Gastric Ultrasound for the Regional Anesthesiologist and Pain Specialist:

Risk estimation for postoperative nausea and vomiting: development and validation of a nomogram based on point-of-care gastric ultrasound

BACKGROUND

We aimed to develop a nomogram that can be combined with point-of-care gastric ultrasound and utilised to predict postoperative nausea and vomiting (PONV) in adult patients after emergency surgery.

METHODS

Imaging and clinical data of 236 adult patients undergoing emergency surgery in a university hospital between April 2022 and February 2023 were prospectively collected. Patients were divided into a training cohort (n = 177) and a verification cohort (n = 59) in a ratio of 3:1, according to a random number table. After univariate analysis and multivariate logistic regression analysis of the training cohort, independent risk factors for PONV were screened to develop the nomogram model. The receiver operating characteristic curve, calibration curve, decision curve analysis (DCA) and clinical impact curve (CIC) were used to evaluate the prediction efficiency, accuracy, and clinical practicability of the model.

RESULTS

Univariate analysis and multivariate logistic regression analysis showed that female sex, history of PONV, history of migraine and gastric cross-sectional area were independent risk factors for PONV. These four independent risk factors were utilised to construct the nomogram model, which achieved significant concordance indices of 0.832 (95% confidence interval [CI], 0.771-0.893) and 0.827 (95% CI, 0.722-0.932) for predicting PONV in the training and validation cohorts, respectively. The nomogram also had well-fitted calibration curves. DCA and CIC indicated that the nomogram had great clinical practicability.

CONCLUSIONS

This study demonstrated the prediction efficacy, differentiation, and clinical practicability of a nomogram for predicting PONV. This nomogram may serve as an intuitive and visual guide for rapid risk assessment in patients with PONV before emergency surgery.

Anesthesia Considerations for a Patient on Semaglutide and Delayed Gastric Emptying

Semaglutide is a class of long-acting glucagon-like peptide-1 receptor agonists (GLP1-RA) used for the treatment of type 2 diabetes mellitus (T2DM) and obesity. We present a 31-year-old female patient with a past medical history of T2DM without complication and no long-term or current use of insulin, class 3 obesity, hypertension, hyperlipidemia, polycystic ovary syndrome (PCOS), and anxiety, who underwent an esophagogastroduodenoscopy (EGD) in preparation for bariatric surgery while taking semaglutide. Despite appropriately following the preoperative fasting guidelines of the American Society of Anesthesiologists (ASA), endoscopy revealed food residue in the gastric body, necessitating abortion of the procedure to reduce the risk of intraoperative pulmonary aspiration. Given the lack of preoperative fasting guidelines for patients on semaglutide to date, and delayed gastric emptying being a known side effect among patients taking semaglutide, anesthesiologists should be aware of alternative methods to ensure no food is present in the stomach to mitigate the risk of pulmonary aspiration during general anesthesia.

Ultrasonic evaluation of metoclopramide's effect on gastric motility in emergency trauma patients

Objective: The present study aimed to use bedside ultrasound to evaluate the effects of metoclopramide on gastric motility in patients being treated for trauma in the emergency department. Methods: Fifty patients underwent an ultrasound immediately after attending the emergency department of Zhang Zhou Hospital due to trauma. The patients were randomly divided into two groups: a metoclopramide group (group M, n = 25) and a normal saline group (group S, n = 25). The cross-sectional area (CSA) of the gastric antrum was measured at 0, 30, 60, 90, and 120 min (T = time). The gastric emptying rate (GER, GER=-AareaTn/AareaTn-30-1×100), GER/min (GER divided by the corresponding interval time), gastric content properties, Perlas grade at different time points, T120 gastric volume (GV), and GV per unit of body weight (GV/W) were evaluated. The risk of vomiting, reflux/aspiration, and type of anesthetic treatment were also evaluated. Results: The differences between the two groups in the CSA of the gastric antrum at each time point were statistically significant (p < 0.001). The CSAs of the gastric antrum in group M were lower than those in group S, and the greatest difference between the two groups occurred at T30 (p < 0.001). The differences between the two groups in GER and GER/min were also statistically significant (p < 0.001); those differences in group M were higher than those in group S, and the greatest differences between the two groups occurred at T30 (p < 0.001). There were no obvious change trends in the properties of the gastric contents and the Perlas grades in either group, and the differences between the two groups were not statistically significant (p = 0.97). The differences between the two groups in the GV and GV/W at T120 were statistically significant (p < 0.001), as was the risk of reflux and aspiration at T120 (p < 0.001). Conclusion: When metoclopramide was used in satiated emergency trauma patients, it accelerated gastric emptying within 30 min and reduced the risk of accidental reflux. However, a normal gastric emptying level was not achieved, which can be attributed to the delaying effect of trauma on gastric emptying.

Effect of a carbohydrṇate lollipop on the gastric volume of fasted pediatric patients

BACKGROUND

Preoperative fasting is part of routine practice. Children subjected to prolonged preoperative fasting often suffer adverse effects. Consuming a preoperative lollipop may lessen their anxiety and have clinical benefits.

AIMS

To assess the effect of consuming a lollipop on gastric volume and the feasibility of administering a lollipop to a child preoperatively.

