Modifiable factors Affecting Propofol Dosing

• Research type

  Research Study

• Full title

  Modifiable factors affecting the dose of Propofol required for Anaesthetic Induction

• IRAS ID

  228141

• Contact name

  Marcela Vizcaychipi

• Contact email

  m.vizcaychipi@imperial.ac.uk

• Sponsor organisation

  Chelsea and Westminster NHS Hospital Trust

• Clinicaltrials.gov Identifier

  NCT03453099, ClinicalTrials.gov Protocol Registration

• Duration of Study in the UK

  0 years, 8 months, 31 days

• Research summary

  There is significant variability in the response to a given dose of the anaesthetic induction agent propofol. Part of these differences are due to the way individuals absorb, distribute and breakdown a drug but there are still large differences in response to the drug amongst individuals at a given blood concentration.

  The factors dictating this variation are poorly described but would be useful for predicting drug dosing in clinical anaesthesia. Indeed current evidence suggests excessive anaesthetic doses cause longer postoperative recovery times and possibly increased long term mortality.

  We hypothesise that modifiable factors may cause reversible changes in a patients neurobiology which affect their responsiveness to anaesthetic drugs. These factors may include chronic caffeine intake, chronic sleep deprivation, 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 allow for better prediction of dose requirements and reduction of the associated complications.

  We also hypothesise that these same factors may affect subjective postoperative pain levels and analgesic requirements. Appropriate postoperative pain control is important clinically not only for improved patient experience but also to reduce cardio-respiratory postoperative complications and decrease hospital length of stay.

  To address these questions, we will be asking patients admitted for any day case surgery at Chelsea & Westminster hospital to complete short questionnaires addressing:
  1) Caffeine intake
  2) Sleeping habits
  3) Anxiety about the operation on the day of surgery
  4) Alcohol intake
  5) Smoking status

  Additionally participants will rate their postoperative pain at 1 and 3 hours on a scale from 1-10 whilst at rest and whilst coughing. We will also record the amount of morphine requested and administered via PCA.

  These factors will be compared to the amount of the anaesthetic drug propofol required to induce loss of consciousness prior to surgery.

• REC name

  London - London Bridge Research Ethics Committee

• REC reference

  18/LO/0541

• Date of REC Opinion

  6 Apr 2018

• REC opinion

  Favourable Opinion