IV/IO Access and Fluid Therapy
Help Questions
NREMT: AEMT Level › IV/IO Access and Fluid Therapy
Which IV access and fluid resuscitation plan is most appropriate for this patient?
Two large-bore (16- or 18-gauge) IVs in the antecubital fossae with Lactated Ringer's administered wide open.
A single 20-gauge IV in the hand with a 500 mL bolus of 0.9% Normal Saline.
An external jugular IV with D5W administered at a TKO rate until hospital arrival.
An IO in the unaffected tibia with 0.45% Normal Saline to rapidly increase circulatory volume.
Explanation
This patient is in hemorrhagic shock. The standard of care is to establish two large-bore IVs for rapid volume replacement. The antecubital fossae are preferred sites for large catheters. Lactated Ringer's is an appropriate isotonic crystalloid for trauma resuscitation.
What is the primary therapeutic goal of this initial fluid resuscitation?
To dilute circulating toxins released from crushed tissues.
To restore blood pressure to a normal level of 120/80 mmHg.
To reverse metabolic acidosis by providing lactate as a buffer.
To achieve permissive hypotension with a systolic BP of 80-90 mmHg.
Explanation
In trauma with suspected uncontrolled internal hemorrhage, the goal is 'permissive hypotension' or 'hypotensive resuscitation.' The aim is to administer just enough fluid to maintain vital organ perfusion (indicated by a palpable radial pulse or a systolic BP of 80-90 mmHg) without raising the pressure so high that it disrupts clot formation and worsens bleeding. Restoring a normal BP is contraindicated as it can 'pop the clot.'
What is the primary physiological purpose of this fluid challenge in the management of septic shock?
To increase intravascular volume and improve cardiac preload, thereby increasing blood pressure.
To decrease the heart rate by stimulating the parasympathetic nervous system.
To flush inflammatory mediators from the microcirculation and reduce the septic response.
To increase hemoglobin concentration for better oxygen delivery to tissues.
Explanation
In septic shock, widespread vasodilation and capillary leakage lead to relative hypovolemia. A fluid challenge (bolus) is given to rapidly increase the volume of fluid within the blood vessels. This increases venous return to the heart (preload), which, according to the Frank-Starling mechanism, increases stroke volume and cardiac output, ultimately improving blood pressure and tissue perfusion.
What is the role of IV fluid therapy in the immediate management of this patient?
IV fluids should be withheld until the effects of epinephrine are fully realized.
A maintenance rate of D5W should be started to support blood glucose levels.
A saline lock is sufficient as fluid shifts are not a major feature of anaphylaxis.
Aggressive fluid resuscitation with an isotonic crystalloid should be initiated immediately.
Explanation
In anaphylactic shock, massive vasodilation and capillary leakage cause a profound drop in blood pressure and relative hypovolemia. Along with epinephrine, aggressive IV fluid resuscitation with an isotonic crystalloid (like 0.9% NS or LR) is critical to fill the expanded vascular space and support blood pressure. Withholding fluids or using a maintenance rate is inadequate.
What is the total volume of the fluid bolus you should prepare to administer?
120 mL
360 mL
240 mL
200 mL
Explanation
The calculation is based on the child's weight and the ordered dose per kilogram. Weight (12 kg) × Dose (20 mL/kg) = 240 mL. The AEMT must be able to accurately calculate weight-based fluid boluses for pediatric patients.
You are preparing to administer medication through a newly established IO line in an adult's proximal tibia. After confirming placement and flushing with saline, what is the next critical step before administering medications?
Attach a pressure infusion bag to the saline flush to overcome intramedullary pressure.
Lower the IO needle by one centimeter to ensure it is seated in the marrow cavity.
Administer a slow push of 2% lidocaine per protocol for pain management.
Administer a rapid 500 mL bolus of an isotonic crystalloid to ensure patency.
Explanation
IO infusion can be extremely painful in a conscious patient. After confirming placement, standard protocol often involves administering 2% preservative-free lidocaine into the IO space prior to the main infusion to anesthetize the bone marrow cavity and reduce patient discomfort. A pressure bag is used for the infusion itself, not the flush. A large bolus is not the next step, and the needle should not be manipulated after insertion.
When considering fluid administration during resuscitation for this patient, which fluid is most appropriate to use and why?
D5W, because the patient is likely hypoglycemic due to their chronic illness.
0.45% Normal Saline, to rapidly shift fluid into the intracellular space and correct dehydration.
0.9% Normal Saline, because it does not contain potassium, which is likely already elevated.
Lactated Ringer's, because its buffer will help correct the severe metabolic acidosis.
Explanation
Patients with ESRD are unable to excrete potassium, leading to chronic hyperkalemia, which is often the cause of their cardiac arrest. Lactated Ringer's contains potassium and would be contraindicated. 0.9% Normal Saline does not contain potassium and is the safest isotonic crystalloid for volume expansion in this patient population. D5W is hypotonic and not a resuscitation fluid. 0.45% saline is also hypotonic and inappropriate for resuscitation.
Which of the following is an absolute contraindication for placing an IO needle in a specific limb?
Presence of a functioning peripheral IV in the contralateral limb.
A fracture in the same bone proximal to the intended insertion site.
A previous, healed surgical procedure near the intended insertion site.
A patient who is awake and able to feel pain at the insertion site.
Explanation
Placing an IO distal to a fracture in the same bone is an absolute contraindication because the infused fluid will leak from the fracture site into the soft tissues, leading to extravasation and potential compartment syndrome, and will not enter central circulation. Pain can be managed with lidocaine. A contralateral IV does not preclude IO placement. A healed surgical site is a relative, not absolute, contraindication.
Given the patient's age and presentation, which of the following represents the most appropriate initial approach to IV fluid therapy?
Place a 22-gauge IV and administer a 250 mL bolus of 0.9% Normal Saline over 30 minutes to avoid fluid overload.
Administer a 1-liter bolus of Lactated Ringer's as quickly as possible using a 16-gauge IV catheter.
Establish an 18-gauge IV and administer a 500 mL bolus of 0.9% Normal Saline, then reassess vital signs.
Start an IV of D5W at a keep-vein-open rate to correct dehydration without raising blood pressure too quickly.
Explanation
The patient is hypotensive and tachycardic, indicating significant hypovolemia. An initial bolus is warranted. However, in geriatric patients, aggressive fluid resuscitation must be balanced with the risk of fluid overload and congestive heart failure. A 500 mL bolus is a prudent starting point, followed by reassessment. 0.9% Normal Saline is an appropriate isotonic crystalloid for this situation.
What is the correct drip rate in drops per minute (gtt/min)?
83 gtt/min
42 gtt/min
167 gtt/min
125 gtt/min
Explanation
The calculation is: (Total Volume in mL × Drip Factor in gtt/mL) / Time in minutes. (1000 mL × 10 gtt/mL) / 120 minutes = 10000 / 120 = 83.33 gtt/min. The closest answer is 83 gtt/min. The other answers represent common calculation errors, such as dividing by 60 minutes instead of 120 or using the wrong volume.