Intravenous sedation Flashcards
Advantages of IV sedation
Given remote from operating site Administered as single dose Rapid onset Mouth breathing not important Pt co-operation less important ***
Disadvantages of IV sedation (6)
Not clinically useful analgesia
Overdose can lead to profound respiratory depression
Laryngeal reflexes obtunded for a short period?
Occasional disinhibition effects
Occurrence of sexual fatasies
Pre/ post op instructions must be followed
Pt management techniques (9)
Time and TLC Local analgesia Psychotherapy Hypnosis Acupuncture Inhalation sedation Oral/ transmucal sedation IV sedation GA
Minimising anxiety (7)
Empathy Kindness Courtesy Explanation Support Time Gentleness
Purpose of sedation (5)
Control of fear, anxiety and apprehension
Reduce stress associated with unpleasant/painful procedures
To control severe gag reflexes
Treatment of uncooperative patients, including children and those with disability
To stabilise the blood pressure of patients with hypertension and a history of cardiovascular cerebro-vascular disease
Medical history (5)
Written questionnaire completed with the patient
Verbal discussion with patient
Contact GP
Liaise with other health care professionals
Advice from consultants
American Society of Anaesthesiologists Physical Status Rating (5)
I II II IV V A moribund pt not expected to live 24hrs ****
Dental history (5)
Attitude to dental care Past history Past experience of sedation and GA Recent history Main dental problem
Dental examination (7)
Tx required Length of procedure Degree of trauma involved Muliple visits Acute infection Degree of pt co-operation required Radiographs required during tx
Social history (7)
Able to provide a responsible escort Ability to understand and follow pre- and post-operative instructions Someone to help at home Able to take time off work Someone to look after the children Someone to stay overnight Transport to and from the surgery
Consent (2)
Informed consent explains the benefits of treatment, the risks and disadvantages of treatment and the treatment alternatives to the patient in a language that they understand. Document for each course of treatment
Patients who lack capacity to give informed consent (6)
Discuss everything with next of kin; discuss treatment with care staff, appoint IMCA
Have 2 professionals (doctor/ dentist) independently agree that this treatment is in the best interests of the patient.
Named person to sign pre/post operative instructions
Liaise with parents/GP regarding medical history
Baseline physical assessment (7)
Colour Pulse Respiration Arterial oxygen saturation Blood pressure Weight BMI Level of consciousness Degree of understanding and co-operation
Special tests e.g. (3)
Liver function test
ECG
Sickle cell test
Contraindications to IV sedation (6)
Allergy to benzodiazepines Pregnancy Age ASA III, IV, V Poor veins Drug interactions
Equipment (6)
Oxygen and emergency oxygen Cylinder capable of giving 15l/ min Attachments capable of administering IPPV Within 'arms reach' Checked each session Records kept
Suction (3)
Emergency suction
Non-mains powered suction
Attachments for oral and pharyngeal suction
Emergency drugs (3)
Flumazenil (Anexate) 0.5mg/5ml, and appropriate emergency drugs
Needles, syringes, cannula, tourniquet, tape, alcohol wipe
Staff trained and confident to use them
Other appropriate emergency drugs (2)
Midazolam 10mg/5ml
Saline for IV administratin
Clinical effects of benzodiazepines (6)
Anxiolysis Sedation Hypnosis Amnesia Anticonvulsant Decrease in skeletal muscle tone
Set up for IV sedation
Midazolam, note expiry date/batch, 5ml syringe, straight needle for drawing up drug, pre injection swap/mediwipes, micropore tape, 22G cannula, gauze/ampoule opener, yellow sharps box, tourniquet
Normal values
Weight: 70kg,
Temperature: 36-37.5C 96.8-99.4F,
Colour: pink, well perfused,
Pulse: 70 beats per minute, full volume, regular,
Respiration: 12-20 regular breaths per minute
Blood pressure: 120/80 mm Hg 16/10 KPa
Colour
Pink, well perfused. Blue, cyanosed, check nailbeds, earlobes, lips, gingivae
Respiratory obstruction
Potentially fatal complication, may lead to coughing, straining, vomiting and regurgitation, suspected if snoring, paradoxical chest and abdominal movement, straining. Airway causes (edentulous patients), tongue, swelling, tumour, stricture, irradiation, epiglottis, restricted jaw opening
Level of consciousness
Stand unaided with eyes closed, Romberg test, touch nose with forefinger, loss of facial expression/animated, eyes open/closed/ptosis, speech slurred/slow, respond to verbal command
Pulse oximetry based on 3 principles (3)
- The difference in absorption spectra of reduced and oxygenated haemoglobin
- The Beer-Lambert Law
- That only reduced and oxy-haemoglobin are present in the blood
Paperwork (4)
Consent, medical history, signed pre and post operative instructions, sedation record sheet
Second appropriate person (1)
BADN Registered Dental Nurse with Certificate in Dental Sedation Nursing
Blood pressure (5)
Manual sphygmomanometer, electronic sphygmomanometer,
Pre-operative, intra-operative, post-operative
Choice of IV sedating agent - historical and nowadays (3)
Diazepam 1966 historical
Midazolam 1984 - quick onset of action and rapid metabolism and excretion
Additional drugs - multidrug sedation - propofol and opiates require advanced airway management training
Midazolam for injection (3)
Clear, colourless isotonic solution containing -sodium chloride -hydrochloric acid -sodium hydroxide -in water for injection pH 3.3 Lipid soluble at physiological pH
CNS - BZD receptors (1)
Benzodiazepines enhance inhibitory action of GABA in the CNS
Midazolam - site of action (2)
BZD potentiate GABA by increasing the flux of Cl ions into the cell, thus decreasing the ability of the cell to initiate an action potential.
