Transcript No Slide Title

Revisiting Fluid Challenge:
New Ideas and New Developments
D. John Doyle MD PhD FRCPC
Cleveland Clinic Foundation
March 2003
Outline
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Physiology
Monitoring the Need for Fluid Resuscitation
The Classical Fluid Challenge
New Approaches to Fluid Challenge
Systolic Pressure Variation
Physiology
ECF and ICF Volumes
• ECF Volume= 1/3 x total body water
• ICF Volume = 2/3 x total body water
• ECF Volume = Plasma Volume +
Interstitial Volume
... from Moyer’s Fluid Balance
Fluid Compartments
• Total Body Water 0.6 L/kg
– 2/3 Intracellular (ICF)
– 1/3 Extracellular (ECF)
• ICF Volume (0.4 L/kg)
• ECF Volume (0.2 L/kg)
– Plasma Volume (0.05 L/kg)
– Interstitial Volume (0.15 /kg)
Ratio of plasma volume to interstitial volume is 1-to-3
[rationale for 3-to-1 replacement of blood losses with crystalloid]
Intravascular Volume
• Influences:
–
–
–
–
–
LV Filling
RV Filling
Cardiac Output
Blood Pressure
Oxygen Transport
• Equilibrates with interstitial compartment
according to Starling’s Law
Plasma Volume Expansion
“Volume expansion is frequently used in critically
ill patients to improve hemodynamics. Because of
the positive relationship between ventricular enddiastolic volume and stroke volume, the expected
hemodynamic response to volume expansion is an
increase in right ventricular end-diastolic volume
(RVEDV), left ventricular end-diastolic volume,
stroke volume, and cardiac output.”
Michard F. Teboul JL. Predicting fluid responsiveness in ICU patients: a critical
analysis of the evidence. Chest. 121(6):2000-8, 2002 Jun.
Clinical Situations Often Requiring
Plasma Volume Expansion
• Management of patients with hemorrhage (eg, GI
bleed, ruptured AAA, cardiac redo cases gone
bad, IVC tear, SVC tear )
• Surgery, especially with large blood losses or large
third space losses, such as liver transplantation or
spinal correction surgery
• Management of burn patients
• Perioperative management of trauma patients
• Management of cardiopulmonary bypass
• Management of patients with “sepsis syndrome”
Fluid Therapy
• Empirical rules exist to help in clinical
management (maintenance IV requirements
formula, Parkland burn protocol)
• Goal: to maintain intravascular volume and
tissue perfusion
• Guidance: Monitored end points
Urine output, orthostatic BP changes, CVP,
PCWP (wedge pressure)
The Ideal
Plasma Volume Expander
• Inexpensive
• No special storage problems; long shelf life
• Can be made in bulk using existing
industrial processes
• Free of pathogens
• Nontoxic
• Crystalloid vs Colloid
Effects of Fluid Administration
 PV = Vi X PV
Vd
PV =
Vi =
Vd =
=
plasma volume (e.g 3 liters)
volume infused
volume of distribution
42 for D5W, 14 for Ringer’s
Effects of Fluid Administration
Replace 500 cc blood loss with D5W
 PV = 500 ml
PV = 3
Vd
42
Vi = 7000 ml
Effects of Fluid Administration
Replace 500 cc blood loss with RL
 PV = 500 ml
PV = 3
Vd
14
Vi = 2300 ml
Fluid Challenge Methods
Classical Fluid Challenge Methods
AIMS
• Systemic blood pressure improvement
• Urine output improvement
MONITORS
• No filling pressure monitoring
• Right-sided filling pressure monitoring (CVP)
• Left-sided filling pressure monitoring (PCWP)
Giving a fluid challenge
(one method)
Step 1 – Administer 250 – 500 ml IV over 5 - 15 min
Step 2 - Re-check the CVP
Step 3 - CVP raised by 2 cm H20?
No -> Step 1
Yes -> Step 4
Step 4 - Clinically improved?
No -> Challenge once more.
If still no improvement get expert help.
Yes -> Stop challenging.
Adapted from
http://www.medicalapproaches.com/html/book1/02blo0104.htm
Approach to
Hypotension
Algorithm for
intraoperative
colloid
administration.
BP = blood pressure
HR = heart rate
Hct = hematocrit
CVP = central venous
pressure
From:
Gan
Anesth Analg
Volume 88
May 1999
pp. 992-998
Case for CVP
• Under normal circumstances, if you
have a low CVP, chances are you have
a low PCWP.
• A CVP above 10 mm Hg indicates that
the patient is likely not hypovolemic
(although, fluid administration may be
required for other reasons).
• An elevated CVP is a nonspecific
marker for the presence of disease.
