NAVLE Emergency & Critical Care, Fluid Therapy and Euthanasia: practice questions

D. Mentation, pupil size and response, and ability to move the limbs

Disability is the neurological assessment: level of consciousness, pupils and motor function. Capillary refill and pulses belong to circulation, rate and lung sounds to breathing, and stridor to airway.

Further reading: Silverstein & Hopper, Small Animal Critical Care Medicine; BSAVA Manual of Canine and Feline Emergency and Critical Care

A. A low score on a 3-18 scale, indicating a poor prognosis

The modified Glasgow Coma Scale adds motor activity, brainstem reflexes and level of consciousness, each scored 1-6, for a total of 3-18; lower is worse, and a score of 8 is associated with a poor prognosis. Students often reverse the direction because the Animal Trauma Triage score runs the other way (higher is worse).

Further reading: Silverstein & Hopper, Small Animal Critical Care Medicine; BSAVA Manual of Canine and Feline Emergency and Critical Care

C. 450 mL

30 kg x 15 mL/kg = 450 mL. 2,700 mL is the old full 'shock dose' of 90 mL/kg (30 x 90), 675 mL is a quarter of that, and 45 mL is a decimal slip. Bolus figures of 10-20 mL/kg are commonly cited — confirm against the product label and your national formulary.

Further reading: Silverstein & Hopper, Small Animal Critical Care Medicine, shock chapters

A. Tall peaked T waves, absent P waves and bradycardia

Hyperkalaemia produces peaked T waves, flattening and loss of P waves, QRS widening, bradycardia and finally a sine-wave rhythm. U waves and ST depression are associated with hypokalaemia.

Further reading: DiBartola, Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice; 2013 AAHA/AAFP Fluid Therapy Guidelines

D. It restores the gap between resting and threshold potentials, protecting the heart

Calcium raises the threshold potential and restores myocardial excitability without changing serum potassium; it buys time while insulin-dextrose or bicarbonate shift potassium into cells and fluids or relief of obstruction remove it.

Further reading: DiBartola, Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice; 2013 AAHA/AAFP Fluid Therapy Guidelines

B. A dog that received a transfusion two weeks ago and needs another

A previously transfused dog may have formed antibodies after its first transfusion (commonly after about four days), so a crossmatch is required. A never-transfused, type-matched dog is low risk, and a donor or autotransfusion recipient does not receive foreign red cells.

Further reading: Yagi & Holowaychuk, Manual of Veterinary Transfusion Medicine and Blood Banking

D. About 4 hours

Blood is started slowly while the patient is watched, then given so the unit finishes within about 4 hours, to limit bacterial growth at room temperature. Ten minutes risks volume overload and missed reactions.

Further reading: Yagi & Holowaychuk, Manual of Veterinary Transfusion Medicine and Blood Banking

A. Vitamin K1 (phytonadione)

Vitamin K1 is effective, given for several weeks for second-generation compounds with a prothrombin time check 48-72 hours after the last dose. Vitamin K3 is ineffective; protamine reverses heparin, not vitamin K antagonists.

Further reading: Peterson & Talcott, Small Animal Toxicology; Gupta, Veterinary Toxicology; Merck Veterinary Manual

A. Pneumothorax

A rapid, shallow, restrictive pattern with quiet dorsal lung sounds points to air in the pleural space. Laryngeal paralysis and tracheal collapse cause noisy upper-airway breathing; lower airway disease causes expiratory effort and wheezes.

Further reading: Silverstein & Hopper, Small Animal Critical Care Medicine, trauma chapters

A. Intraperitoneal injection, accepting a slower onset

Intraperitoneal barbiturate is acceptable in small animals when IV access is impractical, though onset is slower. Intracardiac injection requires unconsciousness, and potassium chloride requires general anaesthesia.

Further reading: AVMA Guidelines for the Euthanasia of Animals, 2020 Edition