Baseline Gastric Volume in Fasting Diabetic Patients Is Not Higher than That in Nondiabetic Patients: A Cross-sectional Noninferiority Study.

BACKGROUND: The physiology of diabetes mellitus can increase the risk of perioperative aspiration, but there is limited and contradictory evidence on the incidence of "full stomach" in fasting diabetic patients. The aim of this study is to assess the baseline gastric content (using gastric ultrasound) in diabetic and nondiabetic patients scheduled for elective surgery who have followed standard preoperative fasting instructions. METHODS: This was a prospective, noninferiority study of 180 patients (84 diabetic and 96 nondiabetic patients). Bedside ultrasound was used for qualitative and quantitative assessment of the gastric antrum in the supine and right lateral decubitus positions. Fasting gastric volume was estimated based on the cross-sectional area of the gastric antrum and a validated model. The hypothesis was that diabetic patients would not have a higher baseline fasting gastric volume compared to nondiabetic patients, with a noninferiority margin of 0.4 ml/kg. Secondary aims included the comparison of the incidence of full stomach (solid content or more than 1.5 mL/kg of clear fluid), estimation of the 95th percentile of the gastric volume distribution in both groups, and examination of the association between gastric volume, glycemic control, and diabetic comorbidities. RESULTS: The baseline gastric volume was not higher in diabetic patients (0.81 ± 0.61 ml/kg) compared to nondiabetic patients (0.87 ± 0.53 ml/kg) with a mean difference of -0.07 ml/kg (95% CI, -0.24 to 0.10 ml/kg). A total of 13 (15.5%) diabetic and 11 (11.5%) nondiabetic patients presented more than 1.5 ml/kg of gastric volume (95% CI for difference, -7.1 to 15.2%). There was little correlation between the gastric volume and either the time since diagnosis or HbA1C. CONCLUSIONS: The data suggest that the baseline gastric volume in diabetic patients who have followed standard fasting instructions is not higher than that in nondiabetic patients.

Implementation and Postoperative Management of Continuous Adductor Canal Catheters for Total Knee Arthroplasty to Reduce Surgical Backlog Related to the COVID-19 Pandemic: An Acute Pain Service Nursing Perspective and Educational Resource.

PURPOSE: In response to the surgical backlog created by the COVID-19 pandemic and to spare valuable hospital resources, we developed and implemented a continuous adductor canal catheter (CACC) program for total knee arthroplasty (TKA) patients. CACC's offer superior analgesia, decrease opioid use, and increase patient satisfaction while simultaneously promoting a decreased length of hospital stay and even same day discharges. The implementation of analgesia protocols using continuous peripheral nerve catheters and isometric pumps has been described for other surgical procedures and populations; however, the role of the Acute Pain Service Nurse (APS RN) in the implementation of such a program has not been described. DESIGN: An best practice initiative for TKA patients receiving CACC was developed and implemented for patients recovering both in the hospital and at home. METHODS: We describe the development and implementation of a CACC program for TKA patients in response to the surgical backlog created by the COVID-19 pandemic from the perspective of the APS RN. We provide a detailed narrative description of our postoperative assessment and experience, and offer practical insights for the postoperative care of these patients. We share the educational resources and assessment tools we developed to ensure consistent, safe, and effective clinical management of CACC patients in the hospital and at home. FINDINGS: CACCs via elastomeric pumps have been shown to offer significant advances to pain control following TKA, decrease opioid use, enable earlier discharge, and improve patient satisfaction, all of which we observed unequivocally in our patients. In our experience, implementation of a daily telephone follow up by an APS RN for discharged TKA patients with a CACC was crucial for patient safety, patient satisfaction, and reducing emergency phone calls and emergency room visits. CONCLUSIONS: We anticipate this description will provide an invaluable educational resource for other Acute Pain Service programs as similar outpatient peripheral nerve catheter programs are developed in response to the pandemic.

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part II: recommendations.

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine Society (ASRA) commissioned this narrative review to provide recommendations for POCUS. The recommendations were written by content and educational experts and were approved by the guidelines committee and the Board of Directors of the ASRA. In part II of this two-part series, learning goals and objectives were identified and outlined for achieving competency in the use of POCUS, specifically, airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma exam, and focused cardiac ultrasound, in the perioperative and chronic pain setting. It also discusses barriers to POCUS education and training and proposes a list of educational resources. For each POCUS section, learning goals and specific skills were presented in the Indication, Acquisition, Interpretation, and Medical decision-making framework.

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part I: clinical indications.

