Principles Flashcards
Criteria for septic shock dx
Evidence of infection
Refractory hypotension (hypotension despite adequate fluid resuscitation and cardiac output)
Two more of ff
Tachypnoea or on BG PCO2<32mmHg
WCC <4000 or >12000
HR>90bpm
Temp >38 or <36
Causes of death in fistulas
Malnutrition
Sepsis
How to classify fistulas
Anatomical position: gastro cutaneous or colon cutaneous
Precipitating pathology: iatrogenic, TB, malignancy
Volume Output: High >500ml a day or Low <200ml a day
Causes of enterocutaneous fistulas
Crohns
Adhesiolysis
Retook laparotomy
Malignancy
TB
Spontaneous
Management principles for a fistula
Control output : stoma therapy
Adequate fluids
Correct electrolytes
Manage sepsis
Aggressive nutrition (dietician)
Multidisciplinary ☑️
Types of shock
Hypovolemia: blood loss
Cardiogenic: myocarditis, endocarditis, arrhythmia, MI)
Obstructive: temponade, pneumothorax
Distributive: sepsis, anaphylaxis, neurogenic shock
4 stages of shock
- Initial: hypoxia, metabolic acidosis from build up of lactic acid.
- Compensatory: hyperventilation (from acodosis), increased BP (due to vasoconstriction), RAAS system activated, blood diverted to vital organs.
- Progressive: compensatory mechanisms fails, increased metabolic acidosis, prolonged vasoconstriction compromises vital organs
- Refractory: vital organs fail and shock can no longer reversed
Commonest cause of septic shock
Endotoxin producing gram negative bacilli
Commonest cause of septic shock
Endotoxin producing gram negative bacilli
Management of Shock
Airway and Oxygen
Circulation: volume administration
Early antibiotics (take blood for investigations first)
Rapid source identification
Support of major organ dysfunction (eg DVT prophylaxis, glucose, stress ulcer prophylaxis, analgesia and sedation, mech vent for lung sepsis)
Complications of surgery
Respiratory:
Atelectasis
Pneumonia
Aspiration
ARDS
PE
Pneumothorax
Pleural effusion
Tx: preventative, optimise ei stop smoking, physio, review meds, steroids short course, bronchodilators, physio and early mobilisation post op. NB CXR, Pulmo func tests and ABG pre op.
Cardiac
Ischemia
MI
Death
(RF: AS, Recent MI, Arrhythmia, HF, Arrhythmia, Angina)
Tx: optimise prior to surgery, ECG, stress ECG, CXR, Ejec fraction or coronary angiogram
GIT complications
Ileus: tx conservative, healed 2-5 days
Constipation
Wound complications
Intraabdominal sepsis: Tx drainage by relocating laparotomy
Enterocutaneous fistula
Stress gastritis
Acute GI dilatation
Jaundice
Pancreatitis
Acute cholecystitis
Enterocolitis
Haemorrhage
-Primary haemorrhage: during surgery continues during post op
-Reactional: within 24h of surgery
-Secondary haemorrhage: 7-14 days post op. usually result of infection and false aneurysm.
Tx: aggressive fluid resusc, collect coagulation deficits
Deep Vein thrombosis
RF: hypercoagulable eg malignancy, oral contraceptive, prev DVT, obese, varicose veins, pelvic fractures HF, >60yo
Tx: prevention, low, oral contraceptive withdrawal. Pneumatic leg compression device, LMWH clexane.
Wound Complications
1. Wound infection
Tx: Ab, drain infected areas?
2. Wound dehiscence/rupture along surgical incision
Tx: urgent repair, some conservative first with sterile dressing then skin grafting
3. Wound sinus
Tx: remove foreign objects, necrotic tissue, drain residual
4. Enterocutaneous fistula
Tx: control output with stoma, fluids, electrolytes, mx sepsis, nutrition -dietician then conservative until it closes or surgical closure if fails
Causes of pyrexia with days post op
Atelectasis 0-3
Pneumonia 3-7
Phlebitis 3-5
UTI 4-10
Wound sepsis 4-10
DVT 5-10
Causes of derilium post op
DIMTOP
Drugs: Benzo, opiates
Drug withdrawal
Infection/ septicaemia
Ischemia of CNS: Stroke,TIA
Metabolic: hypo/hyperglycemia, hyponatremia, acute renal or liver failure
Trauma of CNS: subdural, extramural
Oxygen deficiency: hypoxia
Psych illness
Pain uncontrolled
Tx: Do ABG, glucose, electrolytes
Stress response to surgery
- ADH
- Aldosterone
- Cortisol
- Catecholamines
- Cytokines
Fluid losses in the post op period
- Blood from trauma or surgery= hypovolemia
- Insensible losses: evaporation from prolonged exposure in laparotomy or thoracotomy
- Third space loses: capillary leak of protein rich serum. ascites, dermatitis, pleural effusion.
