Chapters authored
Principles of Anesthesia and Airway Management in Head and Neck Surgery
This topic aims to discuss key aspects of anesthetic and airway management for head and neck surgery. Airway management is a central part of patient care and management in Head and Neck Surgery. Common challenges in Head and Neck surgery are shared airway, distorted airway anatomy due to existing pathology; risk of airway obstruction, disconnection or loss of airway intra-operatively; risk of soiling of the airway due to bleeding and surgical debris; and the potential for airway compromise post-operatively. The option for airway management technique is influenced by patient’s factors, anesthetic needs, and surgical requirements. Intubation technique necessitating either a small or large cuffed tracheal tube with a throat pack provides the highest level of airway protection Non-intubation or open airway techniques involve mask ventilation, apneic techniques, and insufflation techniques, or the use of a laryngeal mask airway. Lastly, jet ventilation techniques may be conducted via a supraglottic, subglottic or transtracheal routes. It is essential to have clear airway management plans including rescue airway strategies that should be communicated with the surgeons and patients at the earliest opportunity.
Part of the book: Surgical Management of Head and Neck Pathologies
Perioperative Considerations for Revascularization and Non-Revascularization Surgeries in Moyamoya Disease
Moyamoya disease is a rare, progressive cerebrovascular occlusive disease; characterized by narrowing of the distal internal carotid arteries and their branches. The incidence is high in East Asians and most commonly presents in the first and fourth decade of life. Its symptoms are headaches, seizures, transient neurological deficits, and cognitive decline. Medical management is based on treating the symptoms and includes antiplatelet and anti-seizure medications. Surgical revascularization is the mainstay of treatment. Unique pathophysiology of moyamoya disease necessitates neuro-anesthesiologists to formulate an individualized plan perioperatively. The overriding goal of perioperative anesthetic management of moyamoya disease is to ensure optimal cerebral perfusion and protection. Maintenance of normotension, normocarbia, normo-oxygenation, normothermia, and euvolemia is the cornerstone during the perioperative period. Perioperative adequate analgesia is crucial to prevent cerebral ischemia and allows close neurological monitoring. This chapter reviews perioperative anesthetic management of patients with moyamoya disease.
Part of the book: Moyamoya Disease
Airway Management in Aviation, Space, and Microgravity
Although medical services in aviation have evolved over years based on our understanding of physiology, advancement in monitoring technology but airway management was only recently studied with a focus on space environment. The barometric pressure of ambient air declines as altitude increases, while the volume of air in a confined space will increase according to Boyle law, and therefore oxygen concentration remains at a constant 21%. Altitude sensitive equipment includes endotracheal and tracheostomy cuffs, pneumatic anti shock garments, air splints, colostomy bags, Foley catheters, orogastric and nasogastric tubes, ventilators, invasive monitors, and intra-aortic balloon pumps. The microgravity reduces the body compensation capacity for hemorrhage, while the redistribution of the blood can affect intubation by causing facial edema. Another change is the decreased gastric emptying during aviation. Acute respiratory failure, hypoxemia or inadequate ventilation and protection of the airway in a patient with impaired consciousness are common indications for advanced airway management in aviation. Airway management requires adequate training to maintain excellent medical care during aviation. Tracheal intubation using laryngoscopy would be difficult in microgravity, since the force exerted by the laryngoscope causes the head and neck move out of the field of vision by lever effect exerted on the head and generated through the laryngoscope blade by hand generating a lack of stability, resulting in the difficulty to insert the tracheal tube. While on the ground with the help of gravity, an adequate positioning of the patient is facilitated to achieve alignment of the laryngeal, pharyngeal and oral axes, which is known as sniffing position that allows visualization of the vocal cords and supraglottic structures allowing the introduction of an endotracheal tube.
Part of the book: Special Considerations in Human Airway Management