Cageside Ultrasonography in the Emergency Room and Intensive Care Unit

A survey of the use of ultrasound by small animal veterinary clinicians

This study aimed to determine the current use of ultrasound amongst small animal veterinarians. A total of 1216 small animal veterinary practitioners responded to an electronic survey that was administered through the Veterinary Information Network to all its members. Descriptive statistics were generated; limited inferential statistics were performed to examine specific relationships. Eighty-four percent of respondents had access to an ultrasound unit, and 86% of respondents reported using their unit multiple times per week. The most common uses were assistance with cystocentesis (93%) and abdominocentesis (71%), pregnancy diagnosis (69%), limited abdominal evaluation (63%), to aid in thoracocentesis (59%), and limited thoracic evaluation (52%). Eighty-nine percent of respondents received some formal training in ultrasound, most commonly from continuing education courses. Most respondents (52%) reported receiving ≤25 h of training. Additionally, 88% of respondents believed it was either extremely or very important for there to be ultrasound training for veterinary students prior to graduation. Based on this survey, most small animal practitioners commonly use ultrasound for limited examinations, being most confident in the sonographic evaluation and centesis of the bladder and for the detection and centesis of effusion in a body cavity. With most respondents having ≤25 h of training in ultrasound, typically obtained in postgraduate courses, an expansion in standardized basic ultrasound training within the veterinary curriculum may be warranted.

Successful management of pulmonary edema secondary to accidental electrocution in a young dog

BACKGROUND

Human records describe pulmonary edema as a life-threatening complication of electric shock. Successful management requires prompt recognition and intensive care. However, in companion animals, electrocutions are rarely reported, even though domestic environments are full of electrical devices and there is always the possibility of accidental injury. Therefore, it is important for veterinarians to know more about this condition in order to achieve successful patient outcomes.

CASE PRESENTATION

A 3-month-old male Labrador Retriever was presented with a history of transient loss of consciousness after chewing on a household electrical cord. On admission, the puppy showed an orthopneic position with moderate respiratory distress. Supplemental oxygen via nasal catheter was provided, but the patient showed marked worsening of respiratory status. Point-of-care ultrasound exams suggested neurogenic pulmonary edema due to electrical shock close to the central nervous system and increased B-lines without evidence of cardiac abnormalities. Mechanical ventilation of the patient was initiated using volume-controlled mode with a tidal volume of 9 to 15 ml/kg until reaching an end-tidal carbon dioxide ≤ 40 mm Hg, followed by a stepwise lung-recruitment maneuver in pressure-controlled mode with increases of the peak inspiratory pressure (15 to 20 cm H2O) and positive end-expiratory pressure (3 to 10 cm H2O) for 30 min, and return to volume-controlled mode with a tidal volume of 15 ml/kg until reaching a peripheral oxygen saturation ≥ 96%. Weaning from the ventilator was achieved in six hours, and the patient was discharged two days after admission without neurological or respiratory deficits.

CONCLUSIONS

We present a rather unusual case of a neurogenic pulmonary edema subsequent to accidental electrocution in a dog. Timely diagnosis by ultrasound and mechanical ventilation settings are described. Our case highlights that pulmonary edema should be considered a potentially life-threatening complication of electrical shock in small animal emergency and critical care medicine.

Evaluation of B-lines with 2 point-of-care lung ultrasound protocols in cats with radiographically normal lungs

OBJECTIVE

To compare 2 point-of-care lung ultrasound (LUS) protocols for quantification of B-lines in cats without evidence of respiratory disease based on history, physical examination, and thoracic radiography.

DESIGN

Prospective observational study.

SETTING

Single center, veterinary teaching hospital.

ANIMALS

Fifty-seven cats without respiratory disease based on history, physical examination, and thoracic radiographs.

INTERVENTIONS

All cats had 2 point-of-care LUS protocols performed bilaterally: a regional protocol (veterinary bedside lung ultrasound evaluation [VetBLUE]) and a more comprehensive vertical sweeping (VS) protocol. The total number of B-lines per cat, number of sites with B-lines, and maximal number of B-lines at each site were recorded and compared.

