Tracheostomy in Critical Ill Morbidly Obese

Morbidly obese patients have a much higher incidence of obstructive sleep apnea (OSA) and also have altered respiratory physiology, including decreased respiratory compliance and increased airway resistance. Morbidly obese patients with ventilatory-dependent respiratory failure (VDRF) are more difficult to wean and extubate. Both OSA and VDRF are common indications of a tracheotomy in this patient population. Although there is a clear benefit to tracheotomy in obese patients with OSA and VDRF, this must be weighed against the increased surgical morbidity and mortality resulting from the patient’s obesity. The 30-day postoperative mortality rate for a tracheotomy in the morbidly obese has been shown to be as high as 29%. With an elevated body mass index, the increased submental and anterior cervical adipose tissue not only adds to the difficulty of the surgical procedure but also leads to a size discrepancy and curvature mismatch between the tracheotomy tube and the stoma. Standard-sized tubes typically are too short and too curved. Modified tracheotomy tubes are available that are longer and more flexible, and although these tubes may fit properly, the longer tracheotomy track, as well as greater collapse of the stoma due to the anterior cervical adipose, complicates postoperative care, including tracheotomy tube changes. With a greater length of the tracheotomy tract, there is an increase risk of granulation tissue, bleeding from raw surfaces, and infection. The greatest concern of the longer track comes in the first couple weeks after surgery due to increased risk of decanulation, increased difficulty in replacing the track tube due to collapse of the stoma, and, therefore, increased risk of death. ^{,  ,}