Extubation and the Risks of Coughing and Laryngospasm in the Era of Coronavirus Disease-19 (COVID-19).

The coronavirus disease-19 (COVID-19) pandemic has prompted new interest among anesthesiologists and intensivists in controlling coughing and expectoration of potentially infectious aerosolized secretions during intubation and extubation. However, the fear of provoking laryngospasm may cause avoidance of deep or sedated extubation techniques which could reduce coughing and infection risk. This fear may be alleviated with clear understanding of the mechanisms and effective management of post-extubation airway obstruction including laryngospasm. We review the dynamic function of the larynx from the vantage point of head-and-neck surgery, highlighting two key concepts: 1. The larynx is a complex organ that may occlude reflexively at levels other than the true vocal folds; 2. The widely held belief that positive-pressure ventilation by mask can "break" laryngospasm is not supported by the otorhinolaryngology literature. We review the differential diagnosis of acute airway obstruction after extubation, discuss techniques for achieving smooth extubation with avoidance of coughing and expectoration of secretions, and recommend, on the basis of this review, a clinical pathway for optimal management of upper airway obstruction including laryngospasm to avoid adverse outcomes.

The Impact of Epidural Analgesia on the Rate of Thromboembolism without Chemical Thromboprophylaxis in Major Oncologic Surgery.

Patients with abdominopelvic cancers are at increased risk of venous thromboembolism (VTE) due to their malignancy. We evaluated outcomes and the rate of VTE in patients undergoing abdominopelvic surgery for malignancy with preoperative epidural analgesia without postoperative chemical VTE prophylaxis. A retrospective review between 2009 and 2015 identified 285 patients with malignancy who underwent abdominopelvic surgery by a single surgeon (AWS). Lower extremity venous duplex scans (VDS) were performed preoperatively and before discharge. Demographics, procedures, and VTE outcomes were reviewed. The median age was 66 years. The average operative time was 315 minutes. All patients ambulated on postoperative day (POD) one or two. Epidural catheters (ECs) were removed on postoperative day four or five. No patient received VTE prophylaxis while an epidural catheter was in place. Preoperative lower extremity VDS revealed above-knee deep vein thrombosis (DVT) in seven patients (2.5%). Postoperative lower extremity VDS revealed acute DVT in 24 patients (8.4%): nine (3.2%) above-knee and 15 (5.2%) below-knee. The nine patients with above-knee DVT were anticoagulated after epidural removal. No patient developed a pulmonary embolism. Our data suggest that patients undergoing major open operations with epidural analgesia have low rates of DVT and may obviate the need for chemical prophylaxis. However, larger studies are required to determine the overall effects of epidural analgesia on the development of DVTs postoperatively.

Machine-learning Algorithm to Predict Hypotension Based on High-fidelity Arterial Pressure Waveform Analysis.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: With appropriate algorithms, computers can learn to detect patterns and associations in large data sets. The authors' goal was to apply machine learning to arterial pressure waveforms and create an algorithm to predict hypotension. The algorithm detects early alteration in waveforms that can herald the weakening of cardiovascular compensatory mechanisms affecting preload, afterload, and contractility. METHODS: The algorithm was developed with two different data sources: (1) a retrospective cohort, used for training, consisting of 1,334 patients' records with 545,959 min of arterial waveform recording and 25,461 episodes of hypotension; and (2) a prospective, local hospital cohort used for external validation, consisting of 204 patients' records with 33,236 min of arterial waveform recording and 1,923 episodes of hypotension. The algorithm relates a large set of features calculated from the high-fidelity arterial pressure waveform to the prediction of an upcoming hypotensive event (mean arterial pressure < 65 mmHg). Receiver-operating characteristic curve analysis evaluated the algorithm's success in predicting hypotension, defined as mean arterial pressure less than 65 mmHg. RESULTS: Using 3,022 individual features per cardiac cycle, the algorithm predicted arterial hypotension with a sensitivity and specificity of 88% (85 to 90%) and 87% (85 to 90%) 15 min before a hypotensive event (area under the curve, 0.95 [0.94 to 0.95]); 89% (87 to 91%) and 90% (87 to 92%) 10 min before (area under the curve, 0.95 [0.95 to 0.96]); 92% (90 to 94%) and 92% (90 to 94%) 5 min before (area under the curve, 0.97 [0.97 to 0.98]). CONCLUSIONS: The results demonstrate that a machine-learning algorithm can be trained, with large data sets of high-fidelity arterial waveforms, to predict hypotension in surgical patients' records.

