Comparison of Peripheral Perfusion Indicators and Lactate Levels

Overview

In patients with septic shock undergoing intensive care unit monitoring, routine assessment of arterial and/or venous blood gas is conducted. During the period when arterial and/or venous blood gas is analyzed in this patient cohort, peripheral perfusion indicators will also be examined. Peripheral perfusion indicators will be appraised using capillary refill and mottling score. In patients experiencing septic shock, elevated lactate levels and progressive elevation of lactate levels during monitoring, prolonged capillary refill time exceeding 3 seconds, protracted capillary refill time, mottling development, and escalating mottling score are prognostic indicators of poor outcomes. The objective of this prospective study is to assess the correlation between capillary refill time and mottling score, concurrently evaluated, and serum lactate levels in arterial and/or venous blood gas.

Sepsis is defined as life-threatening organ dysfunction caused by dysregulated host response to infection(1). Patients with septic shock can be characterized by a clinical table of sepsis with a serum lactate level \>2 mmol/L (18mg/dL) despite adequate fluid resuscitation and persistent hypotension requiring vasopressors to maintain a mean arterial pressure (MAP) ≥65 mm Hg (2). Shock is characterized by signs of tissue hypoperfusion, including increased serum lactate levels and abnormal peripheral perfusion (3). Mottling of the leg is a finding indicating impaired peripheral perfusion(4). Inadequate reduction of high lactate levels with treatment has been associated with an increased risk of death(5). Demographic data of all patients (age, gender, educational status, occupation), comorbidities, APACHE-II score, SOFA score, Charlson Comorbidity index, SAPS-II, MV support, service of transfer to intensive care unit, day of septic shock diagnosis; CRP, procalcitonin, albumin, fibrinogen, WBC, neutrophil count, lymphocyte, platelet count, INR, culture results, disseminated intravascular coagulation (DIC) score, capillary refill, mottling score, blood gas serum lactate level and base deficit, arterial pCO2 value, venous pCO2 value, arterio-venous PCO2 gradient difference, urine volume, vasopressor dose, mean arterial pressure and other vital signs will be noted. Arterial and/or venous blood gases measured every 6 hours from the time of diagnosis and concurrent peripheral perfusion findings (capillary refill time, mottling score) will be noted in the first 24 hours. Capillary refill time was planned to be measured by applying strong pressure to the ventral surface of the distal phalanx of the right index finger with a glass microscope slide. The pressure was planned to continue for 10 seconds after the nail bed turned white. The time to return to normal skin color will be recorded with a chronometer and a refill time longer than 3 seconds will be considered abnormal. In addition, mottling score will be examined as another peripheral perfusion examination outcome. Mottling score is as described below; If there is no mottling, the score will be considered as 0. If there is a coin-sized mottled discoloration in the knee, the score will be evaluated as 1, if the discoloration continues to the upper part of the kneecap, the score will be evaluated as 2, if it reaches to the middle of the thigh, the score will be evaluated as 3, if it reaches to the groin, the score will be evaluated as 4, and if the discoloration exceeds the groin area, the score will be evaluated as 5. Thus, blood gas and peripheral perfusion findings will be noted every 6 hours in the first 24 hours after the patients who are followed up in the intensive care unit with a diagnosis of septic shock and who meet the inclusion criteria are included in the study.