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine (ASRA) commissioned this narrative review to provide recommendations for POCUS. The guidelines were written by content and educational experts and approved by the Guidelines Committee and the Board of Directors of the ASRA. In part I of this two-part series, clinical indications for POCUS in the perioperative and chronic pain setting are described. The clinical review addresses airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma examination and focused cardiac ultrasound for the regional anesthesiologist and pain physician. It also provides foundational knowledge regarding ultrasound physics, discusses the impact of handheld devices and finally, offers insight into the role of POCUS in the pediatric population.

Canadian recommendations for training and performance in basic perioperative point-of-care ultrasound: recommendations from a consensus of Canadian anesthesiology academic centres.

Point-of-care ultrasound (POCUS) uses ultrasound at the bedside to aid decision-making in acute clinical scenarios. The increased use of ultrasound for regional anesthesia and vascular cannulation, together with more anesthesiologists trained in transesophageal echocardiography have contributed to the widespread use of POCUS in perioperative care. Despite the support of international experts, the practice of POCUS in perioperative care is variable as Canadian guidelines for anesthesiologists do not currently exist. Using a Delphi process of online surveys and a face-to-face national Canadian meeting, we developed a consensus statement for basic POCUS (bPOCUS) performance and training with a group of national experts from all Canadian universities. The group of experts consisted of 55 anesthesiologists from 12 Canadian universities considered local leaders in the field. An initial exploratory online survey of 47 statements was conducted. These statements were derived from previous generic guidelines or consensus conferences, or were based on current literature. Fourteen statements reached full consensus, 19 had 90-100% agreement, and 14 had less than 90% agreement. Eight new statements were proposed during the national meeting, and all statements without full agreement were discussed. A second online survey included 42 modified or new statements. From this second survey, 16 statements obtained full consensus, 39 had very good agreement, and one had good agreement. The final document includes 56 statements that define the scope of practice and necessary training for perioperative bPOCUS. The statements include five bPOCUS domains: cardiac, lung, airway, gastric, and abdomen. The use of bPOCUS is evolving and will play a significant role in perioperative medicine. This consensus statement aims to define a Canadian national standard on which curricula may be based. It also provides a framework to allow further development of bPOCUS in the perioperative setting.

RéSUMé: L'échographie ciblée (POCUS) utilise l'échographie au chevet des patients pour faciliter la prise de décisions dans les situations cliniques urgentes. L'utilisation accrue de l'échographie pour l'anesthésie régionale et la cannulation vasculaire, ainsi que l'augmentation du nombre d'anesthésologistes formés à l'échocardiographie transesophagienne, ont contribué à l'utilisation généralisée de l'échographie ciblée dans les soins périopératoires. Malgré son endossement par des experts internationaux, la pratique de l'échographie ciblée en soins périopératoires est variable, car il n'existe pas, à l'heure actuelle, de lignes directrices canadiennes destinées aux anesthésiologistes. À l'aide d'un processus Delphi de sondages en ligne et d'une réunion nationale canadienne en personne, un groupe d'experts nationaux provenant de toutes les universités canadiennes a élaboré une déclaration consensuelle pour la formation de base en et l'exécution de l'échographie ciblée (bPOCUS). Le groupe d'experts était composé de 55 anesthésiologistes issus de 12 universités canadiennes considérés comme des chefs de file locaux dans le domaine. Un premier sondage exploratoire en ligne comportant 47 énoncés a été réalisé. Ces énoncés étaient dérivés de lignes directrices antérieures ou de conférences consensuelles, ou étaient fondés sur la littérature actuelle. Quatorze énoncés ont obtenu un consensus complet, 19 ont atteint un taux de 90 à 100 %, et 14 ont obtenu moins de 90 % d'accord. Huit nouveaux énoncés ont été proposés au cours de la réunion nationale, et tous les énoncés n'ayant pas obtenu d'accord complet ont été discutés. Un deuxième sondage en ligne comprenait 42 énoncés modifiés ou nouveaux. Dans ce deuxième sondage, 16 énoncés ont obtenu un consensus total, 39 un très bon accord et un énoncé un bon accord. Le document final comporte 56 énoncés qui définissent le champ de pratique et la formation nécessaire pour l'échographie ciblée périopératoire de base. Les énoncés portent sur cinq domaines de l'échographie ciblée de base : échographie cardiaque, pulmonaire, des voies respiratoires, gastrique et abdominale. L'utilisation de l'échographie ciblée de base évolue et jouera un rôle important en médecine périopératoire. Cette déclaration consensuelle vise à définir une norme nationale canadienne sur laquelle les programmes d'études pourront s'appuyer. Elle fournit également un cadre pour encourager le développement ultérieur de l'échographie ciblée de base dans un contexte périopératoire.

Diagnostic Accuracy of Point-of-Care Gastric Ultrasound.

