Click here to get the phone app
Vasopressors & Inodilators
| Drug | Stock solution or Reconstitution instructions | Administration |
| Dobutamine | Stock solution 12.5mg/mL 2cc of 12.5mg/mL dobutamine added to 58cc 0.9% NaCl (417mcg/mL) Stable 1-2 weeks, cover/protect from light | 2.5-20mcg/kg/min Start at 2.5mcg/kg/min using syringe pump |
| Dopamine | Stock solution varies, this is for the 40mg/mL stock – Always confirm!! 1cc of 40mg/mL dopamine added to 59cc 0.9% NaCl (667mcg/mL) Stable 1-2 weeks, cover/protect from light | 5-20mcg/kg/min Start at 5mcg/kg/min using syringe pump Solution turns pink as it denatures |
| Epinephrine | Stock solution 1mg/mL in multi-use vial Dose <0.5mcg/kg/min: (8mcg/mL solution) 4mg (4mL) in 500cc D5W or 0.9% NaCl w/ 5% dextrose Dose 0.5mcg/kg/min or higher (40mcg/mL solution) 4mg (4mL) into 100cc D5W or NaCl w/ 5% dextrose Stable 24h, cover/protect from light | 0.05-1mcg/kg/min Use syringe pump, program concentration and dose Anaphylaxis or peri-arrest crisis: 1cc epinephrine in 1L of 0.9% NaCl Start @3cc/kg/h; titrate rapidly to effect May go higher but side effects greatly increase, treat underlying cause if possible before increasing |
| Isoproterenol | Stock solution 0.2mg/mL 5cc of 0.2mg/mL added to 500cc D5W (2mcg/mL) | 0.02-0.5mcg/kg/min (most commonly 0.02-0.08mcg/kg/min) Start at 0.04mcg/kg/min using a syringe pump |
| Norepinephrine | Stock solution 1mg/mL in 4mL single-use vial Dose <0.5mcg/kg/min: (8mcg/mL solution) 4mg (4mL) in 500cc D5W or 0.9% NaCl w/ 5% dextrose Dose 0.5mcg/kg/min or higher: (40mcg/mL solution) 4mg (4mL) into 100cc D5W or NaCl w/ 5% dextrose Stable 24h, cover/protect from light | 0.05-2mcg/kg/min Draw into syringe and deliver using syringe pump for appropriate level of accuracy Crisis resuscitation: 4mg (4mL) NE in 250cc 0.9% NaCl Start at 0.5cc/kg/h |
| Phenylephrine | Stock solution 10mg/mL 2cc of 10mg/mL added to 250cc 0.9% NaCl (0.08mcg/mL) | 1-3mcg/kg/min Start at 1mcg/kg/min using syringe pump for appropriate level of accuracy Cases using up to 10mcg/kg/min are reported but use caution and only with intensive monitoring >3mcg/kg/min May see reflex bradycardia, and vasoconstriction can lead to clinically significant decreased blood flow to liver, kidneys, GI tract |
| Vasopressin | Stock solution 20U/mL in 1mL or 10mL vials Dose <3mU/kg/min (5mU/mL) 0.25mL vasopressin (5U) into 1L 0.9%NaCl or D5W Dose 3mU/kg/min or higher (10mU/mL) 0.5mL vasopressin (5U) into 1L 0.9%NaCl or D5W Stable 18h at room temperature or 24h in refrigerator Vial is stable 30d in refrigerator after first puncture | 0.5-5mU/kg/min (start at 0.5mU/kg/min) Draw into syringe and deliver using syringe pump for appropriate level of accuracy Pay careful attention to concentration: stock solution is in pressor units, dose is in milliunits. |
Vasodilators
| Drug | Stock solution or Reconstitution instructions | Administration |
| Hydralazine | Stock solution 20mg/mL in 1mL vials Dose <3mcg/kg/min (5mcg/mL) 0.25mL hydralazine (5mg) into 1L 0.9% NaCl or D5W Dose 3mcg/kg/min or higher (10mcg/mL) 0.5mL hydralazine (10mg) into 1L 0.9% NaCl or D5W | 0.1mg/kg IV loading dose followed by 1.5-5mcg/kg/min CRI IV Use syringe pump to deliver with the required level of accuracy Titrate up by 0.1mcg/kg/min very carefully every 10-15 minutes until reach target pressure or max 5mcg/kg/min |
