Perioperative Care Flashcards
What are the types of surgery (surgery grade)
Grade 1 (minor) – Eg. Excision of skin lesion, draining abscesses
Grade 2 (intermediate) – Eg. Excision of varicose veins, tonsillectomy, arthroscopy
Grade 3 (major) – Eg. Hysterectomy, resection of prostate, thyroidectomy
Grade 4 (major+) – Eg. Total joint replacement, lung operation, colonic resection
Neurosurgery and cardiovascular surgery have their own gradings
What are the ASA Grades
ASA 1 – Normal healthy patients, no clinically important comorbidity and insignificant past medical history
ASA 2 – Patients with mild systemic disease
ASA 3 – Patients with severe systemic disease
ASA 4 – Patients with severe systemic disease, threatening to life
When should an ECG be done Pre Op
Should always be considered in any patient over 40 years old and should be performed in 80+ year olds – done routinely in patients with hypertension or pre-existing heart disease
When should an FBC be done Pre-op
Should always be considered in any patient over 60 years old
When should Renal function tests be done pre op
Should always be considered in any patient over 60 years old
When should Urine analysis be done Pre op
Should be considered in all patients
Pregnancy testing – in all fertile women
UTI
Undiagnosed diabetes or renal disease
Why should you ask about reflux in a Pre-op assessment?
Reflux is an important factor as patients who experience it definitely need intubation, laryngeal mask leaves too high a risk of aspiration
Give medication such as PPI or H2 receptor antagonist in an attempt to prevent reflux and the complications thereof
If a patient is found to be thrombocytopaenic pre op, what should be done?
Look for cause of thrombocytopaenia, such as myeloid conditions (leukaemia, myelodysplasia, etc.), infections or spleen issues (splenomegaly)
Patients will need coagulation testing
If a patient is found to have Neutrophilia pre op, what should be done?
May be artefactual – read blood film report to be sure, use citrate sample (green bottle) instead if platelet clumping is reported
IV immunoglobulin may improve the platelet count
If a patient is found to be thrombocytopaenic pre op, what should be done?
Suggests an ongoing infection – treat it first
If a patient is found to be Anaemic pre op, what should be done?
Patients will bleed more during surgery and will have poor wound healing, will need cross match and transfusion in emergency surgery
Try to correct anaemia before surgery if possible, try to find out what could be the cause, erythropoietin injections may be required
When to do a Group and save or cross match
For surgeries where blood loss is expected
Group and save if there is a low chance of bleeds
Cross-match if blood-loss is predicted or if patient is found to have atypical antibodies on blood testing, as this will make it harder to source blood at the time with just a G+S on record
Why will you ask about allergies Pre-op?
Allergy to egg or soya is important as this often indicates an allergy to propofol will also be present
Patients with an allergy to latex should be done first on the list (so latex spores aren’t floating around), non-latex gloves must be worn
Why is it It is important to know the patient’s alcohol history pre-op
If the patient is a heavy drinker then the liver may be damaged, leading to reduced production of clotting factors and a reduced rate of drug metabolism
What is Malignant hyperthermia
An Autosomal dominant inherited condition
Fast rise in body temperature due to severe muscle contractions when subjected to general anaesthetics – inhaled agents such as isoflurane/sevoflurane but also suxamethonium
Do not use anaesthetic gases or suxamethonium in these patients if the condition is known prior to surgery
Local anaesthetics work fine so a spinal block or epidural may be the best thing for it
Atracurium or rocuronium instead of suxamethonium (succinylcholine)
Dantrolene should be on hand to reverse this problem
Wrap the patient in a cooling blanket to reduce the temperature
What is Suxamethonium apnoea
May be inherited or acquired
Patient is unable to correctly metabolise suxamethonium and therefore it is not removed from the body at the correct rate
Patients will remain paralysed following surgery and must be given fresh frozen plasma, which contains cholinesterase enzymes, to break down the suxamethonium
Use atracurium in these patients instead
What risks are higher in a surgery if a patient has asthma?
Patient is more likely to undergo pneumothorax or form bullae during the operation
Risk of bronchospasm
What risks are higher in a surgery if a patient has impaired Renal and Liver function?
