title: Effects of pneumoperitoneum with carbon dioxide and helium on renal function and morphology in rats.
abstract: OBJECTIVE
  To evaluate the effects of pneumoperitoneum with carbon dioxide and helium on renal function and morphology in a rat model.
  
  
  METHODS
  Twenty four rats were randomized into three groups (n=8): gasless insufflation ('open', Pressure=0 mmHg), carbon dioxide pneumoperitoneum at 12 mmHg, and helium pneumoperitoneum at 12 mmHg; all lasting 90 minutes.. A cystostomy was performed and the bladder was emptied. At the end of the experiment, the urine produced, a blood sample and the left kidney of each animal were collected. The following variables were obtained: serum sodium, potassium, urea and creatinine, urine volume and creatinine. The creatinine clearance was estimated for each animal. The kidneys were stained with hematoxylin and eosin (HE) and evaluated by a pathologist blinded to the groups.
  
  
  RESULTS
  The CO2 and Helium groups did not differ in the variables evaluated. Both developed oliguria (p<0.001 vs. gasless). The CO2 group presented hyperkalemia compared to gasless (p=0.05), which did not attain significance in the helium group. Histopathological analysis revealed mild hydropic degeneration and congestion in the three groups, with no significant difference among them.
  
  
  CONCLUSIONS
  The type of gas resulted in no difference in the variables of renal function and morphology assessed. The increase in serum potassium was only observed with CO2 insufflation suggests a combined effect of elevated intra-abdominal pressure and metabolic effects of pneumoperitoneum.
authors.affiliation: School of Medicine, UnB, Brasilia-DF, Brazil.
authors.forename: Pedro Felipe Silva de
authors.initials: PF
authors.lastname: Freitas
authors.forename: Leonardo Castro
authors.initials: LC
authors.lastname: Durães
authors.forename: Felipe Augusto Neves Oliveira de
authors.initials: FA
authors.lastname: Carvalho
authors.forename: Sérgio Andurte Carvalho
authors.initials: SA
authors.lastname: Duarte
authors.forename: Fabiana Pirani
authors.initials: FP
authors.lastname: Carneiro
authors.forename: João Batista de
authors.initials: JB
authors.lastname: Sousa
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000008:administration & dosage* / Q000009:adverse effects; D003404:Creatinine / Q000097:blood; D006371:Helium / Q000008:administration & dosage* / Q000009:adverse effects; D007668:Kidney / Q000187:drug effects / Q000502:physiology; D007677:Kidney Function Tests; D008297:Male; D023421:Models, Animal; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects / Q000379:methods*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000097:blood; D013997:Time Factors; D014508:Urea / Q000097:blood; D014554:Urination / Q000502:physiology
chemical_list: D002245:Carbon Dioxide; D006371:Helium; D014508:Urea; D012964:Sodium; D003404:Creatinine