Perioperative medicine: Overview

Abstract
Background: Intraoperative hypotension (IOH) is strongly linked to organ system injuries and postoperative death. Blood pressure itself is a powerful predictor of IOH; however, it is unclear which pressures carry the lowest risk and may be leveraged to prevent subsequent hypotension. Our objective was to develop a model that predicts, before surgery and according to a patient's unique characteristics, which intraoperative mean arterial pressures (MAPs) between 65 and 100 mm Hg have a low risk of IOH, defined as an MAP <65 mm Hg, and may serve as testable hemodynamic targets to prevent IOH.

Methods: Adult, noncardiac surgeries under general anesthesia at 2 tertiary care hospitals of the University of Pittsburgh Medical Center were divided into training and validation cohorts, then assigned into smaller subgroups according to preoperative risk factors. Primary outcome was hypotension risk, defined for each intraoperative MAP value from 65 to 100 mm Hg as the proportion of a value's total measurements followed by at least 1 MAP <65 mm Hg within 5 or 10 minutes, and calculated for all values in each subgroup. Five models depicting MAP-associated IOH risk were compared according to best fit across subgroups with proportions whose confidence interval was <0.05. For the best fitting model, (1) performance was validated, (2) low-risk MAP targets were identified according to applied benchmarks, and (3) preoperative risk factors were evaluated as predictors of model parameters.

Results: A total of 166,091 surgeries were included, with 121,032 and 45,059 surgeries containing 5.4 million and 1.9 million MAP measurements included in the training and validation sets, respectively. Thirty-six subgroups with at least 21 eligible proportions (confidence interval <0.05) were identified, representing 92% and 94% of available MAP measurements, respectively. The exponential with theta constant model demonstrated the best fit (weighted sum of squared error 0.0005), and the mean squared error of hypotension risk per MAP did not exceed 0.01% in validation testing. MAP targets ranged between 69 and 90 mm Hg depending on the subgroup and benchmark used. Increased age, higher American Society of Anesthesiologists physical status, and female sexindependently predicted (P < .05) hypotension risk curves with less rapid decay and higher plateaus.

Conclusions: We demonstrate that IOH risk specific to a given MAP is patient-dependent, but predictable before surgery. Our model can identify intraoperative MAP targets before surgery predicted to reduce a patient's exposure to IOH, potentially allowing clinicians to develop more personalized approaches for managing hemodynamics.

Abstract
Background: Consumer driven research is increasingly being prioritized.

Aim: Our aim was to partner with consumers to identify the top ten research priorities for pediatric anesthesia and perioperative medicine. The ACORN (Anesthesia Consumer Research Network) was formed to collaborate with children and families across Australia.

Methods: A prospective online survey was developed to generate research ideas from consumers. The survey was developed in Qualtrics, a survey research platform. Consumers were invited to participate through poster advertising, social media posts, via consumer networks at participating hospitals and in addition 35 national consumer/patient representative organizations were approached. We also conducted a similar idea generating survey for clinicians through email invitation and via Twitter. A second round of surveys was conducted to prioritize the long list of research questions and a shortlist of priorities developed. A single consensus meeting was held, and a final consensus list of top ten priorities emerged.

Results: A total of 281 research ideas were submitted between 356 consumers in the idea generating survey and from four consumer/patient representative groups. 75 clinicians responded to the clinician idea generation survey. This was consolidated into 20 research ideas/themes for the second survey for each group. 566 responses we received to the consumer prioritization top ten survey and 525 responses to the clinician survey. The consensus meeting produced the final 10 consumer research priorities.

Conclusion: This study has given Australian consumers the opportunity to shape the anesthesia and perioperative medicine research agenda for pediatric patients both nationally and internationally.

The COVID-19 pandemic has strained surgical systems worldwide and placed healthcare providers at risk in their workplace. To protect surgical care providers caring for patients with COVID-19, in May 2020 we developed a COVID-19 Surgical Patient Checklist (C19 SPC), including online training materials, to accompany the World Health Organization Surgical Safety Checklist. In October 2020, an online survey was conducted via partner and social media networks to understand perioperative clinicians' intraoperative practice and perceptions of safety while caring for COVID-19 positive patients and gain feedback on the utility of C19 SPC. Descriptive statistics were used to characterise responses by World Bank income classification. Qualitative analysis was performed to describe respondents' perceptions of C19 SPC and recommended modifications. Respondents included 539 perioperative clinicians from 63 countries. One-third of respondents reported feeling unsafe in their workplace due to COVID-19 with significantly higher proportions in low (39.8%) and lower-middle (33.9%) than higher income countries (15.6%). The most cited concern was the risk of COVID-19 transmission to self, colleagues and family. A large proportion of respondents (65.3%) reported that they had not used C19 SPC, yet 83.8% of these respondents felt it would be useful. Of those who reported that they had used C19 SPC, 62.0% stated feeling safer in the workplace because of its use. Based on survey results, modifications were incorporated into a subsequent version. Our survey findings suggest that perioperative clinicians report feeling unsafe at work during the COVID-19 pandemic. In addition, adjunct tools such as the C19 SPC can help to improve perceived safety.