Patients with reduced eGFR will excrete drugs at a slower rate, meaning they will stay in the system for longer
Patient at risk of overdose or of staying asleep for longer than expected
Caution use of radiocontrast for imaging assisted procedures in patients with low eGFR
Patients with reduced liver function will not metabolise drugs as easily
May not work as quickly
May wear off more slowly
May increase risk of toxic levels
Patients with reduced liver function may also have reduced clotting factors
Liver responsible for factors 1, 2, 5, 7, 8, 9, 10 and 11
Some patients may have a history of waking up sooner than expected in surgery due to hypermetabolism – take this into account
What changes should be made pre-op for diabettic patients
HbA1c should be targeted at <60mmol/mol (<7.5%) for surgery – ideal values
<48mmol/mol (<6.5%) is generally the target for diabetics in everyday life
HbA1c must be at least below 69mmol/mol (8.5%) – this is the highest acceptable value
Patients going for elective surgery should have their HbA1c assessed and reduced if necessary in primary care
This will reduce the risk of complications and reduce the time taken to heal
Diabetic patients should have eGFR taken to look for any diabetic nephropathy
Patients missing more than one meal will need to be given a variable rate IV insulin infusion (sliding scale) during the operation
0.45% NaCl and 5% glucose with 0.15-0.3% Kcl (depending on potassium levels)
Target blood glucose for elective surgery is 6-12mmol/L
4-12mmol/L is the acceptable range
Patient should be done first on the list if possible
How can you assess an airway for intubation?
LEMON assessment for difficult airways
Look at the external airway, is there anything that may obstruct entry?
e.g. Obesity, micrognathia (small jaw), evidence of previous surgery, trauma or irradiation, facial hair (large beard hard to mask ventilate), dental abnormalities (including large teeth and poor hygiene), high arched palate, thick or short neck
Evaluate 3, 3, 2 rule – 3 fingers should fit in the jaw vertically, 3 fingers from the mentum (front of chin) to the hyoid bone, 2 fingers from the hyoid to the thyroid cartilage notch
Mallampati score – used to predict the ease of endotracheal intubation
Visual assessment of the distance from the tongue base to the roof of the mouth, indicating the amount of available space to work in
An increasing score indicates increasing difficulty of intubation
Cormack-Lehane scale is more accurate and describes what is seen on laryngoscopy during intubation
Obstruction – soft tissue swellings, burns, broken necks, trauma to face or neck, foreign bodies lodged in the airway, excessive soft tissue and obesity
Neck mobility – preferably, neck should be able to be extended during laryngoscopy
What Blood thinners and anti-clot agents
will you stop pre-op?
Clopidogrel – antiplatelet agent (inhibit ADP receptors)
Stop 1 week before surgery
May not need to be stopped – depends on patient risk of clot and how soon after a throboembolic event or MI
Aspirin – antiplatelet agent (blocks thromboxane A2 formation)
Stop 1 week before surgery
May not need to be stopped – depends on patient risk of clot
Restart following surgery at surgeon’s discretion
Warfarin – inhibits vitamin K dependent synthesis of clotting factors 2, 7, 9 and 10
Stop 1 week before surgery, cover with dalteparin prophylactic dose (5000 units daily) to prevent thromboembolic events during this week
May not stop if surgery has low bleed risk and risk of thromboembolism is very high
What Respiratory medicine will you stop pre-op?
Inhalers should be taken all the way up to the day of surgery, taken on the morning of the day of surgery
What Blood pressure medication will you stop pre-op?
Ace inhibitors and ARBs eg. ramipril, lisinopril, losartan, candesartan
Not taken on the day of surgery and continue following procedure
Calcium channel blockers eg. amlodipine, nifedipine, diltiazem
Not taken on the day of surgery and continue following procedure
Beta blockers eg. atenolol, bisoprolol, propranolol
Taken on day of surgery and continued following procedure
Sudden cessation can lead to rebound angina/infarction – may need some during op
Thiazide diuretics
Stop the day before surgery and continue when back on oral fluids
What Diabetes medications
medication will you stop pre-op?
Oral hypoglycaemics, eg. Metformin
Omit dose on day of surgery to prevent issues caused by possible changes in renal function
Insulin if necessary while undergoing surgery – Variable rate IV insulin infusion (VRIII)
Insulin until patient can take substances orally again following surgery
Insulin
Omit short acting but continue long acting on day of surgery
Insulin (VRIII) if necessary during surgery and usual dosing following surgery
Will you stop Thyroxine pre-op?
Take on morning of surgery and start dose again following surgery
Will you stop NSAIDs pre-op?
Short acting (short half life) eg. Ibuprofen and diclofenac – discontinue 2-3 days before surgery
Long acting (long half life) eg. Naproxen and nabumetone – discontinue 1 week before surgery
Why is food stopped pre-op, and how long pre-op?
