p e r i o p Flashcards
before going to theatre what things need to be addressed
Pre-operative assessment (pre-op) Consent Bloods (including groups and save / crossmatch) Fasting Medication changes Venous thromboembolism assessment
what is pre op assessment and what does it involve
assess if pt fit to undergo the specific operation.
involves exploring their co-morbidities, risk from anaesthesia, their frailty status and their cardiorespiratory fitness.
pre operative assessment involves asking about
Past medical problems Previous surgery Previous adverse responses to anaesthesia Medications Allergies Smoking Alcohol use
what must be considered in females undergoing surgery
pregnancy
what other factors need to be assessed pre operatively
asking about a family history of sickle cell disease.
general examination is performed to look for cardiovascular and respiratory disease.
Patients who may be malnourished (e.g., BMI under 18.5 or significant unintentional weight loss) may need input from a dietician and additional nutritional support before surgery and during admission.
what is an ASA Grade
classifies the physical status of the patient for anaesthesia.
patients are given a grade to describe their current fitness prior to undergoing anaesthesia/surgery
what are the grades for asa
ASA I – normal healthy patient
ASA II – mild systemic disease
ASA III – severe systemic disease
ASA IV – severe systemic disease that constantly threatens life
ASA V – “moribund” and expected to die without the operation
ASA VI – declared brain-dead and undergoing an organ donation operation
E – this is used for emergency operations
what pre operative investigations are required pts
ECG - Known or possibly cv disease
Echocardiogram if there are heart murmurs, cardiac symptoms or heart failure
Lung function tests may be required if there is known or possible respiratory disease
Arterial blood gas testing may be required if there is known or possible respiratory disease
HbA1C (within the last 3 months) for people with known diabetes
U&Es for patients at risk of developing an acute kidney injury or electrolyte abnormalities (e.g., taking diuretics)
FBC may be required if there is possible anaemia, cardiovascular or kidney disease
Clotting testing may be required if there is known or possible liver disease
group and save vs cross matching
group and save = send off to establish blood group and match them. used when there is lower probability they weill require blood products
cross macthing involving taking a unit or more of blood and assigning it to pt
why do pt fast before surgery
ensure they have an empty stomach for the duration of their operation.
The aim is to reduce the risk of reflux of food around the time of surgery (particularly during intubation and extubation), which subsequently can result in the patient aspirating their stomach contents into their lungs.
fasting for an operation involves
6 hours of no food or feeds before operation
2 hours no clear fluids (fully “nil by mouth”)
what specific meds may need changing before a major surgery
anticoagulants
oestrogen containing contraception
long term corticosteroids
describe how anti coagulants are stopped before surgery
ing can be mounted in to to ensure normal before operation
warfarin can be rapidly reversed with vitamin k
treatment dose LMWH OR unfractionated heparin infusion can be used to bridge the gap between stopping warfarin and surgery in higher risk pt (mechanical heart valve) ), and stopped shortly before surgery depending on the risk of bleeding and thrombosis
when are docs stopped before surgery
24-72hrs before surgery
depending on half life, produce and renal function
OCP or HRT needs to be stopped how many weeks before surgery
4 weeks = reduce risk of vte
pt with long term corticosteroids before surgery need management because
in pts on long-term steroids, there is adrenal suppression that prevents them from creating the extra steroids required to deal with this stress
management of patients on long term steroids 5mg oral pred or more
Management involves:
Additional IV hydrocortisone at induction and for the immediate postoperative period (e.g., first 24 hours)
Doubling of their normal dose once they are eating and drinking for 24 – 72 hours depending on the operation
which oral anti diabetics meds need to be adjusted or omitted around surgery
Sulfonylureas (e.g., gliclazide) can cause hypoglycaemia and are omitted until the patient is eating and drinking
Metformin is associated with lactic acidosis, particularly in patients with renal impairment
SGLT2 inhibitors (e.g., dapagliflozin) can cause diabetic ketoacidosis in dehydrated or acutely unwell patients
patients on insulin going for surgery require
continue a lower dose of their long actin insulin
stop short acting insulin whilst fasting or not eating until E+D again
NEED sliding scale/ variable rate insulin infusion alongside glucose, sodium chloride and potassium
what measures are taken in VTE prophylaxis
Low molecular weight heparin (LMWH) such as enoxaparin
DOACs (e.g., apixaban or rivaroxaban) may be used as an alternative to LMWH
Intermittent pneumatic compression (inflating cuffs around the legs)
Anti-embolic compression stockings
what are the four criteria of capacity
Understand the decision
Retain the information long
enough to make the decision
Weigh up the pros and cons
Communicate their decision
what is enhanced recovery
aims to get patent back to their pre operative condition as quickly as possible = early mobility and appropriate diet
what are the principles of enhanced recovery
Good preparation for surgery (e.g., healthy diet and exercise)
Minimally invasive surgery (keyhole or local anaesthetic where possible)
Adequate analgesia
Good nutritional support around surgery
Early return to oral diet and fluid intake
Early mobilisation
Avoiding drains and NG tubes where possible, early catheter removal
Early discharge
post operative analgesia is important because
allows pt to mobilise
ventilate lungs fully + reducing
risk of chest infections and atelectasis
have adequate oral intake
NSAIDS may be cl in pts with
Asthma
Renal impairment
Heart disease
Stomach ulcers
what is pca
patient controlled analgesia - iv infusion of strong opiate e.g morphine attached to patient controlled pump
the button will stop responding for a set time after administering a bolus to prevent over-use. Only the patient should press the button (not a nurse or doctor).
