Haemodynamic Effects of Low-dose Spinal Anaesthesia for Hip Fracture Surgery.

March 22, 2023 updated by: Stuart White, Royal Sussex County Hospital

A Retrospective, Observational, Single-centre, Cohort Database Analysis of the Haemodynamic Effects of Low-dose Spinal Anaesthesia for Hip Fracture Surgery.

Approximately 65, 000 hip fractures occur in the United Kingdom (UK) each year, and more than 99% are repaired by surgery. Roughly half of patients receive spinal anaesthesia, where a small amount (usually less than half a teaspoonful) of local anaesthetic is injected into the lower back, around the nerves that go to and from the hip.

Low blood pressure is very common during surgery (at least > 30%, depending on definition), and appears to be linked to a greater chance of death within a month after surgery.

There are 2 main ways of managing low blood pressure during surgery: treatment and prevention. Treatments (fluids, drugs) have side effects in the older, frailer population with hip fracture. Prevention involves giving anaesthesia at lower doses. National guidelines recommend that lower doses are given, but this recommendation is based on historical research selectively involving younger, fitter people having hip fracture surgery. Importantly, these studies did not record blood pressure either accurately or often enough.

The Anaesthesia Sprint Audit of Practice (ASAP) 2 study suggested that a safe level of low blood pressure occurs when only 1.5 mls of spinal anaesthesia is given, and the investigator has been using this amount in Brighton since 2011. Recently, the investigator has reported a way of transferring vital signs data from anaesthetic monitors to storage computers for medicolegal purposes (e.g. in Coroner's investigations: approximately 4000 people in the UK die annually within a month of hip fracture surgery).

However, analyzing such observational data should also allow the investigator to describe accurately how blood pressure changes around the time of surgery, and in patient groups that are normally excluded from prospective research (e.g. the very old, the very frail, people with dementia). By comparing this data to published national data from the ASAP 1 study, the investigator hopes to determine whether lower doses of spinal anaesthesia are linked with a lower rate of low blood pressure during surgery, potentially improving people's survival and recovery after hip fracture.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

Approximately 65, 000 hip fractures occur in the UK each year, and more than 99% are repaired by surgery. Roughly half of patients receive spinal anaesthesia, where a small amount (usually ~ 2.5mls) of local anaesthetic is injected into the lower back, around the nerves that go to and from the hip.

The investigator has found that low blood pressure (hypotension) is very common during surgery (occurring in at least > 30%, depending on the definition of hypotension), and appears to be significantly linked to a greater chance of death within a month after surgery (~3% rise in mortality/5 mmHg fall in SBP).

There are 2 main ways of managing low blood pressure during surgery: treatment and prevention. Treatments (fluids, drugs) have side effects in the older, frailer population with hip fracture, including fluid overload with heart failure, and cardiac/kidney/gut ischaemia.

Prevention involves giving anaesthesia at lower doses. UK national guidelines recommend that lower doses are given (< 2mls 0.5% hyperbaric bupivacaine), but this recommendation is based on historical research selectively involving younger, fitter people having hip fracture surgery. Importantly, these studies did not record blood pressure either accurately (i.e. invasively) or often enough (i.e. > every 5 minutes).

The ASAP 2 study suggested that a safe level of low blood pressure occurs when only 1.44 mls 0.5% hyperbaric/normobaric spinal anaesthesia is administered, and the investigator has been using this amount (1.5mls) in Brighton since 2011.

Recently, it has become possible to transfer vital signs data from anaesthetic monitors to storage computers for medicolegal purposes (eg in Coroner's investigations - approximately 4000 people in the UK die annually within a month of hip fracture surgery).

However, analyzing such observational medicolegal data should also allow accurate description of how blood pressure changes around the time of surgery, and in patient groups that are normally excluded from prospective research (eg the very old, the very frail, people with dementia). By comparing this data to published national data from the ASAP 1 study, it should be possible to determine whether lower doses of spinal anaesthesia are linked with a lower rate of low blood pressure during surgery. By merging individuals' data with that held on the Brighton Hip Fracture Database, it should be possible to determine whether prevalence (and/or depth+duration of hypotension) are correlated with outcomes (survival, length of inpatient stay) after hip fracture repair.

Study Type

Observational

Enrollment (Anticipated)

300

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
    • E Sussex
      • Brighton, E Sussex, United Kingdom, BN2 5BE
        • Royal Sussex County Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

People undergoing surgical hip fracture repair (hemiarthoplasty, dynamic hip screw, cortical screws, proximal femoral nail) administered spinal anaesthesia for whom contemporaneous vital signs (including blood pressure, heart rate, oxygen saturation, breathing rate) have been stored in an anonymised, double password-protected database held on secure computers at Princess Royal Hospital, Hayward's Heath (E. Sussex).

