J o u r n a l P r e -p r o o f Dear editor, Older COVID-19 patients with comorbidities like cardiovascular and pulmonary disease are the main group requiring tracheal intubation for invasive ventilation support [1, 2] . Here, we report an elderly COVID-19 patient who experienced cardiac arrest during intubation. Written consent for publication was obtained from the patient's relative.
On 27 February, 2020, a 60-year-old male patient with confirmed COVID-19 infection was transferred to the general ward of our hospital. His symptoms included fever, cough, and chest tightness, and he had a history of chronic bronchitis. Nine days later, he developed increased airway secretions, and sputum sounds were heard on lung auscultation. The medical staff promoted the drainage of sputum by strengthening back patting and providing intermittent manual sputum suction. Under continuous nasal catheter oxygenation (4 L/min), oxygen saturation was maintained at 90%-95%, his heart rate (HR) was 84 bpm, blood pressure (BP) was 122/78 mmHg and his respiratory rate (RR) was 20 breaths per min. At 15:00 h the same day, the patient suffered an acute shortness of breath. Lung auscultation revealed the exacerbation of bilateral wet rales, he experienced loss of consciousness, his HR increased to 145 bpm, BP decreased to 93/58 mmHg, and RR to 35 breaths per min.
Blood gas analysis showed a pH of 7.091; pO 2 , 96.8 mmHg; pCO 2 , 94.3 mmHg; 
because most of these patients were in a coma, it was not possible to perform a comprehensive difficult airway assessment before intubation. Therefore, we suggest that large suction tubes should be prepared for thorough cleaning of airway sputum before intubating COVID-19 patients. We also recommend that the support of the difficult airway management team and the cardiopulmonary resuscitation team should be readily available during the intubation of high-risk patients, and frequent teamwork exercises on cardiopulmonary resuscitation simulators are helpful to improving the quality of cardiopulmonary resuscitation in emergencies [4] .
None.
Written informed consents were received from the patient's relative both for the procedure and publishing of the case.
The authors received no funding for this study.
The authors have no conflict of interest to declare. Approximately 20 s after anaesthesia-inducing drug infusion, the patient experienced acute cardiac arrest; at this time pre-oxygenation was still underway and the endotracheal tube had not been placed. C, the glottis was covered with viscous sputum and could not be exposed. After suction, the endotracheal tube was successfully inserted under the guidance of video laryngoscopy. D, the defibrillator was ready for use while a physician performed chest compressions, and 1 mg of epinephrine was continuously intravenously injected three times at 2-min intervals.
With the support of mechanical ventilation and 5 min of continuous cardiopulmonary resuscitation, the patient recovered sinus rhythm without defibrillation. Figure 1 