Anaesthetics / Peri-Op Flashcards
Describe the grading used to asses patient fitness for surgery.
ASA Grading:
- ASA1: Healthy Patient
- ASA2: Mil Systemic Disease
- ASA3: Severe Systemic Disease
- ASA4: Life threatening
What tests make up a pre surgical assesment at low surgery and ASA grades?
- ECGs considered >40yrs
- U+Es / eGFR / FBCs >60yrs Urine Test
- Preg: fertile women UTI
- UTI
- Glucose for DM
What pre op investigations may be done on certain patients?
- CXr (infection)
- ECG (arrhythmias)
- FBCs (anemia + crp)
- Hemostasis / Coagulatiuon (warfarin or genetic clotting disorders)
- eGFR / Liver Function (GA metabolism / excretion)
- Random Glucose (Diabetes)
- Blood Glucose (Acidosis / Alkalosis / Lactate)
- Lung Function Tests (COPD)
- Group + Save (High risk for bleeds)
Why is asking about reflux an important part of a pre op assesment
Must use endotracheal intubation, LMAs carry a too high risk for aspirationGive PPI + H2antagonist prior to surg
What complications will anemic pts. liekly suffer from during surgery?
- Bleeding
* Poor Wound Healing
What allergies indicate an allergy to propofol
Egg / Soya
Name 2inherited conditions that cause problems with surgery.
Malignant Hyperthermia
- Rise in temp due to sever muscle contraction when subjected to GAs
- Treated with dantrolene + cooling blanket Suxamethonium Apnoea
- Pt. cannot metabolise suxamethonium and must be given FFP at the end of the OP.
What are asthmatic patients more likely to suffer from when anethetised?
- Pneumothorax
- Bullae
- Bronchospasm
How do you asses a difficult airway
LEMON Lookat the external airway * Obesity * Micrognathia (Small Jaw) * Trauma * Facial Hair * Poor Dental Hygiene Evaluate3/3/2 rule * 3 fingers in the mouth vertically * 3 fingers from chin to hyoid * 2 fingers from hyoid to thyroid notch Mallampatiscore * Class 1: Soft Palate Visible * Class 2: Uvula Visible * Class 3: Uvual Partially Visible * Class 4: Soft Palate Not Visible Obstruction Swelling * Burns * Trauma * Foreign Bodies Neck Should be extended
What drugs need to be stopped before OPsHow long before OPs are they stopped
Blood Thinners
- Clopidogrel (1 Week)
- Aspirin (1 Week)
- Warfarin (1 Week) BP Meds
- ACEi (Day of surg) Ca2+Channel Blockers (Day of Surg)
- Beta Blockers (Day of Surg)
- Thiazide diuretics (Day of Surg/Continue when back on fluids) Diabetic Meds
- Oral Hypoglycemics (Day of Surg (Changes in renal function))
- Short Acting Insulin (Day of Surg) Thyroid
- Thyroxine (Take in Morn and following surg) NSAIDS
- Short Acting (2/3 days)
- Long Acting (1 Week) Others
- COCP (4 Weeks / Restart 2 Weeks Post)
- Hormone Replacment (4 Weeks/ Restart 2 Weeks Post)
- Herbal Meds (2 Weeks) Nutrition
- Food (6 Hours)
- Water (2 Hours)
- Breast Milk (4 Hours)
How do you reverse wargarinisation in emergency surgery?
- Vitamin K (6-12hrs) FFP
- Immediate but causes fluid overload
- Needs to thaw Prothrombin Complex Concs. (Beriplex/Octaplex) 2/7/9/10 and Vit K
- Immediate
- Expensive £1,000
What happens concerning MRSA prior to surgery
All Pts. swabbed prior to surg
- Groin/Pernium
- Nasal Mucosa
- Skin Lesions
- Catheters
- Tracheostomies Asymptomatic
- Treated with Mupirocin Nasally TDS for 5 days
- Clorhexidine Gluconate wash 5 days
- Addition Peri Op Abxs given Symptomatic
- IV Vancomycin
How does induction of anesthetics begin?
- Propofol IV to induce the initial unconsciousness in a patient
- Thiopental can be used for rapid sequence induction
- Etomidate or ketamine can be used in cardiovascularly unstable patients (won’t depress cardiac output)
- Sevoflurane can be used as a volatile inducing agent
How do you maintain an anesthetist pt.?
