The Nuts and Bolts of Performing Focused Cardiovascular Ultrasound (FoCUS)

Perioperative Point of Care Ultrasound for Hemodynamic Assessment: A Narrative Review

While transesophageal echocardiography (TEE) has traditionally been used in perioperative care, there is growing evidence supporting point of care ultrasound (POCUS) for the anesthesiologist in guiding patient care. It is a quick way to non-invasively evaluate hemodynamically unstable patients and ascertain their state of shock, determine volume status, and guide resuscitation in cardiac arrest. In addition, through use of POCUS, the anesthesiologist is able to identify signs of chronic heart disease to provide a more tailored and safer approach to perioperative care.

The Year in Perioperative Echocardiography: Selected Highlights From 2022

THIS SPECIAL article is part of an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan, and the Editorial Board for the opportunity to continue this series, which focuses on the past year's research highlights that pertain to perioperative echocardiography in relation to cardiothoracic and vascular anesthesia. The major selected themes for 2022 include (1) updates on mitral valve assessments and interventions, (2) training and simulation updates, (3) outcomes and complications of transesophageal echocardiography, and (4) point-of-care cardiac ultrasound. The themes selected for this special article are just a sample of the advances in perioperative echocardiography during 2022. An appreciation and understanding of these highlights will help to ensure and improve the perioperative outcomes for patients with cardiovascular disease undergoing cardiac surgery.

Advanced diagnostic and therapeutic techniques for anaesthetists in thoracic trauma: an evidence-based review

Anaesthetists play an important role in the evaluation and treatment of patients with signs of thoracic trauma. Anaesthesia involvement can provide valuable input using both advanced diagnostic and therapeutic interventions. Commonly performed interventions may be complicated in this setting including airway management, damage control resuscitation, and acute pain management. Anaesthetists must consider additional factors including airway injuries, vascular injuries, and coagulopathy when treating this population. This evidence-based review discusses traumatic thoracic injuries with a focus on new interventions and modern anaesthesia techniques. This review further serves to support the early involvement of anaesthetists in the emergency department and other areas where they can provide value to the trauma care pathway.

Competence of anesthesiology residents following a longitudinal point-of-care ultrasound curriculum

PURPOSE

Point-of-care ultrasound (POCUS) facilitates diagnostic, procedural, and resuscitative applications in anesthesiology. Structured POCUS curricula improve learner satisfaction, test scores, and clinical management, but the learning curve towards competency and retention of skills over time remain unknown.

METHODS

We conducted a prospective observational study to determine when anesthesiology trainees enrolled in a POCUS curriculum achieve competency in POCUS skills. We also investigated the learning curve of trainees' competency using a POCUS-specific competency-based medical education assessment. The structured, longitudinal POCUS curriculum included online lectures, journal articles, live model scanning sessions, video review of cases, and a portfolio of supervised scans. Point-of-care ultrasound scanning sessions on standardized patients were conducted in the simulation lab for 2.5 hr a week and each resident completed eight sessions (20 hr) per academic year. At each scanning session, timed image acquisition scores were collected and POCUS skills entrustment scale evaluations were conducted. The primary outcome was the number of supervised scans and sessions required to achieve a mean entrustment score of 4 ("may use independently"). Secondary outcomes included image acquisition scores and retention of skills after six months.

RESULTS

The mean (standard deviation) number of supervised scans required for trainees (n = 29) to reach a mean entrustment score of ≥ 4 was 36 (10) scans over nine sessions for rescue echo. A mean entrustment score of ≥ 4 was observed for lung ultrasound after a mean (SD) of 8 (3) scans over two sessions.

CONCLUSIONS

Our study shows that anesthesiology residents can achieve competence in rescue echo and lung ultrasound through participation in a structured, longitudinal POCUS curriculum, and outlines the learning curve for progression towards competency.

Utility of bedside ultrasound derived hepatic and renal parenchymal flow patterns to guide management of acute kidney injury

PURPOSE OF REVIEW

Ideal fluid management of critically ill patients is maintaining an adequate perfusion pressure but avoiding venous congestion. Venous excess ultrasound score (VExUS) quantifies venous congestion to guide the management of fluid balance.