MEASUREMENTS AND MAIN RESULTS

Ten cats (18%) had at least 1 B-line identified with VetBLUE, versus 29 (51%) with VS. Comparing protocols, VS had a statistically higher total number of B-lines per cat, higher number of sites with B-lines, and higher maximal number of B-lines per site. B-lines that were too numerous to count were identified at a single location in 1 cat with VetBLUE and 2 cats with VS. A maximum of 3 B-lines were identified at all other positive sites regardless of the protocol used. On average, it took 1.79 times longer to complete VS bilaterally compared to VetBLUE (median [interquartile range]: 140 [33] and 78 [14] s, respectively) (P = 0.001).

CONCLUSIONS

This study demonstrates it is not uncommon to identify a single or even multiple B-lines in 1 or several sites on LUS in cats deemed to be clinically free of respiratory pathology-essential knowledge when using LUS as a screening test and to monitor intrathoracic lesions. In cats asymptomatic for respiratory disease, VS generally identifies more B-lines than VetBLUE, likely because it assesses a larger lung surface area. The sonographic identification of B-lines should be interpreted considering the LUS protocol used, history, and other diagnostics to determine their clinical significance.

Assessment of a standing position during abdominal point-of-care ultrasound on abdominal fluid score in dogs

OBJECTIVE

To assess the use of a standing position during abdominal point-of-care ultrasound (POCUS) examination when evaluating dogs for peritoneal effusion.

DESIGN

Randomized prospective study over 17 months.

SETTING

Single-center, university veterinary teaching hospital.

ANIMALS

Thirty dogs presenting for acute abdominal disease. Eligibility included suspicion for free peritoneal effusion and the ability to stand.

INTERVENTIONS

Dogs underwent standing abdominal POCUS, right lateral abdominal POCUS, and a full abdominal ultrasound. We originally had nothing listed. It now includes all three ultrasound evaluations that were performed for each patient.

MEASUREMENTS AND MAIN RESULTS

Patients underwent both a right lateral and standing abdominal POCUS via a previously described abdominal focused assessment with sonography for trauma (A-FASTrl and A-FASTs, respectively) technique in a randomized and sequential order followed by a full abdominal ultrasound (AUS-full). The A-FASTs examination included a right flank location in addition to the following standard views: subxiphoid, left flank, urinary bladder, and umbilicus. Five-second cine loops were obtained at each location for each examination and reviewed in the order they were obtained. Locations for both A-FAST exams were interrogated in the same order every time. The cine loops were scored for the degree of peritoneal effusion based on a previously published abdominal fluid scoring system by a board-certified radiologist, radiology resident, and radiology intern. The overall abdominal fluid score (AFS) was compared to a subjective full abdominal ultrasound score given by a board-certified radiologist. Six dogs had no peritoneal effusion, 13 had a small volume (AFS 1 or 2), and 11 had a moderate to large volume (AFS 3 or 4). Excellent agreement (intraclass correlation coefficient) was found between the A-FASTs and A-FASTrl techniques (0.95, 0.93, 0.94), good agreement between A-FASTs and AUS-full (0.80, 0.77, 0.82), and good agreement between A-FASTrl and AUS-full (0.80, 0.82, 0.84). The interobserver agreement was good (0.87) for the A-FASTs technique and excellent (0.91) for the A-FASTrl technique. Mean observer agreement score was excellent (0.94) when evaluating A-FASTrl to A-FASTs, good (0.86) when evaluating A-FASTs to AUS-full, and good (0.87) when evaluating A-FASTrl to AUS-full.

CONCLUSION

Performing a standing abdominal POCUS examination may be a valid option for identifying and quantifying peritoneal effusion in situations when a more traditional right lateral approach cannot be performed.

Diagnostic value of the ultrasonographic description of a splenic mass or nodule as cavitated in 106 dogs with nontraumatic hemoabdomen

OBJECTIVE

To assess the diagnostic value of the ultrasonographic description of a splenic mass or nodule as cavitated in dogs with nontraumatic hemoabdomen.