| Nitroglycerin, Intravenous | Available in many concentrations including 5mg/mL stock solution that must be diluted, or 100mcg/mL, 200mcg/mL, and 400mcg/mL ready-to-administer vials Must be diluted in 5% dextrose in water Must be diluted in glass vials If using 5mg/mL stock solution: Add 10mL (50mg) nitroglycerin to 500cc D5W (100mcg/mL) | Use a syringe pump to deliver with required level of accuracy Dogs (based on 2020 case series): 1-6mcg/kg/min Start at 1mcg/kg/min Titrate up by 1mcg/kg/min every 10 minutes until clinical signs improve or hypotension develops |
| Nitroglycerin, Topical | Apply to bare skin or oral mucous membranes q6h for up to 48h | Wear gloves to administer Doses are based on patient size Cats: 1/8-1/4 inch Small dog: 1/4-1/2 inch Medium dog: 1/2 – 1 inch Large dog: 1-2 inches |
| Sodium Nitroprusside | Dilute only with D5W Supplied as powder: 50mg in 2mL vial Add 3cc D5W to powder in vial, and swirl until fully dissolved Draw up contents of vial and add to 250mL of D5W (makes 200mcg/mL stock solution) Protect from light – Stable 24h after reconstituted | Use syringe pump to deliver with the required level of accuracy Hypertensive emergency – 0.5mcg/kg/min – titrate up q5 min until target BP reached (generally 25% reduction in first 4h) Adjunctive Treatment of Congestive Heart Failure: Cardiogenic shock; fulminant pulmonary edema – Dogs: 1mcg/kg/min – Cats: 0.5mcg/kg/min – Monitor blood pressure continuously – Target MAP 70mmHg or Systolic 90-100mmHg – Titrate up in 0.5-1mcg/kg/min increments every 10-15 min as long as blood pressure remains stable, and until perfusion and pulmonary function improves Max rate is reported as high as 10mcg/kg/min but most references sugget 5mcg/kg/min If hypotension occurs stop SNP for 10-15 minutes then restart at lower dose (if drug is to be continued) Can use dobutamine to reduce or prevent hypotension if poor contractility is confirmed on echocardiogram Max duration of treatment is 24h (will develop cyanide toxicity) |
Vasopressor Extravasation Emergency
DO NOT REMOVE THE CATHETER!!
Leave the catheter in place for the first few steps
1. Stop the infusion (duh) – move it to another line
2. Slowly aspirate as much of the drug as possible through the catheter
3. Administer phentolamine 0.1-0.2mg/kg (10mg max total dose) through the IV
4. AND dilute 5mg phentolamine (1cc) in 9cc 0.9% NaCl (10cc total volume): then inject this with a 25g needle into the subcutaneous tissues all around the area of extravasation
5. AND apply a 1” strip of 2% nitroglycerin paste to the site of ischemia (repeat q8h PRN)
6. Now remove the blown/tissued IV catheter
7. Monitor the patient for hypotension (caused by treatment)
8. Place a new IV line in the patient to continue administering the vasopressor (consider a long line or central line to reduce the chance of extravasation)
IF YOU DON’T HAVE PHENTOLAMINE:
Terbutaline option
– Dilute 1mg terbutaline in 10cc normal saline. Inject locally with a 25g needle across affected sites (use in the same manner as phentolamine above)
Other things to try (not as effective)
– Apply heat PROXIMAL to the site of extravasation
– Elevate the site of extravasation above the heart if possible (often not possible in dogs and cats)
– Topical nitroglycerin 2% – apply a 1” strip to the site of ischemia q8h, monitor for hypotension
REFERENCES
– Stier PA, Bogner MP, Webster K, Leikin JB, Burda A. Use of subcutaneous terbutaline to reverse peripheral ischemia. Am J Emerg Med. 1999 Jan;17(1):91-4. doi: 10.1016/s0735-6757(99)90028-1. PMID: 9928712.
– Reynolds PM, MacLaren R, Mueller SW, Fish DN, Kiser TH. Management of extravasation injuries: a focused evaluation of noncytotoxic medications. Pharmacotherapy. 2014 Jun;34(6):617-32. doi: 10.1002/phar.1396. Epub 2014 Jan 13. PMID: 24420913.
