Correlation between Tissue Oxygen Saturation and Global Oxygenation Parameters in Emergency Patients: A Pilot Clinical Study.
	    		
		   		
	    	
    	
    	
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Young Woong YOON
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Young Mo CHO
			        		
			        		;
		        		
		        		
		        		
			        		Hyung Bin KIM
			        		
			        		;
		        		
		        		
		        		
			        		Ji Ho RYU
			        		
			        		;
		        		
		        		
		        		
			        		Maeng Ryul PARK
			        		
			        		;
		        		
		        		
		        		
			        		Mun Ki MIN
			        		
			        		;
		        		
		        		
		        		
			        		Yong In KIM
			        		
			        		;
		        		
		        		
		        		
			        		Sung Wook PARK
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. Department of Emergency Medicine, Pusan National Univerisity College of Medicine, Pusan, Korea. psu52156@naver.com
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:Original Article
 
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Microcirculation;
			        		
			        		
			        		
				        		Spectroscopy Near-Infrared;
			        		
			        		
			        		
				        		Tissue oxygen saturation
			        		
			        		
	        			
        			
        		
 
        	
            
            	- MeSH:
            	
	        			
	        				
	        				
				        		
					        		Central Venous Catheters;
				        		
			        		
				        		
					        		Clinical Study*;
				        		
			        		
				        		
					        		Critical Illness;
				        		
			        		
				        		
					        		Emergencies*;
				        		
			        		
				        		
					        		Emergency Service, Hospital;
				        		
			        		
				        		
					        		Humans;
				        		
			        		
				        		
					        		Lactic Acid;
				        		
			        		
				        		
					        		Microcirculation;
				        		
			        		
				        		
					        		Observational Study;
				        		
			        		
				        		
					        		Oxygen*;
				        		
			        		
				        		
					        		Prospective Studies;
				        		
			        		
				        		
					        		Spectroscopy, Near-Infrared
				        		
			        		
	        			
	        			
            	
            	
 
            
            
            	- From:Journal of the Korean Society of Emergency Medicine
	            		
	            		 2016;27(3):223-230
	            	
            	
 
            
            
            	- CountryRepublic of Korea
 
            
            
            	- Language:Korean
 
            
            
            	- 
		        	Abstract:
			       	
			       		
				        
				        	PURPOSE: Near-infrared spectroscopy (NIRS) can noninvasively assess changes in tissue oxygen saturation (StO₂). The primary concern of the current study is to determine whether StO₂ can be used as a surrogate for global oxygenation parameters such as central venous oxygen saturation (ScvO₂), lactic acid, and base deficit (BD) in patients presenting to the emergency department (ED). METHODS: This was a prospective, observational study in patients requiring central venous catheter placement, admitted to the ED with complaints classified as infectious and non-infectious etiology. The NIRS sensor (15 mm probe) was applied on the thenar eminence for at least 3 minutes and ScvO₂, arterial lactic acid, and BD were measured during insertion of a central venous catheter. Data were analyzed using a simple correlation and Bland-Altman plot. RESULTS: A total of 120 patients were enrolled in the study and further classified as an infection (n=39) and a noninfection (n=81) group. Lactic acid BD showed significant correlation with StO₂ in total and in non-infection patients but the degree of correlation was weak and these correlations were not observed in infection patients. Approximately 94% of the difference between StO₂ and ScvO₂ was placed within limit of agreement but there was a risk that StO₂ may overestimate ScvO₂ when ScvO₂ becomes lower. When patients were assigned to two groups according to laboratory results (lactic acid 4.0 mmol/L; BD > 3.0 mmol/L; ScvO₂> 65% or 75%), no significant difference in StO₂ was observed between the two groups. CONCLUSION: In ED patients suspected of having systemic hypoperfusion, StO₂ showed a weak correlation with lactic acid and BD in non-infection patients and no correlation in infection patients. In addition, as ScvO₂ decreased, the difference between StO₂ and ScvO₂ showed a tendency to increase, and StO₂ was much higher than ScvO₂ at low ScvO₂ level. Therefore, before using StO₂ as surrogate for ScvO₂, lactic acid and BD in critically ill patients presenting to the ED, further investigation should be conducted to overcome the limitations of NIRS addressed in this study.