1. Anaesthesia for Emergency Surgery
Student tutorial
4th year MBChB

2. Definitions Emergency Urgent Imminent threat to life or limb exists
Surgery must be done in 1 hour
Urgent
Require surgery within 24 hours
Allows time for optimisation

3. GSH Colour code for emergency surgery
Red = Immediate surgery
Orange = Surgery within 2 hours
Yellow = Surgery within 6 hours
Green = Surgery within 24 hours
Blue = Surgery within 72 hours (or next elective list)
Purple = Need to be reclassified

4. Common emergency operations
General surgery
Appendicectomy
Incision and drainage of abscesses
Laparatomies for small or large bowel obstruction
Strangulated hernia
Acute upper or lower gastro-intestinal bleed
Trauma (blunt or penetrating)
Gynaecological surgery
Ruptured ectopic pregnancy
Evacuation of retained products of conception
Obstetrics
Caesarean sections with a variety of indications
Orthopaedic surgery
Open fracture debridement
Poly-trauma
Vascular surgery
Ruptured abdominal aortic aneurysm
Amputations
Neurosurgery
Intracranial haemorrhage with raised intracranial pressure or falling Glasgow coma scale (GCS)
Oto-rhino-laryngology (ENT)
Epistaxis
Tonsillar abscess

5. Concepts of Emergency Anaesthesia
Higher risk of adverse events (10 x)
Objective
Correction of surgical pathology with minimum risk to patient
Reduce risks by making a thorough assessment of the patient

6. “Think outside the box”

7. Peri-operative Approach
Ask your surgical colleague...
Surgical diagnosis
Magnitude of surgery
Urgency
Pre-operative preparation
Outstanding work-up
Any ongoing resuscitation
Method of anaesthesia
Post-operative requirements
Anticipate complications
Ongoing haemorrhage
Hypovolaemia
Hypotension
Coagulopathies
Vomiting and Aspiration
Dysrhythmias
Adverse drug reactions in the presence of electrolyte abnormalities / renal dysfunction
Hypothermia
Sepsis and Septic Shock
Potential cervical spine injuries

8. Risk Factors Limited time to assess and prepare patient
Uncertain diagnoses
Exploratory lap for acute abdomen
Full stomach
Intravascular depletion
Electrolyte derangements
Anaemia and coagulation abnormalities
Co-morbidity
Pain
Junior staff
Unsociable hours

9. Limited time ... need for multi-tasking!

10. Pre-op Evaluation Basic investigations History Examination
Renal function + elecs
FBC + X-match
ABG + lactate
Serum glucose
CXR
ECG
Special investigations
History
Starved???
Current problem list
Co-morbidity
Examination
Airway assessment .... ? Difficult airway
Fluid status
CVS and Respiratory

11. ASA Fasting Guidelines
Nil per os (NPO) status
Clear fluids are emptied from stomach within 2 hours of ingestion.
Gastric emptying of solids is slower .
ASA Fasting Guidelines
Clear Fluids
2 hours
Breast milk
4 hours
Non – human milk
6 hours
Solids
BUT….This slows down with stress e.g. trauma

12. Aspiration – “Mendelson’s Syndrome”
Definition: Chemical pneumonitis caused by aspiration during anaesthesia
Aspiration of vomited or regurgitated gastric contents occurs with loss of laryngeal reflexes
During general anaesthesia, sedation or ↓LOC
Fluid particulate matter in the trachea may cause a bronchopulmonary reaction

13. Clinical features of aspiration
Usually occur 2 – 5 hours after anaesthesia
Cyanosis
Dyspnoea
Wheezes and crackles
Hypoxia
Tachyardia with a high BP
CXR signs are delayed even further – RML and RLL involvement

14. Confusing terminology: Vomiting or Regurgitation
Vomiting is an active process
Occurs at lighter planes of anaesthesia
Induction and emergence
Vomitus stimulates spasm of the cords + apnoea

15. Regurgitation Regurgitation is a passive process Occurs at any time
Often “silent”
Usually at deeper planes of anaesthesia
Laryngeal reflexes are reduced or paralysed

16. Who is at risk of aspiration?
Full stomach
History of gastric reflux
Abnormal oesophageal anatomy or function
Pregnancy and labour
Paediatrics
Obesity (BMI > 30 kg m-2)
Muscle weakness
ASA III – IV
Difficult airway management
Particularly trauma around airway with bleeding
Decreased level of consciousness
Pain and opiates
Emergency procedures
Trauma

17. Assume a full stomach ... Absent or abnormal peristalsis Ileus
Post-op
Metabolic
DKA, uraemia, ↓K+
Drug-induced
Opioids, anticholinergics
Obstructed peristalsis
Bowel obstruction
Gastric carcinoma
Pyloric stenosis
Delayed gastric emptying
Shock of any cause
Diabetes
Trauma
Pregnancy and labour
Fear, pain, anxiety Opioids

