View source for Unintentional intra-arterial injection

==Background==
*A significant and potentially severe complication of medication administration  
*Must consider this scenario any time patient begins complaining of paresthesias or pain distal to IV site
*Self-inflicted cases are also being described in patients with IVDA

===Risk Factors<ref>Sen S, Chini E, Brown M. Complications After Unintentional Intra-arterial Injection of Drugs: Risks, Outcomes, and Management Strategies.  Mayo Clinic Proceedings 2005. 80(6):783-795</ref>===
*Obesity
*Hypotension
*Procedurally difficult situations (ie. agitated patient, back of ambulance)
*Aberrant vascular anatomy

===Pathophysiology===
Is often multifactorial and dependent upon type of medication administered. Theories include NE induced vasospasm, crystal formation, venous constriction, lipid solubility, direct cytoxicity, endothelial damage and high osmolality.  All pathways suggest the primary mediator of tissue injury is '''thrombosis'''<ref>Sen S, Chini E, Brown M. Complications After Unintentional Intra-arterial Injection of Drugs: Risks, Outcomes, and Management Strategies.  Mayo Clinic Proceedings 2005. 80(6):783-795</ref>

===Medications known to cause severe injury if administered IA:===
*Benzodiazepines
*Barbiturates
*Propofol
*Penicillins
*Amphetamines
*Phenothiazines
*Phenytoin
*Heroin
*Tubocurarine
*Atrcurium
*TPN
*NaHCO3
*Hypertonic Dextrose (D50)

==Clinical Features==
''Presentation is a spectrum of severity''
===Symptoms===
*Immediate:  pain on injection, numbness, weakness
*30 min-24 hours: decreased cap refill, pallor, skin mottling, cramping, paresthesias motor deficit
*24- 48 hours: swelling, edema, contractures, signs of compartment syndrome
*1-2 weeks:  clinical evidence of rhabdo, necrosis, gangrene, autoamputation<ref> Sen S, Chini E, Brown M. Complications After Unintentional Intra-arterial Injection of Drugs: Risks, Outcomes, and Management Strategies. Mayo Clinic Proceedings 2005. 80(6):783-795</ref>

===Tissue Severity Score===
''Assesses severity of symptoms'' 
*Skin color 
*Capillary refill 
*Distal sensation
*Distal extremity temperature

:Receives 1 point for every finding that is abnormal
:Score of >2 is associated with higher likelihood of requiring amputation despite early treatment and management.<ref>Treiman G, Yellin A, Weaver F, et al. An effective treatment protocol for intra-arterial drug injection. Journal of Vascular Surgery 1990; 12:456-466</ref>

==Differential Diagnosis==
*[[Skin and soft tissue infections]]
*[[DVT]]
*[[CT contrast media extravasation]]
*[[Allergic reaction]]

==Evaluation==
*Typically clinical

==Management==
''Treatment recommendations based off of case reports and animal models.  No good human clinical studies to guide therapy at this time.''

===Goals of Management:<ref> Sen S, Chini E, Brown M. Complications After Unintentional Intra-arterial Injection of Drugs: Risks, Outcomes, and Management Strategies. Mayo Clinic Proceedings 2005. 80(6):783-795</ref>===
*Symptom relief 
*Evaluate and manage arterial spasm
*Reestablish distal perfusion
*Manage clinical sequelae of tissue injury
*Rehabilitation of limb

===Initial steps:<ref> Sen S, Chini E, Brown M. Complications After Unintentional Intra-arterial Injection of Drugs: Risks, Outcomes, and Management Strategies. Mayo Clinic Proceedings 2005. 80(6):783-795</ref>===
#If iatrogenic, maintain catheter in place:
#*Start slow infusion of isotonic solution to keep patent
#*to be used for arteriogram and administration of vasodilators
#Thoroughly evaluate medications administered through this catheter
#Evaluate severity of injury (soft compartments, neuro-vascular exam)
#Anticoagulation with IV [[heparin]] recommended
#Treat pain and symptoms

===Antibiotics===
*Some clinicians advocate initiation of coverage for [[gram positive]] and [[anaerobic]] organisms if patient is IV drug abuser
*Troer et al. withheld Antibiotics in this patient population if no sign of infection present.  No cellulitic changes or spreading infection noted in those managed with antibiotic.<ref>Treiman, GS, Yellin, AE, Weaver, FA, Barlow, WE, Treiman, RL, and Gaspar, MR. An effective treatment protocol for intraarterial drug injection. J Vasc Surg. 1990; 12: 456–465</ref>

===If Evidence of Vasospasm===
Consider initiation of the following:
#IA Papaverine 30MG followed by infusion of 180mg over 10 hours<ref>Arquilla, B, Gupta, R, Gernshiemer, J, and Fischer, M. Acute arterial spasm in an extremity caused by inadvertent intra-arterial injection successfully treated in the emergency department. J Emerg Med. 2000; 19: 139–143</ref>
#Extremity sympatholysis with plexus or nerve block<ref>Berger, JL, Nimier, M, and Desmonts, JM. Continuous axillary plexus block in the treatment of accidental intraarterial injection of cocaine [letter]. N Engl J Med. 1988; 318: 930</ref>
#IA CCB → Nicardipine IA infusion<ref>Boudaoud, S, Jacob, L, Lagneau, F, Payen, D, Servant, JM, and Eurin, B. Successful treatment of vasospastic acute ischaemia with intra-arterial nicardipine. Eur J Anaesthesiol. 1993; 10: 133–134</ref>

==Disposition==
*Much of management depends on extent of injury and timing. 
*Admission for serial neurovascular exams and compartment checks is recommended with early elevation and aggressive pain management.

==See Also==
*[[CT contrast media extravasation]]

==External Links==

==References==
<references/>

[[Category:Toxicology]][[Category:Critical Care]][[Category:Pharmacology]]