Peri-operative management, fluids and nutrition Flashcards
How much blood should be crossmatched for AAA surgery?
6 units
How long before surgery should patients be NBM for and for what?
> =2 hours clear fluids
>=6 hours solids
What surgeries would bowel prep be indicated for?
Left sided bowel surgeries
What DVT prophylaxis should lwo medium and high risk be given?
Low - early mobilisation
Med - early mobilisation + TEDS + 20mg enoxaparin
High - early mobilisation + TEDS + 40mg enoxaparin + intermittent compression boots perioperatively
What is the pathology of surgical risk to DM patients?
Surgery causes stress hormone release which antagonises insulin. Gombined with NBM and often concomitant IHD, this increases risk of infection and dysglycaemica
What are the surgical considerations around patients on longterm steroids?
Poor wound healing
Infection
Adrenal crisis
Why is it best to avoid operating on patients with jaundice?
High risk of renal failure in obstructive jaundice
Coagulopathy
Infection ->cholangitis
How many days before an operation should warfarin be stopped, and what is the target INR in most cases?
5 days
<1.5
What are the surgical risks in COPD/smokders?
Basal atelectasis
Aspiration
Pneumonia
What are the complications of anaesthesia?
Cardiorespiratory depression 2ary to propofol induction
Local trauma due to intubation
Loss of pain sensation can cause nerve palsies
Loss of muscle power can cause atelectasis and pneumonia (no coughing)
Anaphylaxis
What are some general complications to surgery?
Immediate (<24hrs)
Intubation related oropharyngeal trauma
Surgical trauma to local structures
Primary or reactive haemorrhage
Early (1d-1mo) 2ary haemorrhage VTE Urinary retention Atelectasis and pneurmonia Wound infection and dehiscence Antibiotic associated colitis
Late (>1mo)
Scarring
Neuropathy
Failure/recurrence
What are the definitions of reactive and secondary haemorrhage?
Reactive haemorrhage is bleeding at the end of surgery/early post op, commonly 2ary to increased CO and BP
Secondary haemorrhage is bleeding >24 post-op which is usually due to infection
Why are so many surgeries complicated by atelectasis?
Pre op smoking
Anaesthetics increase mucous production and decrease mucociliary clearance
Pain inhibits respiratory excursion and cough
What are some risk factors for post op infection/dehiscence?
Pre-op Age Comorbidities Existing infection Steroids
Intra-op
Duration
Closure technique
Post-op
Poor hospital hygiene
What complications might occur following cholecystectomy?
Conversion to open CBD injury Bile leak Retained stones Steatorrhoea
What complications may occur folowing inguinal hernia repair?
Early Haematoma/seroma formation Injury Infection Urinary retention
Late
Recurrence
Chronic groin pain/parasthesia
Ischaemic orchitis
What are the risk factors following colonic surgery?
Early Ileus Anastomotic leak Enterocutaneous fistulae Abscesses
Late
Adhesions -> obstruction
Incisional hernia
What are the causes of post op ileus?
Bowel handling
Anaesthesia
Electrolyte imbalance
How might a post op ileus present and what is the treatmnt?
Distention
Constipation +- vomiting
Absent bowel sounds
treat with IV fluids and NGT
What are the complications following anorectal surgery?
Incontinence
Stenosis
Anal fissuring
What is the main complication following small bowel surgery?
Short gut syndrome
WHat are the common side effects following spelectomy?
Gastric dilatation
VTE 2ary to thrombocytosis
Infection by encapsulates (haemophilus, strep, neisseria, salmonella)
What are the complications following aortic surgery?
Gut ischaemia Renal failure Aorto-enteric fistula Anterior spinal syndrome Thromboemboli
What are the complications following prostatectomy?
Urinary incontinence
ED
Retrograde ejaculation
Prostatitis
What are the complications following thyroidectomy?
Haematoma ->obstruction Recurrent laryngeal nerve trauma Hypoparathyroidism Thyroid storm Hypothyroidism
What are the complications following a fracture repair?
Mal/non-union
Osteomyelitis
Avascular necrosis
Compartment syndrome
WHat are the complications following a hip replacement?
Deep infection VTE Dislocation Sciatic nerve injury Leg length discrepancy
When might post-op pyrexia be physiological and why?
0-5 days post op - SIRS 2ary to trauma
What is the mangement of a DVT?
Start therapeutic LMWH @1.5mg/kg/24hrs SC
Start warfarin and stop LMWH when INR reaches 2.5
What measures should be taken to prevent VTE?
Pre VTE risk assess TED stockings Hydrate Stop OCP 4 weeks prior
Intra
Minimise duration
Minimal access
Intermittent pneumatic compression boots
Post LMWH Early mobilisation Analgesia Physio Hydration
What might cause post op hypoxia?
Existing lung disease Atelectasis Aspiration Pneumonia LVF PE Pneumothorax Pain -> hypoventilation
What might cause reduced post op urine output?
Hypovolaemia
NSAIDs/gentamicin
Post renal blocked catheter (commonest)
What might cause post op N/V?
Obstruction
Ileus
Emetics e.g. opioids
What might cause post op hypotension?
CHOD
Cardiogenic - MI, fluid overload
Hypovolaemia -(Haemorrhage)
Obstructive - PE
Distributive - Sepsis, neurogenic shock
What might cause post op delerium?
DELERIUM
Drugs - opioids, sedatives Eyes, ears and other sensory deficit Low 02 states Infection Retention Ictal Underhydration Metabolic derangement
What is the minimum urine output for a patient?
0.5ml/kg/hr (30ml/hr for a 60kg pt)
What is our daily Na and K requirement?
Na - 1.5-2mmol/kg/day
K - 1mmol/kg/day
What is a normal CVP?
5-10cmH2O
How much NaCl is there in a litre bag of 0.9% saline?
154mmol
How much dextrose in in a liter bag of 5% dextrose?
50g
What are the components of a bag of dextrose saline?
4% dextrose = 40g.L
0.18%NaCl = 31mM NaCl
What is Parkland’s formula and when is it used?
Used for assessing fluid for burn victims
4 x weight x %burn = ml in 1st 24hrs
What are the sodium and potassium levels in a liter of Hartmann’s?
131mmol Na
5mmol K
What is the definition of refeeding syndrome?
Life threatening metabolic complication of refeeding via any route after a prolonged period of starvation
What is the pathophysiology of refeeding syndrome?
Low carbs put you in a catabolic state with low insulin fat and protein with depletion of Po4 intracellularly
Refeeding causes increase in insulin and cellular PO4 uptake
Hypophosphataemia causes: Rhabdomyolysis Resp insufficiency Arrhythmias Shock Seizures
What are the biochemical abnormalities in refeeding syndrome?
Hypokalaemia
Hypomagnesasemia
Hypophosphataemia
What is the management of refeeding syndrome
Prevention by recognising at risk patients
PO4 supplementation