An unusual cause of airway obstruction in a patient in the endoscopy suite.

A 74-year-old man presented for outpatient endoscopy because of dysphagia and the sensation of a mass in the back of his throat. Esophagogastroduodenoscopy demonstrated a soft tissue mass in the proximal esophagus that prolapsed into the hypopharynx on withdrawal of the endoscope. Complete airway obstruction ensued, requiring emergent tracheotomy. The patient was transferred to the hospital for further treatment. Surgical resection revealed a rare giant fibrovascular polyp, which may be associated with asphyxiation and sudden death.

Thromboprophylaxis and major oncologic surgery performed with epidural analgesia.

OBJECTIVE: To evaluate clinical outcomes in patients with cancer undergoing major abdominal surgery who received preoperative indwelling epidural catheters (ECs) and no postoperative thromboprophylaxis. DESIGN: Retrospective analysis of a prospective database. SETTING: Tertiary referral medical center. PATIENTS Between January 1, 2009, and July 31, 2011, 119 patients, with a mean age of 64.5 years (range, 34-95 years), underwent major abdominal oncologic surgery with an indwelling EC. MAIN OUTCOME MEASURES: Records of all patients were reviewed for age, duration of surgery, hospital length of stay, and clinical outcomes. All patients underwent lower extremity venous duplex ultrasonography prior to hospital discharge. RESULTS: The average operative time was 338 minutes. Mean (SD) intensive care unit stay was 2.8 (1.4) days (range, 1-7 days). Patients ambulated by postoperative day 1 or 2. Most ECs were removed on postoperative day 4. There were no major complications from the EC. Fifty-two patients (44%) were treated with deep venous thrombosis prophylaxis on postoperative day 4 after removal of the EC. Lower extremity duplex studies showed 8 patients (6.7%) had an acute thrombus. One patient (0.8%) developed an asymptomatic proximal deep venous thrombosis and 7 patients (5.9%) developed distal superficial thrombi. No patient developed a pulmonary embolus. CONCLUSIONS Thromboembolic complications following major abdominal surgery for cancer may be reduced with the use of ECs. Epidural catheters may directly prevent deep venous thrombosis through sympathetic blockade, resulting in increased blood flow to the lower extremities. This effect may also be attributable to earlier ambulation. These results suggest that patients who have an EC and do not receive concurrent postoperative thromboprophylaxis do not have an increased risk for thromboembolic events.

Tumors at the aortoiliac/inferior vena cava bifurcation: preoperative, anesthetic, and intraoperative considerations.

Primary and recurrent retroperitoneal tumors can involve the aortoiliac vasculature. They are often considered inoperable or incurable because of the locally advanced nature of the disease or the technical aspects involved in safely resecting the lesion. Safe resection of these lesions requires experience and extensive preoperative planning for success. A retrospective database review of 76 patients with retroperitoneal tumors identified tumors involving major vascular structures in the abdomen and pelvis undergoing resection of tumor en bloc with the aortoiliac vasculature. Preoperative planning and intraoperative technical maneuvers are reviewed. Patients were followed until time of this report. Four patients with retroperitoneal tumors involving the aortoiliac vessels underwent surgery: two patients with sarcoma (one primary and one recurrent), one with metastatic renal cell carcinoma, and one with a paraganglioma. All patients had resection of the aorta and vena cava or the iliac artery and vein. Arterial reconstruction (anatomic or extra-anatomic) was performed in all cases. The patient with renal cell carcinoma also required venous reconstruction to support a renal autotransplant. Veno-venous bypass was required in one patient. Local control was achieved in 3 of 4 cases. Surgery for retroperitoneal tumors involving major vascular structures is technically feasible with appropriate planning and technique. Multiple disciplines are required, including general surgical oncology, vascular surgery, and possibly, cardiothoracic surgery.