[Intravenous isoflurane in lipid emulsion promotes cardiovascular and respiratory stability. Experimental model.].

Background And Objectives: Intravenous infusion of inhalation anesthetics may promote lung injury. Intravenous halothane in lipid emulsion induces anesthesia with hemodynamic and respiratory stability. This investigation aimed at establishing the induction dose of isoflurane in 10% lipid emulsion and at observing cardiovascular and respiratory effects in experimental anesthesia.

Methods: This study involved 7 male piglets. Animals received intravenous propofol for invasive surgical preparations: femoral artery and jugular vein dissection and esophageal ecodopplercardiographic sensor. Heart rate (HR), electrocardiography (ECG), systolic (SBP), diastolic (DBP), mean (MBP) blood pressure and central venous pressure (CVP), cardiac index (CI) and bispectral index (BIS) were recorded. Inspired and expired gases fractions were continuously evaluated. Isoflurane lipid emulsion was injected until bispectral index had decreased to 40 +/- 5 (BIS40). Animals were kept anesthetized and submitted to laparotomy for gastric suture.

Results: Total volume to reach BIS40 was 25.6 +/- 11.2 mL (2.56 mL isoflurane). Mean time to reach BIS40 was 15.6 +/- 6.9 minutes. The higher the infusion rate the shorter the time to reach BIS40. Cardiovascular and respiratory conditions were stable throughout the experiment. Heart rate has increased with increased end tidal isoflurane.

Conclusions: Intravenous isoflurane in lipid emulsion has promoted bispectral index decrease, hemodynamic and respiratory stability and direct correlation with its expired fraction. Intravenous isoflurane in lipid emulsion may be a safe modality for this anesthetic delivery.