ABSTRACT
ObjectiveTo evaluate the efficacy of PEEP set according to pressure-volume (P-V) curve for one lung ventilation (OLV) in patients undergoing thoracic surgery.MethodsOne hundred and twenty ASA Ⅱ or Ⅲ patients of both sexes aged 20-60 yr weighing 40-80 kg undergoing lobectomy under general anesthesia were enrolled in this study.Double lumen tube was inserted.Correct positioning was verified by fiberoptic bronchoscopy.The patients were mechanically ventilated.P-V curve was determined at 3 min of two-lung ventilation (TLV).Lower inflection point (LIP) was measured and the pressure at LIP (PLIP) was recorded.The patients were randomly divided into 5 groups (n ＝ 24 each):control group (group C) and 4 lung protective ventilation regimen groups ( groups P1-4 ).PEEP was set at 0 and VT was set at 10 ml/kg in group C.PEEP was set at 0 and VT was set at 6 ml/kg in group P1.PEEP was set at PLIP- 2 cm H2O and VT was set at 6 ml/kg in group P2.PEEP was set at PLIP and VT was set at 6 ml/kg in group P3.PEEP was set at PLIP + 2 cm H2O and VT was set at 6 ml/kg in group P4.Peak airway pressure (Ppeak),plateau airway pressure (Pplat),airway resistance (Raw) and lung compliance (CL ) were measured and recorded during OLV and TLV after a period of stabilization.Arterial blood samples were taken before induction of anesthesia and at 20 min of TLV and 20 min of OLV for blood gas analysis.Qs/Qt was calculated.Arterial blood samples were collected at the beginning and end of OLV for determination of plasma concentrations of IL-6 and TNF-α(by ELISA).ResultsCompared with group C,Ppeak and Pplat were significantly increased while Raw was decreased and plasma IL-6 concentration was significantly decreased at the end of OLV in group P4.PaCO2 was significantly higher during TLV and OLV in groups P1-4 than in group C.There was no significant difference in the parameters of respiratory mechanics,blood gases and plasma IL-6 and TNF-α concentrations among groups P1,2.3.Compared with groups P1,2,3,Ppeak and Pplat were significantly increased while plasma IL-6 concentration was decreased at the end of OLV in group P4.ConclusionMechanical ventilation with VT set at 6ml/kg and PEEP at PLIP + 2 cm H2 O provides best venfilatory efficacy for OLV in terms of oxygenation and inhibition of inflammatory response.
ABSTRACT
Objective To evaluate feasibility of high frequency jet ventilation (HFJV) during trachea and carinal reconstruction. Methods Ten patients with lung cancer ,scheduled for elective trachea and carinal reconstruction ,were intubated with double lumen tube following routine anesthesia induction. A HFJV tube (ID=3mm) was inserted 3cm into main bronchus. HFJV was applied ,with the respiratory rate of 120/min,I:E=1:2 and drive pressure of 0.15-1.20MPa, after cut off the main bronchus of the opposite side. Blood gas analysis was made before the operation, 15min following one-lung ventilation, 5, 10, 20 min following HFJV and 15min following one-lung ventilation,respectively.Results PaO 2 was significantly higher following HFJV than that one-lung ventilation (P
ABSTRACT
Objective To investigate the effects of different positions of the patients mechanically ventilated under general anesthesia on respiratory mechanics during one or both lung ventilation before thoracotomy.Methods Twelve ASA Ⅰ or Ⅱ patients of both sexes (8 males, 4 females) aged 33-63 years weighing 62-85 kg scheduled for general thoracic surgery were studied. The preoperative lung function of the patients was normal. The patients were premedicated with intramuscular pethidine, promethazine and atropine. Anesthesia was induced with fentanyl, droperidol, midazolam, propofol and vecuronium. Left-sided double-lumen tube was inserted and correct placement was confirmed using a fiberoptic bronchoscope inserted through the bronchial lumen. Anesthesia was maintained with propofol and vecuronium infusion. The magnitude of neuro-muscular blockade was monitored by stimulation of radial nerve with TOF pulses. T4/T1 was maintained at 0 during study. The patients were placed in supine, left and right lateral position. In each position both lungs, left and right lung were ventilated for 10 min respectively. The non-ventilated bronchial lumen was open to the air during one-lung ventilation. The ventilatory parameters were kept unchanged during the study (VT = 8-10 ml?kg-1 , RR = 12 bpm, I:E = 1:2). Pressure-volume loop (P-V loop), peak airway pressure (Ppeak), airway resistance (Raw), total compliance (CT) (lung and thorax) and PETCO2 were measured and recorded at the end of each 10 min ventilation using S/5 monitor ( Datex-Ohmeda Finland) . Results During both lung ventilation Ppeak was significantly increased and CT was significantly decreased in left and right lateral position as compared with supine position ( P