Discontinued to lower the risk of regurgitation and aspiration
Discontinue food 6 hours before surgery
Discontinue water 2 hours before surgery
Breast milk 4 hours, formula milk 4-6 hours
Will you stop Oral contraceptive pill pre-op?
Increases risk of DVT by 5x
Stop at least 4 weeks before surgery
Counsel on appropriate alternative contraception
Restart 2 weeks post-surgery
Will you stop Hormone replacement therapy pre-op?
Increases risk of DVT by 1.5x
Stop at least 4 weeks prior to surgery
Restart 2 weeks post surgery
Will you stop Herbal medicines pre-op?
May affect platelet function, stop them 2 weeks pre-operatively
Will you stop Corticosteroids pre-op?
Should not be stopped as this can lead to addisonian crisis
Will probably need to be given IV during some surgeries
Make sure that patient is continued on their steroids following surgery
How will you reverse Warfarin in an emergency?
Vitamin K will reduce warfarinisation to drop the INR in 6-12 hours
Obviously not the best solution if the surgery is an emergency
Fresh frozen plasma works better acutely but needs time to thaw and can cause fluid overload in older patients and patients with renal failure
Prothrombin complex concentrates (beriplex/octaplex) – contain clotting factors 2, 7, 9, 10 and vitamin K
Works immediately and is therefore the best solution before emergency surgical intervention
What is the treatment for MRSA
Mupirocin 2% nasally TDS for 5 days
Clorhexidine gluconate wash, all over body, for 5 days
Additional pre-operative and intraoperative antibiotics may be given
What should all patients be swabbed for prior to surgery
MRSA
What are the main induction sedation agents
Propofol IV to induce the initial unconsciousness in a patient
Etomidate or ketamine can be used in cardiovascularly unstable patients (won’t depress cardiac output) e.g. trauma
Sevoflurane can be used as a volatile inducing agent
What are the main maintenance sedation agents
Sevoflurane is an inhaled isopropyl ether which can be used for both induction and maintenance of general anaesthesia
Isoflurane and desflurane are other maintenance gases (cheaper than sevo)
Propofol infusion can be used if volatiles must be avoided eg. In malignant hyperthermia
What are the main Muscle relaxants
Atracurium, rocuronium or suxamethonium
Not necessarily needed in all procedures, eg. Arthroscopy not normally necessary
Why are muscle relaxants used?
Important to stop the patient from moving and to relax abdominal muscles to make incisions easier
What are the main Analgesics used pre-operatively
Remifentanil is generally used throughout surgery
Morphine is generally used following the procedure
Inhaled N2O (nitrous oxide, laughing gas) acts as an analgesic but is likely to cause nausea and vomiting in patients with risks of post-op N&V
What is the most important monitor pre-op
Capnography (CO2) monitoring
How can you tell that a muscle relaxant is wearing off if the patient
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
When would you use Bag-valve-mask ventilation?
Used to ventilate patients while equipment is being readied for more invasive ventilation methods
What is the Procedure of a Bag-valve-mask ventilation?
The mask is placed over the patient’s face, forming a seal around their mouth and nose so that air cannot escape
Head tilt, chin lift
No head tilt in patients with suspected C-spine injury, just the chin lift (jaw thrust)
Squeeze the air bag regularly, but not too hard or fast, to ventilate the patient – 10-12 breaths per minute is a good rate, roughly 500ml per breath should do in an adult
Can use oropharyngeal airway (guedel airway) to assist with ventilation if necessary – measure a size from pinna of ear/angle of jaw to corner of mouth
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
Contraindicated in the presence of complete airway obstruction – air will all go to stomach
Relatively contraindicated after paralysis/anaesthesia as the risk of aspiration is increased
Procedure of a Tracheal intubation
Insert the laryngoscope down the tongue to the vallecula (near the epiglottis) and pull up while tilting the head back
The epiglottis should move with the tongue, allowing visualisation and access to the vocal cords and trachea
Feed the ET tube into the trachea and attach the bag mask, inflate the cuff to stop the tube from slipping out and secure it to the face to stop it from moving about
Can use a bougie to aid intubation if it is hard to feed an ET tube straight in
Ventilating the patient should give a CO2 reading on the capnograph, should make the chest rise and fall and air will be heard entering if auscultated
Pull back a bit if chest rising and falling is one sided – likely that the tube has gone too far and entered the right main bronchus
Problems with endotracheal intubation
Patients with a mallampati scores of 4 are hard to intubate as their trachea can’t be visualised, do not try to intubate blind
Use fibre optic laryngoscopy in these patients to visualise more easily
It can be hard to enter the trachea on the first try, while attempting to intubate the patient is not ventilated, if necessary pull out and bag-valve-mask ventilate back to 100% saturation before going at it again
May accidentally enter the stomach, leading to greater likelihood of aspiration and stopping the patient’s ventilation – no reading on capnography indicates you are in the stomach
Contraindications of endotracheal intubation
Inability to extend the head/neck as in spinal trauma, spinal degeneration or septic arthritis may be a contraindication
Epiglottal infection
Mandibular fracture
Uncontrolled, oropharyngeal haemorrhage
Procedure of a Laryngeal mask airway
Inflate the cuff to make sure it won’t leak, then lubricate and deflate before insertion
Pass down the back of the tongue and advance until the cuff can’t be seen
Inflate the cuff and attach the ventilation system
Contraindications of a Laryngeal mask airway
Complete upper airway obstruction
Risk of aspiration in patients with GORD
When is Rapid sequence induction/intubation used?