BACKGROUND: Pulmonary aspiration of gastric contents is associated with significant perioperative morbidity and mortality. Previous studies have investigated the validity, reliability, and possible clinical impact of gastric ultrasound for the assessment of gastric content at the bedside. In the present study, we examined the accuracy (evaluated as sensitivity, specificity, and likelihood ratios) of point-of-care gastric ultrasound to detect a "full stomach" in a simulated scenario of clinical equipoise. METHODS: After a minimum fasting period of 8 hours, 40 healthy volunteers were randomized in a 1:1 ratio to either remain fasted or ingest a standardized quantity of clear fluid or solid. Each subject was randomized twice on 2 independent study sessions at least 24 hours apart. A gastric ultrasound examination was performed by a blinded sonographer following a standardized scanning protocol. Using a combination of qualitative and quantitative findings, the result was summarized in a dichotomous manner as positive (any solid or >1.5 mL/kg of clear fluid) or negative (no solid and ≤1.5 mL/kg of clear fluid) for full stomach. RESULTS: Data from 80 study sessions were analyzed. In this simulated clinical scenario with a pretest probability of 50%, point-of-care gastric ultrasound had a sensitivity of 1.0 (95% confidence interval [CI], 0.925-1.0), a specificity of 0.975 (95% CI, 0.95-1.0), a positive likelihood ratio of 40.0 (95% CI, 10.33-∞), a negative likelihood ratio of 0 (95% CI, 0-0.072), a positive predictive value of 0.976 (95% CI, 0.878-1.0), and a negative predictive value of 1.0 (95% CI, 0.92-1.0). CONCLUSIONS: Our results suggest that bedside gastric ultrasound is highly sensitive and specific to detect or rule out a full stomach in clinical scenarios in which the presence of gastric content is uncertain.

Serratus Plane Block: A Cadaveric Study to Evaluate Optimal Injectate Spread.

BACKGROUND AND OBJECTIVES: Although serratus plane block reportedly provides satisfactory analgesia for breast and thoracic surgeries, the optimal technique for consistent success has not been studied. The goal of this anatomical study was to evaluate the impact of volume, level, and site of injection on the extent of injectate spread that can influence anesthetic coverage. METHODS: Ultrasound-guided dye injection and subsequent dissection were performed in 39 cadaveric hemithoraces. Methylene blue was injected according to 1 of 4 injection protocols as follows: one 20-mL bolus, either superficial or deep to the serratus anterior muscle (SAM), at the fifth rib level (groups SUP-20 and DEEP-20, respectively), or two 20-mL boluses, either superior or deep to the SAM, one at the third rib and one at the fifth rib level (group SUP-40 and group DEEP-40, respectively). Following injection, dissection and 3-dimensional digitization were performed to map the area of dye spread. RESULTS: We found that the extent of dye spread was mostly influenced by the volume of injection rather than the plane of injection (superficial vs deep to SAM). Increasing the volume from 20 to 40 mL doubled the area of injectate spread and promoted dye spread preferentially to the anterior chest wall, with some impact on cephalad-to-caudad spread and no impact on posterior spread. Dye was found most consistently in the axilla when a separate injection was performed at the third rib level. CONCLUSIONS: Our data showed that a high-volume double-injection technique provides extensive and consistent dye spread in the anterior chest wall and axilla, regardless of the plane of injection relative to the SAM. This technique likely provides more reliable analgesic coverage for breast procedures especially those that involve the axilla, pending confirmation in future clinical studies.

Gastric Ultrasound for the Regional Anesthesiologist and Pain Specialist.

This article in our series on point-of-care ultrasound (US) for the regional anesthesiologist and pain management specialist describes the emerging role of gastric ultrasonography. Although gastric US is a relatively new point-of-care US application in the perioperative setting, its relevance for the regional anesthesiologist and pain specialist is significant as our clinical practice often involves providing deep sedation without a secured airway. Given that pulmonary aspiration is a well-known cause of perioperative morbidity and mortality, the ability to evaluate for NPO (nil per os) status and risk stratify patients scheduled for anesthesia is a powerful skill set. Gastric US can provide valuable insight into the nature and volume of gastric content before performing a block with sedation or inducing anesthesia for an urgent or emergent procedure where NPO status is unknown. Patients with comorbidities that delay gastric emptying, such as diabetic gastroparesis, neuromuscular disorders, morbid obesity, and advanced hepatic or renal disease, may potentially benefit from additional assessment via gastric US before an elective procedure. Although gastric US should not replace strict adherence to current fasting guidelines or be used routinely in situations when clinical risk is clearly high or low, it can be a useful tool to guide clinical decision making when there is uncertainty about gastric contents.In this review, we will cover the relevant scanning technique and the desired views for gastric US. We provide a methodology for interpretation of findings and for guiding medical management for adult patients. We also summarize the current literature on specific patient populations including obstetrics, pediatrics, and severely obese subjects.

