Conduction of General Anaesthetics Flashcards
What are the stages of anaesthetics
- Pre-op assessment and planning
- Preperation (setup)
- Induction (pateint goes to sleep)
- Maintenance (keeping pt asleep)
- Emergence (Awakening)
- Recovery (period after teh anaestehtic)
- Psot-op care period (visti/follow-ups)
What are the important parts of preperation for anaestheisa?
Step 2
- Team: anaesthetist, anaesthetic assistant, opertaing deprtament practitioners
- Specialist type fo anaesthetist
- Right place
- Right time (no elective procedure during evening hours)
- Equiment check
- Team brief (talk trhough cases of the day, concerns, issues)
- Check-in: WHO theatre check
- Monitoring
- IV access (Cannula)
- Pre-oxygenation (additional O2 to preathe prior to anaesthesia, 100% O2 fro few mins)
What are the checks of the WHO theatre check-list?
Correct:
* Patient
* Procedure
* Site (Marked)
* Consent
What are the 5 standards for monitoring anaesthetic procedures?
Association of Anaestheticsts minimum standard
All anaesthetists msut have thses pieces of equipment prior to commensing:
* ECG
* O2 sats
* Non-invasive BP
* End tidal CO2 (ETCO2)
* Airway pressure Monitoring
Why do patients recieve pre-supplimental O2 prior to undegoing anaesthesia?
Under anaesthesia:
* Common for patients to become apnoeic and stop breathing (desirable at times)
- Muscles relax, total vol of lungs reduces. Functional residual capacity allows O2 to be continued to be taken up between breaths. Reduced FRC, less O2 available for blood to take up, less time before desatuartion of patient. If more of the gas is made up of O2 than CO2, longer time before pt becomes desaturated (instead of 1 min takes 5 mins))
Describe the steps involved in the 1st phase of anaesthetic
Induction (IV, inhalation)
How are children induced differently from adults?
- Children cannot tolerate being cannulated -> Inhaled anaesthesia
- Adulst tolerate cannula better -> IV anaesthesia
Describe the steps of an IV induction
What is commonly the combination of agents used for IV induction?
- Analgesic: Fentanil, Alfentanil
- Hyponitic: Propofol, Thiopentone, Ketamine
- Muscle relaxant (some cases, avoid if unnecissary)
Name the Gidell planes of Anasthesia
- Analgesia and amnesia
- Delerium to unconcioussness (excitatory behaviour)
- Surgical anaesthesia (no movement in response to surgical stimulus)
- Apnoea to death
Why do pateints require airway management?
Induction: ABC approach
- Anaesthtic process causes relaxation of msucles of teh airway (collapse of muscles of the airway)
- Loss of airway reflexes (pts do not cough/swallow)
What are the steps in airway management?
Induction: ABC approach
- Triple airway manouvre
- Anaesthetic mask application
- Oropharyngeal airway (“Guedel” airways)
- Laryngeal Mask Airway (LMA): sits over larynx
- Endotracheal Tube (ETT) using laryngoscopes, placed beyond vocal cords
What are indications for intubation
Induction: ABC approach
- Protection from aspirastion (e.g. unfasted pts)
- Patients require muscle relaxants
- Shared airway procedures (operations around mouth/face)
- Need for tight CO2 control (neurosurgical cases)
- Minimal access to patient
What are the systems in place to support patient breathing during anaesthesia?
Induction: ABC approach
- Spontaneous ventilation
- Controlled ventilation (pts paralysed)
- Supported ventilation (monitored using saturation probe, ETCO2, airway pressure monitoring)
What are systems in place to support patients circulation when under anaetshesia?
Induction: ABC approach
- Control hameodynamics: BP taken at leats every 5 mins
- Vasoactive drugs
What are the risks of induction?
Induction
- Anaphylaxis (to anaesthetic agents)
- Regurgitation and aspiration (pateints need to be fasted when possible)
- Airway obstructiona nd hypoxia
- Laryngospasm (vocal cords constrict, prevent passage of air)
- CVS instability
- Rarely, cardiac arrest
What are risks of anaesthetic awareness occuring in a patient?
- 1/8200: with use of muscle relaxants
- 1/135900: without muscle relaxant
What signs do anaesthetists look for in pateints when concerned about anaesthetic awareness?
- Tachycardia
- High BP
- Being sweaty
Movement under anaesthetic is not sigh of awareness necissarily
What monitoring can be used to reduce risk of awareness under anaesthesia?
Depth of anaesthesia monitors (measures amount of anaetshetic agent being breathed in and out)
* BIS( Bispectral Index) : Limited EEG (measure depth of anaesthesia) gievs index number indicating how asleep teh pateint is
What are some risks to concider once the pateint is induced?
- Awareness under anaesthesia (1:8200, 1:135900)
- Eye injury (cornea can dry out from lack of blinking) (1:1000)
- Hypothermia (1:25, 1:2)
- Pressure injury (1:5)
- VTE (1:100-1:4)
- Nerve injury (1:1000)
How is risk of hypothermia during surgical procedures managed?
- Check pt temperature every 30 mins
- Oesophageal temeprature probe (continuous temp monitoring)
- Covering patient
- Forced warm air blankets (“Bear Huggers”)
How are pressure injuries averted during surgicla procedures?
- Padding areas under pressure (gel pad)
- Awairness of cables/tubes
How are risks fo VTE reduced?
- Kepp patients active as long as possibel prior to procedure
- Ted stockings
- Flowtrons (tubes that inflate and deflate to pump blood in venbous system of the legs)
- Chemical prophylaxis (Delta power) night before
How are risks fo VTE reduced?
- Kepp patients active as long as possibel prior to procedure
- Ted stockings
- Flowtrons (tubes that inflate and deflate to pump blood in venbous system of the legs)
- Chemical prophylaxis (Delta power) night before
