Monthly journal round-up

Monthly Journal Round-Up - July/August 2018

Thanks as always to Lara Brunori DVM CertAVP MRCVS

Clinical review:

  • Nafe, L.A. et al. (2018) ‘Aspiration-related respiratory disorders in dogs’ Journal of the American Veterinary Medical Association, 253(3), pp. 292-301. See below.

Clinical studies:

Prospective:

  • Darnis, E. et al. (2018) ‘Establishment of reference values of the caudal vena cava by fast‐ultrasonography through different views in healthy dogs’. Journal of Veterinary Internal Medicine, 32(4), pp. 1308-1318.

  • Hogen, T. et al. (2018) ‘Evaluation of end‐tidal carbon dioxide as a predictor of return of spontaneous circulation in dogs and cats undergoing cardiopulmonary resuscitation’. Journal of Veterinary Emergency and Critical Care (Early view).

Retrospective:

  • Skulberg, R. et al. (2018) ‘Description of the Use of Plasma Exchange in Dogs With Cutaneous and Renal Glomerular Vasculopathy’. Frontiers in Veterinary Science, https://doi.org/10.3389/fvets.2018.00161

  • Ohad, D.G. et al (2018) ‘Constant rate infusion vs. intermittent bolus administration of IV furosemide in 100 pets with acute left-sided congestive heart failure: A retrospective study’. The Veterinary Journal, 238, pp.70-75.

  • Ruiz, M.D. et al. (2018) ‘Characterization of and factors associated with causes of pleural effusion in cats’. Journal of the American Veterinary Medical Association, 253(2), pp. 181-188.

  • DePompeo, C.M. et al. (2018) ‘Intra-abdominal complications following intestinal anastomoses by suture and staple techniques in dogs’. Journal of the American Veterinary Medical Association, 253(4), pp. 437-443.

  • Lux, C.N et al. (2018) ‘Factors associated with survival to hospital discharge for cats treated surgically for thoracic trauma’. Journal of the American Veterinary Medical Association, 253(5), pp. 598-605.

  • Walton, K.L. & Otto, C.M. (2018) ‘Retrospective evaluation of feline rodenticide exposure and gastrointestinal decontamination:146 cases (2000-2010)’. Journal of Veterinary Emergency and Critical Care (Early view).

Case series:

  • Teh, H. et al. (2018) ‘Medical management of esophageal perforation secondary to esophageal foreign bodies in 5 dogs’. Journal of Veterinary Emergency and Critical Care (Early view).

Case reports:

  • Bellamy, E.J. & Steele, H. (2018) ‘Abdominal wall rupture with gastric herniation in an 8‐week‐old puppy’. Journal of Small Animal Practice (Early view).

For a copy of any of the papers mentioned in this post (personal education purposes only), please email lara.brunori@gmail.com.

Pick of the Month

‘Aspiration-related respiratory disorders in dogs’

Nafe, L.A. et al. (2018) Journal of the American Veterinary Medical Association, 253(3), pp.292-300

Aspiration is defined as the intake of solid or liquid material into the airways and pulmonary parenchyma. The term aspiration is often used interchangeably with aspiration pneumonia, however other aspiration-related respiratory disorders exist and have been well characterised in human medicine.

This paper offers a comprehensive overview of all aspiration-related disorders involving canine patients based on the parallels recognised in human medicine.

An anatomical approach has been adopted to classify these disorders:

Airways

Upper-airway disorder secondary to gastroesophageal reflux (GER)

Repeated micro-aspiration of gastric contents in the upper airways can result in oropharyngeal, nasopharyngeal, laryngeal and proximal tracheal inflammation.

In humans clinical signs of reflux (heartburn, belching and nausea) in combination with visible evidence of laryngeal or oropharyngeal inflammation are often enough to make a diagnosis and institute treatment.

In dogs, however, diagnosis can prove challenging. Laryngeal dysfunction and hyperaemia are unspecific signs amongst the canine population and GER can act both as a cause and a consequence in the perpetuation of laryngeal disease.

Therapeutic trials with proton pump inhibitors resolving upper respiratory signs have been considered diagnostic for laryngeal dysfunction secondary to GER in dogs.

Alternatively, CT examination of the head often shows thickening of the soft palate without evidence of a nasal or nasopharyngeal mass and tracheoscopy might reveal a specific demarcation between an hyperaemic proximal tracheal region and a normally appearing mucosa in the distal portion.