- External losses: gastrointestinal losses NGT, vomiting, diarrhoea, stoma
Electrolytes derangement in surgical patients
Hypo-
1. Excessive loss of electrolyte
2. Excess water administration or retention
3. Shift of electrolyte in the intracellular space
Hyper
1. Excess electrolyte administration or retension
2. Water loss
3. Electrolyte shift in the extracellular space
- Hyponatremia
Cx: ADH, Na shift in intracellukar space due to third space shift of fluid, K low. Hypo Na fluids.
Sx: fatigue, n&v, confusion,muscle cramps, coma and death
Tx: often resolves on its own, stop fluids and diuretics in fluid overload
Hypernatremia
Cx: dehydration, hypernatremia fluids or diabetic insipidus
Hypokalemia
Cx: diuretics, diarrhea, third space shifts
Sx: constipation, gut dysfunction, Ileus, arrhythmias, muscle weakness
Tx: oral or IV K
Hyperkalemia
Cx: rhabdomyolysis, ATN, severe acidosis
Sx: arrhythmias, cardiac arrest
Tx: stop IV K, insulin/dextrose infusion and urgent dialysis
Hypocalcemia
Sx: tingling and parathesis, spasms and cramps
Cx: space fluid shifts, parathyroidectomy and thyroidetomy
Tx: give it?
Hypercalcemia
Sx: confusion, coma, arrhythmia
Tx:
What is Refeeding syndrome, what are the complications
Refeeding syndrome is a collection of electrolyte deraingments associated with massive intracellular shift of electrolytes
Hypophosphatemia
Hypokalemia
Hypomagnesemia
Hypophosphatemia: extracellular phosphate is rapidly taken into cells to generate ATP.
Hypokalemia for movement of potassium back into the cells as well as Magnesium.
PP: Peripheral oedema, Congestive heart failure, seizures, haemolysis, rhabdomyolysis, sudden cardiac arrest, weakness, struggling to mobilise and wean off mech ventilation.
Measure of urine output for acute renal failure dx
<0.5 ml/h
How do we categorise surgical risk
1- healthy patient
2. Mild systemic disease eg mild HPT
3. Severe systemic disease but not incapacitating eg severe DM
4. Incapacitating systemic disease, life threatening eg cardiac disease
5. Moribund- not expected to survive 24h with or without surgery
6. Emergency surgery
Pathophysiological response to surgery
- Inflammatory response- SIRS
- Sympathetic nervous system activation: Adrenalin and noradrenalin= tachycardia+vasoconstriction
- Endocrine: cortisol and glucagon fir gluconeogenesis
- RAAS system: Na and H20 retention
ADH and Aldosterone - Metabolic rate increases, increased muscle protein catabolismand hepatic synthesis of coagulation factors .
Difference between enteral and parenteral nutrition
Enteral- oral
Parenteral-IV
Differentials for skin erythema, edema, tenderness/ cellulitis
Infections vs non infectious
Infections
Necrotising fasciitis
Gas gangrene
Osteomyelitis
Herpes zoster
Erythema migrans
Skin absess
Non infectios
Contact dermatitis
DVT
Active gout
Drug reactions
Insect stings
Malignancy
Risk factors for cellulitis
Local vs systemic
Local
Trauma
Inflammation
Edema (vascular insufficiency)
Pre existing skin condition eg Tinea pedis, impetigo
Systemic
DM
HIV
Immune compromised eg splenectomy, chemotherapy, steroid , neutropenia
Cardiac failure
Tx of cellulitis
Elevation
Compression stockings for to with oedema (also diuretics)
Treat underlying conditions
Keep skin hydrated and not cracked
Pharmaco
Cloxacillin for 5-10 days (S.aureus and beta haemolytic strep)
Alternative is Augmentin (amoxiclav) or clindamycin
Erysipelas
Parenteral therapy for systemic manifestation (fever+chills) e.g
Penicillin
Cloxacillin
Ceftriaxone
Cefazolin