Used in emergencies when patients are unfasted
What drugs are commonly used for Rapid sequence induction/intubation
Propofol and succinylcholine (suxamethonium) still commonly used
What is the technique for Rapid sequence induction/intubation
Preparation – assessment for which size tube will be needed, IV access achieved
Pre-oxygenation to 100% saturation – gives more time (up to 8 minutes) to be able to work without needing to use rescue ventilation procedures
Pre-treatment as necessary – try to prevent raised intracranial pressure or bronchospasm using atropine and lidocaine
Paralysis – opioids and hypnotics (induction agents) administered, muscle relaxant administered
Sodium thiopentone often used instead of propofol for induction – fast onset
Positioning – get patient in “sniffing” position
Head propped on pillow and tilted back in order to align oral, pharyngeal and laryngeal axes to bring the epiglottis and vocal cords into view
Place the tube – intubate the patient
Post-intubation management – proceed as normal, checking capnograph to make sure the tube is in the right place
How do you wake up a patient in an Emergency
Stop giving the patient gases so they begin to wear off
Neostigmine is used to reverse the affects of muscle relaxants
Naloxone can be used to reverse opiates if necessary
Benzodiazepines (used for sedation before surgery) can be reversed with flumazenil
Those at risk of aspiration (patients who would have trouble maintaining their own airway) must be fully awake, and therefore able to maintain their own airway, before taking out assisted ventilation tubes
Once they are awake
Patients will likely need an anti-emetic to stop post-operative nausea and vomiting
Give local anaesthetic to incision areas and analgesia such as morphine should be continued to prevent post-operative pain
What are the requirements to be discharged from the recovery room?
Fully conscious, maintain a clear airway and exhibits airway reflexes
Respiration and oxygen rates satisfactory
Cardiovascular system stable, meeting normal pre-op levels of BP, HR and adequate peripheral perfusion
Pain and emesis controlled
Temperature within acceptable limits
Oxygen and IV therapy if appropriate
What is a Tracheostomy
A surgical opening in the trachea, made to allow for ventilation in the event of a closed larynx
Indications for a Emergency Tracheostomy
Trauma, including facial fractures
Infection
Foreign body
Neurological reasons for reduced ventilation – stroke, head trauma, etc.
