Pre-operative Flashcards
In regards to airway assessment, what 5 things would make it difficult to mask ventilate a patient?
-We use the acronym BONES B- beard O-obesity N-no teeth E-elderly S-snoring
What conditions would make it difficult to intubate a patient?
The 4 D’s
- disproportion-macroglossia(big tongue), macrognathia(small chin)
- dysmobility-fixed cervical spine
- distortion-airway trauma
- dentition-passion gap, buck teeth
How do we do the mallampati score?
- patient sitting upright with head in neutral position
- patient to open mouth
What is the thyromental distance?
- The thyromental distance is the distance between the patients chin (with the neck extended) to the thyroid notch
- anything less than 6 cm means that the patient will have a difficult intubation
How do we check that spontaneous breathing has been achieved pre-operatively using effective mask ventilation?
- check for adequate chest rise
- absence of tracheal tug and accessory muscle use
- inspection of the reservoir bag attached to the breathing circuit
What are some of the advantages of tracheal intubation?
- guaranteed airway
- effective positive pressure ventilation
- prevention of aspiration
What size endotracheal tubes do we use for men and women?
- male-7,5mm to 8mm
2. female-7,0mm to 7,5mm
How do you calculate endotracheal tube sizes in children?
(age/4) plus 4
How can we ensure that the endotracheal tube is at the correct place/length?
- We can ensure by checking with an X-ray
- We can use auscultation to check
What do you need to do before you fully extubate a patient?
-ensure that the patient is not “light” because this can cause laryngospasm
What do we need to do to washout nitrous oxide?
-High flow oxygen with air for at least 1-2 minutes
What should you do if a patient experiences laryngospasm upon extubation?
-You should provide CPAP( continuous positive airway pressure, give 25mg of suxamethenonium and reintubate
What are the complications of extubation?
- hoarseness and sore throat
- oedema of the trachea and larynx
- tracheal stenosis
Does LMA protect you from aspiration?
No it does not
What are the drugs we can consider pre-operatively?
- midazolam
- lorazepam
- diazepam
- ketamine
- flumazenil
- benzodiazepine antagonist
When do we give midazolam pre-operatively?
What is the dosage?
- 30 minutes prior
- 7,5mg to 15mg(orally)
- 0,01-0,05 IV
If someone is allergic to penicillin what would be the alternatives?
-clindamycin and erythromycin
How many centimeters should we expect the patient’s mouth to be open by?
should not be less than 2-2.5cm
How long should the patient remain nil per os?
8 hrs- big meal with fat and protein
6 hrs- food, formula milk
4 hrs- breast milk
2 hrs- clear fluids, apple juice, dextrose containing fluid
What are the characteristics of ASA 1 and 2?
ASA 1- healthy patient that does not smoke or drink
ASA 2- healthy patient that occasionally drinks and smokes, has well controlled DM or DM and has a BMI of between 30 and 40(mild systemic conditions)
What are the characteristics of ASA 3 and 4?
ASA 3- severe systemic conditions- MI in the more than 3 months, CVA, TIA, uncontrolled DM and HPT, active hepatitis, alcohol abuse
ASA 4- patient with life threatening systemic disease: patient not undergoing scheduled dialysis, <3 months MI, TIA, CVA, cardiac disease or stents
What are the characteristics of ASA 5 and 6?
ASA 5- moribund patient that would die without the operation(example being abdominal aortic aneurysm rupture, massive trauma, intracranial bleed with mass effect
ASA 6- patient brain dead and harvested for organ donation
What are some indications for doing a spinal over general anaesthesia?
- the op is less than 2 hours
- the patient has easy airway access
- the op is below the umbilicus
- no major blood loss
What are some aspiration risks?
- decreased lower oesophageal sphincter tone
- increased gastric pressure
- delayed gastric emptying
- defective laryngeal protective reflexes
What are the causes of delayed gastric emptying?
- pain
- diabetes
- active labour
- opiates
- anticholinergics
What are the causes of increased gastric pressure?
- pregnancy
- diabetes
- not nil per os
- ascites
- obesity
What are the causes of decreased oesophageal sphincter tone?
- achalasia
- gastro-oesophageal reflux history
- caffeine and alcohol
- pregnancy
- obesity
What are the characteristics of the laryngeal protective reflexes?
- GCS <8/15
- CEREBRAL PALSY, parkinsons, multiple sclerosis, myopathies