Sevoflurane is an inhaled isopropyl ether which can be used for both induction and maintenance of general anaesthesiaIsoflurane and desflurane are other maintenance gases (cheaper than sevo)Propofol infusion can be used if volatiles must be avoided eg. In malignant hyperthermia
Why is it important to administer muscle relaxants and which drugs are used to do this?
- Important to stop the patient from moving and to relax abdominal muscles to make incisions easier
- Atracurium, rocuronium or suxamethonium
Why are analgesics important when pt is anesthetised?Which drugs are used?
- Prevent nociception (pain signalling) to prevent increases in heart rate, blood pressure, etc. Drugs
- Fentanil is generally used throughout surgery
- Morphine is generally used following the procedure Inhaled N2O acts as an analgesic but is likely to cause nausea and vomiting in patients with risks of post-op N&V
How is a pt. monitored when anesthetised?
Capnography (CO2) monitoring
- Possibly the most important monitor
- Can see that muscle relaxant is wearing off if the patient begins to form 2 peaks on capnography – shows that the patient is breathing = diaphragm movement = muscles not relaxed
- ECG – check for arrhythmias
- Pulse oximetry
- Blood pressure
What are the problems and contraindications of bag mask ventilation
Problems with bag-valve-mask ventilation
- Harder on men with large beards
- Harder on patients with high BMI (>26)
- Age >55
- History of snoring and sleep apnoea – oropharyngeal airway will help with this
- Lack of teeth Contraindication
- Complete airway obstruction (air will all go to stomach)
- Paralysis/anaesthesia (risk of aspiration is increased)
Advantages of tracheal intubation?How do you confirm endotracheal tube is correctly located?
Advantages
- Least likely to aspirate
- Ensure air reaches lungs not stomach Ventilation should
- Give a capnograph reading
- Make chest rise and fall
- Audible on ascultation
During intubation what has happened if only one side of the chest is rising and falling and how do you deal with this?
The tube has gone down either the L/R bronchi therefore you should pull back a bit on the endotracheal tube. (usually the R. bronchus)
Problems and contraindications for endotracheal intubation
Problems Mallampati scores of 4 are hard to intubate
- Use fibre optic laryngoscopy Its much harder to do
- Stop and bag mask ventilate back to 100% O2 before tryign again May accidentally enter the stomach increasing chance of aspiration
- Capnograph reading can confirm this Contraindications Spinal problems
- Trauma/Arthritis/degeneration
- Epiglottal infection
- Mandibular Fracture
- Oropharyngeal haemorrhage
When are SGA devices used?What are the different types?
When
- Rescue ventilation when endotracheal intubation not possible.
- Short simple operations
- Cardiac arrests Types
- iGEL (cardiac arrest)
- LMA
- Supreme
Disadvantages of SGAs over endotracheal intubation?
Airway not fully protected so increased risk of aspiration.
What is rapid seqeunce induction?
Intubation in an emergency setting where the patient is unfasted and therfore has a much higher risk of aspiration
How do you perform a rapid sequence induction
Preoxygenate to 100% sats
- Gives 5 mins without needing to ventilate Intubation directly after drug administration
- No bag/mask or SGAs Use rapid sequence drugs
- Thiopental + suxamethonium
What steps are required to wake a patient up?
- Stop giving gases Neostigmine
- reverse effects of muscle relaxants Naloxone
- reverse effects of opiates Flumazenil
- reverse effects of benzodiazepines
- Patients must be able to maintain their own airway before ventilation is removed.
What are the 6 criteria a patient must meet before they are discharged from the recovery room
- Patient is fully conscious and able to maintain a clear airway O2Sats are sufficient CVS is normal
- Pulse/BP/Peripheral perfusion
- Pain and emesis under control
- Temperature is normal
- Oxygen and IV therapy are prescribed if needed
When are tracheostomies indicated?
Acute
- Facial Fractures
- Epiglotal infection
- Forgein Body
- Angiodema Chronic (less iritating than endotracheal)
- Wean patients off ventilatory support
- Laryngeal tumour
- Clearing of secretions (cystic fibrosis)