MR. I, 73, IS RUSHED TO THE ED at 0800 this morning following a sudden-onset of right-sided hemiparesis at home. On arrival to the ED, Mr. I's vital signs are: temperature, 99[degrees] F (37.2[degrees] C); pulse, 118 and regular; respirations, 20 and regular; SpO2, 95% on supplemental oxygen at 2 L/minute via nasal cannula; and BP, 150/90 mm Hg with the head of bed elevated at 30 degrees.
A stat noncontrast head computed tomography scan shows a left-sided intracerebral hemorrhage. As a result, Mr. I is aphasic and has right-sided hemiparesis. He's admitted to the neuroscience ICU for intracranial pressure (ICP) monitoring and further management.
The next day, Mr. I's level of consciousness deteriorates secondary to intracranial hypertension, which requires endotracheal intubation and mechanical ventilation. The healthcare provider (HCP) also prescribes an I.V. weight-based bolus of mannitol to be infused over 20 minutes via a 20-gauge peripheral I.V. catheter located in Mr. I's left cephalic vein.
Clinical decisions
Mannitol is a potent osmotic diuretic that expands intravascular volume by inducing the movement of intracellular water to the extracellular spaces.1 Mannitol is used to decrease ICP, intracranial edema, and intraocular pressure.1 It's classified as a noncytotoxic (nonantineoplastic) vesicant (a medication or solution that causes blisters to form and the sloughing of tissues from tissue necrosis). Its potent osmotic properties can damage tissue when it extravasates into a closed space.2
Extravasation is the inadvertent leakage from the intended vascular path of an I.V. vesicant medication or solution into surrounding tissues.2,3 Extravasation can lead to severe and progressive tissue destruction, including blistering and/or sloughing of skin, deep tissue injury, and tissue necrosis.2 These effects can ultimately interfere with the function of the affected extremity. Immediate signs and symptoms of mannitol extravasation include burning or stinging pain, edema, and erythema; these are followed by induration and blistering.4
Damage from a vesicant extravasation can continue for months and involve nerves, tendons, and joints. If treatment is delayed, surgical debridement, skin grafting, and even amputation may be required.5 Because of these serious potential consequences, vesicant infusions should be monitored every 5 to 10 minutes.6 The nurse must be able to identify medications capable of causing tissue injury due to extravasation before administration and monitor the patient closely throughout the infusion to recognize complications and prevent injuries.4 Some antineoplastic drugs that can act as vesicants include doxorubicin, vinblastine, and vincristine. Common nonantineoplastic drugs that can act as vesicants include hydroxyzine, promethazine, digoxin, and dopamine.7
When a central venous access isn't available, careful peripheral vein selection is important, especially when infusing known vesicants. Veins that are small and/or fragile, veins in areas of flexion, veins in extremities with preexisting edema, or veins in areas with known neurologic impairment should be avoided when infusing vesicants.1,2,8,9 Large veins are preferred because smaller veins may not tolerate the required flow rate and may become irritated during vesicant administration.4 Common high-risk I.V. sites where extravasation is known to occur include the dorsum of the hand, the radial and ulnar aspects of the forearm, and the commonly cannulated antecubital fossa.10
Immediate interventions
Mr. I's 20-gauge peripheral I.V. catheter is located in the left cephalic vein 1 inch (2.5 cm) above his wrist. Before administering I.V. mannitol, the nurse thoroughly disinfects the needleless connector with an alcohol pad before access.8 After noting a brisk blood return, the nurse flushes the I.V. catheter with 5 mL 0.9% sodium chloride.2
The mannitol infusion is prepared using filtered tubing and the I.V. pump is programmed to deliver the prescribed dosage. Because Mr. I has a decreased level of consciousness, he can't alert the nurse to pain or other discomfort at the peripheral venous access insertion site during mannitol administration. The nurse must closely monitor the site for any evidence of extravasation and be prepared to immediately discontinue the infusion if signs of extravasation appear.
After 5 minutes, the nurse notes a 2-cm (0.79 in) area of blanched skin and edema that's cool to touch at the I.V. insertion site. The nurse immediately discontinues the mannitol infusion (leaving the I.V. catheter in place), disconnects the I.V. administration set, and attempts to aspirate any residual medication and blood from the I.V. catheter with a small (3 mL) syringe; less than 2 mL is aspirated. The nurse then removes the I.V. catheter, being careful to avoid excessive manual pressure to the extravasated area while achieving hemostasis, applies a sterile dressing over the insertion site, and elevates the extremity to limit edema.2 The peripheral catheter should be removed following attempted aspiration to prevent subsequent injection of any solutions that can increase the size and extent of the extravasation.4,8
The nurse notifies Mr. I's HCP and continues to assess sensation, motor function, and circulation of the affected extremity.
A new 20-gauge I.V. catheter is placed in a large straight section of the cubital vein in Mr. I's right forearm to complete mannitol administration. Although he has right-sided hemiparesis, the new I.V. catheter is placed in his affected extremity to permit continued assessment and treatment to the vesicant extravasation in his left forearm. Because extravasation can lead to significant tissue destruction and even compartment syndrome (which would require surgical intervention), Mr. I's left arm won't be used for further I.V. placement.13
The extravasated area in Mr. I's distal left forearm is marked to ensure consistency in subsequent assessments.
Mr. I's HCP instructs the nurse to apply a hospital-approved cold pack to provide a stimulus for vasoconstriction and extravasated drug reabsorption. Cold application is recommended for use with hyperosmolar fluids, such as mannitol.11 Pharmacy is consulted on antidote options for Mr. I's mannitol extravasation and hyaluronidase injections are prescribed. Hyaluronidase is commercially available and recommended for treatment, but hasn't been approved for this indication.7,11
Hyaluronidase is a proteolytic enzyme that enhances tissue permeability, facilitating diffusion of extravasated I.V. fluid into the vasculature.12 The most frequently reported adverse reactions include mild local injection site reactions such as erythema, edema, and pain. To assess the risk of anaphylaxis, a test dose of hyaluronidase followed by an observation period of 5 to 20 minutes is recommended.12
Mr. I receives the recommended dose of hyaluronidase infiltrated subcutaneously through a 25-gauge needle as five separate injections into the extravasated site. The needle is changed after each injection to reduce the risk of infection and discarded following sharps disposal guidelines.9 Mr. I then undergoes craniotomy and hematoma evacuation to prevent further brain tissue damage from both presence of the blood and increased ICP.
Summary
Mr. I is stable post-op and remains sedated on mechanical ventilation throughout the next day. He continues to have right-sided hemiparesis.
Over the next two days, Mr. I's neurological status improves; he's awake, able to nod his head in response to questions, and follow commands. He's successfully weaned from mechanical ventilation on post-op day three.
The nurse continues to apply cold packs to the extravasated site for 1 more day. Cold packs should be applied for 15 to 20 minutes every 4 hours for 24 to 48 hours following the extravasation.11 Mr. I will experience a full recovery from mannitol extravasation without developing deep tissue damage or permanent injury because of the nurse's rapid recognition of the event and prompt intervention.
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