Anaesthesia for head & neck surgery.
Anesthesia for head and neck surgery requires careful planning and a multidisciplinary approach primarily due to the challenges of managing a "shared airway" with the surgical team and the potential for anatomical distortion from disease or previous treatment. Key considerations include a high risk of difficult airway management, significant comorbidities in the patient population, and specific intraoperative and postoperative challenges. A specialised and skilled “Team Approach” is essential.
Preoperative considerations
Airway Assessment: A thorough evaluation of the airway is critical, as cancer, previous radiotherapy, or other pathology can lead to restricted neck movement, limited mouth opening, and non-compliant tissues, making intubation and ventilation difficult. Imaging studies (CT/MRI) and highly specialist airway techniques are often required for a safe airway strategy.
Comorbidities: Patients often have a history of tobacco and alcohol use, leading to associated cardiovascular and respiratory issues (e.g., COPD, heart disease) that require optimization before surgery.
Airway Plan: A comprehensive plan, including backup and rescue strategies (e.g., awake intubation, emergency tracheostomy), must be formulated and discussed between anaesthetist and surgeon. A specific skilled team can make all the difference.
Intraoperative considerations
Shared Airway: The anaesthesiologist and surgeon operate in the same anatomical space, requiring close communication and the use of specialized equipment and techniques (e.g., small-diameter tubes, jet ventilation, or even tubeless anaesthesia) to provide a clear surgical field.
Airway Security: Securing the endotracheal tube is challenging due to head manipulation and potential surgical encroachment. Specialist airway devices and considered fixation are used to prevent intra -operative problems and assist surgical access for a better outcome.
Specialized Equipment & Risks:
o Laser Surgery: Requires the use of laser-resistant ETTs and strict precautions to prevent airway fires (the fire triad of fuel, oxygen, and ignition source is present).
o Nerve Monitoring: Specialist techniques avoiding neuromuscular blocking agents can be used to assist with surgical nerve monitoring (e.g., facial or recurrent laryngeal nerve) during the procedure.
Fluid and Hemodynamic Management: Strategies may vary from controlled hypotension to reduce blood loss to maintaining a hyperdynamic circulation for free flap survival, sometimes requiring invasive monitoring in major cases.
Positioning: Patients are often placed in a supine position with a head-up tilt, and the anesthesia machine may be turned away from the patient, necessitating long tubing and careful monitoring of pressure points.
Postoperative considerations
Airway Monitoring: The risk of airway obstruction due to swelling, hematoma formation, or bleeding is high in the immediate postoperative period. Patients may remain intubated or require a temporary tracheostomy and specialized care in a high-dependency or intensive care unit. A skilled specialist anaesthetist can react quickly and safely to these specific issues.
Extubation: The decision to extubate must be made carefully after consulting with the surgeon and re-assessing the airway, with all difficult airway equipment readily available for re-intubation if needed.
Pain and Nausea Management: A multimodal approach to analgesia and aggressive prophylaxis for postoperative nausea and vomiting (PONV) are crucial to avoid coughing and straining, which can precipitate bleeding or airway compromise.