Postoperative Continuous Non-invasive Haemodynamic Monitoring on the Ward (PostConMon)

Postoperative Continuous Non-invasive Haemodynamic Monitoring on the Ward: a Feasibility Study

The patient's clinical care will not be altered apart from an the use of a non-invasive monitor for a short time, without any biological sample acquisition, or follow-up. This is low risk.

The device works through a complex pressure measurement in the fingers and by slightly squashing the fingers it can cause minor impairments to circulation. This represents a very small risk. To mitigate this risk the investigators will exclude patients with impaired circulation to the fingers and fingers will be monitored.

The approach is necessarily on the day of surgery and for many people this is an anxious time. The investigators have a lot of experience of approaching patients on the day of surgery for providing consent for observational studies - the investigators use caution and sensitivity. The investigators do not approach patients who the clinical team consider anxious or where there is significant pressure on time.

Study Overview

• Status: Unknown
• Conditions: Blood Pressure Disorders; Surgical Procedures, Operative; Hemodynamic Instability
• Intervention / Treatment: Device: LIDCO CNAP device

Detailed Description

Enrolled patients will have the CNAP sited in the post-anaesthetic care unit (PACU) and it will stay on their arm until at least 12 hours have passed. The device will collect continuous heart rate, blood pressure, and nominal cardiac output; it also derives a range of values from these measurements. There is minimal risk attributable to the use of the CNAP device. These devices are already in routine clinical use in the UK in intensive care units, high-dependency units and operating theatres.

To reduce burden on the patient, no additional HR/BP monitor is required and whenever the usual care team would like to know the HR or BP these values will be displayed. The additional parameters (related to measurement of cardiac output) will not be shared with the clinical team - they will remain blinded to these data because otherwise there is the risk that they would use this additional information to alter clinical management.

Medical notes will be examined to provide information about demographics, physical characteristics (height, weight), and previous medical history - please see case report form (CRF, appendix 1) for more details.

There are no blood tests, or other acquisition of biological samples.

• Study Type: Interventional
• Enrollment (Anticipated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ben Creagh-Brown; Phone Number: 01483402724; Email: bencb@nhs.net
• Study Contact Backup: Name: Charlotte E King; Phone Number: 07516372025; Email: ck2g17@soton.ac.uk

Study Locations

• United Kingdom
  • Guildford, United Kingdom, GU2 7XX
    • Recruiting
    • Royal Surrey County Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Has capacity to provide informed consent
• Surgery: planned or unplanned; all types including gastrointestinal, urology, orthopaedics and gynaecological
• Due for an inpatient stay (i.e. not day case surgery) on either Frensham or Bramshott wards (staff will have had training with the device on these wards)
• Aged 18 years or over

Exclusion Criteria:

• Admission to intensive care unit ICU / high dependency unit HDU
• Declines consent to participate, or lack capacity to provide consent
• Impaired circulation of the hands: Raynaud's disease or severe peripheral vascular disease.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: DEVICE_FEASIBILITY
• Allocation: NA
• Interventional Model: SINGLE_GROUP
• Masking: NONE

