Objective/Hypothesis This study aimed to determine the incidence of facial pressure injuries associated with prone positioning for COVID‐19 patients as well as to characterize the location of injuries and treatments provided. Methods This was a retrospective chart review of 263 COVID‐19 positive patients requiring intubation in the intensive care units at MedStar Georgetown University Hospital and MedStar Washington Hospital Center between March 1st and July 26th, 2020. Information regarding proning status, duration of proning, presence, or absence of facial pressure injuries and interventions were collected. Paired two‐tailed t‐test was used to evaluate differences between proned patients who developed pressure injuries with those who did not. Results Overall, 143 COVID‐19 positive patients required proning while intubated with the average duration of proning being 5.15 days. Of those proned, 68 (47.6%) developed a facial pressure injury. The most common site involved was the cheek with a total of 57 (84%) followed by ears (50%). The average duration of proning for patients who developed a pressure injury was significantly longer when compared to those who did not develop pressure injuries (6.79 days vs. 3.64 days, P < .001). Conclusions Facial pressure injuries occur with high incidence in patients with COVID‐19 who undergo prone positioning. Longer duration of proning appears to confer greater risk for developing these pressure injuries. Hence, improved preventative measures and early interventions are needed. Level of Evidence 4 Laryngoscope, 131:E2139–E2142, 2021

Assembly of polymerase chain reactions at room temperature can sometimes lead to low yields or unintentional products due to mispriming. Mutation of isoleucine 707 to leucine in DNA polymerase I from Thermus aquaticus substantially decreases its activity at room temperature without compromising its ability to amplify DNA. To understand why a conservative change to the enzyme over 20 Å from the active site can have a large impact on its activity at low temperature, we solved the X-ray crystal structure of the large (5′-to-3′ exonuclease-deleted) fragment of Taq DNA polymerase containing the cold-sensitive mutation in the ternary (E–DNA–ddNTP) and binary (E–DNA) complexes. The I707L KlenTaq1 ternary complex was identical to the wild-type in the closed conformation except for the mutation and a rotamer change in nearby phenylalanine 749, suggesting that the enzyme should remain active. However, soaking out of the nucleotide substrate at low temperature results in an altered binary complex made possible by the rotamer change at F749 near the tip of the polymerase O-helix. Surprisingly, two adenosines in the 5′-template overhang fill the vacated active site by stacking with the primer strand, thereby blocking the active site at low temperature. Replacement of the two overhanging adenosines with pyrimidines substantially increased activity at room temperature by keeping the template overhang out of the active site, confirming the importance of base stacking. These results explain the cold-sensitive phenotype of the I707L mutation in KlenTaq1 and serve as an example of a large conformational change affected by a conservative mutation.

Background There is a paucity of literature characterizing outcomes in older adult patients with head and neck cancer (HNC). This study aims to describe patients from this group, their adherence to National Comprehensive Cancer Network (NCCN) adjuvant treatment guidelines, and the impact of guideline adherence on overall survival (OS). Methods In this retrospective cohort study, we reviewed all patients ≥80 years old with HNC who underwent surgery with curative intent from 2008 to 2016. Adherence to NCCN guidelines was determined in blinded fashion, and quality metrics and OS were compared. Results One hundred fifty‐nine patients met inclusion criteria. The majority of patients (n = 94, 59%) underwent treatment in accordance with NCCN recommendations while 65 (41%) deviated from NCCN guidelines. The two cohorts did not demonstrate a difference in 2‐year OS (62% vs 66%, P = .50). Conclusion Older adult patient outcomes were not different when treatment deviated from NCCN guidelines.

Objectives/Hypothesis Prone positioning is frequently used in patients intubated for COVID‐19‐related lung injury to improve oxygenation. At our institution, we observed severe tongue edema develop in some of these patients. Hence, we sought to determine the incidence of tongue edema in this cohort and whether prone positioning was a risk factor associated with this complication. Study Design Retrospective cohort study. Methods A single‐system retrospective cohort study of patients intubated for respiratory failure secondary to COVID‐19 who subsequently developed clinically notable tongue edema from March 13 to July 5, 2020. Results 260 patients were intubated for COVID‐19‐related respiratory failure during the study period. 158 patients (60.8%) underwent at least one episode of proning. Twelve patients in total (4.6%) developed clinically significant tongue edema. Eleven of the twelve patients (91.7%) who developed tongue edema underwent proning prior to the development of edema. Prone positioning was associated with an increased incidence of tongue edema (odds ratio [OR] 7.56, 95% confidence interval [CI] 0.96–59.46, P = .027). In all proned patients who developed edema, this complication was noted during proning or shortly after supination (range, 0–4 days). Tongue edema was primarily managed with conservative measures; one patient required tracheostomy for definitive management. Conclusions Tongue edema appears to develop in a subset of patients with COVID‐19 who are intubated. It appears to be associated with prone positioning but is likely multifactorial in nature. Further investigation into its incidence and pathophysiology is warranted. Level of Evidence 4 Laryngoscope , 2021

Permanent seed implant cesium-131 (131 Cs) brachytherapy provides highly localized radiation for patients with recurrent head and neck cancer (HNC), who may be ineligible for external beam radiation therapy due to a high-risk of toxicity. As carotid blowout is a concern in the setting of re-irradiation, a dose to the carotid artery was examined for 131 Cs brachytherapy implants. Material and methods: Eleven patients were implanted with 131 Cs adjacent to carotid at the time of resection for recurrent HNC. Vascularized tissue flaps were used in some patients. The carotid artery was contoured on the post-implant brachytherapy treatment plan, and the maximum carotid point dose and minimum carotid-seed distances are reported. The incidence of carotid blowout in the follow-up period was also measured. Results: The maximum carotid dose was 77 ±52 Gy (range, 3-158 Gy). The closest seed to the carotid artery was 0.8 ±0.8 cm (range, 0.2-2.6 cm). One patient without a flap experienced carotid blowout, which was attributed to a non-healing wound rather than to high radiation doses. Conclusions: Carotid artery doses from 131 Cs are reported. Vascularized tissue flaps should be considered when planning 131 Cs brachytherapy.