title: Assessing the impact of lung hyperinflation maneuver on systemic inflammatory response and lung collapse in patients undergoing surgeries under spontaneous ventilation.
abstract: OBJECTIVE
  Lung hyperinflation maneuvers (LHM) reverse intraoperative atelectasis; however, they can lead to pulmonary-induced systemic inflammatory response. The objective of this study was to determine the impact of LHM on systemic inflammatory response and lung structure in patients undergoing subarachnoid block.
  
  
  METHODS
  After approval by the Ethics Committee of the institution and signing the informed consent, 20 patients undergoing small and medium surgical procedures were randomly separated into two groups: 1) control (CG), and 2) LHM (LHMG). One hour after the spinal anesthesia, LHM was performed in LHMG by applying bilevel positive pressure in the airways (BIPAP) with an expiratory pressure of 20 cmH(2)O and inspiratory pressure of 20 cmH(2)O for 1 to 2 minutes. Blood levels of TNFalpha, IL-1, IL-6, IL-8, IL-10, and IL-12 were determined by flow cytometry at baseline and at 90, 180, and 780 minutes. Lung volumes and weights were determined using CT scans obtained immediately after the surgery.
  
  
  RESULTS
  The use of LHM resulted in a reduction in the fraction of non-aerated pulmonary parenchyma (7.5 +/- 4.3%, in the Control Group, vs. 4 +/- 2.1%, in the LHM Group, p = 0.02) without changing pulmonary volumes. A progressive increase in plasma levels of IL-1, IL-6, IL-8, and IL-10, similar in both groups, was observed. Plasma levels of TNFalpha and IL-12 were undetectable during the study.
  
  
  CONCLUSIONS
  The use of LHM reduced the incidence of atelectasis, but it did not amplify the inflammatory response in patients with normal lungs undergoing small and medium surgeries under subarachnoid block.
authors.affiliation: Hospital das Clínicas (HC) of the Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brasil. malbouisson@hcnet.usp.br
authors.forename: Luiz Marcelo Sá
authors.initials: LM
authors.lastname: Malbouisson
authors.forename: Elton Lúcio Silva
authors.initials: EL
authors.lastname: de Souza
authors.forename: Larissa
authors.initials: L
authors.lastname: Barbalho
authors.forename: Cristina de Oliveira
authors.initials: Cde O
authors.lastname: Massoco
authors.forename: Maria José Carvalho
authors.initials: MJ
authors.lastname: Carmona
authors.forename: José Otávio Costa
authors.initials: JO
authors.lastname: Auler
mesh_terms: D000775:Anesthesia, Spinal; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000209:etiology* / Q000473:pathology; D007431:Intraoperative Complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D001261:Pulmonary Atelectasis / Q000097:blood / Q000473:pathology / Q000628:therapy*; D012138:Respiratory Therapy / Q000009:adverse effects*; D013514:Surgical Procedures, Operative