Vasoactive Agents in Acute Mesenteric Ischemia

Who is conducting the research?

Dr Rachael Eimear McClenaghan – University of Edinburgh, Aberdeen Royal Infirmary
Mr George Ramsay – University of Aberdeen, Aberdeen Royal Infirmary
Dr Callum Kaye – University of Aberdeen, Aberdeen Royal Infirmary
Prof Patrice Forget – University of Aberdeen, Aberdeen Royal Infirmary

What is the purpose of this project?

Acute mesenteric ischaemia (AMI) is defined as a sudden inadequacy of arterial supply or venous drainage to the bowel, leading to ischemia and cellular damage (with or without necrosis) (1,2). AMI comprises of four pathophysiological processes (nonocclusive mesenteric ischaemia (NOMI), mesenteric arterial embolism, mesenteric venous & arterial thrombosis) that have a common end point: splanchnic hypoperfusion. These processes can cause gut-derived systemic inflammatory response syndrome (SIRS) or mesenteric ischaemic necrosis; leading to severe metabolic derangement and culminating in multiple organ dysfunction requiring critical care support (3,4).

Acute mesenteric ischemia (AMI) is a surgical emergency with an increasing incidence and a prevalence of ~1:1000 hospital admissions (5-9). In patients who undergo emergency laparotomy, 11.8% have mesenteric ischemia which is associated with a 23.9% 30 day, and 27.7% 90-day, mortality rate (2). AMI is associated with a variable but often high mortality, especially when detected late or with accompanying metabolic derangement (5,6). This variability may be secondary to differences in both local practice (2,10,11) and between clinicians. Such variation in management could be attributed to the lack of evidence based guidelines available for AMI (12-17).

The optimal management of AMI depends on the underlying pathophysiology and whether the affected bowel is ischaemic or infarcted. Universal to the basic management of AMI is the recommendation for critical care and perioperative support. However, the use of vasoactive drugs for patients with AMI and haemodynamic instability is widely contested. The use of vasoactive drugs, or perhaps the preceding hypotension leading to a vasoactive drug requirement, have been linked to a decrease in splanchnic perfusion (7,14).

This is a major cause of concern for surgeons, anaesthetists and critical care clinicians involved in managing AMI in critical care or perioperatively.

We aim to perform a plain survey to establish variations in management of AMI perioperatively and in critical care. At the end of the survey, you will be invited to participate in a Delphi process.

Why have I been invited?

You have been invited to participate in this survey, and the subsequent Delphi process, because we think you are involved in the care of patients in a critical care or perioperative setting with acute mesenteric ischaemia.

Part of the Delphi process will assess participant eligibility to be part of a multicentre trial committee; including appropriate aknowledgement/authorship (according to the ICMJE criteria).

If you have not been involved in the care of such patients, please disregard this invitation.

What does participation involve?

Participation involves completing the survey on management of AMI in critical care or perioperatively. This survey should take 5 to 10 minutes to answer. At the end of this survey, you will be invited to participate in a Delphi process. We are using a Delphi process to establish a common consensus on the management of AMI in critical care or perioperatively. If you choose to proceed, we will email you subsequent surveys where we will share anonymised analyses of the previous surveys and allow you to reflect and feedback on your own and other participant’s anonymous answers.

A new survey will be emailed to you every two weeks, and you will have one week to respond to each survey.

The entire process will likely take 6 weeks (3 surveys in total) but may be longer or shorter depending on responses. You can withdraw at any point if you cannot or do not want to continue.

Are there risks or benefits in participating?

You may not benefit personally from taking part. By taking part you will be directly helping us to establish variations in management of AMI in critical care. This will identify further avenues for research in this field – specifically developing a randomised controlled trial on pharmacological treatment.

We do not anticipate any risks to participating in this study. All data is stored securely for interpretation by the researchers listed above, and will be anonymised at the point of analysis.

How will my data be used and stored?

Identifiable and personal information, including your name and country of practice, will be confidential and known only to the researchers listed above. These details are kept to verify our inclusion criteria, and to enable us to contact you with subsequent surveys if you choose to participate in the Delphi process.

All information obtained will be stored securely using a confidential, encrypted database. All data will be held in accordance with the General Data Protection Regulation (EU – 2016/789) and the UK Data Protection Act (2018). If, at any point, you decide to withdraw from the study your data prior to the point of withdrawal will be retained securely.

Who has reviewed this project?

This study has been discussed with the Life Sciences and Medicine Ethics Review Board (CERB) at the University of Aberdeen, and NHS Grampian North of Scotland Research Ethics Service (NoSRES). Both bodies advised formal ethical approval was not required for this project.

Funding

This study has been funded intramurally by the University of Aberdeen and NHS Grampian.

Contact

(Rachael) Eimear McClenaghan
Core Trainee Anaesthesia - North of Scotland
University of Edinburgh - Surgical Sciences Msc student
Honorary Teaching Fellow - University of Aberdeen
r.e.c.mcclenaghan@sms.ed.ac.uk
Department of Anaesthesia, Aberdeen Royal Infirmary, Aberdeen AB252ZN