INTRAPERITONEAL INJECTION. 



II 



INTRAPERITONEAL injection is employed most frequently 

 Intraperito- among rabbits and guinea-pigs. The main danger associated 

 neal with this method is possible injury to the intestines; but by 

 Injection, heeding the following advice, this can be prevented. The ani- 

 mal should be fixed or held head down. In this position, the 



loops of intestines tend to sink toward the diaphragm. This is further 



helped along by gentle downward massage over the 'abdomen thus leaving 



an area, above the bladder, which is sometimes free from intestines.- Another 



protective measure, consists in 



using a blunt canula which can be 



made by breaking off the sharp 



point of the needle. As it is at 



times difficult to pierce the skin 



with this blunt instrument, it is 



advisable to previously make a 



minute incision through the cutis 



and subcutis with a sharp pair 



of scissors and pass the needle 



through this small opening. The 



needle should not be plunged 



directly into the peritoneal cavity, 



because at the withdrawal, the 



injected fluid easily escapes through 



the punctured opening. First, it is 



inserted subcutaneously upward, 



in the long direction of the animal ; 



then the hand is raised and the 



needle forced horizontally forward 



through the peritoneum, thus leav- 

 ing the opening in the peritoneum 



at a different level than the one 



through the muscles and fascia, thereby making the escape of fluid more 



difficult. One readily realizes that he has gone through the peritoneum by 



a relaxation of the reflex abdominal rigidity (Fig. 4) . 



For the intraperitoneal injection in guinea-pigs, Friedberger has devised 



a procedure which is very satisfactory and furthermore does away 



with the necessity of an assistant. It can also be employed in Pfeiffer's 



test for the removal of exudates from the peritoneal cavity. The giunea- 



pig is allowed to creep into the breast pocket of the laboratory gown 



until its head and thorax are inside of the pocket. Its hind legs are 



grasped between the middle and ring fingers of the left hand and 



flexed on the back, thus giving a free exposure of the lower parts of the 



abdomen (Fig. 5). 



FiG. 4. Intraperitoneal injection of rabbit. 

 (After Uhlenhuth.} 