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility	Number of suitable patients who provide consent and have the device sited / number of suitable patients who provide consent (%)	3 months
Acceptability	In those patients who have provided consent and had the monitor sited, how many tolerate the device and keep it on throughout the observation period (at least 12 hours) and provide useable data / number of suitable patients who provide consent and have the device sited (%)	3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
What proportion of patients have any recorded episodes of hypotension?	Endpoint: proportion of patients with hypotension Outcome 1: number of patients with SBP<90mmHg / total number of patients (%)	3 months
What proportion of patients have any recorded episodes of hypotension? Just considering the time on the ward, after PACU	Endpoint: proportion of patients with hypotension Outcome: number of patients with SBP<90mmHg / total number of patients (%)	3 months
In the PACU, considering those with at least one episode of SBP<90mmHg, how long are patients hypotensive for? (CNAP data)	Endpoint: duration of hypotension, sum of all episodes Outcome 1: minutes of hypotension Outcome 2: proportion of total time in PACU with hypotension	3 months
On the ward, considering those with at least one episode of SBP<90mmHg, when using data from the CNAP, how long are patients hypotensive for?	Duration of hypotension from CNAP, sum of all episodes (CNAP min) Episodes of hypotension with CNAP, total duration as sum of individual episode durations	3 months
On the ward, considering those with at least one episode of SBP<90mmHg, when using data from VitalPAC, how long are patients hypotensive for?	Duration of hypotension from VitalPAC, sum of all episodes (VitalPACmin) Episodes of hypotension with VitalPAC, total duration as sum of individual episode durations	3 months
On the ward, when there are discrete episodes of hypotension, what is the distribution of nominal stroke volume index?	nominal stroke volume index (nSVI) Outcome 1: Histogram of nSVI Outcome 2: Proportion of episodes of hypotension with an nSVI: low (<35ml/m2), normal (35-65ml/m2) and high (>65ml/m2)	3 months
On the ward, when there are discrete episodes of hypotension, when paired with MAP and a notional RAP, what is the distribution of systemic vascular resistance index, SVRI?	systemic vascular resistance index (SVRI) Distribution of SVRI	3 months
During an episode of hypotension, what intravenous fluids are given, at what prescribed rate?	Endpoint: observation of clinical care Outcome: which intravenous fluids, at what prescribed rate?	3 months
During episodes of hypotension treated with an intravenous fluid bolus (IVFB) what is the haemodynamic response? Is the response predictable using either baseline nSVI or SVV?	Endpoint: SBP and nSVI before and during/after IVFB (30 minutes after start) Outcome 1: Categorise episodes into the following: responders (≥15% increase in nSVI or ≥15% SBP) or non-responders (<15% increase in nSVI and SBP) Outcome 2: Display distribution of nSVI (low/normal/high) prior to IVFB between responders and non-responders. Outcome 3: Compare % change in nSVI in response to IVFB between those with low nSVI (potentially more responsive) to normal/high nSVI. Outcome 4: Compare SVV (%) measured before IVFB between responders and non-responders.	3 months
What proportion of IVF boluses are associated with a significant improvement in haemodynamics?	Endpoint: Number of IVFB that are associated with haemodynamic benefit (≥15% increase in nSVI or ≥15% SBP) / Total number of IVFB	3 months
Volume of IVF given that would not have been indicated by CNAP readings	Endpoint: Sum of individual IVF boluses given when both of the following conditions are met at the start of the IVF bolus: Prior IVF did not improve nSVI by ≥15%; Stroke Volume Variation <5%	3 months
What treatments were delivered intra-operatively and in PACU.	Endpoint: observation of clinical care Outcome: Receipt of intravenous fluids, blood products, vasopressor drugs, admission to critical care.	3 months
What are the clinical outcomes? length of stay (LOS)	Clinical outcomes from medical records : length of stay (LOS)	3 months
What are the clinical outcomes? critical care admission	Endpoint: Clinical outcomes from medical records: critical care admission (ICU LOS)	3 months
What are the clinical outcomes? acute kidney injury	Endpoint: Clinical outcomes from medical records: acute kidney injury (from urine output and change in creatinine)	3 months
What are the clinical outcomes? acute myocardial infarction	Endpoint: Clinical outcomes from medical records: acute myocardial infarction (EPCO definition)	3 months
What are the clinical outcomes? incidence of blood transfusion	Endpoint: Clinical outcomes from medical records: incidence of blood transfusion	3 months
What are the clinical outcomes? unplanned ICU admission	Endpoint: Clinical outcomes from medical records: unplanned ICU admission.	3 months

Collaborators and Investigators

• Sponsor: Royal Surrey County Hospital NHS Foundation Trust

Publications and helpful links

General Publications

• King CE, Kermode A, Saxena G, Carvelli P, Edwards M, Creagh-Brown BC. Postoperative continuous non-invasive cardiac output monitoring on the ward: a feasibility study. J Clin Monit Comput. 2021 Dec;35(6):1349-1356. doi: 10.1007/s10877-020-00601-z. Epub 2020 Oct 22.

Study record dates

Study Major Dates

• Study Start (ACTUAL): September 2, 2019
• Primary Completion (ANTICIPATED): November 22, 2019
• Study Completion (ANTICIPATED): November 22, 2019

Study Registration Dates

• First Submitted: June 27, 2019
• First Submitted That Met QC Criteria: July 2, 2019
• First Posted (ACTUAL): July 8, 2019

Study Record Updates

• Last Update Posted (ACTUAL): September 24, 2019
• Last Update Submitted That Met QC Criteria: September 21, 2019
• Last Verified: September 1, 2019

More Information

Terms related to this study

• Other Study ID Numbers: 19SURN268889

Drug and device information, study documents

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