Traumatic urothorax in a dog: a case report

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CASE REPORT

Traumatic urothorax in a dog: a case report S. Klainbart, R. Merchav and D. G. Ohad Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel

Pleural effusion caused by post-traumatic extravasation of urine from the abdominal cavity to the pleural cavity (urothorax) is an uncommon complication following traumatic injury. To the authors’ knowledge, this is the first report of a case of traumatic urothorax in a dog presented with pleural and abdominal urine effusion. Combined urothorax and uroabdomen should be included in the differentialdiagnosis list for dogs with recent trauma and a bicavitary effusion. The diagnosis can be confirmed by elevated creatinine concentrations in both effusates, compared to its serum concentration.

Journal of Small Animal Practice (2011) 52, 544–546 DOI: 10.1111/j.1748-5827.2011.01107.x Accepted: 13 June 2011

INTRODUCTION The presence of urine within the thoracic cavity, termed urothorax or urinothorax, has been so far reported almost exclusively in human beings. It can result from urine accumulation and extravasation from the abdominal cavity or retroperitoneal space (Hase and others 1999, Sheleyfer and others 2006, Tortora and others 2006) because of blunt or penetrating abdominal or pelvic trauma (Waldron 2003, Adams and Syme 2005) with its leakage to the pleural cavity through an anatomical defect in the diaphragm (Kinasewitz 1997, Hase and others 1999, Störk and others 2002, Parvathy and others 2003), via diaphragmatic lymphatics (Corrier and others 1968, Kinasewitz 1997, Tortora and others 2006), or by passive leakage into the mediastinum followed by its rupture into the pleural space (Friedland and others 1971, Akpek and others 1995). The present communication reports, for the first time, a case of traumatic urothorax in a dog.

CASE REPORT A 12-year-old, 30 kg, entire female mixed-breed dog was referred to the Koret School Veterinary Teaching Hospital 90 minutes after having been hit by a car. On physical examination, the dog was found to be painful, unable to stand, reluctant to move, and had dyspnoea, tachypnoea (80 breaths/minute) and sinus-tachycardia (160 beats/minute). Body temperature, hydration, nutritional status and femoral pulse quality were normal. The complete blood-count (CBC) (Abacus, Hematology analyzer, Diatron, Wien, Austria) was unremarkable. Serum544

biochemistry (Reflovet plus, Roche Diagnostic, Mannheim, Germany) showed azotaemia [creatinine, 163·54 µmol/L, reference interval (RI) 53·04 to 123·76 µmol/L]. Following intravenous (iv) administration of 20 mL/kg/hour lactated Ringer’s solution for the first 2 hours, 4 mg/kg pethidine HCl (Demerol, Teva) intramuscularly (im), and oxygen via a face-mask, radiography demonstrated diffuse abdominal and pleural (Fig 1) effusions. A definitive outline of the urinary bladder could not be identified. Thoracic and abdominal-fluid packed cell volume (PCV) was 5% and 9%, respectively. In both cavities, effusate total protein (TP) and creatinine concentrations were 18 g/L and greater than 884 µmol/L, respectively. Retrograde positive contrast cystography with iohexol (Omnipaque, Amersham Health) demonstrated marked contrast-material leakage into the peritoneal cavity (Fig 2). This contrast medium was chosen based on it being a non-ionic, non-osmolar and non-irritant iodine-based material, not contraindicated when urinary tract ruptures are suspected. Intravenous pyelography was declined On the basis of radiography and clinical pathology, a tentative diagnosis of traumatic urinary bladder and diaphragmatic rupture was made. Thoracocentesis yielded 500 mL of clear serosanguineous fluid, alleviating dyspnoea and tachypnoea. General anaesthesia was induced with 1 mg/kg propofol (Lipuro 1%, B. Braun, Nelsungen AG) and 0·5 mg/kg diazepam (Assival, Teva) iv and maintained by inhaled isofluorane in 98·5% oxygen. Two milligram per kilogram pethidine HCl was added im q2h throughout and following the procedure. Exploratory coeliotomy revealed diaphragmatic rupture with avulsion of the diaphragm from the ventral body wall and herniation of omentum into the thoracic cavity. The urinary bladder was ruptured