RECENT FINDINGS

VExUS of abdominal veins measures fluid tolerance and helps clinicians avoid congestion. VExUS scoring predicts the development of acute kidney injury (AKI) that is a common hospital problem resulting in higher mortality and morbidity. VExUS can predict patients at risk of developing AKI post cardiac surgery. VExUS has been associated with an increase in adverse outcomes in a general intensive care population. Hepatic vein ultrasound can manifest as a sequela of right heart failure and pulmonary hypertension. Intrarenal congestion suggests poorer prognosis in heart failure patients. VExUS score has been used in decision-making to remove fluid in patients with cardiorenal syndrome. VExUS scoring may help curtail overly aggressive fluid resuscitation for patients with septic shock and help avoid iatrogenic 'salt water drowning'.

SUMMARY

We summarize the technique and clinical practice of VExUS to help guide fluid balance across different populations of critically ill patients.

Point of Care Ultrasound on Labor and Delivery

Point of care ultrasound (POCUS) in the field of obstetric anesthesiology, including cardiac, pulmonary, neuraxial, gastric, and airway ultrasound, can facilitate rapid diagnosis, management, and clinical decision-making surrounding common maternal peripartum comorbidities, and obstetric complications. Routine and proficient utilization of POCUS can ultimately aid in anesthesiologists' role as critical care physicians in the multidisciplinary practice on labor and delivery, with potential future research aiming to determine the potential impact on maternal morbidity and mortality.

An Approach to Standard Perioperative Transthoracic Echocardiography Practice for Anesthesiologists-Perioperative Transthoracic Echocardiography Protocols

The use of intraoperative transesophageal echocardiography (TEE) has become the standard of care for most cardiac surgical procedures. There are guidelines established for training, practice, and quality improvement in perioperative TEE by the joint efforts of the American Society of Echocardiography and Society of Cardiovascular Anesthesiologists. Cardiac point-of-care ultrasound (POCUS) increasingly is being incorporated into anesthesiologists' training and practice. While a special "certification in Critical Care Echocardiography" was created by the National Board of Echocardiography in 2019, there currently exist no guidelines for training, certification, and practice of perioperative TTE by anesthesiologists. In this review, the authors describe the categories, indications and applications of perioperative TTE and provide a recommended sequence for performing an examination tailored to the evaluation of perioperative patients. Although the authors describe a protocol utilized at their institution, there are no standards described in the literature for PTTE. Cardiac anesthesiologists and cardiac anesthesia societies (Society of Cardiovascular Anesthesiologists, European Association of Cardiothoracic Anesthesiologists) must come forward to establish standards working in collaboration with echocardiography societies (American Society of Echocardiography, European Society of Cardiology).

The Evaluation Point-of-Care Ultrasound in the Post-Anesthesia Unit-A Multicenter Prospective Observational Study

Introduction: Point-of-care ultrasound (POCUS) is the most rapidly growing imaging modality for acute care. Despite increased use, there is still wide variability and less evidence regarding its clinical utility for the perioperative setting compared to other acute care settings. This study sought to demonstrate the impact of POCUS examinations for acute hypoxia and hypotension occurring in the post-anesthesia care unit (PACU) versus traditional bedside examinations. Methods: This study was designed as a multi-center prospective observational study. Adult patients who experienced a reduced mean arterial blood pressure (MAP < 60mmHG) and/or a reduced oxygen saturation (SpO2 < 88%) in the PACU from 7AM to 4PM were targeted. POCUS was available or not for patient assessment based on PACU team training. All providers who performed POCUS exams received standardized training on cardiac and pulmonary POCUS. All POCUS exam findings were recorded on a standardized form and the number of suspected mechanisms to trigger the acute event were captured before and after the POCUS exam. PACU length of stay (minutes) across groups was the primary outcome_. Results: In total, 128 patients were included in the study, with 92 patients receiving a POCUS exam. Comparison of PACU time between the POCUS group (median = 96.5 min) and no-POCUS groups (median = 120.5 min) demonstrated a reduction for the POCUS group, p = 0.019. Hospital length of stay and 30-day hospital readmission did not show a significant difference between groups. Finally, there was a reduction in the number of suspected diagnoses from before to after the POCUS examination for both pulmonary and cardiac exams, p-values < 0.001. Conclusions: Implementation of POCUS for assessment of acute hypotension and hypoxia in the PACU setting is associated with a reduced PACU length of stay and a reduction in suspected number of diagnoses.

