Anaesthesia UK : Anaesthesia for general surgery
Thyrotoxicosis symptoms
Anxiety, tremor, heat intolerance, fatigue, weight loss
TFT, Ca2+, FBE, U&E, ECG, CXR, CT if indicated
Goitre, atrial fibrillation, SVC obstruction
Airway compromise, stridor, tracheomalacia
Eye complications of Graves’ disease
Antithyroid drugs, radioactive iodine
Complications of therapy: marrow suppression
Other therapy: β-blockers
Determine fitness for surgery
Euthyroid, little risk of thyroid storm
Airway and vascular compromise determined and manageable
Preparation, premedication, transport
Monitoring, access
Routine relaxant technique
Tube placement commonly armoured tube with circuit over head
Care with positioning, secure connections, eye protection
Supine with shoulder roll
Balanced technique, IPPV
Poor access to head and airway
Request from surgeon to check vocal cord movement
Often will not change surgical management
Requires deep extubation when reversed and laryngoscopy
Upper airway obstruction due to soft tissues and reduced muscle tone
Laryngospasm, bilateral cord paralysis
Inadequate reversal
Hypocalcaemia due to hypoparathyroidism
May be early (1-3 hours), more commonly 1-3 days
Physiological response to pneumoperitoneum
Intra-abdominal pressure 10-12 cmH2O
Venous pooling in legs, IVC compression --> increased RVR, decreased venous return
Increased vascular resistance of intra-abdominal organs --> increased SVR
Decreased compliance, increased intrathoracic pressure on IPPV
Increased ADH, catecholamines, renin, angiotensin II
Decreased CO, increased MAP
Minimized by filling, head-down position, α2-agonists
Venous stasis in legs --> DVT
PCO2 causes vasodilation if ventilation is not increased (increased ICP)
Arrhythmia: bradycardia due to peritoneal manipulation
Two major patient groups: young inflammatory bowel disease (IBD) and older cancer resections
IBD patients typically slim, otherwise well, may be on long-term corticosteroids and opioids
Cancer patients may have anaemia, hypercoagulability, hepatic dysfunction from metastases, electrolyte disturbance from secretory adenocarcinomas
Bowel preparation may cause dehydration, electrolyte disturbance
Signs of bowel obstruction if present
Investigation of usual comorbidites in old patients
Preoperative investigations as indicated: haematology, electrolytes, liver function, coags
General anaesthesia. Rapid sequence induction indicated in obstructed patients
Additional epidural anaesthesia and post-operative analgesia supported by literature: less opioid use, faster wakeup, earlier return of bowel function, diminished inflammatory response, protection against DVT, better respiratory function. Contraindicated in patients with sepsis or coagulopathy. Test prior to induction.
Potential for substantial bleeding, third-space loss of fluids
Large IVs, arterial line, central line, temperature monitor indicated
Otherwise routine monitoring: ECG, SpO2, gas analysis
Surgeon will commonly request nasogastric tube
Positioning, particularly if in lithotomy for perineal approach
Usual concerns with stress of surgery in older patients
Fluid management guided by CVP, urine output, observed blood loss, duration of surgery. Fluid balance often positive, several litres on paper
Active warming of upper body (and legs if possible)
Epidural dilute local anaesthetic plus fentanyl by infusion usually provides good analgesia
Anastomotic leak may require reoperation
Respiratory, cardiac or renal complications in elderly
Inflammatory bowel disease refractory to medical management
Non-malignant disease causing obstruction
Ischaemic or non-viable bowel
Laparotomy with resection of affected bowel and its mesentery
If anal canal or rectum is to be resected, perineal approach is often required as well
Primary anastomosis commonly performed. Two or three stage procedures with temporary or permanent stomas are sometimes required
Dissection in pelvis for low anterior resections may be difficult