Large airway obstructions

These are usually due to a foreign body inhalation and can represent a potentially life threatening situation. Common foreign bodies in dogs include food, plant material and various chewed objects.

Radiography can be a useful diagnostic tool, however its sensitivity is impaired when the aspirated object is radiolucent.

Evidence of atelectasis and air trapping in the lung tissue could be additional indicative findings. CT scan, although not always readily available provides a more reliable option.

Tracheoscopy with a flexible endoscope is likely the most effective diagnostic and therapeutic tool applicable in these situation. The foreign body can usu-ally be easily identified and subsequently removed via the additional use of alligator forceps.

Bronchiectasis

This is a structural change affecting the elastic and muscular components of the bronchi which leads to an irreversible widening of the airways. In dogs, aspiration pneumonia has been shown to be the most likely underlying cause of this pathological process.

Diagnosis can be achieved via thoracic radiography, CT and bronchoscopy. X-rays typically show a multifocal unstructured interstitial pattern with thickened bronchial walls and bronchi with a wide diameter that does not taper down to the periphery. CT scan provides a superior sensitivity and in some circumstances can even identify the presence of a well-circumscribed foreign material within a bronchus.

Other differentials for bronchiectasis are bacterial infections, eosinophilic infiltrate and ciliary dyskinesia.

Diffuse aspiration bronchiolitis (DAB)

DAB represents a chronic inflammation of the small airways caused by re-current aspiration. Diagnosis include the identification of a predisposing factor (i.e. megaesophagus) and the evidence on CT scan of bilateral diffuse bronchiolocentric lesions.

Since there are no available therapies able to specifically address small airway inflammation, treatment is focused on addressing the underlying causes.

Parenchyma

Aspiration pneumonia and pneumonitis

Aspiration pneumonia is the most commonly recognised pathological manifestation of aspiration disorders in veterinary medicine.

In human medicine there is an interesting distinction between aspiration pneumonia and aspiration pneumonitis.

The first one involves a bacterial infection and it’s usually associated with the aspiration of high pH (>2.5) material containing bacteria from the oropharyngeal or upper gastrointestinal tract. It has a slow and progressive development and it’s associated with a chronic predisposing condition (i.e. laryngeal paralysis).

Aspiration pneumonitis on the other hand is characterised by an hyperacute onset of hypoxia, pyrexia and radiographical changes occurring within hours from a major aspiration event. This presentation is due to the inflammatory reaction associated with the chemical damage caused by the aspirated material and it’s independent from bacterial infections.

This distinction in veterinary medicine is still not clearly recognised. How-ever the more extensive use of CT scans might enhance the specificity of diagnosis and could consequently help implementing more adequate treatments. This is particularly relevant in regards of a more cautious use of antimicrobials. Aspiration pneumonitis in humans is treated mainly with supportive care measures and does not require any antimicrobial interventions.

Acute respiratory distress syndrome (ARDS)

A recognised common consequence of aspiration pneumonitis in humans is ARDS. This is a syndrome defined by an acute onset of impaired gas exchanges and pulmonary vessels leakage without pulmonary hypertension. The radiographical evidence of bilateral infiltrates involving more than one lobe/quadrant is usually considered as a diagnostic confirmation.

This syndrome carries an extremely high mortality with pulmonary protective ventilation identified as the only therapeutic option.

Exogenous lipid pneumonia

This is very rarely described in veterinary medicine and it occurs when there’s inhalation/aspiration of animal, vegetable or mineral oil. Usually the history is quite indicative and radiographically it shows as a patchy pneumonic consolidation. Cytological evidence of lipid-laden macrophages is considered the definitive diagnostic evidence.

Interstitial lung diseases

This is a group of inflammatory disorders affecting the space between the pulmonary and vascular epithelium. Repetitive micro-aspiration is a recognised cause for this presentation in human medicine. In veterinary medicine this cause-effect relationship is still under investigation. However, if confirmed treatment at-tempts to reduce chronic micro-aspiration could prove very useful in slowing down the inevitable decline in lung function connected with these diseases.

Conclusion

In conclusion aspiration can result in a broad range of clinical presentations. A better understanding of the types of aspiration-associated respiratory disorders in dogs will improve early recognition, optimise therapeutic protocols and provide better clinical outcomes.

For a copy of any of the papers mentioned in this post (personal education purposes only), please email lara.brunori@gmail.com.

Lara loves to hear from you!

