Periop Flashcards
(172 cards)
why is a pre operative assessment important
To highlight any potential problems that could be faced in surgery depending on co morbidities, allergies etc.
Identify high risk patients
Allows you to know which conditions need to be optimised before surgery and any additional precautions that need to be taken
Gives an opportunity for patient to express concerns/questions
Who conducts a pre op assessment and when?
anaesthetist:
elective surgery - 2 weeks before
urgent cases - day of surgery
emergency cases - simultaneously with resuscitation
Briefly what should you include in a pre op assessment?
full history including FHx
examination of CVS/resp and any relevant pathologies and mallampati score
ASA grade and identify high risk patients.
Investigations
review assessment with clinician
what should be covered in a history in a pre op assessment?
reason for surgery and site for op and type of procedure discussed with patient.
full history of presenting complaint i.e. reason for surgery
PMHx: comorbidities, previous surgeries and any problems (PONV, reactions). Specifically ask about:
- BP and exercise tolerance (judge risk of MI)
- COPD/asthma - ensure oxygenation will be good. triggers, control, hosp admissions, steroids?
- renal: blood loss and contrast can impair kidney function
- diabetes - what type? how is it managed? related problems?
- pregnant?
DHx: need to assess what needs to be stopped and inform patient.
allergies? medical and any at all because some food allergies are correlated to allergies to anaesthetic agents
FHx: any bad reactions to anaesthetics - often inherited e.g. malignant hyperpyrexia
SHx: drinking and alcohol - are they dependant i.e. withdrawal symptoms during surgery?
think about ethnicity - afrocaribean and undiagnosed sickle cell/keloid scars
what type of disease is malignant hyperpyrexia?
autosomal dominant
What is included in the examination of someone pre op?
A airways: check the mallampati score i.e. how well will they be intubated. Any loose teeth? Ask them to extend and laterally flex neck to assess range of movements.
B: breathing: resp rate, O2 sats, lungs clear?
C: circulation: BP, pulse, cap refil, heart sounds? warm/cold and clammy?
D: Glasgow coma scale/ ASA grade
what scoring system is used for predicting ease of intubation?
Mallampati score
grade 1: can see all of soft palate and uvula
grade 2: can see all of uvula
grade 3: can see base of uvula
grade 4: cant see any soft palate/uvula
what investigations would you want to do pre op?
depends on the type of operation (i.e. minor or major surgery) and the ASA grade of patient (i.e. how high risk they are. but some investigations include:
FBC : anaemic or thrombocytopenia U&Es: kidney function to assess how well they will tolerate fluid loss/ contrast LFTs Clotting MSRA swab urinalysis and preg test ECG CXR
when is a CXR or ECG indicated pre op ?
ECG: only if history of CVS disease or going for major surgery
CXR: lung disease, smoker, come back from country with high TB prevalence
what investigations are done in ASA 1 in a
a) minor
b) moderate
c) major surgery
minor - none
moderate - none
major: consider U and Es if at risk of AKI and consider ECG in those >65 if no ECG results in last 12 months
FBC in all major surgery ASA 1-3
what investigations are done in ASA 2 in a
a) minor
b) moderate
c) major surgery
minor = none moderate = consider ECG/ U and Es severe = FBC, ECG, U and Es
what investigations are done in ASA 3/4 in a
a) minor
b) moderate
c) major surgery
minor: consider ECG and U and Es
moderate: ECG and U and Es. Consider FBC, clotting, Lung function/ ABG
severe: FBC, U and Es, ECG. consider clotting , Lung function/ABG
what planning and preparation is done before surgery (after the pre op assessment)?
reassure patient - may be anxious
prepare - NBM for milk/foods 6hrs and water for 2 hours before
may need a bowel prep
Alter prescriptions
group and save/ Xmatch
referral after surgery - i.e. should they go to HDU, ITU or back to the ward
Discuss with patient the plan and let them ask questions.
pre medications
what is the difference between group and save and cross match? when is each required in regards to surgical patients?
group and save - patients blood is taken and tested for antigens and atypical Abs. Recommended when blood loss is not anticipated but as precaution.
cross match: patients blood is mixed with donors to check for any reaction. This is the second stage before blood transfusion can go ahead. this takes 45mins - 1 hour and is done prior to surgery if blood loss is anticipated.
Why is a patient made NBM before surgery?
there is risk of pulmonary aspiration which will lead to inflammation of the lungs (pneumonitis) and possibly infection (pneumonia)
some people have a slow absorption so a minimum of 6 hours NBM for food/milk is recommended.
in emergency surgery, patients will not have been NBM, how are the risks minimised by anaesthetist?
cricoid pressure applied during induction and intubation.
A cuffed endotracheal tube is then used. The cuff prevents aspirate into lungs.
what are the indications for ITU after surgery?
high ASA grade
long operating time
CVS, major vascular or intrathoracic surgery
emergency procedure
need for renal dialysis or intubation post op
list the drugs that should be stopped before surgery?
clopidogrel hypoglycaemics warfarin COCP and HRT ACEi and diuretics herbal medications
Why would you alter the following medications in surgery? How many days do they need to be stopped?
a) clopidogrel
b) aspirin and dipyramadole
c) hypoglycaemics
d) COCP/ HRT
clopidogrel is stopped 7 days before because of powerful antiplatelet affects and thus risk of bleeding
aspirin and dipyramidole do not need to be stopped because they have short half life so easily reversed and have a cerebrovascular benefit
hypoglycaemics (not insulin) stopped day before surgery - due to risk of hypoglycaemia during surgery. (long acting sulphonylureas stop 2-3 days before)
COCP/HRT - risk of DVT - stop 4 weeks before and commence 2 weeks later.
herbal medication can affect platelet function - stop 2 weeks before
why is metformin a problem during surgery? what precautions are taken?
firstly can lead to hypoglycaemia
secondly fluid loss/contrast can result in reduced kidney function which can result in poor clearance of metformin and the risk of lactic acidosis
therefore U and Es are checked 48-72 hours post op to see if it is safe to restart metformin
should warfarin be stopped during surgery?
yes - but further precautions may need to be taken depending on the reason the individual is on warfarin.
AF - stop warfarin 5 days pre op and check INR day before surgery
prosthetic heart valve: stop warfarin 5 days pre op and wait for INR to get to 2. Start IV unfractionated heparin and keep INR between 2-3. stop heparin 4 hours pre op and restart post op
previous DVT: stop warfarin 5 days pre op , high dose LMWH day before surgery
what INR is required for surgery?
<1.5
how can you adjust INR if it remains high the evening before surgery?
if there are 3 hours of more vitamin K can be given
either orally - a long time
or if shorter time IV infusion of 1-5mg vit K over 3 hours (cant go quicker due to risk of cardiac arrest)
if emergency and no time for Vit K infusion can instead give beriplex.
what is beriplex?
a solution of synthetic clotting factors:
factors 2,7,9, 10 and protein C