METHODS

In this prospective, repeated measures interventional study, we measured gastric antrum volume using ultrasound in children aged 2-18 years. We measured antrum volumes after participants had fasted for a minimum of 6 h for solids and 2 h for clear fluids. They then consumed a standard carbohydrate lollipop, and we repeated the antrum volume measurements after 1 h.

RESULTS

Of the 38 patients enrolled, 32 completed the study; four had ingested additional food or liquid, and two were diagnosed with systemic disease the day after data collection. The gastric volume data were normally distributed. The mean volume change was 0.01 ml kg^-1 (95% CI -0.02 to 0.05; p = .460). The mean postlollipop volume was 0.51 ml kg^-1 (95% CI 0.43 to 0.58).

CONCLUSIONS

Consuming a standard lollipop did not affect the gastric volume of fasted pediatric patients.

Management of pulmonary aspiration due to undiagnosed achalasia during induction of general anesthesia: a case report with literature review - A case report -

Background

Intraoperative pulmonary aspiration is a rare but potentially fatal complication associated with various risk factors. Preoperative recognition of these risk factors can prevent aspiration events during general anesthesia or facilitate prompt corrective measures in patients experiencing this complication.

Case

A 70-year-old female patient with hypertension underwent bilateral total knee arthroplasty under general anesthesia. Despite using a midnight nothing-per-oral (NPO) protocol, an unpredictable intraoperative aspiration event occurred during anesthesia induction. A detailed evaluation of the patient’s medical history and subsequent diagnostic imaging examinations indicated achalasia. She was treated for aspiration pneumonia for 2 weeks. After 2 months, rescheduled total knee arthroplasty was performed under spinal anesthesia without any complications.

Conclusions

Obtaining the patient’s medical history and assessing the risk factors are important to prevent unpredictable intraoperative pulmonary aspiration. High-risk patients should undergo adequate preoperative fasting and regional anesthesia or rapid-sequence intubation should be considered for safe induction of general anesthesia.

Qualitative and quantitative gastric ultrasound assessment in highly skilled regional anesthesiologists

BACKGROUND

Pulmonary aspiration is a major complication in anesthesia, and various studies have shown that gastric sonography can reliably provide valuable information relative to both the qualitative and quantitative aspects of gastric content. This study aimed to determine the accuracy of ultrasound assessment of gastric content compared between two novice anesthesiologist gastric sonographers.

METHODS

This prospective cohort study of two anesthesiologists learning to perform qualitative and quantitative ultrasound assessment of gastric content on healthy volunteers was conducted at Siriraj Hospital (Bangkok, Thailand). This trial was registered with ClinicalTrials.gov (reg. no. NCT04760106).

RESULTS

Of the 50 enrolled participants, three were excluded due to study protocol violation. Each anesthesiologist performed a qualitative assessment on 47 participants for an overall total of 94 scans. There were 15 males and 32 females (age 42 ± 11.7 years, weight 61.2 ± 13.1 kg, height 160.7 ± 7.3 cm, and BMI 23.6 ± 4.3 kg/m²). The overall success rate for all gastric content categories was approximately 96%. From antral cross-sectional area measurement, as the ingested volume increased, there was a tendency toward increased deviation from the actual ingested volume. Interrater agreement between anesthesiologists was analyzed using intraclass correlation coefficients (ICCs). A larger fluid volume was found to be associated with a lower level of agreement between the two anesthesiologists. The ICCs were 0.706 (95% CI: -0.125 to 0.931), 0.669 (95% CI: -0.254 to 0.920), 0.362 (95% CI: -0.498 to 0.807) for the 100 ml, 200 ml, and 300 ml fluid volumes, respectively. The mean duration to perform an ultrasound examination for each gastric content category and for the entire examination did not differ significantly between anesthesiologists (p > 0.05).

CONCLUSION

Our results indicate that qualitative ultrasound assessment of gastric content is highly accurate and can be easily learned. In contrast, quantification of gastric volume by novice gastric sonographers is more complex and requires more training.

TRIAL REGISTRATION

ClinicalTrials.gov no. NCT04760106 Date registered on Feb 11, 2021. Prospectively registered.

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.

Focused assessment with sonography in trauma (FAST) for the regional anesthesiologist and pain specialist

This article in our point-of-care ultrasound (PoCUS) series is dedicated to the role the focused assessment with sonography in trauma (FAST) exam plays for the regional anesthesiologist and pain specialists in the perioperative setting. The FAST exam is a well-established and extensively studied PoCUS exam in both surgical and emergency medicine literature with over 20 years demonstrating its benefit in identifying the presence of free fluid in the abdomen following trauma. However, only recently has the FAST exam been shown to be beneficial to the anesthesiologist in the perioperative setting as a means to identify the extravasation of free fluid into the abdomen from the hip joint following hip arthroscopy. In this article, we will describe how to obtain the basic FAST views (subcostal four-chamber view, perihepatic right upper quadrant view, perisplenic left upper quadrant view, and pelvic view in the longitudinal and short axis) as well as cover the relevant sonoanatomy. We will describe pathological findings seen with the FAST exam, primarily free fluid in the peritoneal space as well as in the pericardial sac. As is the case with any PoCUS skill, the application evolves with understanding and utilization by new clinical specialties. Although this article will provide clinical examples of where the FAST exam is beneficial to the regional anesthesiologist and pain specialist, it also serves as an introduction to this powerful PoCUS skill in order to encourage clinical practitioners to expand the application of the FAST exam within the scope of regional anesthesia and pain management practice.