Pneumothorax

Allogenic blood patch pleurodesis for management of pneumothorax in a Cavalier King Charles Spaniel puppy with multiple pulmonary blebs and bullae

A 9‐week‐old male intact Cavalier King Charles Spaniel was presented for evaluation of acute onset dyspnea caused by left‐sided pneumothorax. Thoracic computed tomography (CT) identified multiple pulmonary bullae and blebs in multiple lung lobes. Rupture of ≥1 pulmonary blebs or bullae, precipitated by low impact trauma, was the suspected cause of pneumothorax. A volume of 7.5 mL/kg of fresh whole blood was collected from a type‐matched donor dog and administered into the left pleural space using a thoracostomy tube. The pneumothorax was successfully resolved and no adverse effects of blood patch pleurodesis were noted. The dog was clinically normal 12 months later.

Clinical and clinicopathological characteristics, treatment, and outcome for dogs and cats with confirmed foxtail foreign body lesions: 791 cases (2009-2018)

OBJECTIVE

To describe the clinical and clinicopathological characteristics, treatment, and outcome for dogs and cats with a confirmed foxtail.

DESIGN

Retrospective study utilizing a medical records database over a 10-year period from January 1, 2009 to December 31, 2018.

SETTING

University teaching hospital.

ANIMALS

Seven hundred and fifty-four dogs and 37 cats with a diagnosis of foxtail foreign body. Cases with direct visualization by a clinician or on histopathology were included. Information extracted for each case included signalment; anatomical foxtail location; clinicopathological and imaging findings; treatments and interventions provided; and outcome.

MEASUREMENTS AND MAIN RESULTS

The prevalence of foxtail associated disease was 0.25% in dogs and 0.07% in cats over this time period. Most animals were young to middle-aged and presented in the summer months. The most common location in dogs was the aural canal, cutaneous/subcutaneous space, and nasal canal. In cats, ocular foxtails were most common (30/37). Blood work changes were nonspecific. Ultrasound supervised by a boarded radiologist was utilized in 114 cases, mainly for subcutaneous, sublumbar, and intracavitary foxtail locations, with successful location of a foxtail in 72.8% of cases scanned. Computed tomography was performed in 78 dogs with suspected intracavitary foxtail migration, and in all cases, structural changes related to the presence of the foxtail were found. Anerobic bacteria were most commonly isolated when a culture was submitted, with Actinomyces spp. rarely isolated. The most common of the 120 anaerobic isolates were Bacteroides/Prevotella spp. (n = 38), Fusobacterium spp. (n = 32), and Peptostreptococcus anaerobius (n = 30).

CONCLUSIONS

The short-term outcome for foxtail-associated lesions is good, and most cases can be managed on an outpatient basis. A minority of cases develop life-threatening disease and may require a multidisciplinary approach of multimodal imaging, endoscopy, or surgery.

Spontaneous pneumothorax in German Shorthair Pointer due to penetration of a grass awn

This case report describes an incident of pneumothorax in 4-month old male German Shorthaired Pointer caused by a grass awn. The patient was brought to the Small Animal Clinic of the Faculty of Veterinary Medicine at Trakia University, Stara Zagora, Bulgaria with respiratory distress and anxiety. Tachypnea, cyanotic mucous membranes and tachycardia were observed during physical examination. Abnormal collection of air in the pleural space between the lung and the chest was observed radiographically. A diagnosis of primary spontaneous closed pneumothorax was made based on these findings. Later pathoanatomical findings showed the presence of the grass awn that had penetrated through the skin.

Spontaneous Pneumothorax: Pathophysiology, Clinical Presentation and Diagnosis

Spontaneous pneumothorax, which may have an acute or insidious onset in dogs and cats, results in respiratory difficulty and has the potential to be life threatening.^1-3 Dogs commonly develop spontaneous pneumothorax due to bullae or blebs, while cats typically have underlying inflammatory disease, like feline allergic airway disease. Urgent therapeutic intervention is essential in animals with respiratory distress. The recommended therapeutic strategies are typically different in each of these species due to underlying etiology. The first part of this review article will focus on physiology, clinical presentation, and diagnosis of spontaneous pneumothorax in dogs and cats. Advances in diagnostics, especially the recent utility of point of care ultrasound, will be discussed. The second part of the series will provide an overview of therapeutic options and management of patients with spontaneous pneumothorax, as well as information on prognosis.