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Traumatic urothorax in a dog

FIG 1. A right lateral thoracic radiograph from a 12-year-old entire female dog demonstrating pleural effusion. Note the soft tissue opacity partially obscuring the cardiac silhouette (short white arrow) and retraction of caudal lung lobes away from the rib cage (long black arrow)

FIG 2. A right lateral positive contrast cystography from the same patient as in Fig 1. Note the massive leakage of contrast material into the peritoneal cavity (black arrow)

at its apex, with severely traumatised and necrotic tear edges. Urine was oozing from the left ureter into the urinary bladder at the trigone area, suggesting that no ureteral breach was present. At the same time, the diffuse, severe soft tissue lesions along with multiple, large but not actively progressive left-retroperitoneal haematomas (requiring no further attempt at controlling haemorrhage), rendered further left-retroperitoneal exploration unnecessarily risky of iatrogenic ureteral compromise. A pubic fracture requiring no surgical correction was detected by palpation. The thoracic cavity was lavaged with warm sterile saline. Hernioraphy was then performed using 3-0 polydioxanone in two layers, with simple-interrupted and continuous Lembert stitches in the first and second layers, respectively. A chest draining tube was placed in the left hemithorax, which demonstrated more severe injury and more haematomas than did the right, and the chest was manually evacuated of air and fluid. The urinary-bladder tear-edges were trimmed, debrided, and sutured over a retrograde urinary catheter with 3-0 PDS using a simple interrupted technique. The abdominal cavity was lavaged with warm sterile saline and routinely closed. Journal of Small Animal Practice

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The chest tube was periodically aspirated while intravenous fluid (2·5 mL/kg/hour lactated Ringer’s solution) and antibiotics [25 mg/kg cefazolin-sodium (Vitamed), iv q8h] were administered along with 4 mg/kg pethidine HCl im q4hr, while urine output and appearance were constantly monitored. During the following two days, the dog’s clinical condition improved progressively, and CBC, serum creatinine and electrolytes were all within RI, with the exception of mild haematuria (Multistix, Bayer Diagnostics, Germany). Urine production was normal. Analysis of the pleural effusate demonstrated PCV, and TP and creatinine concentrations of 4%, 19 g/L and 96·36 µmol/L, respectively. Cytologically, the fluid contained red blood cells (RBCs) and numerous normal-looking neutrophils and macrophages with no evidence of infection. Chest-tube aspiration was non-productive. During the following night, the dog became depressed and febrile (39·8°C). Haematemesis and haematochesia were noted and newly audible crackles developed over all lung fields. Mucous membranes became grey and subcutaneous haematomas appeared on the ventrocaudal abdomen. Systolic blood pressure (Doppler, Parks Medical Electronics Inc., Aloha, OR, USA) was between 90 and 120 mmHg. Intravenous fluid administration was discontinued to decrease the risk of over-hydration with resultant pulmonary oedema. The next morning rectal temperature rose to 41°C, and the following abnormalities were found (Table 1): leucocytosis, decreased PCV and total solids (TS), thrombocytopenia, increased serum creatinine concentration, and hypoglycaemia. Prothrombin time (PT) and partial thromboplastin time (PTT) (ACL 200, Instrumentation Laboratories, Milan, Italy) were prolonged and arterial-blood gas analysis documented hypoxaemia and metabolic acidosis. Repeat radiography demonstrated partial resolution of pleural effusion and improved kidney visualisation. Repeat cystography revealed an irregularly contoured bladder mucosa with no

Table 1. Selected blood-work parameters measured on admission day 3 from a 12-year-old dog with traumatic urothorax when breathing room air Parameter