Perioperative Point-of-Care Ultrasound Use by Anesthesiologists

Point-of-Care ultrasound (POCUS) is the bedside utilization of ultrasound, in real-time, to aid in the diagnosis and treatment of patients. Image acquisition from POCUS utilization by anesthesiologists involves the assessment of multiple organs in different perioperative situations. POCUS can be utilized to enhance clinical decision-making in a variety of perioperative situations due to its ability to assess endotracheal tube placement, cardiac function, pulmonary function, aspiration risk, hemodynamics, vascular access, and nerve visualization for regional procedures. The mounting clinical evidence for the value of POCUS in perioperative settings, its growing affordability, and its low associated risks are responsible for the nationwide movement across many anesthesiology residency programs to increase the focus on perioperative ultrasound training. The purpose of this review is to present to current anesthesiologists and anesthesiology trainees, a broad discussion regarding the diverse utility and importance of POCUS in perioperative settings.

Diagnostic Point-of-Care Ultrasound: Recommendations From an Expert Panel

Diagnostic point-of-care ultrasound (PoCUS) has emerged as a powerful tool to help anesthesiologists guide patient care in both the perioperative setting and the subspecialty arenas. Although anesthesiologists can turn to guideline statements pertaining to other aspects of ultrasound use, to date there remains little in the way of published guidance regarding diagnostic PoCUS. To this end, in 2018, the American Society of Anesthesiologists chartered an ad hoc committee consisting of 23 American Society of Anesthesiologists members to provide recommendations on this topic. The ad hoc committee convened and developed a committee work product. This work product was updated in 2021 by an expert panel of the ad hoc committee to produce the document presented herein. The document, which represents the consensus opinion of a group of practicing anesthesiologists with established expertise in diagnostic ultrasound, addresses the following issues: (1) affirms the practice of diagnostic PoCUS by adequately trained anesthesiologists, (2) identifies the scope of practice of diagnostic PoCUS relevant to anesthesiologists, (3) suggests the minimum level of training needed to achieve competence, (4) provides recommendations for how diagnostic PoCUS can be used safely and ethically, and (5) provides broad guidance about diagnostic ultrasound billing.

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.

Intraoperative Focused Cardiac Ultrasound for Assessment of Hypotension: A Systematic Review

Focused cardiac ultrasound (FoCUS) has become a valuable tool to assess unexplained hypotension in critically ill patients. Due to increasing availability of transthoracic echocardiography (TTE) equipment in the operating room, there is a widespread interest in its usefulness for intraoperative diagnosis of hypotension as an alternative to transesophageal echocardiography (TEE). The objective of this systematic review is to evaluate the utility of intraoperative FoCUS to assess patients experiencing unexplained hypotension while undergoing noncardiac surgery. We performed a systematic literature search of multiple publication databases for studies that evaluated the utility of intraoperative FoCUS for assessment and management of unexplained hypotension in patients undergoing noncardiac surgery, including retro- and prospective clinical studies. A summary of the study findings, study quality, and assessment of level of evidence is presented. We identified 2227 unique articles from the literature search, of which 27 were potentially relevant, and 9 were included in this review. The number of patients pooled from these studies was 255, of whom 228 had intraoperative diagnoses with the aid of intraoperative FoCUS. The level of evidence of all studies included was very low according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines. This systematic review has demonstrated that FoCUS may be a useful, noninvasive method to differentiate causes of intraoperative hypotension and guide correcting interventions, although the quality of evidence is very low. Further prospective high-quality studies are needed to investigate whether intraoperative FoCUS has a diagnostic utility that is associated with improved outcomes.

Perioperative Point-of-Care Ultrasound in Children

Anesthesiologists and other acute care physicians perform and interpret portable ultrasonography-point-of-care ultrasound (POCUS)-at a child's bedside, in the perioperative period. In addition to the established procedural use for central line and nerve block placement, POCUS is being used to guide critical clinical decisions in real-time. Diagnostic point-of-care applications most relevant to the pediatric anesthesiologist include lung ultrasound for assessment of endotracheal tube size and position, pneumothorax, pleural effusion, pneumonia, and atelectasis; cardiac ultrasound for global cardiac function and hydration status, and gastric ultrasound for aspiration risk stratification. This article reviews and discusses select literature regarding the use of various applications of point-of-care ultrasonography in the perioperative period.