[Spontaneous pneumothorax in cats: two case reports and literature review]

Spontaneous pneumothorax (SP) is a non-traumatic accumulation of air in the pleural cavity. This case report describes a cat with SP as a result of primary pulmonary adenocarcinoma. A second cat was diagnosed with primary pulmonary adenocarcinoma and asthma. A thoracostomy tube was inserted in the first cat while in the second cat a thoracostomy tube was placed and lobectomy of the right cranial and middle lung lobes was performed. Both cats died following treatment. The current literature reviewed here covers the comparative etiologies of SP as well as clinical presentation, diagnostic work-up, therapy and prognosis in cats. A total of 64 cases of cats with secondary spontaneous pneumothorax reported in nine articles are discussed. To our knowledge, there has been no previous description in the literature regarding primary SP in cats. Based on prior case reports, surgery was performed in 16% (10 cats) of SP cases. The current review demonstrates that depending on the underlying lung disease, cats with SP have a careful short-term prognosis because 39 of 64 cats (60%) were discharged.

Pneumothorax: A Review

Pneumothorax is a pathological condition in which air accumulates within the thoracic cavity. Pneumothorax affects animals without sex or age predilections; however, it has been suggested that the Siberian husky breed of dog has a predisposition for spontaneous pneumothorax. Pneumothorax occurs as the result of trauma or underlying disease and can present a clinical challenge with regard to diagnostic and therapeutic techniques. Topics reviewed include normal lung physiology; the pathogenesis, diagnosis, treatment, complications, and prognosis of pneumothorax; and current techniques in animals and humans.

Pneumothorax secondary to pulmonary thromboembolism in a dog

OBJECTIVE

To describe a case of spontaneous pneumothorax secondary to pulmonary thromboembolism possibly associated with pituitary dependent hyperadrenocorticism.

CASE SUMMARY

A 7-year-old spayed female Collie weighing 26 kg was referred for evaluation of spontaneous pneumothorax. An exploratory thoracotomy was performed and revealed 2 lung lobes to be diffusely hemorrhagic and they were resected. Histologic examination of multiple sections documented diffuse thromboembolism. A 2-3 cm thrombus was visualized distal to the bifurcation of the pulmonary artery during an echocardiographic examination postoperatively. The dog was discharged to the owner after recovery from surgery. The thrombus had resolved at the 4-week recheck examination. Diagnosis of pituitary dependent hyperadrenocorticism was confirmed based on follow-up endocrine testing.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first report of pulmonary thromboembolism causing spontaneous pneumothorax in the dog.

Outcomes of Heimlich valve drainage in dogs

OBJECTIVE AND DESIGN

Retrospective study of the outcomes of Heimlich valve drainage in dogs.

PROCEDURE

Medical records of the past 3 years were retrospectively reviewed. Heimlich valve drainage was used in 34 dogs (median body weight 30 +/- 5 kg): lobectomy (n = 15), pneumonectomy (n = 9), intrathoracic oesophageal surgery (n = 2), diaphragmatic hernia repair (n = 1), traumatic open pneumothorax (n = 2), bilobectomy (n = 2), ligation of the thoracic duct (n = 1), and chylothorax and pneumothorax (n = 1 each). Evacuation of air and/or fluid from the pleural cavity was performed with the Heimlich valve following thoracostomy tube insertion. During drainage, the dogs were closely monitored for possible respiratory failure. Termination of Heimlich valve drainage was controlled with underwater seal drainage and assessed with thoracic radiography.

RESULTS

Negative intrathoracic pressure was provided in 29 dogs without any complications. Post pneumonectomy respiratory syncope and post lobectomy massive hemothorax, which did not originate from the Heimlich valve, were the only postoperative complications. Dysfunction of the valve diaphragm, open pneumothorax and intrathoracic localisation of an acute gastric dilatation-volvulus syndrome caused by a left-sided diaphragmatic hernia following pneumonectomy were the Heimlich valve drainage complications.

CONCLUSIONS

The Heimlich valve can be used as a continuous drainage device in dogs, but the complications reported here should be considered by veterinary practitioners.