ANIMALS

106 dogs with a nontraumatic hemoabdomen that underwent abdominal ultrasonography and splenectomy with histologic examination of splenic lesions between 2005 and 2018.

PROCEDURES

Medical records were reviewed for abdominal ultrasonographic and histologic findings. Diagnostic performance of ultrasonographic description of a splenic mass or nodule as cavitated as evidence of hemangiosarcoma or any malignancy was evaluated.

RESULTS

Ultrasonographic description of splenic lesions as cavitated had poor diagnostic utility in predicting presence of hemangiosarcoma or malignancy. Sensitivity and specificity of this test were 41.9% (95% CI, 30.5% to 54.3%) and 51.2% (95% CI, 36.8% to 65.4%), respectively, for detecting hemangiosarcoma, with positive and negative predictive values of 55.3% (95% CI, 41.2% to 68.6%) and 37.9% (95% CI, 26.6% to 50.8%), respectively. Results were similar for detecting malignancy. Cavitated lesions outside of the spleen were too rare for statistical analysis to be of value.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that relying on ultrasonographic description of cavitation to diagnose splenic lesions as malignant in dogs with nontraumatic hemoabdomen is unfounded. Other preoperative diagnostic tests may be more valuable in determining short- and long-term prognoses.

TFAST Accurate Diagnosis of Pleural and Pericardial Effusion, Caudal Vena Cava in Dogs and Cats

TFAST, a standardized and validated thoracic point-of-care ultrasound examination, includes 5 acoustic windows: bilaterally applied chest tube site and pericardial site views plus diaphragmatico-hepatic view, also part of AFAST/ Vet BLUE. TFAST is used for rapid detection of pneumothorax and pleural and pericardial effusion. By following a set of TFAST rules, image interpretation errors are avoided, including mistaking cardiac chambers for effusion. Moreover, TFAST echocardiography is used as a screening test for chamber size and soft tissue abnormalities, volume status and contractility, and intracardiac abnormalities.

AFAST Target-Organ Approach and Fluid Scoring System in Dogs and Cats

Point-of-care ultrasonography as part of the physical examination is becoming considered a core skill. AFAST includes 5 acoustic windows over the abdomen and serves as a rapid screening test for free fluid (ascites, retroperitoneal, pleural and pericardial effusion) and soft tissue abnormalities (target-organ approach), and has an abdominal fluid scoring system (semiquantitating volume). Moreover, add-on skills are possible without additional views that include characterizing the caudal vena cava and hepatic veins (volume status), measuring the urinary bladder (volume estimation and urine output), screening for free air (pneumoperitoneum, pneumoretroperitoneum), and assessing gastrointestinal motility.

Global FAST for Patient Monitoring and Staging in Dogs and Cats

Please verify if FAST should be expanded at first use - "focused assessment with sonography for trauma"?: Global FAST consists of abdominal FAST, thoracic FAST, and Vet BLUE combined as a single point-of-care ultrasound examination used as an extension of the physical examination. By applying its unbiased set of 15 data imaging points, information is gained while avoiding image interpretation errors, such as satisfaction of search error and confirmation bias error, through selective POCUS imaging. Moreover, Global FAST is used for integrating information from both cavities, rapidly screening for the Hs and Ts of cardiopulmonary resuscitation, and staging localized versus disseminated disease, helpful diagnostically and prognostically for patient work-up. By seeing a problem list, patient care is improved.

Focused Cardiac Ultrasonography in Cats

Heart disease is a common cause of morbidity and mortality in cats. Focused cardiac ultrasonography (FCU) is a useful diagnostic tool for identifying heart disease in symptomatic and asymptomatic cats when performed by trained veterinarians. When used in conjunction with other diagnostics such as physical examination, blood biomarkers, electrocardiography, Global FAST, and other point-of-care ultrasonographic examinations, FCU may improve clinical decision making and help clinicians prioritize which cats would benefit from referral for complete echocardiography and cardiac consultation. This article reviews the definition, advantages, clinical indications, limitations, training recommendations, and a protocol for FCU in cats.

