Chemical Analysis of Limb Microfluidics (CALM)

Compartment syndrome (CS) is a condition where an increase in pressure in an anatomical compartment (e.g. the lower leg) affects the blood supply of the tissues, leading to tissue damage. The condition is difficult to diagnose, and more difficult to determine when and how to manage it.

Treatment aims to reduce the pressure in the compartment by whatever means possible. Surgical management by of CS is highly invasive and has associated risks including infection, damage to local structures (i.e. nerves), and possibly the inability to close the wound leading to the need for further reconstructive procedures.

The clinical challenge in suspected CS is knowing if and when to intervene. Some cases of mild CS may resolve without an operation, and therefore intervening too soon causes unnecessary harm to the patient. However, waiting too long to operate with high compartmental pressures may lead to irreversible damage to the tissues, resulting in either a useless limb or necrotic tissue needing amputation.

Current strategies for determining limb health include interrogation of symptoms, signs on examination, and serial measurements of compartmental pressures, but no absolute measurement of tissue health. As such, there is an element of clinical judgment in management and no evidence base with which to develop clear treatment guidelines. There is a need for a minimally invasive method of continuously monitoring tissue health to improve the understanding of CS and its management before significant improvement in patient outcomes can be delivered.

It is proposed the application of leg "microfluidics" - analysis of samples of leg fluid - in a series of predictable clinical scenarios which simulate the threatened and unsalvageable limb. This is with an ultimate aim of developing a method of limb fluid sampling that can predict if CS is present and requires intervention.

Study Overview

• Status: Recruiting
• Conditions: Compartment Syndrome of Leg; Limb Ischemia
• Intervention / Treatment: Device: Microdialysis catheter + biosensor

• Study Type: Observational
• Enrollment (Estimated): 12

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, W21NY
    • Recruiting
    • Imperial College London
    • Contact: Madelaine Gimzewska, MBChB; Phone Number: +442075948904; Email: m.gimzewska@imperial.ac.uk
    • Principal Investigator: Richard Kwasnicki, MBChB PhD
    • Sub-Investigator: Madelaine Gimzewska, MBChB

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients (aged greater than or equal to 18 years) who are either:

i. Undergoing an intervention where there is a controlled reduction in blood flow to the limb that is reversible (e.g. using a tourniquet or clamp) or irreversible (e.g. during limb amputation).

ii. At risk of developing compartment syndrome following trauma or surgical intervention as determined by the clinical care team.

Description

Inclusion Criteria:

Adult patients (aged greater than or equal to 18 years) who are either:

i. Undergoing an intervention where there is a controlled reduction in blood flow to the limb that is reversible (e.g. using a tourniquet or clamp) or irreversible (e.g. during limb amputation).

ii. At risk of developing compartment syndrome following trauma or surgical intervention as determined by the clinical care team.

Exclusion Criteria:

Age <18 years old Unable to provide informed consent

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Irreversible ischaemia; patients undergoing elective amputation of a limb (e.g. peripheral vascular disease)	Device: Microdialysis catheter + biosensor; Microdialysis catheter from linton instrumetal "63 MD Catheter"
Reversible ischaemia; patients undergoing an operation with a limb tourniquet or intentional controlled reduction in blood flow to the lower limb (e.g. aortic cross clamping for vascular surgery).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Relative concentrations of key metabolites	Relative concentrations of key metabolites (glucose, potassium, lactate) in lower limb interstitial fluid, estimated against baseline	20 minutes (real time analysis that takes 20 minutes to register from point of sampling to result)

Collaborators and Investigators

• Sponsor: Imperial College London
• Collaborators: The Drummond Foundation (RAMC charity)

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2023
• Primary Completion (Estimated): December 1, 2023
• Study Completion (Estimated): March 1, 2024

Study Registration Dates

• First Submitted: September 6, 2023
• First Submitted That Met QC Criteria: September 21, 2023
• First Posted (Actual): September 22, 2023

Study Record Updates

• Last Update Posted (Actual): September 26, 2023
• Last Update Submitted That Met QC Criteria: September 22, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Keywords: Compartment syndrome; Microfluidics; Limb ischaemia
• Additional Relevant MeSH Terms: Pathologic Processes; Cardiovascular Diseases; Vascular Diseases; Musculoskeletal Diseases; Muscular Diseases; Ischemia; Compartment Syndromes
• Other Study ID Numbers: 20SM5770; IRAS (Other Identifier: 332422)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No