Point-of-Care Ultrasound Techniques for the Small Animal Practitioner. Группа авторов

silhouette missed the PCE because many patients were never scheduled for echocardiography. The patient, with or without help from the attending clinician, often declared themselves survivors or nonsurvivors despite care. In those that survived, the patient likely compensated, stretched its pericardium over time before developing the classic globoid heart and ascites, representing as weak with abdominal distension from ascites and generally stable. Pericardiocentesis was more commonly an elective procedure with high success due to PCE chronicity. In this patient subset, the findings of electrical alternans, pulsus paradoxicus, muffled heart sounds, and a globoid heart on thoracic radiography were possible, although with variable reliability (Johnson et al. 2004).

Table 7.8. Most common causes of pericardial effusion in dogs and cats.

      Source: Reproduced with permission of Dr Gregory Lisciandro, Hill Country Veterinary Specialists and FASTVet.com, Spicewood, TX.

Dogsa	Catsc
Neoplasiab (~70%)	Congestive heart failure (≥75%)
Idiopathic (~20%)	Idiopathic
Right‐sided congestive heart failure	Lymphoma
Left atrial tear/rupture	Feline infectious peritonitis (FIP)
Anticoagulant rodenticides	Hyperthyroidism
Foreign body (plant awn, porcupine quill, projectile, other)	Uremia
Infectious (bacterial, fungal)	Infectious (fungal, bacterial)
Peritoneopericardial diaphragmatic hernia	Peritoneopericardial diaphragmatic hernia
Pericardial cyst	Sepsis
Uremia
Trauma

      ^a Ascites is a more favorable diagnosis with median survival reported to be 605 days compared to 45 days in dogs without ascites (Johnson et al. 2004), thus Global FAST should be done first line.

      ^b ~50–60% have metastatic disease at time of diagnosis (MacDonald et al. 2009), thus Global FAST should be done first line.

      ^c Most common cause in cats is congestive heart failure and most common heart disease is hypertrophic cardiomyopathy (Hall et al. 2007).

      Data from Hall et al. (2007); Davidson et al. (2008); Shaw and Rush (2007); MacDonald et al. (2009); Ward et al. (2018).

       Nonhemoabdomen Ascites Carries a Better Prognosis

      The Global FAST approach is imperative for PCE cases, especially in dogs in which nonhemoabdomen ascites (and echo negative for a mass) has been shown to carry a much more favorable prognosis, with median survival times much different at 605 days versus 45 days (Stafford Johnson et al. 2004). The presence of a mass (echo‐positive versus echo‐negative) also has great influence on the prognosis, with similar large differences in survival between those without echo‐detected masses and those with – 1068 days versus 26 days (Stafford Johnson et al. 2004). Furthermore, in the large study done by MacDonald and colleagues, of those with masses, no matter the type of tumor, metastasis was high (~50–66%) and thoracic radiography only detected ~33% of lung metastasis (MacDonald et al. 2009). Global FAST with its target organ approach has the potential to detect intraabdominal metastasis as well as pulmonary, and Vet BLUE has been shown to perform better than thoracic radiography in a pilot study (Kulhavy and Lisciandro 2015) (see Chapter 36).

       Clinical Signs and Signalment

      Historically, the most common presenting signs for dogs with PCE have been weakness, collapse, and labored breathing (Stafford Johnson et al. 2004; MacDonald et al. 2009; Lisciandro 2016a); however, more recently a study documented that approximately 50% of dogs had a history of vomiting within 48 hours of presentation (Fahey et al. 2017). This finding, from the author's experience, argues for performing a Global FAST prior to a complete detailed abdominal ultrasound not only for ordering the indicated ultrasound study but also for the safety of the patient. Placing a patient with PCE into dorsal recumbency risks acute decompensation. Golden retrievers are the most common breed reported and in one study comprised 33% of the case study population, followed by German shepherds and other large breeds (Stafford Johnson et al. 2004; Fahey et al. 2017). In another study, gastrointestinal signs were reported in 16% of canine cases of PCE (Stafford Johnson et al. 2004).

       Changes in the Paradigm – Recognizing Acute Pericardial Effusion

We are recognizing a new patient subset, the acute PCE case, with an unremarkable cardiac silhouette and respiratory distress, and a likely cardiac chamber rupture as the contributing factor. Traditional signs of muffled heart sounds, pulsus paradoxicus, electrical alternans on electrocardiogram, and a globoid heart on thoracic radiography are insensitive even in the chronic PCE case, let alone the acutely collapsed respiratory distressed case (Stafford Johnson et al. 2004; MacDonald et al. 2009; Guglielmini et al. 2012; Côté et al. 2013). Moreover, treatment strategies differ, as does the success of pericardiocentesis and definitive treatment. For example, if a cardiac chamber has acutely ruptured because of a right atrial mass, then the PCE may return in minutes to hours with repeated cardiac tamponade and obstructive shock. The case of a right atrial mass from hemangiosarcoma is a strong argument for the Global FAST approach, and rapidly staging the patient within minutes of presentation. Metastatic rate is high, 50–66% in one study (MacDonald et al. 2009).

      Global FAST screens for hemoabdomen and lung metastasis, because if the patient is staged as isolated disease, then surgical removal of the cardiac tumor may be effective. The insertion of an indwelling pericardial catheter and autotransfusion(s) may be your only effective option (much different from traditional teaching paradigms). Moreover, performing a rough pericardiocentesis and opening the pericardial sac as a temporary pericardial window, used as a cheap, quick option in the past, will backfire with the patient then exsanguinating into an even larger space, the pleural cavity.

       Pericardiocentesis Becomes a Core Skill

      Veterinarians need to acquire pericardiocentesis as part of their skill set to save these patients (both canine and feline). Pericardiocentesis is not a difficult procedure and is discussed in detail in Chapters 21 and 43. You have nothing to lose and everything to gain if a patient is dying from its PCE and complications are acceptable (Humm et al. 2009).

       Use of TFAST for Accurate Diagnosis of Pericardial Effusion

      See Chapters 17 and 18.

       Use of the DH View and TFAST for Accurate Diagnosis of Pleural Effusion

      See Chapters 17 and