pca requires
requires careful monitoring. There needs to be input from an anaesthetist, and facilities in place if adverse events occur
what additional things are required in pt with pca
access to naloxone for respiratory depression,
antiemetics for nausea
atropine for bradycardia.
The anaesthetist may prescribe background opiates (e.g., patches) in addition to a PCA, but avoid other “as required” opiates whilst a PCA is in use. The machine is locked to prevent tampering.
what are the rx factors of post operative vomiting
Female History of motion sickness or previous PONV Non-smoker Use of postoperative opiates Younger age Use of volatile anaesthetics
which prophylactic antiemetics are given at the end of a procedure in surgery
Ondansetron (5HT3 receptor antagonist) – avoided in patients at risk of prolonged QT interval
Dexamethasone (corticosteroid) – used with caution in diabetic or immunocompromised patients
Cyclizine (histamine (H1) receptor antagonist) – caution with heart failure and elderly patient
when are tubes removed after surgery
- Drains are usually removed once they are draining minimal or no blood or fluid
- Nasogastric tubes are removed when they are no longer required for intake or drainage of gas or fluid
- Catheters are removed when the patient can mobilise to the toilet/ TWOC due to risk of urinary retention
why is good nutrition important post surgery
important for healthy wound healing and overall recovery from surgery.
what is enteral feeding and what are the options
- nutrition via gi tract
Mouth
NG tube
Percutaneous endoscopic gastrostomy (PEG) – a tube from the surface of the abdomen to the stomach
what is tpn
involves meeting the full ongoing nutritional requirements of the patient using an intravenous infusion of a solution of carbohydrates, fats, proteins, vitamins and minerals
when gi tract cannot be used
normally given via central line as peripheral veins are sensitive to tpn - thrombophlebitis risk
what are some post operative complications
- Anaemia
- Atelectasis is where a portion of the lung collapses due to under-ventilation
- Infections (e.g., chest, urinary tract or wound site)
- Wound dehiscence is where there is separation of the surgical wound, particularly after abdominal surgery
- Ileus is where peristalsis in the bowel is reduced (typically after abdominal surgery)
- Haemorrhage with bleeding into a drain, inside the body creating a haematoma or from the wound
- Deep vein thrombosis and pulmonary embolism
- Shock due to hypovolaemia (blood loss), sepsis or heart failure
- Arrhythmias (e.g., atrial fibrillation)
- Acute coronary syndrome (myocardial infarction) and cerebrovascular accident (stroke)
- Acute kidney injury
Urinary retention requiring catheterisation - Delirium refers to fluctuating confusion and is more common in elderly and frail patients
describe treatment of anaemia following surgery
Hb under 100 g/l – start oral iron (e.g., ferrous sulphate 200mg three times daily for three months)
Hb under 70-80 g/l – blood transfusion in addition to oral iron
what are the two main categories of anaesthesia
general anaesthesia – making the patient unconscious
Regional anaesthesia – blocking feeling to an isolated area of the body (e.g., a limb)
why is pre oxgyentation required
gives them a reserve of oxygen for the period between when they lose consciousness and are successfully intubated and ventilated
- several minutes of breathing 100 percent oxygen
what medications can be given before general anaesthetic
- Benzodiazepines (e.g., midazolam) to relax the muscles and reduce anxiety (also causes amnesia)
- Opiates (e.g., fentanyl or alfentanyl) to reduce pain and reduce the hypertensive response to the laryngoscope
- Alpha-2-adrenergic agonists (e.g., clonidine), which can help with sedation and pain
what is the triad of general anaesthesia
- hypnosis
- muscle relaxation
- analgesia
what are hypnotic agents and how are they given
make pt unconscious
inhaled or iv
e.g ketamine, propofol
how do muscle relaxations work and what are examples
block nmj from working
Acetylcholine (the neurotransmitter) is released by the axon but is blocked from stimulating a response from the muscle. Muscle relaxants are given to relax and paralyse the muscles. This makes intubation and surgery easier.
give examples of analgesia given in general anasthesia
fentanyl
morphine
with antiemetics
what is emergence and how are pt woken up
pt given nerve stimulator to see of muscle relaxant has worn pff
Once the muscle relaxant has worn off, the inhaled anaesthetic is stopped. The concentration of the anaesthetic in the body will fall, and the patient will regain consciousness. They are extubated at the point where they are breathing for themselves.