Thoracic trauma in horses

Thoracic trauma represents an important cause of morbidity in mortality after injury in human beings and animals. After any form of suspected chest wall trauma, initial emergency management should include assurance of a patent airway and adequate ventilation, along with treatment for shock if present. As with any open wound, tetanus prophylaxis should be instituted. Types of trauma to the thoracic region of the horse include pectoral and axillary lacerations, penetrating chest wounds, flail chest, fractures of the ribs, blunt thoracic trauma, and several potential sequelae that include pneumothorax, pneumomediastinum, hemothorax, pleuritis, fistulae of the sternum or ribs, and diaphragmatic hernia. Emergency management of these various forms of thoracic trauma is discussed.

Pneumothorax in dairy cattle: 30 cases (1990-2003)

OBJECTIVE

To evaluate the features, underlying causes, results of diagnostic testing, and treatment of pneumothorax in dairy cattle.

DESIGN

Retrospective study.

ANIMALS

30 dairy cattle.

PROCEDURE

Medical records of all cattle with a diagnosis of pneumonia were reviewed. For cattle with pneumothorax, information was obtained pertaining to signalment, anamnesis, diagnosis, treatment, and outcome. Survival data were compared between cattle with pneumonia with or without pneumothorax.

RESULTS

Pneumothorax was associated with bronchopneumonia in 18 cattle, interstitial pneumonia in 7 cattle, pharyngeal or laryngeal trauma in 3 cattle, and neonatal respiratory distress in 2 calves. Bovine respiratory syncytial virus was the most commonly detected infectious agent. Eighteen of 30 (60%) cattle survived; 8 were euthanatized and 4 died. Survival rate was 81% for cattle with pneumonia without pneumothorax during the same time period. Pneumothorax was a significant risk factor for failure to survive to discharge from the hospital for cattle with underlying chronic bronchopneumonia.

CONCLUSIONS AND CLINICAL RELEVANCE

Pneumothorax in dairy cattle appears to occur most commonly in association with chronic bronchopneumonia. Cattle of both sexes and all ages can be affected.

Thoracoscopic treatment of bullous emphysema in 3 dogs

OBJECTIVE

To report thorascopic partial lobectomy for treatment of bullous emphysema in dogs.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Three dogs with spontaneous pneumothorax.

METHODS

Thoracoscopy without pulmonary exclusion was used to identify bulla. The thorascope was introduced into the thorax lateral to the xyphoid process, and instrument portals were made at different levels along the thoracic wall between the third and tenth intercostal spaces. The thorascope was passed through the mediastinum to view the opposite pleural cavity. After identification of bullae, the affected lung was excised using an endoscopic stapler, and the incision line was checked for air leakage. Thoracic drains were used for air aspiration for 2 days after surgery.

RESULTS

Bullae were confirmed histologically as emphysematous lesions. Lung inflation did not interfere with identification of bullae or with surgery. All dogs had full recovery without recurrence for 18 to 29 months after surgery.

CONCLUSIONS

Identification and ablation of bulla can be performed thoracoscopically without pulmonary exclusion in dogs.

CLINICAL RELEVANCE

Thoracoscopy offers several advantages compared with thoracotomy for treatment and diagnosis of idiopathic pneumothorax, including ease of identification of bullae and reduced postoperative pain and morbidity.

Spontaneous pneumothorax in two cats with small airway disease

Two adult domestic shorthair cats were examined because of pneumothorax. Neither had a history of trauma, and spontaneous pneumothorax secondary to small airway disease was diagnosed. In both cats, treatment consisted of thoracocentesis for evacuation of air and administration of anti-inflammatory agents. One cat had multiple episodes of pneumothorax and eventually died; the other had only a single episode of pneumothorax. Small airway disease should be considered as a potential underlying cause in cats that develop spontaneous pneumothorax. Additionally, the potential for pneumothorax should be considered in cats with small airway disease, particularly when clinical signs suddenly become much worse.

Pneumothorax in horses: 40 cases (1980-1997)

OBJECTIVE

To characterize pneumothorax in horses and to describe clinical signs, diagnostic testing, and clinical outcome of horses with pneumothorax.

DESIGN

Retrospective study.

ANIMALS

40 horses.

PROCEDURE

Medical records of horses with pneumothorax were reviewed to obtain information on signalment, history, clinical signs, diagnostic testing, treatment, and clinical outcome.

