The objective of this study is to identify the types of Photoplethysmographic waves present in adults with septic shock and determine whether these waves correlate with other variables of tissue hypoperfusion such as capillary refil, serum lactate and mottling score.

Photoplethysmography is the technology used in pulse oximeters in order to calculate arterial oxygen saturation and pulse rate, this technology generates a wave whose morphology has been related to blood flow and arterial tone. Recently Tusman and collaborators described a morphological classification of the photoplethysmografic wave that has a high correlation with arterial tone, such classification is divided in 6 types; Types I and II indicate vasoconstriction, Type III normal arterial tone and Types IV, V and VI describe mild, medium and severe vasodilation respectively, therefore it could be used to identify the arterial tone in those patients with septic shock. This study will identify the type of photoplethysmographic waves that are present in adults with septic shock based in the Tusman and collaborators classification, it will also describe the frequency of appearance and their correlation with other hemodynamic variables such as capillary refill, serum lactate, mottling score, heart rate, mean arterial pressure, pulse pressure and perfusion index.

Inclusion Criteria:

• Adult patients of 18 years of age and above dignossed with septic shock according to the definition stated in Sepsis 3.0
• Patients with axillary temperature above 36°C
• Patients and/or family that agree to participate in such study and sign the informed consentment
• Patients that tolerate supine position

Exclusion Criteria:

• Patients with Cardiogenic shock, hipovolemic, obstructive and distributive (neurogenic, anafilactic) shock the exception being septic shock
• Patients with history of any type of cardiac arrhythmia
• Patients with history of chronic hepatic disease
• Patients with limited or diffuse systemic sclerosis
• Patients that have scarring, nail polish or thickened nails that may impede the proper placement and accurate measurement of photoplethysmography with the pulse oximeter
• Patients with history of heart insufficiency P- atients with septic shock that already have vasopressor aggents

All adult patients admitted to the emergency department at "Hospital General de México Dr. Eduardo Liceaga" and meet the criteria for septic shock established in Sepsis 3.0 and have signed the informed consentment will be included in the study.