Units

Reference interval

Measurement

Creatinine

µmol/L

53 to 124

138·79

5·4 to 15·3

31

Leucocytes

6

10 /µL

Packed cell volume

%

37 to 55

24

Total solids

g/L

58 to 72

48

Platelets

106/µL

160 to 525

23

Glucose

mmol/L

4.4 to 7.0

1.4

Prothrombin time

Seconds

6 to 8·4

11

Partial thromboplastin time

Seconds

11 to 17·4

46·5

PaO2

mmHg

85 to 95

60·6

PaCO2

mmHg

29 to 36

29·5

Arterial pH

No unit

7·31 to 7·53

7·175

Arterial HCO3-

mmol/L

25 to 35

10·7

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contrast-material leakage. Cytological evaluation of the peritoneal fluid (PCV 1%, TS 20 g/L) revealed a few RBCs and pycnotic neutrophils, numerous activated macrophages, and epithelial cells. No bacteria could be found. At this point the dog was assessed as having either a systemic inflammatory response syndrome (SIRS), or sepsis with disseminated intravascular coagulopathy (DIC), as well as acute respiratory distress syndrome (ARDS). The dog was given dextrose 50% iv (Dextrose 50, Teva), fresh whole blood and 200 mL packed cells, and was put on a ventilator (Narkomat, Heyer Medical AG, Germany) with 100% oxygen. Arterial-blood gas analysis during ventilation revealed PaO2 of 336·2 mmHg, while PaCO2, pH and HCO3 remained essentially unchanged at 27·2 mmHg, 7·158 and 9·4 mmol/L, respectively. Euthanasia was then elected and necropsy was not permitted.

DISCUSSION Urothorax is a rare condition in animals. While 58 cases of urothorax have been reported in the human medical literature by 2010 (Garcia-Pachon and Padilla-Navas 2004, Garcia-Pachon and Romero 2006), only a single feline case was reported in the veterinary literature (Störk and others 2002). To the best of our knowledge, this is the first report of urothorax in a dog. The tentative diagnosis in this case was based on a markedly increased creatinine concentration in both the abdominal and pleural effusates, compared to its peripheral blood concentration (PBCr). Schmiedt and others (2001) suggested that based on abdominal-fluid analysis, a definitive diagnosis of human uroperitoneum can be made if at least two of the following criteria are met: (1) abdominal-fluid creatinine concentration (AFCr) of at least four times the upper reference limit (URL) of its PBCr; (2) the ratio of abdominal-fluid potassium to its PBCr is greater than 1·4:1; (3) the ratio of AFCr to PBCr is greater than 2:1. In the presently reported patient, both AFCr and pleural fluid creatinine were greater than 5·4-fold above PBCr (increasing further to 6·4-fold 48 hours later), and both were at least 7·14-fold above blood URL, meeting two of the three criteria suggested above. Although surgical correction resulted in transient clinical improvement, resolution of the bicavitary effusion and normalisation of pleural-effusion creatinine concentration, evidence of sepsis and SIRS including progressively increasing leukocytosis, hypoglycaemia, fever, metabolic acidosis, hypocarbia and hypoxaemia developed later on. In addition, DIC developed based on the presence of severe thrombocytopenia and prolongation of PT and PTT values, along with evidence of haematemesis, haematochezia and echymoses. In the absence of a necropsy or ancillary diagnostic workup which was unfortunately declined by the dog owner, it remains unclear why the dog deteriorated following short-term improvement. Surgical failure was unlikely because of the favourable outcome over the first 48 post-operative hours. Persistent or recurrent urothorax was unlikely as post-operative thoracic radiography showed partial resolution of pleural effusion, while 546

