MAPD: Modifiable Factors Affecting Propofol Dosing
Condition: Anesthesia
Study type: Observational

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.
    

Intervention name(s): Preoperative Questionnaires; Postoperative Subjective Pain Scores
Intervention type(s): Other; Other
Intervention description(s): The participants will be asked to complete 5 questionnaires:
An abbreviated version of the Caffeine Assessment Tool (CAT)
Sleep Questionnaire (SQ)
Surgical Fear Questionnaire (SFQ)
WHO Alcohol AUDIT Tool
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; 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.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        All patient scheduled for day case general anasethesia at Chelsea & Westminster hospital
        who satisfy the listed inclusion and exclusion criteria
      
Keywords: propofol; anaesthetic dose; sleep; caffeine; anxiety; induction