Diagnosis of pulmonary contusions with point-of-care lung ultrasonography and thoracic radiography compared to thoracic computed tomography in dogs with motor vehicle trauma: 29 cases (2017-2018)

Causes and consequences of feline haemothorax: A retrospective case series

BACKGROUND

The objective of this study was to describe the causes of haemothorax in cats, patient presentation and outcome.

METHODS

This was a retrospective study based in a university teaching hospital. The electronic case records of cats presenting with a haemothorax between January 2005 and January 2023 were searched. Cases were categorised into 'trauma', 'neoplasia', 'coagulopathy' or 'other'. Signalment, physical examination, clinical pathology findings, concurrent injuries and diagnostic imaging findings were recorded. The median hospitalisation time was calculated, and survival to discharge was noted.

RESULTS

Twenty-five cats were eligible for inclusion. Twenty cases of haemothorax were traumatic in origin, two were neoplastic, two were 'other' and one was coagulopathic. Increased respiratory rate (n = 22) and effort (n = 20) were common, and most patients were anaemic at presentation (n = 16). Common concurrent injuries included pulmonary contusions (n = 15) and pneumothorax (n = 11). The median hospitalisation time for the trauma cats was 5 days (range 1‒15). Overall, 83.3% of the cases survived to discharge.

LIMITATIONS

The limitations of this study are related to its retrospective nature and the relatively small number of cats in the study population.

CONCLUSION

Haemothorax requiring a thoracocentesis in cats is rare, with trauma being the most likely cause. These patients tend to have concurrent injuries and require ongoing hospitalisation. Owners can be advised that the short-term outcome is generally favourable.

Retrospective evaluation of the agreement between thoracic point-of-care ultrasound and thoracic radiographs in cats with recent trauma: 111 cats

Introduction

Motor vehicular trauma, bite wounds, high-rise syndrome, and trauma of unknown origin are common reasons cats present to the emergency service. In small animals, thoracic injuries are often associated with trauma. The objective of this retrospective study was to evaluate limits of agreement (LOA) between thoracic point-of-care ultrasound (thoracic POCUS) and thoracic radiography (TXR), and to correlate thoracic POCUS findings to animal trauma triage (ATT) scores and subscores in a population of cats suffering from recent trauma.

Methods

Cats that had thoracic POCUS and TXR performed within 24 h of admission for suspected/witnessed trauma were retrospectively included. Thoracic POCUS and TXR findings were assessed as "positive" or "negative" based on the presence or absence of injuries. Cats positive on thoracic POCUS and TXR were assigned 1 to 5 tentative diagnoses: pulmonary contusions/hemorrhage, pneumothorax, pleural effusion, pericardial effusion, and diaphragmatic hernia. When available ATT scores were calculated. To express LOA between the two imaging modalities a kappa coefficient and 95% CI were calculated. Interpretation of kappa was based on Cohen values.

Results

One hundred and eleven cats were included. 83/111 (74.4%) cats were assessed as positive based on thoracic POCUS and/or TXR. Pulmonary contusion was the most frequent diagnosis. The LOA between thoracic POCUS and TXR were moderate for all combined injuries, moderate for pulmonary contusions/hemorrhage, pneumothorax, diaphragmatic hernia, and fair for pleural effusion. Cats with positive thoracic POCUS had significantly higher median ATT scores and respiratory subscores compared to negative thoracic POCUS cats.

Discussion

The frequency of detecting intrathoracic lesions in cats was similar between thoracic POCUS and TXR with fair to moderate LOA, suggesting thoracic POCUS is useful in cats suffering from trauma. Thoracic POCUS may be more beneficial in cats with higher ATT scores, particularly the respiratory score.

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.

Physical examination and CT to assess thoracic injury in 137 cats presented to UK referral hospitals after trauma

OBJECTIVES

The aim of the study was to describe clinical examination and thoracic CT (TCT) findings in cats after trauma, and to identify physical examination findings associated with both abnormalities on TCT and the need for therapeutic interventions.

METHODS

A multicentre, retrospective, observational study was conducted. Cats admitted to the participating hospitals with a history of blunt trauma and that underwent TCT were eligible. Data were collected on signalment, history, physical examination, TCT findings and subsequent interventions.

RESULTS

In total, 137 cats were included. Road traffic accidents (RTAs) were the most frequently reported cause of trauma (69%). Tachypnoea (32%), pale mucous membranes (22%) and dyspnoea (20%) were the most common abnormal findings on thoracic examination. The most frequently identified thoracic pathologies on TCT were atelectasis (34%), pulmonary contusions (33%), pneumothorax (29%) and pleural effusion (20%). Thoracocentesis was the most commonly performed intervention (12%), followed by chest drain placement (7%). A total of 45 (33%) cats had no physical examination abnormalities but did have abnormalities detected on TCT; six of these cats required interventions. Increasing numbers of thoracic abnormalities on clinical examination were associated with increasing likelihood of having abnormal findings on TCT (odds ratio [OR] 2.04, 95% confidence interval [CI] 1.21-3.44, P = 0.008) and of requiring an intervention (OR 1.82, 95% CI 1.32-2.51, P <0.001).

