Disclaimer

This is an Experimental Protocol, Please Follow Advice of your Doctor. This is not medical advice.

Introduction & Goal

The Clinical Challenge

The optimal strategy for hemodynamic resuscitation in early septic shock remains uncertain.

The Goal

This protocol uses sequential, multilayered assessments of physiological signals to tailor fluids, vasopressors, and inotropes, specifically targeting the normalization of Capillary Refill Time (CRT). CRT assessment can identify tissue hypoperfusion, and its evolution reflects the progress of resuscitation.

Tier 1 Interventions

Patients with an abnormal CRT receive a progressive two-tier intervention, beginning with the evaluation of pulse pressure.

Step 1 Evaluate Pulse Pressure & Diastolic Blood Pressure

Pulse Pressure < 40 mm Hg
Assess Fluid Responsiveness
If fluid-responsive: Administer 500-mL fluid bolus over 30 mins. Reassess CRT.
If CRT remains abnormal, give 2nd fluid bolus if still responsive.
Pulse Pressure ≥ 40 mm Hg
And DAP < 50 mm Hg
Adjust Vasopressors
Titrate norepinephrine to reach a DAP of ≥ 50 mm Hg.
Next Step: If Tier 1 interventions fail to normalize CRT, the patient moves to Tier 2.

Tier 2 Interventions

1

Echocardiography

Perform basic echocardiography to rule out cardiac dysfunction. If right or left ventricular dysfunction is present, provide general treatment recommendations and record interventions.

2

Fluid Boluses

If cardiac dysfunction is ruled out or interventions fail to normalize CRT, reassess fluid responsiveness. Administer further fluid boluses to responsive patients until CRT normalizes, safety limits are met, or the patient becomes unresponsive.

3

MAP Test

If CRT remains abnormal, perform a MAP test only in patients with chronic hypertension by transiently increasing norepinephrine to attain a MAP of 80 to 85 mm Hg for 1 hour. If CRT goal is met, maintain this MAP.

4

Dobutamine Test

If MAP test fails, decrease norepinephrine to previous dose and perform a dobutamine test at fixed low dose (5 µg/kg/min) for 1 hour. Maintain dobutamine only if CRT normalizes.

Measuring Fluid Responsiveness

The protocol encourages dynamic parameters to predict stroke volume increase.

Pulse Pressure Variation (PPV)

Often the first choice for patients who are deeply sedated, on controlled mechanical ventilation, and in sinus rhythm.

Passive Leg Raising (PLR) Test

Primary method for patients with spontaneous breathing, arrhythmias, or low lung compliance. Measure response using Echocardiography (VTI of LVOT) rather than just blood pressure changes.

End-Expiratory Occlusion Test (EEOT)

Assessing changes in cardiac output or pulse pressure after a 15-second pause at the end of expiration.

Tidal Volume Challenge

Transiently increasing tidal volume from 6 mL/kg to 8 mL/kg to see if it "unmasks" pulse pressure variation in patients ventilated with low tidal volumes.

Vena Cava Variability

Assessing respiratory variations in the Inferior Vena Cava (IVC) or Superior Vena Cava (SVC) using ultrasound.

CRT-PHR Algorithm Flowchart

Abnormal CRT? (>3s)
No
Periodic Monitoring
Yes
TIER 1 INTERVENTION
Pulse pressure < 40 mm Hg?
Yes
Fluid responsiveness?
Yes
Fluid Challenge (max 1L)
Abnormal CRT?
No
Periodic Monitoring
Yes
Proceed to TIER 2
No
Proceed to TIER 2
No
Diastolic BP < 50 mm Hg?
Yes
Adjust Norepinephrine (DAP > 50)
Abnormal CRT?
No
Periodic Monitoring
Yes
Proceed to TIER 2
No
Proceed to TIER 2
TIER 2 PROTOCOL
TIER 2 INTERVENTION
Cardiac dysfunction on Echo?
Yes
Specific Treatment
Abnormal CRT?
No
Periodic Monitoring
Yes
Previous Hypertension? (Skip to MAP logic)
No
Fluid responsiveness?
Yes
Fluid Challenges
Abnormal CRT?
No
Periodic Monitoring
Yes
Previous Hypertension?
No
Previous Hypertension?
Previous hypertension?
Yes
MAP Test
Abnormal CRT?
No
Periodic Monitoring
Yes
Dobutamine Test
No
Dobutamine Test
Abnormal CRT Post-Dobutamine?
No
Periodic Monitoring
Yes
Rescue Therapies

Standardized CRT Assessment

1

Apply firm pressure to the ventral surface of the distal phalanx of a finger using a glass microscope slide.

2

Increase the pressure until the skin is blank, maintain it for 10 seconds, and then release it.

3

Measure the time required to return to the normal skin color using a chronometer.

Diagnostic Threshold: A refill time longer than 3 seconds is defined as abnormal.