Monthly Journal Round-Up - May/June 2018

Thanks as always to Lara Brunori DVM CertAVP MRCVS

Clinical practice reviews:

  • MacFarlane, P. (2018) ’Managing perioperative pain in dogs and cats’. In Practice, 40(4), pp.130-140.
  • Bradbrook, C.A. & Clark, L. (2018) ‘State of the art analgesia - recent developments in pharmacological approaches to acute pain management in dogs and cats. Part 1’. The Veterinary Journal (Early view).
  • Bradbrook, C.A. & Clark, L. (2018) ‘State of the art analgesia - recent developments pharmacological approaches to acute pain management in dogs and cats: Part 2’.The Veterinary Journal, 236, pp. 62-67.
  • Hagman, R. (2018) ‘Pyometra in small animals’. Veterinary Clinics of North America: Small Animal Practice, 48(4), pp. 639-661.
  • Clarke, D.L. (2018) ‘Feline ureteral obstructions Part 1: medical management’. Journal of Small Animal Practice, 59(6), pp. 324-333.
  • Clarke, D.L. (2018) ‘Feline ureteral obstructions Part 2: surgical management’. Journal of Small Animal Practice (Early view). 

Clinical studies:

Prospective:

  • Seitz, M.A. et al. (2018) ‘Evaluation for association between indwelling urethral catheter placement and risk of recurrent urethral obstruction in cats’. Journal of the American Veterinary Medical Association, 252 (12), pp. 1059-1520.
  • Ortiz, V. et al. (2018) ‘Evaluating the effect of metronidazole plus amoxicillin-clavulanate versus amoxicillin-clavulanate alone in canine haemorrhagic diarrhoea: a randomised controlled trial in primary care practice’. Journal of Small Animal Practice (Early view).
  • Walters, A.M. ‘Evaluation of the agreement between focused assessment with sonography for trauma (AFAST/TFAST) and computed tomography in dogs and cats with recent trauma’. Journal of Veterinary Emergency and Critical Care (Early view).
  • Ash, K. Et al. (2018) ‘Performance evaluation and validation of the animal trauma triage score and modified Glasgow Coma Scale with suggested category adjustment in dogs: A VetCOT registry study’. Journal of Veterinary Emergency and Critical Care, 28(3), pp.192-200.

Retrospective:

  • Schwartz, Z & Coolman, B.R (2018) ’Closure of gastrointestinal incisions using skin staples alone and in combination with suture in 29 cats’. Journal of Small Animal Practice, 59(9), pp.281-285.
  • Canonne, A.M. et al. (2018) ‘Angiostrongylosis in dogs with negative fecal and in‐clinic rapid serological tests: 7 Cases (2013‐2017)’. Journal of Veterinary Internal Medicine, 32(3), pp. 951-955.

Case reports: 

  • Matiasovic, M. Et al. (2018) ‘Barium peritonitis with abdominal abscessation’. Journal of Small Animal Practice (Early view).
  • Kjaergaard, A.B. et al. (2018) ‘Treatment of carprofen overdose with therapeutic plasma exchange in a dog’. Journal of Veterinary Emergency and Critical Care (Early view). 
  • Leary, M.L. & Sinnott-Stutzman, V. (2018) ‘Spontaneous gastric dilatation-volvulus in two cats’. Journal of Veterinary Emergency and Critical Care (Early view).

For a copy of any of the papers mentioned in this post (personal education purposes only), please email lara.brunori@gmail.com.

Pick of the Month

‘Closure of gastrointestinal incisions using skin staples alone and in combination with suture in 29 cats’
Schwarz, Z. & Coolman, B.R., Journal of Small Animal Practice, 2018, 59(9), pp. 281-285.

Various stapling techniques to close gastrointestinal incisions have been reported in humans and multiple animal species. 

The use of specific devices like linear and circular staplers has been successfully implemented in human medicine. However, their application in veterinary practice is restricted by their high cost, limited availability and size which is often too large for our smaller patients.

The use of standard skin staples instead has been trialled in pigs and successfully used in dogs both in experimental and clinical settings.

According to the authors, this retrospective study is the first publication describing the use of skin staples for closing gastrointestinal incisions in feline patients. 

