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MAPD: Modifiable Factors Affecting Propofol Dosing

Modifiable Factors Affecting the Dose of Propofol Required for Anaesthetic Induction

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT03453099
Enrollment
91
Registered
2018-03-05
Start date
2018-04-01
Completion date
2019-08-31
Last updated
2020-02-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Anesthesia

Keywords

propofol, anaesthetic dose, sleep, caffeine, anxiety, induction

Brief summary

The investigators aim to understand the effect of a caffeine intake, sleep habits, anxiety about surgery, alcohol intake and smoking status upon the dose of the anaesthetic drug, propofol, required for anaesthetic induction.

Detailed description

The investigators hypothesise that modifiable environmental factors may cause reversible changes in a patients neurobiology which affect their responsiveness to anaesthetic drugs. Such factors may include chronic caffeine intake, chronic sleep deprivation, acute anxiety about surgery, alcohol intake and smoking. Investigation of the relationship between such factors and the dose of anaesthetic required for loss of consciousness may not only allow for better prediction of dose requirements but may also allow for optimisation of patients prior to undergoing general anaesthesia with a view to decreasing anaesthetic dose requirements and the complications associated with this. To address this questions, the investigators will be asking patients admitted for any day case surgery at Chelsea & Westminster hospital to complete five short questionnaires and a demographic sheet addressing 1) Caffeine intake 2) Sleep habits 3) Anxiety about the operation 4) Alcohol intake 5) Smoking status. This will then be compared to the amount of the anaesthetic drug Propofol required and the time taken to induce loss of consciousness prior to surgery. Loss of consciousness will be measured subjectively by loss of eye opening response and loss of verbal response when a patient is asked to count upwards from 1. The investigators also wish to investigate whether these same 5 factors affect patient reported postoperative pain and analgesia requirements. As such the investigators will also ask participants to rate their level of pain whilst at rest and whilst coughing at 1 hour after the operation. We will also record how much analgesia is requested and received in the postoperative period.

Interventions

The participants will be asked to complete 5 questionnaires: 1. An abbreviated version of the Caffeine Assessment Tool (CAT) 2. Sleep Questionnaire (SQ) 3. Surgical Fear Questionnaire (SFQ) 4. WHO Alcohol AUDIT Tool 5. WHO Smoking Questionnaire They will also be asked to complete a demographics sheet All participants will undergo standard anaesthetic induction, a research participant will observe the dose of propofol and time taken for loss of consciousness

OTHERPostoperative Subjective Pain Scores

After the operation, participants will be provide with a scale from 1-10 in which to rate their pain at rest and whilst coughing. This will be undertaken at 1hr postoperatively.

Sponsors

Chelsea and Westminster NHS Foundation Trust
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

ASA I or II patients scheduled for elective day case general anaesthesia with Laryngeal Mask Airway (LMA) airway insertion and a standard propofol-fentanyl induction, aged between 18-65 years at Chelsea & Westminster Hospital.

Exclusion criteria

1. Pregnancy 2. Neurological disease 3. Substance abuse 4. Cardiac disease 5. Renal disease 6. Obesity Additional

Design outcomes

Primary

MeasureTime frameDescription
The dose of propofol required for anaesthetic induction10 minutesPropofol will be administered at a rate of 20mg every 10 seconds by the Anaesthetist (as per national guidelines) and a member of the research team will passively record the dose of drug and the time taken for loss of consciousness as defined by a lack of eye opening and a lack of verbal response

Secondary

MeasureTime frameDescription
Postoperative patient reported pain scores5 minutesParticipants will rate their level of postoperative pain whilst at rest and whilst coughing 1hr postoperatively using a Visual Analogue Scale (1-10)

Other

MeasureTime frameDescription
Postoperative Analgesia Requirements5 minutesA member of the research team will passively record the amount of analgesia required at 1hr postoperatively

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026