Description

Inclusion Criteria:

  1. Adults (over 18 years) who have sustained a unilateral hip fracture and received surgery (hemiarthroplasty, dynamic hip screw, cortical screws, proximal femoral nail) under low dose spinal anaesthesia (1.3 mls 0.5% hyperbaric bupivacaine) after fascia iliaca block + sedation, administered by the Chief Investigator (CI) between 3rd March, 2017 and 1st January, 2020 at the Princess Royal Hospital, Hayward's Heath (E Sussex).
  2. For whom crude vital signs data have been stored in pseudo-anonymised electronic form on secure hospital computers, for medico-legal reference

Exclusion Criteria:

  1. People with hip fracture receiving conservative management during the study period;
  2. People with hip fracture requiring total hip arthroplasty (for whom larger volumes of spinal anaesthesia are used);
  3. People with hip fracture administered spinal anaesthesia other than 1.3 mls 0.5% hyperbaric bupivacaine;
  4. People meeting inclusion criteria for whom vital signs could not be stored electronically due to equipment failure.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Hip fracture cohort

Gender, Age, Racial and Ethnic Origin of Subjects Male and female adults over the age of 18 years; all origins, all races will be included.

Inclusion/exclusion criteria as below
Procedure: Intrathecal anaesthesia
Low dose 0.5% hyperbaric bupivacaine (1.3mls, 0.65mg) intrathecal anaesthesia.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cohort mean (SD) mean non-invasive blood pressure (MAP)
Time Frame: Occurring during the 2 hour duration (approximately) of anaesthesia and surgery for each patient
Taken at 2 minute intervals peri-operatively for each patient
Occurring during the 2 hour duration (approximately) of anaesthesia and surgery for each patient

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The cohort prevalence of hypotension
Time Frame: During anaesthesia and surgery

Cohort prevalence of hypotension, variably defined as:

  1. Fall in systolic blood pressure (SBP) from baseline > 20%;
  2. Fall in systolic blood pressure (SBP) from baseline > 30%;
  3. Fall in mean arterial pressure (MAP) from baseline > 20%;
  4. Fall in mean arterial pressure (MAP) from baseline > 30%;
  5. Lowest SBP < 90 millimetres of mercury (mmHg);
  6. Lowest SBP < 100 mmHg
  7. Lowest MAP < 70 mmHg;
  8. Lowest MAP < 55 mmHg.
During anaesthesia and surgery
Mean depth x duration area under curve product for cohort hypotension after low dose spinal anaesthesia for hip fracture surgery
Time Frame: During anaesthesia and surgery
Mean depth x duration area under curve product for cohort hypotension after low dose spinal anaesthesia for hip fracture surgery
During anaesthesia and surgery
Quantification of cohort systolic and mean arterial blood pressure changes before spinal administration
Time Frame: During anaesthesia and surgery
Describing any effects of propofol sedation and local anaesthetic nerve block
During anaesthesia and surgery
Effective cohort duration of spinal anaesthesia
Time Frame: During anaesthesia and surgery
Including number of augmentatory anaesthetic interventions required in mean (SD) time from spinal administration to surgical skin closure
During anaesthesia and surgery
Correlations between individual (a) hypotension (b) hypotension depth/duration product and outcomes (death at 30 days, length of stay in hospital)
Time Frame: During anaesthesia and surgery
Correlations between individual (a) hypotension (b) hypotension depth/duration product and outcomes (death at 30 days, length of stay in hospital)
During anaesthesia and surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Royal Sussex County Hospital

Investigators

  • Principal Investigator: Stu White, FRCA BSc MA, Consultant Anaesthetist

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 3, 2017

Primary Completion (Anticipated)

May 24, 2023

Study Completion (Anticipated)

May 24, 2023

Study Registration Dates

First Submitted

February 23, 2023

First Submitted That Met QC Criteria

March 22, 2023

First Posted (Actual)

April 5, 2023

Study Record Updates

Last Update Posted (Actual)

April 5, 2023

Last Update Submitted That Met QC Criteria

March 22, 2023

Last Verified

March 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RoyalSussex

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

On application to PI

IPD Sharing Time Frame

From submission for publication, indefinite

IPD Sharing Access Criteria

Oral/written application to PI

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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