Anaesthesia for thoracic surgery Flashcards
What are important pre-anaesthetic considerations for thoracic surge patients?
Actelectasis (collapsed lung)
Decreased TLC VC FRC
Ventilatroy mechanism
Very painful procedure
What are the three methods of carrying out thoracic surgery and how are they related to pain?
Lateral thoractotomy
Vertical incision, potential rib resection (more painful involves retraction)
Sternotomy
Incision on the sternum accesse to whole cavity
Thorascopy
Abdominal approach (least invasive and painful)
Why is thoracic surgery so painful?
Skin incision Nerve damage Intercostal and phrenic Retraction Inflammation HYPERALGESIA Unable to immobilise the chest after surgery
What respiratory conditions are corrected in thoracic surgery and what complications may the present with?
Lung lobe torsion Bulla, Neoplasia, Abscess (Pre-existing pneumothorax, hypo ventilation , hypoxaemia)
What cardiovascular conditions are corrected via thoracic surgery and what complications may be presented?
PDA, PRAA, pericardiectomy,
Heart surgery
( bleeding, hypotension, arrhythmias)
Other thoracic surgeries that are not for respiratory or cardiovascular issues and their complications?
Vascular ring, thoracic duct ligation, oesophageal surgery
Regurgitate, aspiration, sepsis
What are the classic problems during thoracic surgery?
Blood loss (PDA, PRAA)
Hypotension
Hypoventillation
What must you always do before surgery commences?
Be prepared
Blood type
Check equipment
What steps should you take to stabilise the patient before surgery?
Pre-oxygenate avoid stress
Place chest drain
Minimise respiratory depression
What should the anaesthetic protocol depend on?
The ASA status of the patient
What are the main aims of the anaesthetic protocol and what drugs should be used to achieve this?
Minimal cardiovascular and respiratory depression Especially in PDA Alpha 2 small volume for sedation Etomidate (highly compromised) Titration Analgesia!! (CRI fentanyl) Multimodal Cardiovascular drugs Dobuta one
Discuss the anaesthetic protocol of the thoracic patient to minimise respiratory depression
Do not deeply sedate patient as need them to move their chest wall Always give opioids Benzodiazepine (good with co-induction) ACP (long acting) Rapid intubation Iv induction Alfaxalone/propofol + etomidate Ketamine Rapid recovery and elimination of drugs ( volatile agents)
What special requests may be asked of you in thoracic surgery?
One lung ventilation
What types of ventilation can be used and what are the advantages?
Manual
Mechanical(much less demanding)
Re deploy lungs gently at the end of surgery
What should the tidal volume be set at on a ventilator and how should it be monitored to ensure it ias adequate?
10-15ml dog 8-10ml cat Observation of the thorax Adapt with monitoirng Intraop visualisation
What should peak inspiratory pressure be set at on a ventilator and how should it be monitored?
8-12cm H2O
Adapt to open and closed thorax
What should respiratory rate be set to on a ventilator?
10-30bpm
Adapt to animal
Increase if Vt (tidal volume) is decreased
What should the I:E ratio be set to on the ventilator?
1:2
Adapt according to the resp rate
When should IPPV be stared?
Respiratory depression due to general anaesthetic drugs and analgesia
Due to decreased sensitivity to CO2
Hyperventilation decreaseing CO2 ( if not increase analgesic doses or midazolam
What drugs can assist you when starting ventilation?
NMB agents Atracurium 0.25-0.5 mg/kg Iv 0.4mb/kg/h Monitoring Anatagoinsts edrophoium and atropine
What are the risks of ventilation?
Lung damage Lung rupture Cardiovascular depression Importance to monitor Reliability of equipmenT
Why should the lungs be expanded slowly after collapsed for a long period of time?
Risk of pulmonary odema
When should you stop ventilation?
End of surgery
Recruitment manoeuvre
Pulmonary re-expansion
(Incremental increases in volume/pressure)
Cannot do this is the lung has been collapsed for greater than 12hrs
How do you stop ventilation?
Stimulating respiratory function Decrease ippv Increased PAO2 Decrease anaesthetic/analgesic drug Antagonise NMBA
What monitoring should you use whilst ventilating a patient?
Capnography (limited reliability open thorax)
Paco2
SpO2
PaO2
What other parameters should be considered when monitoring a thoracic patient?
Fluid loss Haemorrhage Crystalloids colloids Management of hypothermia Warming of lavage fluid
What is an appropriate analgesia strategy for the thoracic patient?
Appropriate
Multimodal
Preventative
Analgesia
What systemic analgesia drugs can be used for the thoracic patient?
Opioids (care respiratory depression, pain and dose)
Methadone 0.3mg/kg or 0.1mg/kg/hr
Fentanly 5mcg/kg + 5-10mcg/kg/hr
NSAIDS ( if normovolemic)
Ketamine (blous or CRI antihyperalgesia and supports cardiovascular system)
Lidocaine CRI better stability anti inflammatory
What local solutions can be administered in the thoracic patient and how can they be given lost-op?
2 spaces before and 2 spaces behind the incision bupivicaine 0.5% 1mg/kg every 6 hours
Intercostal block
Bupivicaine stings on injection either give lidocaine first or given alongside bicarbonate
Epidural
LS morphine 0.1mg/kg + Nacl 1ml/3.5kg
Long action
What should you monitor in recovery of a thoracic patient?
Respiratory rate and effort SpO2 MM and CRT Oxygenate Check chest drain Be ready to induce again Consider blood transfusion if loss of blood Fluid therapy
What must we consider when carrying out postoperative care for the thoracic surgery patient?
Management hypothermia Nursing Padding and bladder Pain management (Multimodal titration to avoid excessive sedation)