Angioedema and other causes of swelling
Can help to wean patient off ventilatory support in intensive care settings
Chronic/elective – when a patient needs longer term ventilation
What are the Chronic/elective indications for a Tracheostomy
Laryngeal tumour or tumour compressing the upper airway
Assists clearance of secretions – eg. Bronchiectasis or cystic fibrosis
Less irritating/damaging than having an endotracheal tube in-situ long term
Complications of a Tracheostomy
Haemorrhage
Hypoxia if not placed fast enough
Trauma to recurrent laryngeal nerve → vocal cord paralysis
Damage to oesophagus
Pneumothorax
Surgical site infection
Aspiration due to pooling of secretions, bleed or the tube
Airway obstruction from poorly fitted tube
Inflammation → narrowed airway
Tracheal stenosis or fistula
What is the Ongoing care
required for a Tracheostomy
Hygiene
The tube requires regular cleaning with replacement of the inner-tube every 5-7 days
The skin around the area needs regular cleaning
Speech
Tracheostomy will prevent speech – speaking valves can be implanted to allow for this
Swallowing
Patient can’t cough to remove secretions → risk of aspiration
Regular suctioning may be beneficial
Trouble swallowing due to increased pressure on oesophagus
Speech and language therapists should be involved
Humidification
Nose and mouth bypassed → no humidification
Keep patients hydrated to keep secretions from being too thick
What are the Classifications of wound contamination
Clean surgery
Elective and non-emergency surgery without any traumatic injury
Surgery begins closed, no acute inflammation
No entry to respiratory, GI, biliary or genitourinary tracts
Clean-contaminated
Urgent or emergency case that would otherwise be considered clean
Elective procedures entering the respiratory, GI, biliary or genitourinary tracts; eg. Appendicectomy
No encounter with infected urine or bile
Contaminated
Non-purulent (pussy) inflammation, gross spillage from GI tract on entry, entry into the biliary or genitourinary tract in the presence of infected bile or urine
Penetrating trauma <4 hours old, chronic open wounds to be grafted or covered
Dirty
Purulent inflammation (eg. Abscess)
Preoperative perforation of respiratory, GI, biliary or genitourinary tract
Penetrating trauma >4 hours old
How do you Reducing risk of a Surgical site infections
Remove hair around the area using electric clippers
Advise patient to shower before the surgery
Reduced area for bacterial flora to live in
Antibiotic prophylaxis before surgery
No need for prophylactic antibiotics in clean surgery as the risk of infection remains at ~2%
Necessary in any surgery involving insertion of a prosthesis or implant
Necessary in clean-contaminated surgery, contaminated surgery and dirty surgery
Use local antibiotic guidelines – generally broad spectrum
Skin preparation at surgery site with antiseptic (clorhexidine or povidone-iodine)
Scrubbing and maintaining sterile field and sterile equipment use
Cover wounds with appropriate dressing following surgery
Avoid further contact with the wound for 48-72 hours
What causes Post-operative chest infection and how do you treat it?
Occur due to lung abnormalities following surgical trauma and anaesthesia – atelectasis
Wound pain leads to shorter, shallower breaths which leads to stasis of air in the lung bases and a greater likelihood of
infection
Coughing reflex is suppressed due to after effects of anaesthesia, meaning bugs are less likely to be coughed out
Treat with chest physio and antibiotics
What causes surgical Urinary Tract Infections
Caused by catheter inserted during or following surgical procedures
What causes surgical Bacteraemias
Indwelling catheters and cannulas increase risk of bacteraemia and therefore septicaemia
Urinary tract infections can lead to bacteraemia
Anastomotic breakdown and abdominal sepsis
What are the bodily requirements for Na, K, and water
Sodium requirement – 1mmol/kg/24hr Potassium requirement – 1mmol/kg/24hr Water requirement – 25-30ml/kg/24hr Slightly different in children: 1st 10kg is 4ml/kg/hr 2nd 10kg is 2ml/kg/hr The rest is 1ml/kg/hr
Causes of low urine output
Pre-renal – dehydration
Renal – CKD or perhaps new AKI
Post-renal – Catheter in-situ may be blocked
What ions are lost in Diarrhoea
K+ and HCO3- ions lost
What ions are lost in Vomit
K+, H+ and Cl- ions
What fluids do you give to a patient in shock?
Do not dilute the blood too much by infusion
Give blood where possible
Do not infuse too fast, as the sharp increase in pressure can dislodge newly formed clots, leading to embolic events such as PE or stroke
When should hartmanns solution be used
Hartmann’s should only be used for
resuscitation purposes
Causes of fluid losses
Urine
High urine output may point towards diabetes mellitus or insipidus
Faeces
Think about stoma output – a patient with a high output stoma should be treated in order to reduce fluid losses
Give PPIs to reduce the rate of gastric secretion
Give loperamide or opiate analgesia to slow movement of faeces
Instead of water, patients should be drinking WHO solution (isotonic)
Minor losses through perspiration (sweat) and respiration (expiration)
Vomiting – give patient anti-emetics
Bleeds
Patient may be losing blood through an occult bleed or an unseen bleed following surgery
Signs and symptoms of dehydration
Dizziness, light headed Headache Dry mouth, lips, eyes Reduced urine output Low blood pressure
Tachycardia with weak pulse
Lethargy and confusion
Reduced skin turgor
Reduced sweating
Can a patient eat with an ileus?
No
Can Patients who have had upper GI surgery eat?
Nil by mouth for 1 week following surgery