Case Against CVP
• CVP measurements cannot be considered a
perfect replacement for pulmonary artery
catheterization.
• CVP may not accurately reflect pulmonary
artery occlusion pressure in patients with right
ventricular failure and other conditions.
• Insertion of a CVP line is invasive and can
lead to complications, such as hemorrhage,
infection, pneumothorax, and air embolism.
United States Department of Defense
Emergency War Surgery NATO Handbook.
Part II: Response of the Body to Wounding.
Chapter IX: Shock and Resuscitation
Replacement Therapy
Peer Review Status: Internally Peer Reviewed
The shock casualty should be given 1,000-2,000 cc of lactated Ringer's solution,
infused as rapidly as possible. Another rule of thumb is an initial fluid challenge of 1025 ml/kg given over a ten minute period. Some will respond promptly and remain
stable with only this therapy. If the hemorrhage has been severe or is ongoing, the
response will usually be only transient, but nevertheless may allow time for typing and
crossmatching of blood. Lactated Ringer's Solution, in addition to providing a rapid
increase in circulating volume, will begin the correction of the reduced extracellular
volume space resulting front compensatory fluid shifts induced by the shock slate.
Crystalloid solution rapidly equilibrates between the intravascular and interstitial
compartments For this reason, adequate restoration of hemostatic stability may require
large volumes of Ringer's lactate. It has been empirically observed that approximately
300 cc of crystalloid is required to compensate for each 100 cc of blood loss. This 3:1
rule is a good beginning point for fluid resuscitation, but obviously is not a hard and fast
rule for those with massive hemorrhage. If the 3:1 ratio were adhered to in a casualty
requiring 5,000 cc of blood replacement, inundation would result. About 3,000-4,000 cc
of Ringer's lactate seems reasonable.
http://www.vnh.org/EWSurg/ch09/09ReplacementTherapy.html
SpecialOpsMedicine.Com
Training is conducted at the Joint Special Operations Medical
Training Ctr. (JSOMTC). Training is 55 weeks long, of which 44
weeks are solely dedicated to medical training.
http://www.specialopsmedicine.com/trauma_pearls_of_wisdom.htm
The procedure for determining the results of the fluid challenge is as follows:
a. Obtain a complete set of baseline vitals, to include an accurate BP.
b. Initiate at least 1 large bore IV for the purpose of administering fluid.
c. Infuse 1 liter of fluid and retake the patient’s BP, if the BP responds with a 10mm increase in
systolic pressure, continue to monitor the BP every 5 minutes for 15 minutes. If the BP holds,
this patient is considered a rapid responder, resuscitate the patient to a systolic pressure of
90mm Hg.
(1) If the BP responds initially with an increase of more than 10mm Hg systolic, but drops back
down during the 15-minute period, this patient is considered a transient responder. The patient
will be treated by maintaining a carotid pulse and monitoring the patient’s mental status. Ideally,
the therapeutic goal of controlled shock is to reach 70mm Hg systolic and a pulse <120 BPM
with a response to verbal stimuli. After 30 minutes, initiate mini fluid challenges of pressure. If
the BP remains stable, continue with the 500cc bolus, or with any of the subsequent boluses,
continue with "controlled shock" management if possible for 30 more minutes then try the mini
fluid challenge again. Continue with this therapy for transient response until the patient is
evacuated or the patient is able to achieve 90mm systolic.
•
If the BP doesn’t respond to the initial fluid challenge, this patient is considered a nonresponder. Keep the patient’s IV and TKO regardless of the BP, monitor and maintain the
patient as best as possible for 30 minutes. Then initiate the same mini fluid challenge therapy
as you would for the transient responder, only this time, if the patient responds, do not raise the
BP above 80mm Hg. Maintain this patient somewhere between 70-80mm Hg until he can be
evacuated.
The procedure for determining the results of the fluid challenge is
as follows:
a. Obtain a complete set of baseline vitals, to include an accurate
BP.
b. Initiate at least 1 large bore IV for the purpose of administering
fluid.
c. Infuse 1 liter of fluid and retake the patient’s BP, if the BP
responds with a 10mm Hg increase in systolic pressure,
continue to monitor the BP every 5 minutes for 15 minutes. If
the BP holds, this patient is considered a rapid responder,
resuscitate the patient to a systolic pressure of 90mm Hg.