RESULTS

Horses developed pneumothorax secondary to pleuropneumonia (17 horses), open wounds of the thorax (9), closed trauma to the thorax (7), surgery on the upper portion of the respiratory tract (3), and surgery involving the thoracic cavity (1); 3 horses had pneumothorax of unknown cause. Clinical signs included tachypnea, dyspnea, cyanosis, lack of lung sounds on auscultation of the dorsal aspect of the thorax, fever, tachycardia, signs of depression or anxiousness, and cough. Radiography and ultrasonography were useful to definitively diagnose pneumothorax. Pneumothorax was bilateral in 47.5% (19/40) and unilateral in 42.5% (17/40) of horses; designation of unilateral versus bilateral was not recorded in the remaining 4 horses. Horses with pneumothorax secondary to pleuropneumonia more commonly had unilateral pneumothorax (64.7% for unilateral vs 29.4% for bilateral; not specified for 1 horse). Horses with pneumothorax secondary to pleuropneumonia were less likely to survive than horses with pneumothorax secondary to other causes (35.3 vs 69.6% survived, respectively).

CONCLUSIONS AND CLINICAL RELEVANCE

Pleuropneumonia is an important cause of pneumothorax in horses. Classic clinical signs of pneumothorax may not be evident. Radiography, ultrasonography, or both may be required for diagnosis. Prognosis for survival is better for horses with pneumothorax not associated with pleuropneumonia.

The efficacy of mechanical abrasion and talc slurry as methods of pleurodesis in normal dogs

OBJECTIVE

To determine the efficacy of mechanical abrasion and talc slurry as methods for pleurodesis in normal dogs.

STUDY DESIGN

Experimental study.

ANIMALS OR SAMPLE POPULATION

Ten normal beagle dogs.

METHODS

Group I dogs had mechanical abrasion (MA) of the pulmonary and costal pleurae performed in one hemithorax with a dry gauze sponge with a median sternotomy approach. Group II dogs had 100 mL of a 1 g talc slurry (TS) administered into one hemithorax through a tube thoracostomy. Administration of the TS was visualized by using video thoracoscopy. All dogs were evaluated at 2, 10, 20, and 30 days postoperatively by means of thoracic radiography and ultrasonographic thoracic wall measurement. The dogs were euthanatized 30 days postoperatively and a gross necropsy was performed. Hemithoraces were assigned a pleurodesis score (0-4) and an obliteration grade (0-6). Tissues were collected for histopathologic examination of pulmonary pleura, costal pleura, and pleural adhesions. Pulmonary and costal pleurae were graded for the degree of fibrosis (0-4).

RESULTS

Obliteration grade and costal pleural fibrosis score were significantly higher for the treated sides in the MA dogs compared with the TS dogs. MA Dogs: Mechanical abrasion dogs had pleurodesis, obliteration, and pleural fibrosis scores that were greater on the treated side than the untreated side, however, the differences were not statistically significant. Only two MA dogs had firm adhesion of the pulmonary pleura to the costal pleura in portions of the cranial and middle lung lobes in the treated hemithorax. Thoracic wall surface area covered with adhesions was 15% and 21% in each of these two dogs. The median pulmonary pleural fibrosis score of all MA dogs for the treated hemithorax was 3 compared to 0 on the untreated side. TS Dogs: There was no statistical difference for pleurodesis scores and obliteration grades between the treated and untreated sides. No dogs showed evidence of pulmonary to costal pleural adhesions. Histopathology showed talc crossover into the untreated side in all five dogs. Median pulmonary fibrosis score of the treated hemithorax was 1 compared with 0 on the untreated side.

CONCLUSIONS

Neither method of pleurodesis produced sufficient pleural adhesions to obliterate the pleural space. It is possible that the degree of pulmonary pleural fibrosis present in MA dogs may be sufficient to limit air leakage from pulmonary blebs and bullae resulting in successful treatment of spontaneous pneumothorax.

Management of fracture-associated thoracic trauma

Animals with thoracic injury that survive long enough to receive veterinary attention are often through the most critical post-traumatic period. A small proportion will require prompt, aggressive treatment of life-threatening injuries. Many have self-limiting thoracic injuries that can endanger the animal if overlooked when general anaesthesia is attempted for surgical repair of more obvious injuries. Other lesions can be exacerbated by inappropriate therapy. Through evaluation is needed for recognition and proper management of thoracic injuries that pose both immediate and delayed threat to life.