Dynamic Intraoperative Kinking of Flexometallic Tube Ajay Kumar and H. H. Dash Department of Neuroanesthesiology, A.I.I.M.S., New Delhi, India Summary: A 22-year-old male patient had two episodes of oxygen desaturation with concomitant increase in end-tidal carbon dioxide and airway pressure while undergoing transoral odontoidectomy under fluoroscopy. Dynamic kinking of the flexometallic en- dotracheal tube from compression by a Dingman retractor was responsible. Fluoroscopic imaging was helpful in confirming the etiology of sudden alteration in the monitoring parameters. Key Words: Operation, surgery: transoral odontoidectomy— Complications: oxygen desaturation—Endotracheal tube: flexometallic (FM)— Equipment: dingman retractor—Monitoring: pulse oximetry (SpO 2 )—End-tidal carbon dioxide (ETCO 2 )—Airway pressure The transoral transpalatopharyngeal approach with palatal incision is used for excision of the odontoid (1), a toothlike projection from the body of vertebra C-2, as a corrective procedure to treat atlantoaxial dislocation (2). A self-retaining Dingman mouth retractor (Medicon, Ger- many) is positioned using the tongue blade for depressing the tongue, and incorporating the flexometallic endotra- cheal tube, which is secured to the middle of the chin and angled away from the surgical field, to avoid kinking. Flexometallic (FM) or armoured endotracheal tubes have been recommended during intraoral surgery to avoid kinking of the endotracheal tube and consequent hypox- emia, hypercarbia, and their sequelae. However, there are many reports of acute respiratory obstruction with flexo- metallic tubes, mostly with those that have been resteril- ized (3). Automatic cuff deflation occurs relatively fre- quently (4). Other problems that can occur are, (1) it can rotate on the stylet during insertion, (2) it is difficult to insert through the nose, (3) it cannot be shortened because of the spiral, (4) fixation is difficult, (5) there is a possi- bility of blister formation, and (6) there is the possibility of aneurysmal dilatation of the cuff (5,6). This report describes a case in which there was severe dynamic kinking of a flexometallic endotracheal tube be- tween the teeth and the Dingman retractor, causing two episodes of oxygen desaturation. CASE REPORT A 22-year-old man was admitted to our neurosurgery ward. He complained of 4 years of neck pain, weakness in his left leg, 2 years of difficult urination, and 1 1 /2 years of pain and weakness in his upper left arm and right lower leg. His past history included an assault on the neck with a heavy club 10 years previously. He had undergone cer- vical traction 1 1 /2 years previously for neck pain. The patient was of average build, weighing 45 kg, and was conscious, oriented, and cooperative. His cardiac and respiratory system examination did not reveal any abnor- mality. He was in cervical traction, and his mouth opening was two fingers with Mallampati Grade IV. Neurologic examination revealed power grade 4/5 in all limbs except his right upper arm, which was normal. Plantar responses were bilaterally extensor. He had hyperesthesia at C-2 level, and vibration sense was impaired in his left lower leg. Cerebellar signs were negative. All routine investiga- tions including electrocardiogram (ECG) and chest x-ray were normal; however, magnetic resonance imaging showed atlantoaxial dislocation with fused second and Address correspondence and reprint requests to H. H. Dash, Depart- ment of Neuroanesthesiology, A.I.I.M.S., New Delhi, 110 029, India. Journal of Neurosurgical Anesthesiology Vol. 13, No. 3, pp. 243–245 © 2001 Lippincott Williams & Wilkins, Inc., Philadelphia 243