Extravasation preparation

During the ongoing assessment, the nurse checks the needle site every 15 to 30 minutes or more frequently if the patient is restless or confused. When one of these preparations is given with a regular IV infusion set, the nurse checks the infusion rate every 15 minutes. The needle site is inspected for signs of extravasation (escape of fluid from a blood vessel into surrounding tissues) orinfiltration (the collection of fluid into tissues). 

Small size (10-100 nm) is one ofthe most interesting features of polymeric micelles. Besides allowing the extravasation of the carriers, it permits the sterilization of the preparation to be done simply by Lltration and minimizes the risks of embolism in capillaries, contrary to larger drug carriers (Kwon and Okano, 1996). Micellar size seldom exceeds 100 nm, but depends on several factors including copolymer molecular weight, relative proportion of hydrophilic and hydrophobic chains, and aggregation number (Yokoyama etal., 1990 Trubetskoy and Torchilin, 1996 Shin etal., 1998). 

A syringe is prepared with heparinized saline and a 21-, 23-, or 25-gauge scalp-vein needle, and the patient is phlebotomized, usually in the antecubital vein. Fluorescein may also be injected into the veins of the back of the hand or wrist. The needle must be monitored, because extravasation of dye results in localized pain. Before injecting fluorescein the photographer takes baseline color photographs and then red-free fundus pictures. 

More expensive and costly to produce Potential for infection at site of injection Potential for sepsis Potential for thrombophlebitis Potential for fluid overload Potential for air embolism Potential for extravasation Psychological distress by the patient Require specialized equipment, devices, and techniques to prepare and administer drugs Potential for pain upon injection Potential for tissue damage upon injection Risk of needlestick injuries and exposure to blood-borne pathogens by health care worker Increased morbidity associated with long-term vascular access devices Disposal of needles, syringes, and other infusion devices requires special consideration... 

FITC-dextran FITC complexed to dextran used for observation and quantification, e.g. plasma extravasation, fixation A method using a fixative to kill cells but to preserve their structure and organization. A stage in microscope slide preparation. 

After Diligently monitor IV site for signs of extravasation (high pH of IV preparation may cause severe... 

Examples abound of drug formulations tbat need to be adjusted to extreme pH in order to dissolve tbe drug. Thiopental bas a pKa of 7.6 at 20°C (McLeish, 1992) and tbe solubility of tbe neutral species is approximately 80 pg/mL (Yalkowsky and He, 2003). Because of tbis low solubility, the formulation pH is almost 4 log units above tbe pKa, approximately 10 to 11. Another example is phenytoin, with a pKa of 8.3 (Larsen, 1989), and an intrinsic solubility of 26 pg/mL (Yalkowsky and He, 2003). Tbe commercial preparation is adjusted to pH 12. At physiologic pH (7.4), the solubility of these compounds is quite low, and injection of these high pH formulations, when diluted in blood, may cause precipitation near the injection site, especially upon rapid injection. Soft tissue irritation and inflammation has occurred at the site of injection with and without extravasation of intravenous phenytoin. Reactions may vary from slight tenderness to necrosis (Wheless, 1998). 

Phentolamine (5 mg IV or IM, 1 to 2 hours before surgery) is indicated in prevention or control of hypertensive episodes that may occur in a patient with pheo-chromocytoma as a result of stress or manipulation during preoperative preparation and surgical excision and in prevention and treatment of dermal necrosis and sloughing following IV administration or extravasation of norepinephrine or dopamine. Phentolamine has been used to treat hypertensive crisis secondary to MAO inhibitors/sympathomimetic amine interactions and rebound hypertension on withdrawal of clonidine, propranolol, or other antihypertensives. It has also been used in combination with papaverine as an intracavern-ous injection for impotence. 

A 26-year-old woman, hospitalised for exacerbation of acute intermittent porphyria, who had a history of hypertension and chronic renal failure, developed hyperpotassaemia (6.7 mPq/L potassium) in the hospital. She was given an intravenous infusion oflOmL calcium gluconate, bullous skin reactions occurred in the infusion area nearly 2 h after administration. Clinicians must be prepared for rare possibility of bullous skin reactions, which may be a predictor of extravasation and necrosis, when treating patients with intravenous calcium gluconate [73 ]. 

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