Focused ultrasound of the caudal vena cava in dogs with cavitary effusions or congestive heart failure: A prospective, observational study

INTRODUCTION

Ultrasonographic indices of the inferior vena cava are useful for predicting right heart filling pressures in people.

OBJECTIVES

To determine whether ultrasonographic indices of caudal vena cava (CVC) differ between dogs with right-sided CHF (R-CHF), left-sided CHF (L-CHF), and noncardiac causes of cavitary effusion (NC).

MATERIALS AND METHODS

113 dogs diagnosed with R-CHF (n = 51), L-CHF (30), or NC effusion (32) were enrolled. Seventeen of the R-CHF dogs had pericardial effusion and tamponade. Focused ultrasound was performed prospectively to obtain 2-dimensional and M-mode subxiphoid measures of CVC maximal and minimal size (CVCmax and CVCmin), CVCmax indexed to aortic dimension (CVC:Ao), and CVC collapsibility index (CVC-CI). Variables were compared between study groups using Kruskal-Wallis and Dunn's-Bonferroni testing, and receiver operating characteristics curves were used to assess sensitivity and specificity.

RESULTS

All sonographic CVC indices were significantly different between R-CHF and NC dogs (P < 0.001). Variables demonstrating the highest diagnostic accuracy for discriminating R-CHF versus NC were CVC-CI <33% in 2D (91% sensitive and 96% specific) and presence of hepatic venous distension (84% sensitive and 90% specific). L-CHF dogs had higher CVC:Ao and lower CVC-CI compared to NC dogs (P = 0.016 and P = 0.043 in 2D, respectively) but increased CVC-CI compared to the R-CHF group (P < 0.001).

CONCLUSIONS

Ultrasonographic indices of CVC size and collapsibility differed between dogs with R-CHF compared to NC causes of cavitary effusions. Dogs with L-CHF have CVC measurements intermediate between R-CHF and NC dogs.

Thirteen dogs and a cat with ultrasonographically detected gallbladder wall edema associated with cardiac disease

Background

Ultrasonographically detected gallbladder wall edema (GBWE) is a marker for anaphylaxis in dogs. Cardiac disease can cause GBWE with similar signs and should be included as a differential diagnosis to prevent interpretation errors.

Hypothesis/Objectives

Document GBWE associated with cardiac disease.

Animals

Fourteen client‐owned animals.

Methods

Prospective case series with abdominal focused assessment with abdominal sonography in trauma, triage and tracking (AFAST), and thoracic focused assessment with abdominal sonography in trauma, triage, and tracking (TFAST) performed at triage. Animals with GBWE and cardiac disease were enrolled. A board‐certified radiologist reviewed images to confirm cardiac disease, GBWE, and characterize the caudal vena cava (CVC) and hepatic veins.

Results

Thirteen dogs and 1 cat had GBWE associated with cardiac disease. Gallbladder findings included mural thickness ranging from 3 to 5 mm, mild to moderate sludge (n = 3), and mild to moderate luminal distension (n = 6). CVC and hepatic venous distension were found in 5/6. Cardiac diagnoses in dogs included 11 with pericardial effusion (PCE) and 1 each with dilated cardiomyopathy and right‐sided myocardial failure. Severity of PCE was rated as mild (n = 1), moderate (n = 6), or severe (n = 4). Seven of 11 had pericardiocentesis performed. Nine of 13 had ascites with 4 having abdominal fluid scores of 1 (n = 2), 2 (n = 2), 3 (n = 1), and 4 (n = 0). Lung ultrasound findings were as follows: dry lung (n = 6), B‐lines (n = 4), and nodules (n = 1). The cat had moderate PCE, ascites scored as 1, and severe right‐sided ventricular enlargement associated with a ventricular septal defect. Primary presenting complaints included acute weakness (n = 9), acute collapse (n = 5), gastrointestinal signs (n = 3), respiratory distress (n = 2), and need for cardiopulmonary resuscitation (n = 1).

Conclusions and Clinical Importance

Ultrasonographically detected GBWE was associated with PCE in this small cohort of cases.