CONCLUSIONS AND RELEVANCE

RTAs were the most common reported cause of blunt trauma. Atelectasis, pulmonary contusions and pneumothorax were the most common abnormalities identified on TCT, and thoracic drainage was the most utilised intervention. TCT may be useful in identifying cats with normal thoracic physical examination findings that have significant thoracic pathology, and a high number of abnormal findings on thoracic examination should raise suspicion for both minor and major thoracic pathology. The results of this study can be used to assist in selecting appropriate cases for TCT after blunt trauma.

Lung ultrasound score in dogs and cats: A reliability study

BACKGROUND

Lung ultrasound (LUS) is a noninvasive tool for examining respiratory distress patients. The lung ultrasound score (LUSS) can be used to quantify and monitor lung aeration loss with good reliability.

HYPOTHESIS/OBJECTIVES

Assess the reliability of a new LUSS among raters with different levels of experience and determine how well the same raters agree on identifying patterns of LUS abnormalities.

ANIMALS

Forty LUS examinations of dogs and cats and 320 videos were reviewed from a digital database.

METHODS

Retrospective reliability study with post hoc analysis. Protocolized LUS were randomly selected; intrarater and interrater reliability of the LUSS and pattern recognition agreement among 4 raters with different levels of experience in LUS were tested.

RESULTS

The intrarater intraclass correlation coefficient (ICC) single measurement, absolute agreement, and 2-way mixed effects model was 0.967 for the high-experience rater (H-Exp), 0.963 and 0.952 for the medium-experience raters (M-Exp-1; M-Exp-2), and 0.950 for the low-experience rater (L-Exp). The interrater ICC average measurement, absolute agreement, and 2-way random effects model among the observers was 0.980. The Fleiss' kappa (k) values showed almost perfect agreement (k = 1) among raters in identifying pleural effusion and translobar tissue-like pattern, strong agreement for A-lines (k = 0.881) and B-lines (k = 0.806), moderate agreement (k = 0.693) for subpleural loss of aeration, and weak agreement (k = 0.474) for irregularities of the pleural line.

CONCLUSIONS AND CLINICAL IMPORTANCE

Our results indicate excellent intra- and interrater reliability for LUS scoring and pattern identification, providing a foundation for the use of the LUSS in emergency medicine and intensive care.

Association between clinical history in the radiographic request and diagnostic accuracy of thorax radiographs in dogs: A retrospective case-control study

BACKGROUND

The effect of clinical history on the interpretation of radiographs has been widely researched in human medicine. There is, however, no data on this topic in veterinary medicine.

HYPOTHESIS/OBJECTIVES

Diagnostic accuracy would improve when history was supplied.

ANIMALS

Thirty client-owned dogs with abnormal findings on thoracic radiographs and confirmation of the disease, and 30 healthy client-owned controls were drawn retrospectively.

METHODS

Retrospective case-control study. Sixty radiographic studies of the thorax were randomized and interpreted by 6 radiologists; first, with no access to the clinical information; and a second time with access to all pertinent clinical information and signalment.

RESULTS

A significant increase in diagnostic accuracy was noted when clinical information was provided (64.4% without and 75.2% with clinical information; P = .002). There was no significant difference in agreement between radiologists when comparing no clinical information and with clinical information (Kappa 0.313 and 0.300, respectively).

CONCLUSIONS AND CLINICAL IMPORTANCE

The addition of pertinent clinical information to the radiographic request significantly improves the diagnostic accuracy of thorax radiographs of dogs and is recommended as standard practice.

Assessing primary care veterinarians' use of and confidence in performing point-of-care ultrasound

BACKGROUND

Point-of-care ultrasound (POCUS) is gaining popularity in the veterinary field, but there is little information on operator confidence.

METHODS

A survey was distributed to primary care veterinarians (PCVs) via social media between May and July 2020. Details of participants' training in and use of POCUS were recorded. Participants' confidence in using thoracic and abdominal POCUS was also assessed using a five-point Likert scale.

RESULTS

Two hundred and one PCVs used POCUS, of which 32% reported using a non-standardised protocol. Fifty percent of PCVs were self-taught and 17.4% had attended a specific practical course. The median confidence score was 4 out of 5 (interquartile range [IQR] 2-5) for identifying abdominal abnormalities, irrespective of the training method. The median confidence score for thoracic abnormalities was 3 out of 5 (IQR 1-4) for those taught by a colleague or who were self-taught using journal articles or videos.

LIMITATIONS

The survey-based nature of the study relies on self-reporting and is therefore liable to recall bias.

CONCLUSIONS

PCVs' confidence in using POCUS is lacking, particularly with thoracic POCUS. Standardised practical training for PCVs, particularly in thoracic POCUS, would be beneficial. Future studies should explore how best to deliver this training.

