ANESTHESIA—KRANTZ 475 
the action is of very short duration. The one most extensively used in 
this country is pentothal sodium. Structurally this compound is 
pentobarbital in which the oxygen atom of the urea group has been 
replaced by a sulfur atom. 
Te see 
CH: ied 
in in 
CHs—C—H C:2H; CH:—C—H C:oH; 
NZ 
Cc Cc 
te rae hee 
HN | UN HN ON 
C—SNa 
C—ONa - 
Pentobarbital sodium Pentothiobarbital sodium 
(Nembutal sodium) (Pentothal sodium) 
The widest use of this compound very recently has been in producing 
anesthesias by intravenous injection for surgical procedures of short 
duration. For this purpose 2 to 3 cc. of a 5-percent solution is injected 
in about 15 seconds. The injection is then discontinued to permit 
the complete effect to become manifest, which requires about 35 sec- 
onds. If relaxation has not occurred, an additional 2 to 3 cc. may be 
slowly injected. 
The importance of pentothal sodium as a combat anesthetic cannot 
be overestimated. The mortality statistics with pentothal sodium are 
favorable and this agent appears to have warranted a permanent and 
enviable position among the anesthetic agents. 
SPINAL ANESTHESIA 
The use of local anesthetic agents in the spinal fluid to produce 
anesthesia dates back to the turn of the century. In the early days of 
this form of anesthesia, the deaths were so numerous that the popu- 
larity diminished. In more recent years, with more skillful technique 
and more numerous new synthetic local anesthetic agents to select from, 
this type of anesthesia has received a new impetus and is at present 
enjoying much popularity. 
When a local anesthetic is injected into the spinal fluid impulses over 
all types of nerve fibers are blocked—sensory, motor, somatic, and 
autonomic. The sensory block occurs in 6 to 8 minutes which is fol- 
lowed by motor paralysis. The duration of the insensibility to pain 
and the motor paralysis is a function of the character and the concen- 
tration of the local anesthetic agent. Procaine hydrochloride in safe 
concentrations produces an anesthesia of 1-hour duration. Tetracaine 
hydrochloride, (pontocaine) can be successfully used for a period of 
3 hours. 
