Risks to healthcare workers following tracheal intubation of patients with COVID-19: a prospective international multicentre cohort study.

Healthcare workers involved in aerosol-generating procedures, such as tracheal intubation, may be at elevated risk of acquiring COVID-19. However, the magnitude of this risk is unknown. We conducted a prospective international multicentre cohort study recruiting healthcare workers participating in tracheal intubation of patients with suspected or confirmed COVID-19. Information on tracheal intubation episodes, personal protective equipment use and subsequent provider health status was collected via self-reporting. The primary endpoint was the incidence of laboratory-confirmed COVID-19 diagnosis or new symptoms requiring self-isolation or hospitalisation after a tracheal intubation episode. Cox regression analysis examined associations between the primary endpoint and healthcare worker characteristics, procedure-related factors and personal protective equipment use. Between 23 March and 2 June 2020, 1718 healthcare workers from 503 hospitals in 17 countries reported 5148 tracheal intubation episodes. The overall incidence of the primary endpoint was 10.7% over a median (IQR [range]) follow-up of 32 (18-48 [0-116]) days. The cumulative incidence within 7, 14 and 21 days of the first tracheal intubation episode was 3.6%, 6.1% and 8.5%, respectively. The risk of the primary endpoint varied by country and was higher in women, but was not associated with other factors. Around 1 in 10 healthcare workers involved in tracheal intubation of patients with suspected or confirmed COVID-19 subsequently reported a COVID-19 outcome. This has human resource implications for institutional capacity to deliver essential healthcare services, and wider societal implications for COVID-19 transmission.

The impact of frailty on outcomes and healthcare resource usage after total joint arthroplasty: a population-based cohort study.

AIMS: Total joint arthroplasty (TJA) is commonly performed in elderly patients. Frailty, an aggregate expression of vulnerability, becomes increasingly common with advanced age, and independently predicts adverse outcomes and the use of resources after a variety of non-cardiac surgical procedures. Our aim was to assess the impact of frailty on outcomes after TJA. PATIENTS AND METHODS: We analysed the impact of pre-operative frailty on death and the use of resources after elective TJA in a population-based cohort study using linked administrative data from Ontario, Canada. RESULTS: Of 125 163 patients aged > 65 years having elective TJA, 3023 (2.4%) were frail according to the Johns Hopkins ACG frailty-defining diagnoses indicator. One year follow-up was complete for all patients. Frail patients had a higher adjusted one year risk of mortality (hazard ratio 3.03, 95% confidence interval (CI) 2.62 to 3.51), a higher rate of admission to intensive care (odds ratio (OR) 2.52, 95% CI 2.21 to 2.89), increased length of stay (incidence rate ratio 1.62, 95% CI 1.59 to 1.65), a higher rate of discharge to institutional care (OR 2.09, 95% CI 1.93 to 2.25), a higher rate of re-admission (OR 1.33, 95% CI 1.07 to 1.66) and increased costs at 30, 90 and 365 days post-operatively. Frailty affected outcomes after total hip arthroplasty more than after total knee arthroplasty. TAKE HOME MESSAGE: Frailty is an important risk factor for death after elective TJA, and increases post-operative resource utilisation across many metrics. Processes to optimise the outcomes and efficiency of TJA in frail patients are needed. Cite this article: Bone Joint J 2016;98-B:799-805.

Risk factors for post-carotid endarterectomy hematoma formation.

