Dextran 70
**Dextran 70** is a high-molecular-weight synthetic colloid used primarily as an adjunctive treatment for **hypovolemic shock**. * **Clinical Role:** It serves as a relatively low-cost plasma volume expander. While **hetastarch** (and newer tetrastarches) are more commonly employed in modern veterinary medicine, Dextran 70 remains a viable option for rapid intravascular volume expansion. * **Composition:** It is a branched polysaccharide with an average molecular weight of 70,000 daltons. * **Clinical Pearl:** Because it is a large molecule, it remains in the vascular space longer than crystalloid fluids (like LRS or normal saline), making it highly effective for small-volume resuscitation in critical patients with head trauma, pulmonary contusions, or closed-cavity hemorrhage.
Mecanismo: **Dextran 70** exerts its effects through oncotic pull: * Acts as an artificial colloid → increases intravascular **colloid osmotic pressure (COP)**. * The high COP → draws fluid from the interstitial spaces into the vascular system. * This fluid shift → rapidly increases circulating blood volume → improves venous return, cardiac output, and systemic perfusion. * *Note:* Dextran 70 has a colloid osmotic pressure of 62 mmHg, which is significantly higher than normal canine plasma (approx. 20 mmHg).
Dosificación por especie
- Small volume resuscitation (hypovolemic shock, head injury, pulmonary contusions, oliguric renal failure) · 2-5 mL/kg over 1-5 minutes (after initial isotonic crystalloids 5-10 mL/kg). Repeat as needed until end-point of resuscitation is reached. · IV · As needed · Acute resuscitation · Reassess perfusion parameters between boluses.
- Volume expansion / Augment colloid oncotic pressure · 10 mL/kg/day; when acute resuscitation is required. May be given as a slow bolus over 30 minutes to an hour. May also be given as a constant rate infusion. · IV · q24h or CRI · As needed · Reduces the volume of crystalloids infused, thereby reducing hemodilution.
- Dehydration secondary to diarrhea (Calves) · 4-5 mL/kg over 4-5 minutes of a 6% dextran 70 in 7.2% NaCl solution. Follow immediately by oral administration of isotonic electrolyte solution. · IV · Once · One time only · To prepare: add 31.6 g NaCl to 60 mL syringe, draw 60 mL of 6% dextran 70 in 0.9% NaCl, dissolve, and filter through 0.22 micron filter. Give ONE TIME ONLY to avoid hypernatremia.
- Small volume resuscitation (hypovolemic shock, head injury, pulmonary contusions, oliguric renal failure) · 5 mL/kg over 1-5 minutes (after initial isotonic crystalloids 10-15 mL/kg). Repeat as needed until end-point of resuscitation is reached. · IV · As needed · Acute resuscitation · Reassess perfusion parameters between boluses.
- Volume expansion / Augment colloid oncotic pressure · 20 mL/kg/day; when acute resuscitation is required, may be given as a slow bolus over 30 minutes to an hour. May also be given as a constant rate infusion. · IV · q24h or CRI · As needed · Reduces the volume of crystalloids infused, thereby reducing hemodilution.
Las dosis son una referencia clínica para veterinarios colegiados. Confirme siempre con la ficha técnica vigente y el paciente individual.
Vías de administración
Contraindicaciones
- Preexisting severe coagulopathies
- Severe heart failure (due to risk of circulatory overload)
- Severe renal failure (oliguric/anuric, unless closely monitored)
- Intramuscular (IM) administration
Efectos adversos
- Increased bleeding times (decreased von Willebrand's factor and factor VIII activity)
- Anaphylactoid reactions (rare in dogs, but higher incidence than hetastarch)
- Acute renal failure (rare)
- Volume overload / circulatory overload
- Gastrointestinal effects (nausea, vomiting, abdominal pain - reported in humans)
Monitorización
- Perfusion parameters (heart rate, blood pressure, capillary refill time, mucous membrane color)
- Signs of fluid/circulatory overload (respiratory rate/effort, lung sounds)
- Coagulation status / bleeding times (if prolonged use or high doses)
- Renal function and urine output
Sobredosis
**Volume Overload:** Overdosage primarily results in circulatory/fluid overload. The drug must be dosed and monitored carefully. Treatment is supportive, potentially requiring diuretics (e.g., furosemide) if severe pulmonary edema or volume overload occurs.
La referencia de fármacos de VetSheet está destinada a veterinarios colegiados como apoyo a la decisión clínica, no sustituye el juicio profesional ni la ficha técnica vigente del fabricante.