If the BP responds initially with an increase of more than 10mm
Hg systolic, but drops back down during the 15-minute period,
this patient is considered a transient responder. The patient will
be treated by maintaining a carotid pulse and monitoring the
patient’s mental status. Ideally, the therapeutic goal of
controlled shock is to reach 70 mm Hg systolic and a pulse
<120 BPM with a response to verbal stimuli. After 30 minutes,
initiate mini fluid challenges of pressure. If the BP remains
stable, continue with the 500cc bolus, or with any of the
subsequent boluses, continue with "controlled shock"
management if possible for 30 more minutes then try the mini
fluid challenge again. Continue with this therapy for transient
response until the patient is evacuated or the patient is able to
achieve 90mm systolic.
If the BP doesn’t respond to the initial fluid challenge, this
patient is considered a non-responder. Keep the patient’s IV
and TKO regardless of the BP, monitor and maintain the patient
as best as possible for 30 minutes. Then initiate the same mini
fluid challenge therapy as you would for the transient
responder, only this time, if the patient responds, do not raise
the BP above 80mm Hg. Maintain this patient somewhere
between 70-80mm Hg until he can be evacuated.
http://www.davidclark.com/MAST/medical.shtml
New Approaches to Fluid Challenge
AIMS
• Systemic blood pressure improvement
• Urine output improvement
MONITORS
• CO
• LVSW
• LVEDA
• Systolic pressure variation
Predicting Fluid Responsiveness in ICU Patients
Only 40 to 72% of critically ill patients have been shown to respond to
volume expansion by a significant increase in stroke volume or cardiac
output in studies designed to examine fluid responsiveness.
This finding emphasizes the need for predictive factors of fluid
responsiveness in order to select patients who might benefit from volume
expansion and to avoid ineffective or even deleterious volume expansion
(worsening in gas exchange, hemodilution) in nonresponder patients, in
whom inotropic and/or vasopressor support should preferentially be used.
Michard F. Teboul JL. Predicting fluid responsiveness in ICU patients: a critical
analysis of the evidence. Chest. 121(6):2000-8, 2002 Jun.
Echocardiographic Measurement of LVEDA
The echocardiographic measurement of
LVEDA has been shown to reflect more
accurately the left ventricular preload when
compared with PAOP, and to improve the
ability to detect changes in left ventricular
function caused by acute blood loss.
Thys DM, Hillel Z, Goldman ME, et al. A comparison of hemodynamic indexes derived by invasive monitoring and
two-dimensional echocardiography. Anesthesiology 1987; 67:630-634
Cheung AT, Savino JS, Weiss SJ, et al. Echocardiographic and hemodynamic indexes of left ventricular preload in
patients with normal and abnormal ventricular function. Anesthesiology 1994; 81:376-387
Swenson Study
Bivariate plots compare the
effect of fluid volume on
end-diastolic area (EDA),
cardiac output (CO), left
ventricular stroke work
(LVSW), and pulmonary
capillary wedge pressure
(PCWP). Note the similar
peaks for EDA, CO, and
LVSW indicating that when
EDA fails to change in
response to fluid
administration there is
likewise no increase in CO
or LVSW. No peak is
evident for PCWP.
From: Swenson: Anesth
Analg, Volume
83(6).December
1996.1149-1153
Systolic Pressure Variation
Systolic pressure variation (SPV) is the cyclic
fluctuation in systolic blood pressure that occurs
during respiration.
Increased SPV has long been recognized as an
indicator of hypovolemia.
Several recent studies have shown a correlation
between SPV and left ventricular end-diastolic
volume.
Systolic Pressure Variation
Plot of airway pressure
(top) and arterial blood
pressure (point by point)
against time. Notice how
there is a dip in systolic
blood pressure with each
period of expiration,
followed by a rise in
pressure with inspiration.
Systolic Pressure Variation
Plot of airway pressure
and systolic blood
pressure against time. By
plotting only the systolic
pressure instead of the
full pressure wave, the
effect of airway pressure
on systolic pressure is
made more evident.
Systolic Pressure Variation
Dividing total SPV into two components, known as Up
and Down, enhances the usefulness of SPV monitoring.
Up is the peak systolic pressure minus the baseline
systolic pressure measured during apnea.
Down is the trough systolic pressure minus the baseline.
It turns out that changes in Down are particularly
sensitive indicators of left ventricular filling.
Arterial pressure records are
shown during mechanical and
spontaneous ventilation at
baseline and after 1000 mL blood
removal. The difference between
the end-expiratory systolic
pressure and the minimum systolic
pressure over a respiratory cycle
defines Delta down. The
difference between the endexpiratory systolic pressure and
the maximum systolic pressure
over a respiratory cycle defines
Delta up. Note that Delta down is
associated with mechanical
exhalation and spontaneous
inhalation. Systolic pressure
variation is the difference between
the maximum and minimum
systolic pressure over a respiratory
cycle.