The sound of air: point-of-care lung ultrasound in perioperative medicine.

PURPOSE: Lung ultrasound (LUS) has emerged as an effective and accurate goal-directed diagnostic tool that can be applied in real time for the bedside assessment of patients with respiratory symptoms and signs. Lung ultrasound has definite and easily recognized findings and has been shown to outperform physical examination and chest radiography for the diagnosis and monitoring of many pulmonary and pleural conditions. In this article, we review the principles of LUS image acquisition and interpretation, summarizing key terms and sonographic findings. PRINCIPAL FINDINGS: Although LUS is easy to learn, adequate training and performance in an organized fashion are crucial to its clinical effectiveness and to prevent harm. Therefore, we review normal LUS findings and propose step-wise approaches to the most common LUS diagnoses, such as pneumothorax, pleural effusion, interstitial syndrome, and lung consolidation. We highlight potential pitfalls to avoid and review a recently published practical algorithm for LUS use in clinical practice. CONCLUSIONS: Because of the unique physical properties of the lungs, only a careful and systematic analysis of both artifacts and anatomical images allows accurate interpretation of sonographic findings. Future studies exploring the use of software for automatic interpretation, quantitative methods for the assessment of interstitial syndrome, and continuous monitoring devices may further simplify and expand the use of this technique at the bedside in acute medicine and the perioperative setting.

Point-of-care ultrasound defines gastric content and changes the anesthetic management of elective surgical patients who have not followed fasting instructions: a prospective case series.

PURPOSE: Pulmonary aspiration of gastric contents is a major cause of anesthesia morbidity and mortality. Point-of-care gastric ultrasound provides information regarding the type and volume of gastric content. The hypothesis of this prospective cohort study was that the addition of point-of-care gastric ultrasound to standard patient assessment results in changes in anesthetic management in at least 30% of elective surgical patients who do not follow fasting instructions. METHODS: Following Research Ethics Board approval and informed consent, elective surgical patients who did not follow fasting instructions were included in this prospective study. Documentation included the type of food ingested, the timing of the ingestion relative to the planned surgical time, and the treating anesthesiologist's management plan based on history alone. Next, an independent anesthesiologist not involved in the medical decision-making performed a focused gastric ultrasound examination. The results of the ultrasound exam were documented in a standardized fashion and made available to the attending anesthesiologist who then confirmed or revised the initial management plan. The treating anesthesiologist's actual (post-test) patient management was documented in a standardized fashion and compared with the initial (pre-test) management plan. RESULTS: Thirty-eight patients were included in this case series. Following point-of-care gastric ultrasound, there was a change in either the timing of anesthesia or the anesthetic technique (or both) in 27 patients (71%), with a net change towards a lower incidence of surgical delays. CONCLUSIONS: This prospective case series suggests that a standardized point-of care gastric ultrasound examination informs anesthesiologists' perceived level of aspiration risk and leads to changes in anesthetic management in a significant proportion of elective patients who did not follow fasting instructions.

Intra- and interrater reliability of ultrasound assessment of gastric volume.

BACKGROUND: Gastric sonography can provide information about gastric content and volume that can help determine aspiration risk at the bedside. The primary objective of this study is to assess the intrarater and interrater reliability of a previously validated method of gastric volume assessment based on gastric antral area. The secondary objective is to evaluate the agreement between two different methods to measure gastric antral area. METHODS: Three independent raters performed a standardized gastric ultrasound assessment in healthy subjects who had been randomly allocated to ingest a predetermined volume of clear fluid (apple juice) from 0 to 400 ml. Each rater measured the gastric antral area, using twice the two-diameter method and twice the free-tracing method. The rater order was allocated at random and raters were unaware of the volume ingested and of one-another's measurements. The Guidelines for Reporting Reliability and Agreement Studies were followed for conducting and reporting this study. RESULTS: Twenty-two volunteers were studied. Ultrasound assessment of antral cross-sectional area and volume was found to have "nearly perfect" intrarater and interrater reliability (correlation coefficient >0.8) with maximum differences within 13%. A Bland-Altman analysis suggests that the free-tracing method and the two-diameter method are essentially equivalent, within a clinically acceptable level of agreement. CONCLUSIONS: Ultrasound assessment of gastric volume by clinical anesthesiologists is highly reproducible with high intrarater and interrater reliability. The free-tracing method to measure antral cross-sectional area is equivalent to the two-diameter method.