Ultrasound in Predicting Difficult Intubation in Acromegaly Patients

Airway management is an important issue for patient safety in anesthesia. Difficult ventilation and difficult intubation are important causes of anesthesia-related perioperative morbidity and mortality. It is reported that approximately 30% of anesthesia-related mortality is related to inadequacy in difficult airway management. The incidence of difficult intubation is 1.5-13.2% in the general population.

Features evaluated for difficult airway risk prediction: age, gender, body mass index, weight, height, history of difficult intubation, facial and jaw features, mouth opening, head and neck mobility, prominent upper incisors, presence of beard, upper lip bite test, mallampati score, thyromental distance, hyomental distance , sternomental distance includes the distance between the incisors.

Acromegaly is an endocrinological disease with significant mortality and morbidity due to high growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels. It usually occurs due to a pituitary tumor. Excessive GH secretion in adults causes acromegaly with overgrowth in the acral areas. Acral changes seen in these patients may cause abnormal airway structure and, accordingly, airway management may become difficult during anesthesia. Typically, large nose and tongue, thick mandible, and thick and large lips can be observed in acromegaly. There is hypertrophy in the pharynx, larynx, tonsil, vocal cords, mucosa and soft tissues. These features of acromegaly may cause difficult mask ventilation and difficult intubation. The incidence of difficult intubation is observed to be 10%-30% in acromegalic individuals.

With developing technology, the use of ultrasonography in preoperative airway evaluation has become widespread. It is a real-time, non-invasive, easily accessible, mobile, safe, painless method that can be used to evaluate both the upper and lower airway. Clinical airway screening tests aim to predict difficult airways. Recent reviews have shown that ultrasonographic measurements have a greater predictive value than airway screening tests performed by physical examination. Measurements obtained from ultrasound include skin-vocal cord distance, skin-hyoid distance and skin-epiglotte distance.

In the preoperative physical examination; Age, gender, height, weight, body mass index, mouth opening, neck extension, mallampati score, thyromental-hyomental and sternomental distance, neck circumference measurement and upper lip bite test will be evaluated.

All airway ultrasonographic evaluations will be performed preoperatively by experienced anesthesiologists who have previously performed airway ultrasonography. Participants will be prepared for ultrasonographic evaluation in the supine position, and skin-hyoid bone, skin-epiglotte, skin-vocal cord anterior commissure distance measurements will be made and recorded.

Intubation of the participants will be performed by experienced anesthesiologists who are unfamiliar with ultrasonography measurements.The assistive stylet used during the intubation of the participants, the need for cricoid pressure, the number of attempts, the number of practitioners and the glottis opening seen during laryngoscopy will be noted in accordance with the Cormack Lehane classification.Advanced airway devices will be used when necessary.

Preoperative physical examination values, ultrasonographic measurements and blood test results of the participants will be analyzed statistically.