Rooke GA, Schwid HA, Shapira
Y: The effect of graded
hemorrhage and intravascular
volume replacement on systolic
pressure variation in humans
during mechanical and
spontaneous ventilation. Anesth
Analg 1995; 80:925-32
Systemic arterial blood pressure curve recorded in one
patient before (A) and after 500 ml (B) and 1,000 ml (C)
administration of hydroxyethylstarch. The difference
between the maximal systolic pressure and the minimal
systolic pressure during one cycle of mechanical breath
defines the systolic pressure variation (SPV). The value of
the systolic arterial pressure (SAP) during a short period of
end-expiratory pause is used as a reference pressure to
measure the delta up (dUp) and delta down (dDown)
components of the SPV. The difference between the
systolic pressure during end-expiratory pause and the
maximum systolic pressure defines dUp. The difference
between the systolic pressure during end-expiratory pause
and the minimum systolic pressure defines dDown. EDAI
= left ventricular end-diastolic area index. HR = heart rate;
MAP = mean arterial pressure; PAOP = pulmonary artery
occlusion pressure; SVI = stroke volume index.
From: Tavernier: Anesthesiology, Volume 89(6).December
1998.1313-1321
Baseline
500 ml HES
1000 ml HES
Receiver operating characteristic
(ROC) curves comparing the
ability of the pulmonary artery
occlusion pressure (PAOP), the
left ventricular end-diastolic area
index (EDAI), and the delta down
component (dDown) of the
positive pressure ventilationinduced arterial systolic pressure
variation to discriminate between
positive (>or= to 15% increase in
stroke volume index [SVI]; n =
21) and negative (< 15% increase
in SVI; n = 14) responses to a
subsequent volume-loading step
in 15 patients. The area under the
ROC curve for dDown is greater
than those for EDAI (P = 0.01)
and PAOP (P = 0.001). There is
no significant difference between
EDAI and PAOP (P = 0.39).
From: Tavernier: Anesthesiology,
Volume 89(6).December
1998.1313-1321
Systolic Pressure Variation
1.
2.
3.
4.
5.
6.
Perel A, Pizov R, Cotev S. Systolic pressure varation is a sensitive indicator of
hypovolemia in ventilated dogs subjected to graded hemorrhage. Anesthesiology
1987; 67:498-502
Tavernier B, Makhotine O, Lebuffe G, Dupont J, Scherpereel P. Systolic pressure
variation as a guide to fluid therapy in patients with sepsis-induced hypotension.
Anesthesiology 1998; 89: 1313-1321
Editorial. Less is more...using systolic pressure variation to assess hypovolaemia.
Br. J. Anaesth. 1999 83: 550-551.
Clemente. A virtual instrument (VI) for haemodynamic management in ICU and
during surgery. Journal of Medical Engineering & Technology, Volume 24, Number
3, (May/June 2000), pages, 111-116
D. John Doyle, Sven Budwill, Patrick Mark, Aamer Shujah. Application of
Contourography and synchronous averaging to the blood pressure waveform.
Journal of Clinical Engineering. Vol. 22, No. 3, pp. 179-187, 1997
Soncini M. A computerized method to measure systolic pressure variation in
mechanically ventilated patients. J Clin Monitoring Comput 2002; 17:141-146.
Static Measurements
•
RAP and PAOP (PCWP) are measured at end-expiration without
ventilator disconnection or removal of PEEP.
•
RVEDV is calculated from the measurement of right ventricular
ejection fraction and cardiac output by using a fast-response thermistor
pulmonary artery catheter as follows: RVEDV = (cardiac output/heart
rate)/right ventricular ejection fraction.
•
•
RVEDV may also be evaluated by cardiac scintigraphy.
LVEDA is measured by transesophageal echocardiography using the
transgastric short-axis view of the left ventricle.
Dynamic Measurements
•
•
•
•
Inspiratory decrease in RAP ( RAP), calculated as the difference between the
expiratory and the inspiratory RAP
Expiratory decrease in arterial systolic pressure ( down), calculated as the
difference between the value of the systolic pressure during an end-expiratory
pause and the minimal value of systolic pressure over a single respiratory cycle
Respiratory changes in arterial pulse pressure ( PP), calculated as the
difference between the maximal and the minimal value of pulse pressure over a
single respiratory cycle, divided by the mean of the two values, and expressed as a
percentage
Respiratory changes in aortic blood velocity ( Vpeak), calculated as the
difference between the maximal and minimal peak velocity of aortic blood flow
over a single respiratory cycle, divided by the mean of the two values, and
expressed as a percentage. Aortic blood flow was measured by a pulsed-wave
Doppler echocardiographic beam at the level of the aortic valve.
The End