4 - Applied Surgical Science Flashcards
What are the contraindications to using a tourniquet?
- peripheral vascular disease
- high risk of VTE (previous DVT or PE)
- vasculitic disorders
- sickle cell anaemia
What are the complications of tourniquets?
At the site - skin: friction burns, chemical burns - nerve injury - increased post-operative pain Distal - vascular injury / thrombosis - muscular ischaemia and reperfusion injury, compartment syndrome Systemic - post-tourniquet syndrome - post op embolic events - myoglobinuria - increased blood viscosity - hypercapnoea and metabolic changes (lactate & K)
What are the uses of a stoma?
Feeding
Lavage
Exteriorisation
Decompression, Diversion & Drainage
What are the different types of stomas?
- Temporary or permanent
- End or loop
- Based on anatomical location
How do you choose an abdominal stoma site?
- mark pre-op whilst standing and sitting
- away from incision, umbilicus and bony points
- create without tension, with viable bowel and adequate vascular supply
What are the potential complications of stomas?
- Immediate: bleeding, ischaemia, necrosis
- Early: high output, obstruction, retraction
- Late: obstruction, prolapse, retraction, stenosis, hernia, skin excoriation, electrolyte disturbance, fistula, calculi (renal & gallstones), psychological & psychosexual
How are drains used in surgery?
To remove
- normal organ contents (urine, gastric contents, CSF)
- abnormal organ contents (pus, blood, air)
What are the indications for inserting drains in surgery?
- removal of harmful substances (minus of infection)
- removal of dead space (third space pooling)
- monitor and prevent operative complications (haemorrhage, anastomotic leak)
- creating a therapeutic tract (T-tube tract)
What are the different types of drains?
Active systems
- open (sump drain)
- closed (Revival drain and chest drain with underwater deal)
Passive systems
- open (ribbon gauze wick, seton, corrugated drain)
- close (Robinson drain)
What are the potential complications of surgical drains?
- infection
- damage to surrounding structures
- obstruction
- migration
- displacement
What are adhesions?
The union of two normally separate surfaces connected by fibrous connective tissue in an inflamed or damaged region. Can be early (fibrinous) or late (fibrous).
What do adhesions cause?
Commonest - small bowel obstruction 60-70% cases
Chronic pain
Secondary infertility
How do you classify adhesions?
Congenital (2%) - Mechel's diverticulum - Malrotation of colon - Congenital bands Acquired (98%) - Post-operative (80%) - Post-inflammatory (18%) - Cause (appendicitis, diverticulitis, cholecystitis, pelvic infections, IBD)
How do you treat adhesions?
Pre-operative - Conservative drip and suck - Nutrition support Operative - surgical relief (bypass, resection, adhesiolysis) - preventative measures (powder-free gloves, minimal handling, peritoneal cavity fluid/gas installation, peristalsis enhancement to disrupt early fibrinous adhesions, covering of anastomosis, enzymes, fibrin deposition inhibitors) Post-operative - drip and suck - nutrition support - antibiotics (if clinically indicated) - early mobilisation - early use of enteral feeding
What are the anaesthetic causes of sudden death in surgery?
Hypoxia
- resp obstruction (kinked or displaced ET tube)
- vagal stimulation
- ventilator disconnection
- tension pneumothorax from +ve pressure ventilation
- Mendelson syndrome or chemical pneumonitis (acid aspiration)
- shock
- embolism (venous, air, fat)
Medication
- inappropriate drugs
- anaphylaxis
- overdose (local anaesthetic)
- dysrhythmias (vasodilators, ganglion blocks, diuretics)
- electrolyte and metabolic imbalances
- opiates
What are the surgical and patient causes of sudden death in surgery?
Surgical
- hypotension (bowel manipulation,, mesenteric stretching, sympathectomy)
- arrhythmias (induced by catheterisation, cardiac surgery)
- oculocardiac reflex (prone position with direct eye pressure causing vagal stimulation)
- damage to surrounding structures (e.g. incision of groin aneurysm during inguinal hernia repair)
Patient
- MI, pulmonary oedema, PE, stroke, dehydration and electrolytes imbalances
What are the protein / nitrogen requirements for a healthy and critically ill patient?
Healthy - 0.15 g/kg/day of nitrogen
Critically ill - 0.2-0.3 g/kg/day nitrogen
What are the indications for TPN?
- patient cannot ingest food
- anorexia (neurological disorders, posterior fossa cranial surgery, head injuries, coma, trauma and tumour involving head&neck&maxilla)
- patients with malfunctioning GI tract (short-bowel syndrome, fistula, obstruction, paralytic ileum, inflammatory disease, peptic ulceration, ischaemia, malignancy, trauma)
- hypercatabolic states
- major GI anomalies (trachea-oesphageal fistula, gastroschisis, intestinal atresia)
What are the major complications of enteral feeding?
Related to intubation of GI tract - fistulation - wound infection - peritonitis - displacement and catheter migration - obstruction of tube Related to delivery of nutrient to GI tract - aspiration pneumonia - feed intolerance - diarrhoea
