To adjust an IV flow rate, you primarily manipulate the roller clamp on the tubing and precisely verify the rate by counting the drops in the drip chamber each minute.
Understanding IV Flow Rate Adjustment
Controlling the infusion rate of an intravenous (IV) solution is a critical task in healthcare. The adjustment process involves a manual mechanism on the tubing and a verification step using the drip chamber.
Using the Roller Clamp
The most direct way to adjust the IV flow is by manipulating the roller clamp located on the IV tubing. This clamp works by compressing or releasing the tubing to control the fluid's passage.
- To increase the flow rate: Roll the clamp down or away from the drip chamber. This action widens the lumen of the tubing, allowing more fluid to flow through.
- To decrease the flow rate: Roll the clamp up or towards the drip chamber. This action constricts the tubing, thereby restricting the fluid flow.
Counting Drops Per Minute (gtt/min)
After making an initial adjustment with the roller clamp, it is essential to verify the accuracy of the flow rate by counting the drops.
- Locate the Drip Chamber: Identify the clear chamber located just below the IV bag. This is where you can observe individual drops of fluid falling.
- Determine the Drip Factor: The IV tubing you are using has a specific "drip factor," which indicates how many drops (gtt) are equivalent to one milliliter (mL). For instance, with macrodrip tubing, a common drip factor is 20 gtt/mL. This means that 20 drops passing into the drip chamber equate to 1 mL of fluid infused.
- Count Drops: Using a watch or timer, count the number of drops that fall into the drip chamber for one full minute.
- Calculate and Adjust: Compare your counted drops per minute to the prescribed or calculated target drops per minute.
- If your counted rate is lower than the target, loosen the roller clamp slightly and recount.
- If your counted rate is higher than the target, tighten the roller clamp slightly and recount.
- Repeat this process until the observed drops per minute accurately match the desired infusion rate.
Example Scenario for Adjusting Flow Rate:
Consider a situation where a patient requires an IV infusion rate of 100 mL/hr, and you are using macrodrip tubing with a drip factor of 20 gtt/mL. To achieve the correct flow, you would need to calculate the target drops per minute (gtt/min):
- Calculate total drops per hour: 100 mL/hr × 20 gtt/mL = 2000 gtt/hr
- Convert to drops per minute: 2000 gtt/hr ÷ 60 min/hr = 33.33 gtt/min
Therefore, you would adjust the roller clamp until you observe approximately 33 to 34 drops falling into the drip chamber each minute to achieve the desired infusion rate.
