peripheral cyanosis

• Dusky bluish discoloration of tissue 
• Due to increased deoxygenated Hb in blood 
• More than 5 g/dl 

• Inadequate tissue perfusion 
• Due to relative or absolute reduction of cardiac output 
• Hypovolemic shock occurs due to reduction of total blood ( fluid ) volume 

• Cardiac output = Stroke volume  ×  Heart rate 
• Stroke volume = End diastolic volume (EDV) – End systolic volume (ESV) 
• End systolic volume depends on venous return 
• Venous return depends on 

Skeletal muscle pump Respiratory pump
Total blood volume
Pericardial pressure
Venous tone

• In hypovolemic shock total blood volume reduces 
• Venous return reduces 
• Stroke volume decrease 
• Cardiac output reduces 

• Velocity of blood flow depends on cardiac output 
• Due to reduce cardiac output 
• Velocity ( speed ) of blood flow reduces 
• Blood stagnated at pheripheris 
• Tissue extract more and more oxygen form Hb 
• Release more and more deoxygenated O2 into  blood 
• When the deoxygenated Hb level increased more than 5 g /dl 
• It results peripheral cyanosis 

Labels: CVS, CVS SEQs, Physiology SEQ