Test your medicine knowledge with the MKSAP challenge, in partnership with the American College of Physicians.
A 57-year-old woman is evaluated in the emergency department for an episode of hematemesis that occurred 1 hour ago. She had previously felt well except for a recent knee injury, for which she has been taking ibuprofen. She currently is experiencing lightheadedness and weakness. Medical history is otherwise unremarkable. She does not smoke or drink alcohol. She takes no other medications.
On physical examination, she appears ill and pale. Temperature is 36.5 °C (97.7 °F). Blood pressure and pulse rate in the supine position are 90/60 mm Hg and 105/min. When sitting, her blood pressure and pulse rate are 70/35 mm Hg and 128/min. Respiration rate is 14/min; BMI is 26. Mild diaphoresis is noted. Abdominal examination reveals no tenderness and no hepatosplenomegaly. No ecchymoses, rashes, or petechiae are noted.
Laboratory studies are pending and blood typing and cross-match are sent.
Which of the following is the most appropriate form of access for this patient?
A. Intraosseous catheter
B. Large-caliber peripheral intervenous catheter
C. Single-lumen peripherally inserted central venous catheter
D. Triple-lumen internal jugular venous catheter
MKSAP Answer and Critique
The correct answer is B. Large-caliber peripheral intervenous catheter.
Large-caliber peripheral intravenous (IV) access is the preferred route of access in this patient with a hemodynamically significant gastrointestinal bleed. She requires emergent fluid resuscitation because of her bleeding and intravascular volume depletion. When large volumes of crystalloid fluid and blood are needed quickly, large-caliber, shorter catheters allow the highest flow rates to be achieved. Flow of fluid through a catheter is inversely proportional to catheter length and proportional to the radius of the catheter to the fourth power. Therefore, the highest flow rates may be achieved through shorter, large-bore catheters. Peripheral IV catheters are typically significantly shorter than either catheters used for central access or peripherally inserted central catheters. Peripheral IV catheters may also be significantly larger than most central catheters, allowing for increased fluid flow. For example, potential flow rates for a 14-gauge (1.73-mm inner diameter) catheter are approximately 3 times greater than an 18-gauge (0.95-mm inner diameter) catheter of equal length. For this reason, use of larger, shorter peripheral catheters is preferred for fluid resuscitation in patients requiring emergent treatment.
Although central access remains a way to administer fluids, it is not recommended for rapid volume infusion. Therefore, a single-lumen peripherally inserted central venous catheter or triple-lumen internal jugular venous catheter would not be appropriate for this patient who requires large fluid volumes quickly. Central access may ultimately be necessary to administer vasopressor therapy, which cannot be given through peripheral access, if this patient does not respond to fluid resuscitation.
Intraosseous infusion is an immediate alternative in medical or trauma resuscitation when other forms of access cannot be rapidly obtained. Sites for intraosseous access in adults include 1 to 2 cm below the tibial tuberosity and the humeral head. Alternative access should replace the intraosseous access catheter within approximately 24 hours of placement to minimize complications.
Key Point
- Large-caliber peripheral intravenous access is the preferred route of infusion when large volumes of crystalloid fluid and blood are needed quickly.
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