Effects of Fluid Resuscitation on Capillary Refilling Time and Organ Functions in Septic Shock

Since the ultimate target of resuscitation is the microcirculation, normal microcirculatory perfusion appears to be the primary target of ideal resuscitation in septic shock patients. In septic shock patients, microcirculation of the skin may be impaired in the early period due to early sympathetic nervous system activation.

Assessment of skin perfusion has also become popular in shock resuscitation because it is easily accessible for clinical assessment. Studies in septic shock patients, showed that capillary refill time correlated with lactate levels measured at 6 hours of resuscitation and was associated with mortality. Additionally, early normalization of capillary refill time has been associated with improved survival in septic shock This study aimed to evaluate the relationship between the change in capillary filling time (microcirculation) and organ perfusion after fluid resuscitation in sepsis patients in intensive care.

An aggressive approach to fluid resuscitation in patients with sepsis is recommended by international guidelines and is considered the cornerstone of treatment. This approach is based on historical concepts and the theory that septic shock is a form of hypovolemic shock characterized by tissue hypoperfusion.

Studies show that capillary refill time is a valuable method to measure the severity of acute disease both in the early and late stages. However, it remains unclear why abnormal peripheral perfusion increases morbidity and mortality. Because from a pathophysiological point of view, the main purpose of activation of the sympathetic nervous system is to maintain the perfusion of vital organs (brain, heart, lung).

The Sequential Organ Failure Assessment (SOFA) score is a simple and objective score that allows for calculation of both the number and the severity of organ dysfunction in six organ systems (respiratory, coagulatory, liver, cardiovascular, renal, and neurologic) and the score can measure individual or aggregate organ dysfunction.

This study aimed to evaluate the relationship between the change in capillary filling time (microcirculation) and SOFA score (organ perfusion) after fluid resuscitation in sepsis patients in intensive care.

After the first admission to the intensive care unit \[T0 (baseline)\], demographic information of the patients, source of sepsis, Sequential Organ Failure Assessment (SOFA) score, which shows the severity of the disease, Acute Physiology and Chronic Health Evaluation (APACHE II) score, additional systemic diseases, hemodynamic variables, blood gas parameters, and transthoracic echocardiogram findings will be recorded.

Capillary refill time (CRT) will be measured by applying pressure to the index finger for 15 seconds.

As recommended in the Surviving Sepsis Campaign Guidelines, after 30 mL/kg/3 hours crystalloid infusion (T1) and 24 hours (T2), Sequential Organ Failure Assessment (SOFA) score, hemodynamic variables, blood gas parameters, transthoracic echocardiogram findings and capillary refill time will be recorded again.

Patients will be divided into two groups; If the CRT measured at T1 decreased equal to or more than 25% compared to the CRT measured at T0, the patients as responders to capillary refill time (Group CRT-R); If the CRT measured at T1 decreased by less than 25% compared to the CRT measured at T0, the patients as non-responders to capillary refill time (Group CRT-NR) The effect of 30 mL/kg/3 hours crystalloid infusion on peripheral perfusion (in Group CRT-R and Group CRT-NR, which are divided into two by CRT measurement at T0 and T1 times) and the effect on the SOFA scores will be compared.

Eligibility Criteria:
Inclusion Criteria

* Over 18 years old
* Admitted to intensive care with a diagnosis of sepsis or septic shock
* Systolic blood pressure \< 90 mmHg or Mean blood pressure \< 65 mmHg
* Those who need vasopressor medication
* Urine output \< 0.5 ml/kg/h for at least two hours
* Tachycardia (Heart rate \> 100/min)
* Serum Lactate \> 2 mmol/L
* Patients with central venous oxygen saturation (ScvO) \< 70%

Exclusion Criteria

* Not approved by the patient or his/her guardian
* Known heart, kidney, liver failure
* The initial cause of shock is neurogenic, cardiogenic or obstructive shock.
* Pregnancy or suspected pregnancy
* Those with amputation or severe organ ischemia
* Those with peripheral artery disease
* Cannot be evaluated optimally with transthoracic echo
* Patients who died in the first 24 hours