Point-of-care ultrasound for the pediatric regional anesthesiologist and pain specialist: a technique review

Point-of-care ultrasound (PoCUS) has been well described for adult perioperative patients; however, the literature on children remains limited. Regional anesthesiologists have gained interest in expanding their clinical repertoire of PoCUS from regional anesthesia to increasing numbers of applications. This manuscript reviews and highlights emerging PoCUS applications that may improve the quality and safety of pediatric care.

In infants and children, lung and airway PoCUS can be used to identify esophageal intubation, size airway devices such as endotracheal tubes, and rule in or out a pulmonary etiology for clinical decompensation. Gastric ultrasound can be used to stratify aspiration risk when nil-per-os compliance and gastric emptying are uncertain. Cardiac PoCUS imaging is useful to triage causes of undifferentiated hypotension or tachycardia and to determine reversible causes of cardiac arrest. Cardiac PoCUS can assess for pericardial effusion, gross ventricular systolic function, cardiac volume and filling, and gross valvular pathology. When PoCUS is used, a more rapid institution of problem-specific therapy with improved patient outcomes is demonstrated in the pediatric emergency medicine and critical care literature.

Overall, PoCUS saves time, expedites the differential diagnosis, and helps direct therapy when used in infants and children. PoCUS is low risk and should be readily accessible to pediatric anesthesiologists in the operating room.

Point-of-care ultrasound in pediatric anesthesia: perioperative considerations

PURPOSE OF REVIEW

To review the perioperative applications of point-of-care ultrasound (POCUS).

RECENT FINDINGS

The role of point-of-care ultrasonography for perioperative care is expanding with respect to perioperative application. The imaging approach can complement the physical exam and provide additional information for decision-making in pediatric perioperative medicine. This review will focus on applications in the following organ systems: airway, cardiac, pulmonary and gastric. Specifically, POCUS of the airway has been used to optimize endotracheal tube depth, aid in tube size selection and predict difficulty with laryngoscopy and intubation. Lung POCUS has been used to assess for causes hypoxemia as well as to optimize ventilatory mechanics. Cardiac POCUS has been used for assessment of hemodynamics, valvular and ventricular function. Gastric ultrasound has emerged as an evaluative mechanism of gastric content in the setting of fasting as well as to confirm placement of gastric tubes. The applications of POCUS in the perioperative setting continue to evolve as a reliable diagnostic tool that can assist in timely diagnosis, improve procedural safety and has the potential to improve patient outcomes.

SUMMARY

The utility of perioperative POCUS has been well demonstrated, specifically for examination of the airway, stomach and cardiopulmonary system. It is advisable for the novice sonographer to perform POCUS within the guidelines set by the American Society of Echocardiography regarding basic POCUS. As with all diagnostic modalities, understanding the limitations of ultrasound and POCUS as well as continuous self-assessment is crucial.

Perioperative Point-of-Care Ultrasound

This clinical focus review targets all anesthesiologists and seeks to highlight the following aspects of perioperative point-of-care ultrasound: clinical utility, technology advancements, training/certification, education, reporting/billing, and limitations.

Improved diagnostic accuracy of pathology with the implementation of a perioperative point-of-care ultrasound service: quality improvement initiative

Introduction

The utility of perioperative point-of-care ultrasound (P-POCUS) is rapidly growing. The successful implementation of a comprehensive P-POCUS curriculum, Focused PeriOperative Risk Evaluation Sonography Involving Gastro-abdominal, Hemodynamic, and Trans-thoracic Ultrasound (FORESIGHT), has been demonstrated. This project sought to further evaluate the utility of P-POCUS with the following aims: (1) to assess the ability to train the FORESIGHT curriculum via a free, open-access, online platform; (2) to launch a P-POCUS clinical service as a quality improvement (QI) initiative; (3) to evaluate the diagnostic accuracy of the P-POCUS examinations to formal diagnostic studies; and (4) to compare the P-POCUS diagnostic accuracy with the diagnostic accuracy of traditional assessment (TA).