18. Prevention Empty the stomach Neutralise the stomach acid
Delay
NGT & suction
Prokinetics – e.g. Metoclopramide
Neutralise the stomach acid
Antacids e.g. Sodium Citrate
H2-blockers – e.g. Ranitidine
PPI’s – e.g. Omeprazole
Avoid GA if possible
Rapid Sequence Induction with Cricoid pressure

19. Immediate Management
Most important is identifying those at risk, thus PREVENTION !
80 % O2
Minimise risk of further aspiration…
Left lateral position (L side down)
Head down (always use a tilting table in theatre)
Oropharyngeal suction before ventilation
ETT if ventilation or suctioning required

20. Further Management Treat as foreign body Consider ICU admission
Minimise positive pressure ventilation
Consider bronchoscopy
NGT to help empty stomach
Monitor respiratory function
CXR looking for collapse or consolidation
Consider ICU admission
Do well with 12 – 24 hours IPPV
No routine antibiotics or steroids

21. Anaesthesia for emergency surgery

22. Anaesthesia for emergency surgery
There are very few patients whose clinical state is so life threatening that they need immediate surgery, ie. a true emergency!
Most patients will benefit from a short period of optimisation

23. General Anaesthetic Consider patient’s clinical condition
Consider the implications of the anaesthetic drugs in the face of
Hypovolaemia
Hypokalaemia
Uraemia
Sepsis

24. General Anaesthetic Consider the WHOLE anaesthetic Preparation
Induction and Airway control Rapid Sequence Induction
Maintenance
Reversal and emergence
Recovery and post-operative placement

25. Rapid Sequence Induction (RSI or “Crash induction”)
Risk : Benefit
Risk of losing control of the airway against the risk of aspiration
Must prepare a contingency plan for failed intubation
Haemodynamic instability of rapid induction
Relative overdose of anaesthetic (hypotension)
Insufficient induction (hypertension, tachycardia, dysrhythmia)

26. Preparation for RSI Routine machine and equipment check
Skilled assistant for cricoid pressure
Tilting bed / table / trolley
Patient supine in sniffing position
Suction at arms length and switched on
Patient monitoring attached with baseline readings
Plan for failed intubation
Wake up patient?

27. RSI Pre-oxygenate Running drip Drugs 80 % (100 %) O2 for 3 min
Tight fitting mask on anaesthetic breathing circuit.
O2 flow rate > 4 l min-1
Running drip
Drugs
Induction agent: Predetermined dose
Suxamethonium mg kg-1

28. Assistant applies CP with LOC
ETT insertion after fasciculations (45-60 sec after sux)
Inflate ETT cuff
IPPV and tests to confirm ETT position (CO2)
Assistant releases cricoid pressure only after confirmation of ETT in correct position
ETT strapped / tied in position

30. Cricoid Pressure
Assistant identifies cricoid cartilage before anaesthesia is induced
Patient warned about discomfort
Aim: Compress the oesophagus between the cricoid and the vertebral column preventing regurgitation
Why cricoid specifically?
If the patient vomits actively then cricoid pressure should be relieved to prevent oesophageal injury

31. Choice of Anaesthetic Agents in Emergency Surgery
Risk of haemodynamic instability
Use cardiac stable drugs
Induction Agents:
Etomidate, Ketamine, Thiopentone, ? Propofol
Volatiles:
Iso, Sevo, Des
Opiate-based anaesthetic
Trauma patients at high risk of awareness

32. Intra-operative Management
Monitoring
Invasive
Ongoing resuscitation
Regular repeat ABG and bloods
Blood transfusion
Transfusion triggers
Haemoconcentration
Blood products for coagulation defects

33. Emergence and Extubation
Risk of aspiration still present at emergence
Extubate only once protective airway reflexes have returned
Patient should be awake in left lateral or upright position
Some patients require post-operative ventilation and ICU

34. Post-operative Management for Emergency Surgery
Postoperatively patients usually require ongoing resuscitation
Fluids
Blood or blood products
Repeat investigations
Analgesia
Placement?
Ward, high-care, ICU

35. Who needs ICU?
Patients to consider for postop ventilation or ICU are those with:-
Pulmonary disease
Requiring inotropes
Hypothermia (temp < 34°C)
Intra-abdominal packs
Respiratory failure
Renal failure
Prolonged shock of any cause
Massive sepsis
Ischaemic heart disease
Extreme obesity
Overt gastric acid aspiration

36. Anaesthesia for the trauma victim

37. Specific Issues Airway and cervical spine Full stomach
Decreased LOC and potential traumatic brain injury
Haemorrhage – potentially occult
Blunt chest and abdo trauma
Long bone and pelvic fractures
Hypothermia
Intoxication

38. Assessment Team approach ATLS guidelines Primary survey
Secondary survey

39. Yay! End of all the lectures!
Good luck for the exams next week 