Comparison of thoracic ultrasonography and thoracic radiography between healthy adult horses and horses with bacterial pneumonia using a novel, objective ultrasonographic scoring system

Background

Thoracic ultrasonography (TUS) is widely used in equine practice but comparison to radiography is limited in horses.

Objectives

To validate a novel, objective scoring system for TUS in adult horses and to compare ultrasonographic and radiographic findings.

Animals

13 healthy horses and 9 with confirmed bacterial pneumonia

Methods

Prospective study in which TUS and radiography were performed on healthy horses and those with bacterial pneumonia confirmed by clinical signs and results of transtracheal wash analysis. Ultrasonography was scored utilizing a novel scoring system evaluating number of comet tail lesions, the presence or absence of pleural effusion and/or pulmonary consolidation in each intercostal space. Eighteen horses had thoracic radiographs taken that were scored by a board-certified radiologist utilizing a previously described system. Total scores were recorded and compared between control and diseased patients.

Results/Findings

Ultrasonographic scores were significantly higher in the diseased group (median= 126) than in the control group (median = 20, p = 0.01). Receiver operating characteristics (ROC) analysis identified a sensitivity of 66.7% (95% CI 0.417–1) and specificity of 92.3% (95% CI 0.462–1) for the ability of ultrasonography to identify bacterial pneumonia utilizing a TUS score cutoff of 37.

Conclusions and clinical importance

TUS had moderate sensitivity and high specificity for identification of bacterial pneumonia in adult horses. TUS appears to be an acceptable stand-alone imaging modality for diagnosis of bacterial pneumonia in horses when radiography is not practical.

Imaging and endoscopic diagnosis of lung diseases in small animals. A review

Diagnostic imaging plays a fundamental role in the diagnosis of pulmonary diseases. Radiography, ultrasound, computed tomography, and endoscopy are important tools for achieving a diagnosis. The choice of diagnostic procedure varies according to the patient, the suspected diagnosis and the risk/benefit ratio. Culture, cytology and histology are nearly always necessary to obtain a definitive diagnosis. Several biopsy sampling techniques are described. Surgical biopsies are the gold standard for the diagnosis of bronchiolitis or interstitial lung diseases but often not performed due to the high risk. In humans, the introduction of transbronchial cryobiopsies has led to excellent results in the study of interstitial lung diseases.

Influence of concurrent lower respiratory tract disease on point-of-care lung ultrasound in small-breed dogs with myxomatous mitral valve disease

Background

Small‐breed dogs commonly have concurrent myxomatous mitral valve disease (MMVD) and lower respiratory tract disease (LRTD).

Hypothesis

Small‐breed dogs with preclinical MMVD and concurrent LRTD have more B‐lines on point‐of‐care lung ultrasound (POC‐LUS) compared to dogs without concurrent LRTD and are prone to misdiagnose as cardiogenic pulmonary edema (CPE).

Animals

A total of 114 small‐breed dogs with preclinical MMVD.

Methods

A prospective study was conducted, in which POC‐LUS was obtained and the number of B‐lines was calculated by a single clinician using the Veterinary Bedside Lung Ultrasound Examination protocol. The presence/absence of LRTD was assessed by clinicians blinded to the POC‐LUS results.

Results

Fifty and 64 dogs were in ACVIM stage B1 and B2, respectively. The presence of LRTD was prevalent in 74.6% (85/114) of small‐breed dogs with preclinical MMVD. When a previously reported criterion for CPE diagnosis (≥2 sites with >3 B‐lines/site) was applied, false‐positive results were observed in 15.8% (18/114) of dogs with preclinical MMVD. The summated number of B‐lines (3 vs. 1, P = .003), as well as the false‐positive rate (20% vs 3%, P = .04), were significantly higher in dogs with LRTD compared with dogs without LRTD. Multivariable logistic regression showed the presence of abnormalities other than B‐line on POC‐LUS (eg, thickened pleura or consolidation) could predict false‐positive results (odds ratio = 3.75, 95% confidence intervals 1.12‐12.54; P = .03) after adjustment for other clinical and echocardiographic factors.

Conclusions and Clinical Importance

Concurrent LRTD and abnormalities other than B‐lines should be considered in the interpretation of POC‐LUS in MMVD dogs.

Lung Ultrasound Fundamentals, "Wet Versus Dry" Lung, Signs of Consolidation in Dogs and Cats

Vet BLUE, a standardized and validated rapid lung ultrasound examination, includes 9 acoustic windows: 4 transthoracic bilaterally applied named Caudodorsal, Perihilar, Middle, and Cranial Lung Regions plus the Diaphragmatico-Hepatic view of AFAST/TFAST. Moreover, Vet BLUE has a B-line scoring system (weak positives-1, 2, and 3 and strong positives->3 and infinite) that semiquantitate degree of alveolar-interstitial syndrome and a visual lung language for signs of consolidation (Shred Sign [air bronchogram], Tissue Sign [hepatization], Nodule Sign, and Wedge Sign [pulmonary infarction]). Using its regional, pattern-based approach, a respiratory working diagnosis may be rapidly developed point-of-care and followed serially.