Researches have shown that eight in every ten hospitalized patients receive intravenous infusion, making it the most common therapy in Nigerian hospitals and the world at large. Though safe when proper protocols are followed, it is one of the leading cause of morbidity and mortality when not properly utilized. The rate at which the infusion is set to flow and type of fluid used are the leading keys to success and the prime causes of failure.
• Intravenous infusion therapy: This is a type of therapy where fluid and medications are delivered directly into the vein to the heart.
• Rate of intravenous infusion: this refers to the time and frequency an infusion is set to flow
• Infusion flow regulation: This is the manual or automated control of rate of flow of intravenous infusions
RATE OF FLOW:
The rate of flow of intravenous infusions can be classified as:
• Continuous infusion: This can be rapid or slow continuous infusion aimed at correcting electrolyte imbalance or replacement of fluid loss. It denotes non – stop flow of fluid. Employed as resuscitative measures, it can also be deployed for Maintainace of fluid balanced normally regulated based on patient need. E.g. over 30mins. 4hrly, 8hrly or 12hrly
• Intermittent Infusion: This process is employed when patient requires intravenous medications only at certain times. e.g. twice (bd), thrice (tds), quarterly (qid) etc.
• Patient controlled infusion: it is otherwise known as infusion on demand, usually programmed to be released controlled dose of medication to the patient based on patient’s order. It is has a preprogrammed ceiling to avoid intoxication due to over dosage. E.g. patient controlled analgesia
• Total parenteral nutrition: in unconscious patients or severely malnourished, nutrients are being delivered via the intravenous route similar to normal mealtime. It is programmed to meat patients body need, in those who are unable to ingest food substance via the enteral route
METHODS OF INTRAVENOUS FLUID DELIVERY
• Standard gravity drip: utilizing the pressure supplied by gravity when the bag is placed above the patient’s level connected by a gravity drip delivery set, fluid is delivered into the body and regulated by a clamp. Using this method, the number of drips needed per minute must be calculated to correspond with the required duration
• Gravity drip with dosage burette: In addition to the aforementioned this contains a metered small – volume chamber designed to limit the amount of solution available to the patient and also for intermittent drug or medication mixture before infusion. It is primarily employed for neonatal and pediatric patients
• External pressure: this involves the usage of pressure bag or inflatable cuff to squeeze the fluid bag aimed at forcing large amount of fluid into the patient for resuscitation.
• Automated intravenous fluid delivery: this involve the use of infusion pumps or automated delivery pump to regulate fluid flow, it is very effective, 99% accurate, and generally safe.
PURPOSE OF INTRAVENOUS INFUSION AND GENERAL GUIDELINES
• Resuscitation: To restore circulation following severe fluid loss or depletion of intravascular volume; intravenous fluid are needed urgently and fast until patient is stable.
• Guideline: though fluid is needed at rapid rate, the rate must be properly regulated and the appropriate type of fluid must be used to prevent morbidity. Example in patients with severe hypotension due to head injury; late resuscitation can lead to cerebral edema variable extremely rapid infusion of isotonic solution also leads to cerebral edema, additionally using hypertonic solution instead of isotonic solution also leads to cerebral edema. In this case proper regulation of isotonic solution is required. It is therefore mandatory for nurses to manage every patient according to his needs.
• Routine Maintenance: This is needed in patients who cannot meet their normal daily fluid requirement by oral or enteral route or in stabilized patients following resuscitation.
• Guideline: Estimate routine maintenance requirement daily based on patients response as most patients are euvolemic at this level
• Replacement: This is employed in treating loss of certain electrolyte or nutrients.
• Guideline: This requires frequent reassessment of the agent infused. Example. In patients on potassium supplement infusion due to non potassium sparing induced dieresis; strict monitoring and re adjustment of the infusion is required to prevent arrhythmias due to hyperkalemia.
FACTORS THAT DETERMINE THE RATE OF INFUSION
• Patient related factors: This includes the primary need for the therapy and the underlying secondary mal – physiologies; both must be considered before determining the rate and of intravenous infusions. For Example in patient with hypotension secondary to head injury; isotonic solution is required at regulated rate to prevent cerebral edema, though hypotension hitherto requires rapid infusion. Other considerations include renal, cardio – vascular and neurro abnormalities
• Fluid related factors: Some intravenous medications are open and their rates are only patient determined while others having established rates based on their physiologies. Example; isotonic saline can be regulated or given at rapid rate depending on the patients need, while intravenous mannitol, intravenous potassium, and intravenous Chemotherapy MUST be regulated to flow at slow rates.
FACTORS THAT INFLUENCE RATE OF INFUSION
• Size of veins
• Temperature of fluid
• Nature of fluid (i.e. some fluids induce vasodilatation while others induce vasoconstriction
• Pressure on fluid container
• Viscosity of fluid
EFFECTIVE WAYS OF PROPERLY REGULATING FLUID FLOW RATE
• Proper adjustment of roller clamp adaptor until it reaches the calculated flow rate/minute. This can be achieved with full minute count of drip rate
• Check Iv progress every 30 minutes, hourly or according to facility protocols
• Ensure that delivery tube if free from strangulation
• For automated pumps; ensure that the tubing is threaded into the machine correctly
• To deliver the entire dosage volume to be infused (VTBI), the fluid should be increased by 30 cc – 50 cc, else some amount of the fluid will remain in the delivery tube. If increment can not be attained the tube should be emptied completely into the system
Nurse. Abdulmuttalib Musa Maibasira, R.N. Kano State