Page 2162 - Cote clinical veterinary advisor dogs and cats 4th

Central Venous Pressure Monitoring 1080.e1

Central Venous Pressure Monitoring
VetBooks.ir

the catheter by a blood clot. Periodic flushing
Difficulty level: ♦♦
the line contains only fluid and no air.
with heparinized saline is desirable. ○ Fluid should run through the line until
Overview and Goal • Cardiac function needs to be factored in • Unclamp the manometer tubing and turn
Central venous pressure (CVP) is a measure- when interpreting results. For example, the 3-way stopcock such that flow exists
ment that reflects the ability of the heart, animals with tricuspid regurgitation may have between the fluid line from the fluid bag
specifically the right side of the heart, to accept elevated CVP irrespective of intravascular and the fluid line of the manometer.
and pump blood through the circulatory system. volume loads. • Fill the manometer line with fluid to within
The CVP reflects the interaction of the heart, • The CVP level represents mostly loading 3 cm of its extremity.
vascular tone, and blood volume. Monitoring conditions of the right side of the heart Connecting CVP set to patient:
of CVP allows a better understanding of the (right ventricular preload), not afterload. • Next, connect the remaining end (male end)
circulatory status of the body and of the impact of the CVP set to the jugular catheter. The Procedures and Techniques
of fluid therapy. Procedure stopcock is usually integral to the set.
Before connecting CVP set to patient’s jugular ○ If using individual materials rather than a
Indications catheter: purpose-made set, connect the male end of
• Monitoring the administration of large • One end (female end) of the CVP set goes the 3-way stopcock directly to the jugular
volumes of fluids in animals that are in to a suspended IV fluid bag. The line on catheter.
shock or have impaired urine production that end should be closed using a clamp. • Turn the stopcock so that a column of fluid
• Diagnostic help in difficult-to-diagnose • A second end connects to tubing that is exists between the jugular catheter and the
right heart failure cases (e.g., constrictive fixed to a scale (i.e., manometer scale or manometer.
pericarditis) ruler). This line also should be closed using a • The fluid in the manometer falls until it
clamp. reflects the CVP (measured in centimeters
Contraindications • The manometer tubing is pressed into the of water).
Only those of jugular catheter placement (e.g., scale groove:
hypercoagulable or hypocoagulable states, skin ○ If using individual materials, tape the Postprocedure
infection over jugular site) sterile IV fluid–type plastic tubing to Interpretation:
the ruler. • Normal CVP varies; oscillates between −1
Equipment, Anesthesia • Using adhesive strips, fix the manometer on and +5 cm H 2 O.
• Intravenous (IV) jugular catheter (Mila or a vertical surface, such as the wall of a cage • Values between +5 and +10 cm H 2 O are
Arrow double-lumen catheters) or a vertical stand, next to the animal and borderline.
• Sterile 500-mL saline bag with IV drip set at a height such that the 0 on the scale of • Values above +10 cm H 2 O may indicate too
• CVP set (Universal CVP set); alternatively, if the manometer/ruler is at the level of the much blood volume expansion. IV fluids
a purpose-made kit is not available, use the animal’s heart (right atrium). should no longer be administered.
following: a sterile 3-way stopcock, sterile IV • Unclamp the fluid line coming from the • Values above +15 cm H 2 O may indicate
fluid–type tubing, and a ruler (centimeter fluid bag. right-sided congestive heart failure.
grading and at least 30 cm long). The
sterile tubing is taped to the ruler, and it
is held vertically, creating a simple pressure
manometer. Manometer (cm)
Anticipated Time 40
• About 15 minutes to install the set 35
• About 2 minutes for each CVP reading
30
Preparation: Important 25 Level reached by the fluid line
Checkpoints when measuring the CVP
• The prerequisite is the placement of an IV Manometer 20
tubing
jugular catheter. 15
○ The distal tip of this catheter should be 10
in the cranial vena cava, just cranial to IV fluid line
the right atrium, which allows accurate 5
measurement of CVP without inducing 0
premature atrial contractions. Confirm
position radiographically. -5
○ Mila or Arrow catheters are the most
commonly used because their double Jugular catheter
lumen allows CVP measurement and/or Stopcock
blood sampling through one port and fluid
delivery through the other.
Possible Complications and CENTRAL VENOUS PRESSURE MONITORING Dashed line represents the level of the right atrium, the
Common Errors to Avoid zero point for setting the manometer. The stopcock is closed to the intravenous fluid line; the jugular catheter
and manometer tubing are in continuity. The dog’s central venous pressure (CVP) reading is markedly elevated
• One must allow fluid to flow frequently at 19 cm H 2 O. (Reprinted with permission from Sattler FP: Shock. In Kirk RW, editor: Current veterinary therapy
through the IV line to avoid plugging of III, Philadelphia, 1968, Saunders.)

www.ExpertConsult.com