The study involved 29 cats undergoing gastrointestinal surgeries in a US-based referral centre. Each gastrointestinal incision and closure has been considered separately, for a total of 42 procedures: 

  • 15 gastrostomies 
  • 1 partial gastrectomy 
  • 12 jejunotomies 
  • 2 jejunal anastomosis 
  • 12 colonic anastomosis 

The procedures were performed by four different surgeons with different skill levels: one Board-certified surgeon, one residency-trained surgeon, one surgical resident and one emergency veterinarian. All surgeons underwent a short training session by one of the senior surgeons who was comfortable using the stapling method.

Gastrostomies and gastrectomy were closed with a hybrid technique combining sutures with monofilament material including the mucosa and submucosa and skin staples for the seromuscular layer. 

Jejunotomies and jejunal anastomosis were closed with only one layer of staples while colonic anastomosis was either closed with the hybrid method (when the surgeon could distinguish the mucosa/submucosa from the seromuscular layer) or with only one layer of skin staples. 

Overall 26 out of 29 cats survived at a 12-day follow up. No dehiscence of any of the gastrointestinal closures was reported and the three deaths were deemed not directly related to surgical procedure failure: two cats were euthanised as a consequence of a neoplastic process diagnosis and the third cat suffered a cardiovascular arrest in the immediate post-operative period.

This study, however interesting and bearing encouraging results, presents several intrinsic limitations:

  • A small sample size
  • No control group
  • The decision of using a hybrid or single technique was not randomised and left to the surgeon’s subjective judgment
  • The stapling technique described requires a scrubbed-in assistant which is not always possible in primary/Out-of-Hours practice
  • Stapling was not considered for linear incisions of the small intestine unless already dilated (i.e. from the previous presence of a foreign body)
  • No post-mortems were performed on the deceased cats
  • The follow-up period reported is fairly short and mainly focuses on evaluating the risk of dehiscence for the stapling technique. No long-term consequences have been assessed. There was a brief mention of a few cats (unspecified number) undergoing radiography and followed up to a 6-week period in which the authors found the staples migrating into the gastrointestinal lumen to then be passed with the faecal material.

Conclusion:

In conclusion, this study shows that standard disposable skin staples can be safely used alone or in combination with regular sutures for feline gastrointestinal closures. These techniques can be performed by surgeons of various levels of experience without any significant short-term complications. Nevertheless, further studies with larger samples and longer follow-up periods are needed to confirm the encouraging results reported by the authors.

For a copy of any of the papers mentioned in this post (personal education purposes only), please email lara.brunori@gmail.com.

Lara loves to hear from you!

Monthly Journal Round-Up - April 2018

Thanks as always to Lara Brunori DVM CertAVP MRCVS

Clinical studies:

Prospective:

  • Bhalla, R.J. et al. (2018) ‘Comparison of intramuscular butorphanol and buprenorphine combined with dexmedetomidine for sedation in cats’. Journal of Feline Medicine and Surgery, 20(4), pp.325-331
  • Sylvane, B. et al. (2018) ‘Effect of cross-match on packed cell volume after transfusion of packed red blood cells in transfusion-naïve anemic cats’. Journal of Veterinary Internal Medicine, doi: 10.1111/jvim.15120 (Early view)
  • Ateca, L.B. et al (2018) ‘Evaluation of the relationship between peripheral pulse palpation and Doppler systolic blood pressure in dogs presenting to an emergency service’. Journal of Veterinary Emergency and Critical Care, doi: 10.1111/vec.12718 (Early view)

Retrospective:

  • Lux, C.N. et al. (2018) ‘Perioperative mortality rate and risk factors for death in dogs undergoing surgery for treatment of thoracic trauma: 157 cases (1990-2014)’. Journal of the American Veterinary Medical Association, 252(9), pp.1090-1097. 
  • Gremillion, C.L. et al. (2018) ‘Radiographic findings and clinical factors in dogs with surgically confirmed or presumed colonic torsion’. Veterinary Radiology & Ultrasound, doi: 10.1111/vru.12595 (Early view)

Observational:

  • Ash, K. et al. (2018) ‘Performance evaluation and validation of the animal trauma triage score and modified Glasgow Coma Scale with suggested category adjustment in dogs: A VetCOT registry study’. Journal of Veterinary Emergency and Critical Care, doi: 10.1111/vec.12717 (Early view)
  • Reminga, C.L. et al. (2018) ‘Evaluation of the placement and maintenance of central venous jugular catheters in critically ill dogs and cats’. Journal of Veterinary Emergency and Critical Care, doi: 10.1111/vec.12714 (Early view) 

Case report:

  • Scagnelli, A.M. et al. (2018) ‘Effects of therapeutic plasma exchange on serum immunoglobulin concentrations in a dog with refractory immune-mediated hemolytic anemia’. Journal of the American Veterinary Medical Association, 252(9), pp. 1097-1108
  • Ueda, Y. Et al. (2018) ‘Severe lactic acidosis and hypoglycemia due to acute metformin intoxication in a dog’. Journal of Veterinary Emergency and Critical Care, doi: 10.1111/vec.12711 (Early view)

For a copy of any of the papers mentioned in this post (personal education purposes only), please email lara.brunori@gmail.com.

