Reusing personal protective equipment (PPE) did not increase surgical site infection in trauma surgical patients during the COVID-19 pandemic: A retrospective cohort study in Michigan Trauma Centers.

BACKGROUND: Reuse of personal protective equipment (PPE), masks more specifically, during the COVID-19 pandemic was common. The primary objective of this study was to compare pre-pandemic surgical site infection (SSI) rates prior to reuse of PPE, to pandemic SSI rates after reuse of PPE in trauma surgical patients. METHODS: A retrospective cohort analysis collected from the Michigan Trauma Quality Improvement Program database was performed. The pre-COVID cohort was from March 1, 2019 to December 31, 2019 and post-COVID cohort was March 1, 2020 to December 31,2020. Descriptive statistics were used to assess differences between variables in each cohort. RESULTS: Nearly half (49.8%) of our cohort (n = 48,987) was in the post-COVID group. There was no significant difference in frequency of operative intervention between groups (p > .05). There was no significant increase (p > .05) between pre- and post-COVID cohorts for superficial, deep, or organ space SSI when reuse of masks was common. CONCLUSION: Reuse of PPE did not lead to an increase in SSI in surgical patients. These findings are consistent with previous studies, but the first to be described in the trauma surgical patient population. Studies such as this may help inform further discussion regarding PPE usage as we continue to emerge from the current pandemic with the continuous threat of future pandemics.

The Effect of Antiplatelet Agents on Thromboelastography.

BACKGROUND: Thomboelastography (TEG) is a point of care viscoelastic test that provides an assessment of clot formation and kinetics. Antiplatelet agents are commonly used but there is limited literature evaluating their possible effects on overall clot kinetics. We aimed to evaluate the relationship between antiplatelet agents and clot kinetics as defined by TEG. METHODS: This is a retrospective study of adult patients who underwent TEG from February 2018 to July 2020. Patients who received anticoagulants or blood transfusions within 72 hours, had an incomplete TEG, were diagnosed with COVID-19, or had liver failure were excluded. Patients were stratified based on antiplatelet status. RESULTS: Of 1060 patients, 119 were included (50 controls, 69 antiplatelet agents-37 aspirin monotherapy, 26 dual antiplatelet therapy). Between the control and antiplatelet therapy groups, there was no significant difference in clot time, maximal clot strength, or fibrinogen level. When compared to control patients, patients on dual antiplatelets had significantly higher fibrinogen levels (408.1 mg/dL vs 481.5 mg/dL, P = .013) but no significant differences in clot time or maximal clot strength. In our subgroup analysis, patients on dual antiplatelets had increased maximal clot strength (58.8° vs 63°, P = .005) and fibrinogen levels (384.1 mg/dL vs 481.5 mg/dL, P = .005) compared to those on aspirin alone. DISCUSSION: Compared to control patients and those on aspirin alone, patients on dual antiplatelets have increased maximal clot strength and increased fibrinogen levels. These results can help physicians better target product resuscitation in patients who are on antiplatelet agents.

Myocardial infarction after craniotomy for asymptomatic meningioma.

A man in his 40s with a history of coronary artery disease previously treated with a drug-eluting stent presented for elective craniotomy and resection of an asymptomatic but enlarging meningioma. During his craniotomy, he received desmopressin and tranexamic acid for surgical bleeding. Postoperatively, the patient developed chest pain and was found to have an ST-elevation myocardial infarction (MI). Because of the patient's recent neurosurgery, standard post-MI care was contraindicated and he was instead managed symptomatically in the intensive care unit. Echocardiogram on postoperative day 1 demonstrated no regional wall motion abnormalities and an ejection fraction of 60%. His presentation was consistent with thrombosis of his diagonal stent. He was transferred out of the intensive care unit on postoperative day 1 and discharged home on postoperative day 3.

IGF-1R inhibition induces schedule-dependent sensitization of human melanoma to temozolomide.

Prior studies implicate type 1 IGF receptor (IGF-1R) in mediating chemo-resistance. Here, we investigated whether IGF-1R influences response to temozolomide (TMZ), which generates DNA adducts that are removed by O6-methylguanine-DNA methyltransferase (MGMT), or persist causing replication-associated double-strand breaks (DSBs). Initial assessment in 10 melanoma cell lines revealed that TMZ resistance correlated with MGMT expression (r = 0.79, p = 0.009), and in MGMT-proficient cell lines, with phospho-IGF-1R (r = 0.81, p = 0.038), suggesting that TMZ resistance associates with IGF-1R activation. Next, effects of IGF-1R inhibitors (IGF-1Ri) AZ3801 and linsitinib (OSI-906) were tested on TMZ-sensitivity, cell cycle progression and DSB induction. IGF-1Ri sensitized BRAF wild-type and mutant melanoma cells to TMZ in vitro, an effect that was independent of MGMT. Cells harboring wild-type p53 were more sensitive to IGF-1Ri, and showed schedule-dependent chemo-sensitization that was most effective when IGF-1Ri followed TMZ. This sequence sensitized to clinically-achievable TMZ concentrations and enhanced TMZ-induced apoptosis. Simultaneous or prior IGF-1Ri caused less effective chemo-sensitization, associated with increased G1 population and reduced accumulation of TMZ-induced DSBs. Clinically relevant sequential (TMZ → IGF-1Ri) treatment was tested in mice bearing A375M (V600E BRAF, wild-type p53) melanoma xenografts, achieving peak plasma/tumor IGF-1Ri levels comparable to clinical Cmax, and inducing extensive intratumoral apoptosis. TMZ or IGF-1Ri caused minor inhibition of tumor growth (gradient reduction 13%, 25% respectively), while combination treatment caused supra-additive growth delay (72%) that was significantly different from control (p < 0.01), TMZ (p < 0.01) and IGF-1Ri (p < 0.05) groups. These data highlight the importance of scheduling when combining IGF-1Ri and other targeted agents with drugs that induce replication-associated DNA damage.

Sentinel lymph node biopsy in melanoma: The Oxford ten year clinical experience.

Sentinel lymph node biopsy (SLNB) has become an established investigation for assessing microscopic nodal metastasis in melanoma. The American Joint Committee on Cancer (AJCC) incorporates the sentinel node status in its staging criteria for melanoma. We present our clinical evaluation of performing SLNB in a single UK centre between 1998 and 2008. There were 697 patients with a mean age 53 years (range 13-92). We were able to surgically harvest at least one sentinel node in 694 patients of which 532 (76%) were negative. Of the 162 positive patients, 129 underwent further completion lymphadenectomy with 29 showing further pathologically positive nodes. At median follow up of 46 months, mortality from melanoma for SLN positive and negative patients was 32% and 4%, respectively. Disease recurrence was noted in 10% of the SLN negative group. Survival curves showed significant difference (p<0.001) in outcomes for patients grouped by Breslow thickness. Postoperative complications were noted in 6% of patients. No life-threatening complications were noted. Our results are comparable to other national and international studies. We await the outcomes of ongoing trials to assess the therapeutic value of SLNB for melanoma.