PURPOSE: To identify risk factors for post-carotid endarterectomy (CEA) hematoma formation and establish the incidence of this complication at The Ottawa Hospital - Civic Campus (TOH-CC). METHODS: A chart review of all patients who underwent CEA at TOH-CC from January 1, 1996 to December 31, 1997 was completed. Identified cases of post-CEA wound hematoma were entered into a case-control study using age and sex-matched controls from within the cohort. These matched pairs were assessed for 31 potential risk factors including demographic details, co-existing medical conditions, preoperative medications, intraoperative management, and postoperative parameters. Risk factors associated with post-CEA hematoma with P<0.05 were entered into a backward step-wise logistic regression model for multivariate analysis. RESULTS: Charts from 249 patients were reviewed and 29 cases of post-carotid endarterectomy hematoma were identified (12% incidence). Six of the initial 31 potential risk factors emerged as univariate predictors of post-CEA hematoma formation (P<0.05): general anesthesia, carotid shunt placement, intraoperative hypotension, non-reversal of heparin, neurosurgery service, and preoperative aspirin use. Following logistic regression only non-reversal of heparin, intraoperative hypotension, and carotid shunt placement were identified as multivariate predictors of post-CEA hematoma formation. More time was spent in critical care settings (ICU/PACU) (P<0.01) and there was increased perioperative mortality (P = 0.04) within the hematoma group. CONCLUSIONS: Post-CEA hematoma formation is associated with increased morbidity and mortality. Non-reversal of heparin, intraoperative hypotension, and carotid shunt placement are multi-variate predictors of post-CEA hematoma formation.

The effect of perioperative aspirin therapy in peripheral vascular surgery: a decision analysis.

Patients who undergo infrainguinal revascularization surgery are at increased risk for perioperative thrombotic complications. Aspirin decreases thrombotic events in the nonoperative setting; however, aspirin is often discontinued to avoid perioperative hemorrhagic complications. We used a decision analysis to determine whether aspirin should be discontinued before infrainguinal revascularization surgery. Two strategies were compared: aspirin cessation 2 wk before surgery and aspirin continuation throughout the perioperative period. Clinical events examined included myocardial infarction, thrombotic cerebrovascular accident, hemorrhagic cerebrovascular accident, gastrointestinal hemorrhage, and incisional hemorrhagic complications. Event rates and effect of aspirin were obtained by using MEDLINE. The outcomes were perioperative mortality, life expectancy, and quality-adjusted life expectancy. According to the model, continued aspirin use decreased perioperative mortality rates from 2.78% to 2.05%. Continued aspirin use increased life expectancy from 14.83 to 14.89 yr and increased quality-adjusted life expectancy from 14.72 to 14.79 yr. Aspirin increased the number of hemorrhagic complications by 2.46%, primarily because of an increased incidence of non-life-threatening complications.

Does acute normovolemic hemodilution reduce perioperative allogeneic transfusion? A meta-analysis. The International Study of Perioperative Transfusion.

UNLABELLED: The objective of this study was to systematically review the literature and to statistically summarize the evidence evaluating acute normovolemic hemodilution (ANH). Prospective, randomized, controlled trials of ANH that reported either the proportion of patients exposed to allogeneic blood or the units of allogeneic blood transfused were included. All types and languages of publication were eligible. Of 1573 identified publications, 24 trials (containing a total of 1218 patients) were included in the meta-analysis. When all trials were pooled, ANH reduced the likelihood of exposure to allogeneic blood (odds ratio [OR] 0.31, 95% confidence interval [CI] 0.15, 0.62) and the total units of allogeneic blood transfused (weighted mean difference [WMD] -2.22 U, 95% CI -3.57, -0.86). However, there was marked heterogeneity of the results. In trials using a protocol to guide perioperative transfusion, ANH failed to reduce either the likelihood of transfusion (OR 0.64, 95% CI 0.31, 1.31) or the units administered (WMD -0.25 U, 95% CI -0.60, 0.10). Adverse events were incompletely reported. It is possible that biased experimental design is, in part, responsible for the reported efficacy of this technique. IMPLICATIONS: after a systematic literature review, 24 randomized trials examining the role of acute normovolemic hemodilution were identified, pooled, and summarized using statistical techniques. Many studies reported an impressive reduction in blood transfused. Closer examination suggests that these reductions in blood exposure may be due to flawed study design.

Gene structure, sequence, and chromosomal localization of the human red cell-type low-molecular-weight acid phosphotyrosyl phosphatase gene, ACP1.

