1. STATIC AND DYNAMIC INDICES OF
HEMODYNAMIC MONITORING
Dr.BHARGAV.M
What is best evidence as of today?
OR
What kind of evidence is least likely to be
wrong or harm my patient ????

2. EVIDENCE BASED MEDICINE
Answer
Re-
Question
Question If you get the same
answer every time for
a question- “you
haven't actually
progressed an inch”
-unknown
“It answers all your questions and re-questions all your answers”

3. A BRIEF HISTORY
1980’s: McMasters University in Ontario, Canada
Dr. David Sackett and colleagues proposed Evidence
Based Medicine (EBM) as a new way of teaching, learning
and practicing medicine.
Dr. Sackett defines EBM as:
“…The conscientious, explicit, and judicious use
of current best evidence in making decisions
about the care of individual patients.”

4. The Clinical Question
The FIRST step
The HARDEST step
The MOST IMPORTANT step!

5. Should I give this patient more fluids?
Will this patient improve hemodynamically in response to fluids?
Does my fluid bolus likely to augment cardiac output and there
by tissue perfusion
Does my patient really needs fluid? How much? how long?
Good questions are the backbone of practicing EBM. It
takes practice to ask the well-formulated question

6. More than 50 % of critically ill hypotensive patients ,fluid
boluses fail to augment perfusion
Hypovolemia is not the only cause for hypotension
If the fluid boluses doesn’t augment cardiac output, shall result
in wasted resuscitation and iatrogenic harm
If the patient is fluid responsive doesn’t necessarily mean fluid
should be given.
Whereas under-resuscitation results in inadequate organ
perfusion, accumulating data suggest that over-resuscitation
increases the morbidity and mortality of critically ill patients

7. What is PRELOAD ?
Ventricular preload is defined as the degree of cardiac muscle
tension at the initiation of contraction. Clinically it is impractical
to measure the “tension” in the myocardium.
Guyton AH, Hall JE. Heart muscle: the heart as a pump and function of the heart valves. In:Elsevier, S,
ed., Textbook of medical physiology. 11th edn. Elsevier, Philadelphia, 2006: 103–115.

8. WHAT IS VOLUME RESPONSIVENESS?“
Fluid responsive” means, response to a fluid challenge by
improvement in stroke volume by at least 10%”.
Marik et al . Annals of Intensive Care 2011, 1:1

9.  Clinical studies have, demonstrated that only approximately
50% of hemodynamically unstable critically ill patients are
“volume-responsive”.
Marik PE, Cavallazzi R, Vasu T, Hirani A: Dynamic changes in arterial waveform derivedvariables and fluid
responsiveness in mechanically ventilated patients. A systematic reviewof the literature. Crit Care Med
2009, 37:2642-264

12. STATIC INDICES
 CVP
 PAOP
 RVEDVI
 LVEDA and LVEDAI
 GEDV and ITBV

13. CVP
 Large number of studies failed to discriminate b/w fluid
responders and non responders
 Only extreme values are of some clinical significance
 Degree of Hypovolemia doesn’t correlate with CVP
 Factors which increase intramural and transmural (pump failure,
valvular diseases, dysrhythmias, PPV, PEEP, Pneumothorax,
asthma, IAP can effect the CVP
 Needs invasive line

14.  Role of CVP More than 100 studies have been
published to date that have demonstrated no
relationship between the CVP and fluid
responsiveness in various clinical settings.
Marik PE, Baram M, Vahid B: Does the central venous pressure predict fluid responsiveness?A systematic
review of the literature and the tale of seven mares. Chest 2008, 134:172-178.Nolen-Walston RD, Norton
JL, de Solis C, Underwood C, Boston R, Slack J, Dallap BL:The effects of hypohydration on central venous
pressure and splenic volume in adulthorses. J Vet Intern Med 2010.

15.  Role of CVP in “Dynamic assessment ”As noted earlier, it is best
NOT to use a single value of CVP to predict volume
responsiveness
Sheldon Magder et al Curr Opin Crit Care 11:264—270

16. PAOP
 Considered gold standard for determination of LV preload
 Needs invasive pulmonary artery catheter
 Limitation:
 Poor correlation b/w PAOP and LVEDV
 No better than CVP in predicting preload responsiveness

17.  Recent studies have clearly demonstrated that the PAOP is a
poor predictor of preload and volume responsiveness.
 It suffers many of the limitations of the CVP.
Osman D, Ridel C, Ray P, et al. Cardiac filling pressures are not appropriate to predict
hemodynamic response to volume challenge. CritCare Med. 2007;35:64–68.

18. WHY DYNAMIC ASSESSMENT?
 More than 50% of icu patients suffer from iatrogenic harm
(fluids, interventions, polypharma, irrational antibiotics)
 More evident, clinical signs and symptoms are seen after
established florid organ dysfunction ( fluid overload, gut and
organ edema etc) which might bring poor clinical out comes.
 In the early coarse of organ dysfunction, clinical signs and
symptoms are sub clinical and subtle. So need for constant and
dynamic assessment to find optimal goal directed fluid therapy.
 Too little fluid may result in tissue hypoperfusion and worsen
organ dysfunction.
 On other hand, overzealous fluid resuscitation has been
associated with increased complications, increased length of
intensive care unit (ICU) and hospital stay, and increased
mortality

19.  Fluid resuscitation based on down stream parameters of
microcirculation (s.lactates,scvo2) may be harmful.
 Normalization /decay to baseline of these parameters happen
long after the actual organ recovery happen.
 So continued fluid resuscitation to normalize these parameters
might result in tissue edema and organ dysfunction
 So dynamic assessment of indices of hemodynamics gained
momentum as it questions
? Does this patient really need fluid before actual fluid is given
? Does this patient fluid responsive and fall in steep portion of
ventricular contraction
? How much and how long?