Pick of the Month

‘Evaluation of the relationship between peripheral pulse palpation and Doppler systolic blood pressure in dogs presenting to an emergency service’
Ateca, L.B. et al. (2018) Journal of Emergency and Critical Care, doi: 10.111/vec.12718

Peripheral pulse palpation is considered a key parameter of the emergency patient’s triage. Its evaluation is relevant for the identification of cardiovascular abnormalities like hypotension, dysrhythmias, hyperdynamic states, decreased cardiac output and peripheral vasoconstriction. 

Pulse quality is closely related to stroke volume, arterial wall compliance and intrathoracic pressure and it is determined by the difference between systolic and diastolic blood pressure. It is, therefore, a common assumption that a strong peripheral pulse is indicative of a normal/high systolic blood pressure, while a weak one represents a low systolic blood pressure or an arterial clot. 

However, recent publications in the human medical literature are no longer supportive of this assumption. Several studies demonstrated that measured arterial blood pressure was significantly lower than expected from the peripheral pulse palpation alone. 

The evidence in veterinary medicine is lacking and this prospective observational study is aimed at filling the gap evaluating the relationship between pulse quality and measured blood pressure in dogs. 

Ninety-three canine patients presented to the Emergency Department of the University of Pennsylvania Veterinary Teaching Hospital between February 2012 and December 2013 were enrolled. Inclusion criteria consisted of a complete physical examination and systemic blood pressure measurement prior to any other intervention. Dogs with suspected arterial thromboembolism were excluded from the study. 

Pulse quality of both femoral and dorsal metatarsal arteries was assessed by digital palpation. Normal pulses were defined as easily palpable, while weak or absent pulses were difficult to find or not found at all. 

Systolic blood pressure was measured via Doppler flow detector. The cuff was appropriately chosen and at least 3 measurements were obtained. The average value was then recorded.

The study’s results are clearly summarised in a table within the text (Table 1), which shows a noticeable trend for both femoral and dorsal metatarsal pulses: when quality weakens, median systolic blood pressure decreases and heart rate increases. However, the differences were only statistically significant for blood pressure values in relation to dorsal metatarsal pulse quality and for heart rate values in relation to femoral pulse quality.

Sensitivity, specificity and relative confidence interval values were calculated for the reliability of metatarsal pulse palpation to detect hypotension. A specificity of 93% vs a sensitivity of 33% was found. This means that a dog with an absent metatarsal pulse is very likely to be hypotensive, but a palpable dorsal metatarsal pulse is not enough to rule out a hypotensive status. 

This study, although generally well designed, presents several limitations. The main ones refer to the variability in the assessors’ clinical experience and the fact that they were not blinded to the systemic blood pressure measurements, nor assessed for inter-rater or intra-rater reliability. Inconsistencies in patients’ sizes and body condition scores were taken into consideration by the authors and deemed not significant in the assessment of pulse quality; nevertheless, a more homogeneous sample would have been preferable.

Ultimately the choice to use Doppler blood pressure measurement instead of more invasive methods could be justified in terms of study feasibility and patient welfare. However, it has previously been demonstrated that Doppler flow tends to underestimate systolic blood pressure values.

Conclusion:

In conclusion, this study demonstrates that an absent dorsal metatarsal pulse is very specific for hypotension and should trigger prompt interventions to re-establish adequate perfusion and blood pressure values. Nevertheless, it is not advisable to rely on a single parameter when evaluating the emergency patient’s cardiovascular status. The presence of dorsal metatarsal pulse alone does not rule out hypotension and evaluation of other indicators of poor perfusion like mucous membrane colour, capillary refill time, heart rate, mental status and systolic blood pressure should always be performed.

For a copy of any of the papers mentioned in this post (personal education purposes only), please email lara.brunori@gmail.com.

Lara loves to hear from you!