Two distinct isoenzymes of the human red cell-type acid phosphatase (RCAP) have been known to exist for some time, but the genetic basis of this phenomenon was uncertain. We previously reported the isolation and characterization of two cDNA clones for human RCAP. We showed that the coding regions of the two cDNAs for the human isoenzymes were identical except for a divergent segment spanning nucleotides 176-274, called the variable region. We have now cloned, characterized, and mapped the gene encoding the red cell-type acid phosphatase isoenzymes. The human ACP1 gene is shown to span about 18 kb and to consist of seven exons. The promoter region of ACP1 is very GC-rich and has no apparent TATA or CCAAT boxes. The sequence information confirms that the variable regions of the isoenzymes exist in the gDNA sequence as separate and distinct exons, apparently subject to mutually exclusive alternative splicing. Using a genomic ACP1 clone, we have established the chromosomal localization of the gene to the distal portion of 2p25 by fluorescence in situ hybridization.

Epidural sufentanil does not attenuate the central haemodynamic effects of caesarean section performed under epidural anaesthesia.

The effect of sufentanil 30 micrograms added to the epidural local anaesthetic solutions used for anaesthesia during elective Caesarean section on central haemodynamic variables was studied. Haemodynamic measurements made by thoracic electrical bioimpedance (TEB) monitoring were compared in 21 healthy parturients undergoing Caesarean section under epidural anaesthesia with and without the addition of epidural sufentanil. The patients were randomized to control (Group C) and study (Group S) groups. Following iv prehydration, an epidural catheter was placed at the L2-3 or L3-4 interspace. After a negative test dose, in a double-blinded protocol, patients in Group S received sufentanil 30 micrograms (0.6 ml) in 4.4 ml lidocaine carbonate 2% with 5 micrograms.ml-1 epinephrine and those in Group C received 5 ml lidocaine carbonate 2% with epinephrine. Lidocaine carbonate 2% with 5 micrograms.ml-1 epinephrine was then titrated to establish an anaesthetic level of T4. Haemodynamic variables (heart rate, mean arterial blood pressure, cardiac index, ejection fraction and end-diastolic index) were measured non-invasively, continuously throughout the perioperative period. There were no differences noted in haemodynamic measurements between the groups at any time perioperatively. However, differences occurred within the groups when compared with baseline values. Heart rate was increased in both groups intraoperatively. Cardiac index was increased throughout the intraoperative period in Group S but was less frequently elevated in Group C. Ejection fraction was increased throughout the perioperative period in Group S but not in Group C. End-diastolic index increased following iv preloading in both groups and returned to baseline with induction of epidural block.(ABSTRACT TRUNCATED AT 250 WORDS)

Feasibility of blinding in a randomized controlled trial comparing preoperative autologous blood donation and acute normovolemic hemodilution in adult cardiac surgery.

BACKGROUND: Acute normovolemic hemodilution and preoperative autologous donation have been shown to be effective techniques for decreasing the exposure of patients to allogeneic blood during cardiac surgery. They have not, however, been compared to each other, because of perceived difficulties in blinding in such a clinical study. The feasibility of blinding was tested in a pilot trial. STUDY DESIGN AND METHODS: Ten patients were randomly assigned to undergo preoperative autologous blood donation or acute normovolemic hemodilution during cardiac surgery. Patients were blinded during this process by shielding of the arm and by insertion of an intravenous line in each patient. Every attempt was made to blind the clinical staff during and after surgery. The effectiveness of this blinding was determined by using a questionnaire. RESULTS: In the 10 cases, six patients, four surgeons, and one anesthetist answered, "I do not know," with respect to whether preoperative autologous blood donation had occurred. The remaining people interviewed believed the blinding was unsuccessful. However, correct answers were given by 75 percent of the patients (95% CI, 19-99%), 83 percent of the surgeons (95% CI, 36-99.6%), and 66 percent of the anesthetists (95% CI, 29.9-92.5%). The frequency of correct answers did not differ significantly from the 50 percent expected by chance, but the CIs are wide. CONCLUSIONS: Blinding of patients and all members of the surgical team during both the preoperative donation process and acute normovolemic hemodilution in the operating theater was successful most of the time, as the frequency of correct answers did not differ significantly from the 50 percent expected by chance. However, more accurate estimates of the success of blinding require a study with a larger sample. It is possible that, with a larger series, the physician's ability to determine patient assignment would be significantly better than that by chance alone.