurement in recovery room 19. Postoperative complications are measured using Comprehensive Complications Index at 120 days 20. Discharge destination is measured using patient notes at time of hospital discharge 21. Residential status is measured using patient or carer report at 120 days post-surgery 22. Mobility is measured using patient or carer report at 120 days post-surgery 23. Quality of life is measured using EuroQol EQ5D5L questionnaire at 120 days (+/-7 days) post-surgery
Completion date	01/04/2028

Eligibility

Participant type(s)	Patient
Age group	Senior
Lower age limit	65 Years
Sex	All
Target sample size at registration	100
Key inclusion criteria	1. ≥65 years old 2. Clinically frail – assessed as a Clinical Frailty Scale (CFS) Score of 5 or more 3. Primary proximal hip fracture (fractured neck of femur)
Key exclusion criteria	1. Planned continuous arterial blood pressure monitoring or use of non-invasive blood pressure monitoring at a high frequency 2. Refusal to consent
Date of first enrolment	01/10/2025
Date of final enrolment	01/10/2027

Locations

Countries of recruitment

United Kingdom
England

Study participating centre

South Tees Hospitals NHS Foundation Trust

James Cook University Hospital
Marton Road
Middlesbrough
TS4 3BW
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Published as a supplement to the results publication
IPD sharing plan	All data generated or analysed during this study will be included in the subsequent results publication

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes

Editorial Notes

07/10/2025: Ethics approval added.
03/10/2025: Internal review.
24/07/2025: Trial's existence confirmed by the National Institute for Health and Care Research (NIHR) (UK).