Live from CVC San Diego: 7 emergency and critical care pearls
Dr. Todd Duffy, DACVECC, discussed several pointers with it comes to common emergencies on Friday, Nov. 1, during a presentation at the CVC in San Diego. Here's just a sampling:
1. Consider peripherally inserted central catheters
For intravenous access, a peripherally inserted central catheter line may be preferred in patients that require the administration of substances with increased osmolality (e.g. diazepam infusions, parenteral nutrition, dextrose-supplemented fluids) or that require frequent blood sampling. Standard through-the-needle catheters are prone to kinking. Replacing the needle with a similar sized peripheral catheter has proven to lower the risk for kinking. These catheters may be successfully placed in most common peripheral vascular sites, but venous valves may provide added obstacles with full catheter advancement.
2. Respiratory problems? Administer anxiolytics
Many respiratory patients are anxious. Anxiety contributes to increased oxygen consumption through the added work of breathing and restlessness. Anxiolytics—specifically butorphanol (0.4 mg/kg)—help limit this increased oxygen consumption. By limiting how much oxygen is used for skeletal muscle consumption, more oxygen is available for distribution to vital organs. And oxygen administration itself can result in anxiety in patients, so anxiolytics also allow patients to tolerate oxygen administration techniques.
3. Evaluate those electrolytes
A common oversight in vomiting patients is that electrolyte evaluation is not included in the basic serum chemistry profile. Not only does electrolyte evaluation help detect hypoadrenocorticism, but it also helps evaluate for evidence of an upper gastrointestinal obstruction. The latter is strongly suspected when a hypochloremic metabolic alkalosis is present. This not only helps with diagnosis, but also provides justification for using physiologic saline solution as the initial replacement and maintenance fluid. Hypokalemia should also be therapeutically addressed because of the role that hypokalemia plays in inducing an ileus. The presence of an ileus will also further contribute to nausea and vomiting.
4. Appropriately handle hypoglycemia
When treating a patient with clinical hypoglycemia, always give an initial dextrose bolus, followed by a supplemental infusion until the patient no longer needs this supplementation. Keep in mind that a low blood glucose concentration on human glucometers can occur if a patient has a relative or absolute polycythemia. Consider performing a glucose measurement on plasma, instead of whole blood, if this is the case.
5. Think pericardial effusion
If a large-breed dog presents with acute collapse and if a physical examination reveals pale pink mucous membranes and no palpable abdominal mass or effusion or if mucous membrane cyanosis is present, think pericardial effusion. Vomiting before presentation is also a common component to the history. The patient is almost certain to have pericardial effusion if thoracic radiographs are normal and no appreciable upper airway noise is present. The other major differential is a pulmonary thromboembolism.
6. Don't rely on blood pressure measurements
A normal blood pressure does not rule out a patient from being in shock. Oscillometric measurements require more specific cuff placement because the cuff is sensing the vibrations. As such, patient movement can cause erroneous readings. A patient’s heart rate must correspond with the rate obtained by the blood pressure unit.
7. Target the cause of tachycardia
Major differentials for a sinus tachycardia in a dog are pain, stress, excitement, and hypovolemic shock. Electrocardiographic analysis is necessary to document the presence of alternative arrhythmias.