GABA - inhibitory neurotransmitter (2)
GABA - A modulated by other receptors -benzodiazepines -barbiturates -some steroids -alcohol GABA - B skeletal muscle role
GABA - A modulation (6)
Opening of receptor channels (Cl influx) Anxiolytic effect Hypnotic sedative Anticonvulsive Amnestic effect Muscular relaxation
Midazolam - pharmacokinetics (2)
Elimination half life 1-2.8hrs Onset of action: IV *3 minutes IM 5 minutes Oral 15 minutes Nasal 15 minutes Rectal 15minutes
Increased Midazolam availability (3)
Factors increasing half life:
age ( elderly)
sepsis
poor renal function
Midazolam - additional effects (3)
Decreases ventilatory response to CO2
Decreases mean arterial pressure
Reduction of cerebral blood flow
Midazolam contraindications (4)
Hypersensitivity to BZP Myasthenia Gravis Shock or vital sign depression Acute narrow angle glaucoma - open angle glaucoma with app. Rx - ask treating physician
Midazolam care (5)
BZP use Opiates Alcohol abuse other sedatives Social drugs
Signs of midazolam overdose (5)
over sedation confusion impaired coordination diminished reflexes decreasing vital signs/O2 sats
What to do in a midazolam overdose (3)
Stop Midazolam
Oxygen
Reversal - Flumazanil 200ug in intial dose
Flumazenil - pharmacokinetics (3)
Dose: 200-600ug IV
Competitive inhibitor of BZP
Elimination half life 53 minutes
Potential for re-sedation due to differences in half life
Patient preparation (4)
Pre assessed - Baseline observations MH inc allergies and drugs noted (ASA assessment) Written consent - treatment checked Escort/ transport/ childcare etc checked
Venepuncture (2)
IV access gained
- practice/ cannula knowledge
IA access - accidental
-pre drug admin: remove cannula - apply P
-post drug admin: leave cannula in place and
contact local vascular surgeons urgently
Watch for which 3 things (3)
TRANSFIXATION
HAEMATOMA
EMBOLISM
Types of embolism (3)
Thromboembolism
Cannula embolism
Air embolism
Monitoring (4)
BP, HR and O2 Saturation
BP required Pre and Post treatment can be continuously monitored
O2 Saturation required throughout
Observation of patient - Vital signs
Supplemental oxygen - always consider (5)
Epilepsy IHD Previous CVA Heart Failure Anaemia/Sickle cell trait
Operator behaviour (3)
Behaviour to induce confidence/relaxation
Quieten voices
Appropriate language
*Always have operator and additional trained person in room - record this
Preparation of IV drugs (4)
NPSA guidelines on preparation and administration of drugs for injection
Sterility
Labelling
Disposal
Recording
Local anaesthetic in sedation (2)
Midazolam has no analgesic properties
LA is required
-however suggestion can be powerful
Midazolam titration (3)
Slow IV administration of 2mg Wait 90 seconds assess sedation 1mg Wait 90 seconds assess sedation 1mg … until desired sedation achieved
Midazolam sedation (3)
Golden 20 minutes
Another 30 minutes possible
May require top ups
Realistic treatment in time
Dose range 2-10 mg usual
Complications (4)
Falling sats Under sedated Over sedated Venepuncture related -failed -bruising -extravasation
Recovery and discharge (5)
Monitor whilst recovering
Keep one hour after last IV dose of midazolam
Written and verbal post -op instructions to escort
Rhomberg
Steady on feet/walk unaided
Additional post-op instructions - for 24 hours (4)
No driving/operating machinery inc. cooking, ironing
No alcohol/sedative drugs
No legal responsibilities inc. signing legal documents, looking after children, attending work
Patient not to be left alone
Recording (5)
Keep accurate contemporaneous notes Have a log of all medications used Dispose of unused Midazolam properly and witnessed Record any flumazanil use Regularly check drugs -exp dates
Regular training/ checks (3)
All Resus drugs/equip checks
Staff training resus/emergencies
Have these logged within the practice
Unusual side effects (1)
Sexual fantasy is thought to occur in 1 in 200 cases of midazolam sedation
Drug abuse (4)
Dentists are high risk
Ensure drug recording/disposal practices are exemplary
Seek advice if you have any concerns
Senior colleague/MDU/MPS
You have a duty to report