repeated contrast abdominal radiography did not demonstrate contrast-material leakage from the urinary system. Major trauma and major surgery may have been potential contributing factors to sepsis, SIRS and DIC (Muckart and Bhagwanjee 1997, De Laforcade and others 2003). Ventilation with 100% oxygen resulted in improvement of PaO2. The newly developed crackles supported the suspicion of pulmonary oedema, possibly due to ARDS, as a potential secondary complication of SIRS. Progressive respiratory compromise might have also been aggravated by pulmonary thromboembolism or in-hospital development of pneumonia. Whether sepsis, pneumonia, SIRS and DIC are associated risks to be considered when managing dogs with trauma-induced urothrax in general, or were potential unique complications in the present case, is uncertain. In light of the outcome despite the intensive care provided, prognosis in future similar cases should probably be guarded. Combined urothorax and uroabdomen should be included in the differential-diagnosis list for dogs with a history of recent trauma and evidence of a bicavitary effusion. The diagnosis can be confirmed by the presence of increased creatinine concentration in both effusates, compared to its serum concentration. Conflict of interest None of the authors of this article has a financial or personal relationship with other people or organisations that could inappropriately influence or bias the content of the paper. References ADAMS, L. G. & SYME, H. M. (2005) Canine lower urinary tract diseases. In: Textbook of Veterinary Internal Medicine. 6th edn. Eds S. J. Ettinger and S. C. Feldman. Elsevier, St Louis, MO, USA. pp 1850-1879 AKPEK, S., ILGIT, E. T., ARAC, M., OZDEMIR, H., ATILLA, S. & IS‚IK, S. (1995) Bilateral perirenal urinoma with mediastinal extension. Abdominal Imaging 20, 267-269 CORRIER, J. N., MILLER, W. T. & MURPHY, J. J. (1968) Hydronephrosis as a cause of pleural effusion. Radiology 90, 79-84 DE LAFORCADE, A. M., FREEMAN, L. M., SHAW, S. P., BROOKS, M. B., ROZANSKI, E. A. & RUSH, J. E. (2003) Hemostatic changes in dogs with naturally occurring sepsis. Journal of Veterinary Internal Medicine 17, 674-679 FRIEDLAND, G. N., AXMAN, N. M. & LOVE, T. (1971) Neonatal “urinothorax” associated with posterior ureteral valves. The British Journal of Radiology 44, 471-474 GARCIA-PACHON, E. & PADILLA-NAVAS, I. (2004) Urinothorax: case report and review of the literature with emphasis on biochemical diagnosis. Respiration 71, 533-536 GARCIA-PACHON, E. & ROMERO, S. (2006) Urinothorax: a new approach. Current Opinion in Pulmonary Medicine 12, 259-263 HASE, T., KODAMA, M., DOMASU, S., NAKAMURA, K., MORITA, K., TARUMI, T., NAKAGAWA, K. & NAKAMURA, K. (1999) A case of urothorax that manifested as posttraumatic pleural effusion after a motorcycle crash. The Journal of Trauma 46, 967-969 KINASEWITZ, G. T. (1997) Transudative effusion. The European Respiratory Journal 10, 714-718 MUCKART, D. J. & BHAGWANJEE, S. (1997) American College of Chest Physicians/ Society of Critical Care Medicine consensus conference definitions of the systemic inflammatory response syndrome and allied disorders in relation to critically injured patients. Critical Care Medicine 25, 1789-1795 PARVATHY, U., SALDANHA, R. & BALAKRISHNAN, K. R. (2003) Blunt abdominal trauma resulting in urinothorax from a missed uretero-pelvic junction avulsion: case report. The Journal of Trauma 54, 187-189 SCHMIEDT, C., TOBIAS, K. M. & OTTO, C. M. (2001) Evaluation of abdominal fluid: peripheral blood creatinine and potassium ratios for diagnosis of uroperitoneum in dogs. Journal of Veterinary Emergency and Critical Care 11, 275-280 SHELEYFER, E., NEVZOROV, R., JOTKOWITZ, A. B., NOVACK, V., AVNON, L. & PORATH, A. (2006) Urinothorax: an unexpected cause of pleural effusion. European Journal of Internal Medicine 17, 300-302 STÖRK, C. K., HAMAIDE, A. J., SCHWEDES, C., CLERCX, C. M., SNAPS, F. R. & BALLIGAND, M. H. (2002) Hemiurothorax following diaphragmatic hernia and kidney prolapse in a cat. Journal of Feline Medicine and Surgery 5, 91-96 TORTORA, A., CASCIANI, E., KHARRUB, Z. & GUALDI, G. (2006) Urinothorax: an unexpected cause of severe dyspnea. Emergency Radiology 12, 189-191 WALDRON, D. R. (2003) Urinary bladder. In: Textbook of Small Animal Surgery. 3rd edn. Eds I. Slatter and H. Douglas. Elsevier, Philadelphia, PA, USA. pp 1629-1637

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© 2011 British Small Animal Veterinary Association