Methods

This study was launched as a QI project for the implementation of a P-POCUS service. A group of attending and resident anesthesiologists completed P-POCUS training supported by an online curriculum. After training, a P-POCUS service was launched. The P-POCUS service was available for any perioperative event, and specific triggers were also identified. All examinations were documented on a validated datasheet. The diagnostic accuracy of the two index tests, P-POCUS and TA, were compared with formal diagnostic testing. TA was defined as a combination of the anesthesiologist’s bedside assessment and physical examination. The primary outcome marker was a comparison in the accuracy of new diagnosis detected by P-POCUS service versus the TA performed by the primary anesthesiologist.

Results

A total of 686 P-POCUS examinations were performed with 466 examinations having formal diagnostic studies for comparison. Of these, 92 examinations were detected as having new diagnoses. Performance for detection of a new diagnosis demonstrated a statistically higher sensitivity for the P-POCUS examinations (p<0.0001). Performance comparison of all P-POCUS examinations that were matched to formal diagnostic studies (n=466) also demonstrated a significantly higher sensitivity. These findings were consistent across cardiovascular, pulmonary and abdominal P-POCUS categories (p<0.01). Additionally, multiple pathologies demonstrated complete agreement between the P-POCUS examination and the formal study.

Conclusion

A P-POCUS service can be developed after training facilitated by an online curriculum. P-POCUS examinations can be performed by anesthesiologists with a high degree of accuracy to formal studies, which is superior to TA.

Ultrasound for predicting difficult airway in obstetric anesthesia: Protocol and methods for a prospective observational clinical study

BACKGROUND

Failed intubation and ventilation during cesarean deliveries are important causes of anesthetic-related maternal mortality. Due to the physiological changes in airway anatomy, parturient had higher incidences of difficult airway than non-obstetric population. Accurate airway assessment is the first step and the most important in airway management. However, the common clinical screening tests, shown low sensitivity and specificity with a limited predictive value. Ultrasound is a quick, noninvasive, inexpensive tool, with the advancement of ultrasound technology, modern ultrasound machine is more portable with better resolution and enhanced tissue penetration, provide better imaging in tissues like epiglottis, vocal cords, ring-shaped membrane, and can be used in airway assessment. Here, the aim of the current study was to find whether preoperative ultrasound assessment of neck anatomy can predict difficult airway in parturient, and provide new ideas and a theoretical basis in the airway management of obstetric anesthesia.

METHODS

This is a prospective, observational single-blinded study in a single-center. Subjects will be recruited from patients aged from 18 to 60 years, gestational age ≥ 36 weeks, scheduled for cesarean section under general anesthesia and tracheal intubation. Ultrasound measurement will be performed to detect anterior cervical soft tissue thickness at five anatomical levels (hyoid bone, epiglottis, cricothyroid membrane, thyroid isthmus and suprasternal notch) in the upper airway. The thickness of the soft tissue in the front of the neck and clinical airway measurements will be compared between the "easy intubation" and "difficult intubation" group divided by Cormack-Lehane grade. Receiver-operating characteristic curves were used to determine the sensitivity and specificity of "difficulty prediction capability" of each sonographic and physical measurements. Clinical factors associated with difficult intubation will be determined by univariate analyses. Multiple logistic regression analysis performed to determine independent predictors of difficult intubation.

CONCLUSIONS

The study outlined in this protocol will explore the possibility of ultrasound for predicting difficult airway in obstetric anesthesia. This may provide new insight into the practice of airway management.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1800018949.

Point-of-Care Ultrasound in the Periarrest Setting-Lessons Learned: A Case Report

Point-of-care ultrasound may elucidate reversible causes of cardiac arrest, and its use is supported by international guidelines in the periarrest setting. We present a case in which the treatment of cardiac arrest caused tension pneumothoraces and cardiac tamponade by pneumopericardium. Both pneumothorax and tamponade were expected to be identified with ultrasound, but were not. Subcutaneous emphysema precluded the diagnosis of pneumothorax. Cardiac imaging was false negative for tamponade, because the latter was caused by air and not fluid. Diagnoses are not to be excluded with inconclusive point-of-care ultrasound examinations, which should prompt further clinical evaluation and imaging.