20. Concept of “fluid Responsiveness”
 Only preload assessment does not mean the patient’s stroke
volume will increase after a fluid challenge.
 The only reason to give a patient a fluid challenge is to
increase stroke volume.
 If the fluid challenge does not increase stroke volume, then
volume loading is of no benefit and can be even harmful.
Marik et al . Annals of Intensive Care 2011, 1:1

21.  “DYNAMIC” MEASURES OF INTRAVASCULAR VOLUME Using
heart–lung interactions to assess fluid responsiveness is called
“Dynamic” method of assessment.
P.E. Marik, Handbook of Evidence-Based Critical Care, DOI 10.1007/978-1-4419-5923

22.  Dynamic Measurements can be ..
A) in Mechanically Ventilated patient
B) in Spontaneously Breathing Patient

25. DYNAMIC” MEASURES OF INTRAVASCULAR
VOLUME
 CVP change to fluid challenge
 IVC/SVC Caliber changes in response to breathing
 Stroke Volume Variation (SVV)
 Pulse Pressure Variation (PPV)
 Dynamic Changes in Aortic Flow Velocity/Stroke Volume
Assessed by Echocardiography

31. AORTIC VELOCITY TIME INTEGRAL AND PEAK
AORTIC VELOCITIES

32. Limitations of the respiratory variation in
stroke volume for predicting fluid
responsiveness
 When a patient has some breathing efforts under mechanical
ventilation –and even more when the patient is not intubated
 cardiac arrhythmias
 conditions in which the variations in intravascular pressure
induced by mechanical ventilation are of small amplitude like
low tidal volumes
 high frequency ventilation. If the ratio of heart rate to
respiratory rate is low, e. g., if the respiratory rate is elevated,
the number of cardiac cycles per respiratory cycle may be too
low to allow respiratory stroke volume variation (SVV) to occur
 increased abdominal pressure
 open-chest conditions

33. Alternatives to the respiratory variation of
hemodynamic signals: recent advances
The end-expiratory occlusion test
The ‘mini’ fluid challenge
The passive leg-raising test

34. The passive leg-raising test

35. Passive Leg Raising
 PLR is based on the principle that it can induce an abrupt
increase in venous return secondary to auto-transfusion of
peripheral blood from capacitive veins of the lower part of the
body
 Non invasive
 Doesn’t need fluids
 Its repeatable and reproducible
 Its easily reversible unlike fluid bolus
 Can be safely performed in patients with poor cardiac reserve
 Can reliably assess volume responsiveness even if pt has
spontaneous breathing effort or arrhythmias

36. In response to PLR…
• Descending aortic blood flow is measured by esophageal
Doppler
• LVEDV, stroke Volume etc are measured by transthoracic
echocardiography
• PPV and SVV can be measured by PiCOO or FloTrac Vigileo etc
Marik et al. Annals of Intensive Care 2011, 1:1

37. LIMITATIONS..
 Intra-abdominal hypertension (intra-abdominal pressure > 16
mmHg) impairs venous return and reduces the ability of PLR to
detect fluid responsiveness
 Echocardiographic techniques are operator dependent.
 It can not be used as continuous real-time monitoring.
Marik et al. Annals of Intensive Care 2011, 1:1

38.  A meta-analysis, which pooled the results of eight recent
studies, confirmed excellent value of PLR to predict fluid
responsiveness in critically ill patients
Intensive Care Med 2010, 36:1475-1483

39. FLUID RESPONSIVENESS IN “SPONTANEOUSLY
BREATHING PATIENT
 ” During spontaneous breathing, due to variable (and
sometimes inadequate) Tidal Volumes, variable results are
produced, which will be difficult to assess.
Assessment of fluid responsiveness in patients under spontaneous breathing activityRev
Bras Ter Intensiva. 2009; 21(2):212-218

42. SV min

48. TAKE HOME MESSAGE
 More than 50% of icu patients suffer from iatrogenic harm
(fluids, interventions, polypharma, irrational antibiotics)
 Too little fluid may result in tissue hypoperfusion and worsen
organ dysfunction. On other hand, overzealous fluid
resuscitation has been associated with increased complications,
increased length of intensive care unit (ICU) and hospital stay,
and increased mortality
 Even normal healthy person is fluid responsive, doesn't mean
fluids should be given. fluids should be given only if there is
hypotension or signs of tissue hypoperfusion and patient is fluid
responsive
 dynamic assessment of indices of hemodynamics should be
done more often as it questions
? Does this patient really need fluid before actual fluid is given
? Does this patient fluid responsive and fall in steep portion of
ventricular contraction
? How much and how long?
 More research is need to validate and see outcomes

49. “Every question has an answer ,if there is
question without answer, the problem is not in
the question, but in the search itself”
THANK YOU