Importance of anesthesia for the genesis of neurogenic pulmonary edema in spinal cord injury.
There are reports describing both provocation and inhibition of neurogenic pulmonary edema by anesthetic drugs. Therefore, we compared the effect of two types of anesthesia on the formation of neurogenic pulmonary edema in rats with balloon-induced acute spinal cord injury. Animals with sham procedure (group 1) were anesthesized by intraperitoneal sodium pentobarbital. In the experimental groups, rats were submitted to acute spinal cord lesion by insufflations of a balloon in the epidural space at T8 for 1 min (group 3 under i.p. sodium pentobarbital and group 2 under i.p. xylazine-ketamine anesthesia). In rats with pentobarbital anesthesia, systolic blood pressure doubled the baseline value during compression, whereas this effect was less pronounced in the ketamine-xylazine group. The pulmonary index (100 x wet lung weight/body weight) was 0.395 (+/-0.018) in sham-operated rats, rose to 0.499 (+/-0.060) in group 2, and was maximum under pentobarbital anesthesia (0.639+/-0.14; p=0.0018). Histologic examination of the spinal cord showed parenchymal ruptures and acute hemorrhage. Comparison of the pulmonary index with histologic slides of lung parenchyma revealed that relevant intra-alveolar edema occurred only for index values above 0.55. On electron microscopy, endothelial alterations, and damage of the alveolar lining cells were found. Our study indicates that neurogenic pulmonary edema caused by spinal cord injury is less pronounced in rats under xylazine-ketamine anesthesia, when compared with pentobarbital.
Leal Filho
Manoel Baldoino
MB
Curso de Pósgraduação em Ciências Médicas, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, PO Box 6111, 13084-971 Campinas, SP, Brazil.
Morandin
Rosana Celestina
RC
de Almeida
Amanda Roberta
AR
Cambiucci
Elizabeth Cristina
EC
Borges
Guilherme
G
Gontijo
Jose Antonio Rocha
JA
Metze
Konradin
K
D018681:Anesthetics, General / Q000009:adverse effects*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D007649:Ketamine / Q000494:pharmacology; D008168:Lung / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D010424:Pentobarbital / Q000494:pharmacology; D011654:Pulmonary Edema / Q000209:etiology* / Q000473:pathology*; D051381:Rats; D013119:Spinal Cord Injuries / Q000150:complications*; D014991:Xylazine / Q000494:pharmacology
D018681:Anesthetics, General; D014991:Xylazine; D007649:Ketamine; D010424:Pentobarbital