[Total intravenous anesthesia in thoracotomy with one-lung ventilation]. A comparison of the effects of propofol-alfentanil versus isoflurane anesthesia on arterial oxygenation during one-lung ventilation. Effects of sevoflurane and propofol on pulmonary shunt fraction during one-lung ventilation for thoracic surgery. One-lung anesthesia--a comparison of pulmonary gas exchange during anesthesia with ketamine or enflurane. Comparison of the effects of propofol and isoflurane anaesthesia on right ventricular function and shunt fraction during thoracic surgery. [A comparison of enflurane and propofol in thoracic surgery].
The aim of this study was to evaluate the benefits of total intravenous anaesthesia (TIVA), with the administration of drugs intravenously and the maintenance of pulmonary ventilation with oxygen enriched air, with respect to inhalatory anaesthesia, in thoracotomies with single lung ventilation.
                The study, devoloped in collaboration between the Service of Anaesthesia and Resuscitation and the Division of Thoracic Surgery of the Hospital of Teramo, was carried out in two groups of patients chosen at random; fifty patients divided into two groups of twenty-five were studied. Pre-medication and induction was similar in both groups; maintenance, however, varied: a total intravenous anaesthesia was given to patients in group A whereas patients in group B received an inhalatory anaesthesia. These parameters were considered: pressure values, heartbeat, PaO2 and PaCO2 levels, SatO2 and EtCO2.
                Both protocols respected anaesthetic guidelines in terms of controlling pressure values, heartbeat and levels of PaCO2 during bipulmonary ventilation. Significantly statistical differences were observed in the oxygenation during one lung ventilation: the mean values of PaO2 being significantly higher in group A.
                On the basis of this experience, it can be conclude that TIVA offers the following advantages: a better oxygenation during one lung ventilation, good recovery of post operative consciousness with no psychomotor disturbances, absence of pollution in the operating theatre. To determine whether intravenous propofol-alfentanil anesthesia provides superior arterial oxygenation (Pao2) during one-lung ventilation (OLV) compared with isoflurane inhalation anesthesia.
                A prospective, randomized, cross-over study.
                Tertiary-care university hospital.
                Thirty adults having either thoracoscopic pulmonary surgery or esophageal surgery.
                Patients received either propofol-alfentanil infusion anesthesia or one minimum alveolar concentration (MAC) of isoflurane during the initial period of two-lung ventilation and the first 30 minutes of OLV and then were switched to the other anesthetic for the duration of OLV.
                Arterial blood gases and hemodynamics were recorded during two-lung ventilation and after 20 and 30 minutes of OLV with each anesthetic technique. The mean values (+/- SD) for Pao2 during propofol-alfentanil anesthesia after 20 minutes (222 +/- 100) and 30 minutes (228 +/- 102 mmHg) of one-lung ventilation were not significantly different than after 20 minutes (213 +/- 99) or 30 minutes (214 +/- 96 mmHg) of isoflurane; beta error less than 0.1. Mean heart rate was lower during intravenous (78 +/- 15 min) than inhalation (85 +/- 17 min) anesthesia (rho = 0.03).
                This study does not support the theory that total intravenous anesthesia will decrease the risk of hypoxemia during OLV. Forty patients requiring one-lung ventilation (OLV) for thoracic surgery were randomly assigned to receive propofol (4-6 mg kg(-1) h(-1)) or sevoflurane (1 MAC) for maintenance of anaesthesia. Three sets of measurements were taken: (i) after 30 min of two-lung ventilation (TLV), (ii) after 30 min of one-lung ventilation (OLV-1) in the supine position and (iii) during OLV in the lateral position (OLV-2) with the chest open and before surgical manipulation of the lung. There were no differences between groups in patient characteristics or preoperative condition. Increases in shunt fraction during OLV-1 were 17.4% and 17.2% (P=0.94), those during OLV-2 were 18.3% and 16.5% (P=0.59) for the propofol and sevoflurane group, respectively. Cardiac index and other haemodynamic and respiratory variables were similar for the two groups. We conclude that inhibition of hypoxic pulmonary vasoconstriction by sevoflurane may only account for small increases in shunt fraction and that much of the overall shunt fraction during OLV has other causes. Twenty-four men undergoing elective pulmonary resection with a period of one-lung ventilation were studied to compare the effects of ketamine-O2 and enflurane-O2 anesthesia on arterial oxygen tension (PaO2) and intrapulmonary shunting (Qs/Qt). No statistically significant differences were demonstrated between ketamine and enflurane in mean peak Qs/Qt, 43% and 42%, respectively, or minimum PaO2 values, 169 torr and 127 torr, respectively. Stroke volume index, left ventricular stroke work index, and cardiac index were, however, significantly greater with ketamine. No emergence hallucinations were observed in either group. These findings suggest that ketamine affords no advantage over enflurane anesthesia in terms of Qs/Qt, and arterial oxygen desaturation during endobronchial anesthesia. I.v. anaesthetic agents, including propofol, have not been shown to inhibit hypoxic pulmonary vasoconstriction (HPV). This may encourage the use of propofol in thoracic surgery where one lung ventilation (OLV) is required. We have compared the effects of maintaining anaesthesia with either isoflurane or propofol infusion on right ventricular function and shunt fraction. We studied 10 patients who received isoflurane and 12 who received propofol. When OLV commenced there was a greater reduction in both mean cardiac index (3.2 (SEM 0.2) to 2.4 (0.1) litre min-1 m-2 for propofol, and 3.4 (0.2) to 3.3 (0.4) litre min-1 m-2 for isoflurane) and right ventricular ejection fraction (0.45 (0.03) to 0.37 (0.02) for propofol, and 0.48 (0.02) to 0.42 (0.02) for isoflurane) in patients who received propofol. Furthermore, these reductions were sustained for longer in the propofol group. However, propofol was not associated with a significant increase in shunt fraction during OLV, which increased threefold in patients who received isoflurane. Comparisons between propofol and inhalational anesthetics for maintenance of anesthesia are limited. The purpose of our prospective study was to examine differences between enflurane and propofol during pulmonary resections with one-lung ventilation (1LV). METHOD. 28 patients, ASA risk group II-III, gave written informed consent for inclusion in this institutionally approved study. The patients were randomly allocated to one of the following groups: A: propofol 10 mg kg-1 h-1, B: 1 MAC enflurane, for maintenance of anesthesia. In both groups analgesia was achieved by fentanyl and muscle relaxation, by pancuronium. Ventilation via a double-lumen tube was controlled (FiO2 = 1.0, PaCO2 35-40 mmHg). Measurements, including hemodynamics and arterial and mixed venous blood gases, were obtained before induction (I), during two-lung ventilation (2LV) 15 min after induction in the supine position (II) and 20 min after surgical opening of the chest in the lateral decubitus position (III), 20 min after starting 1LV (IV), and after extubation (V). RESULTS. No significant differences between the two groups were found before induction (I), during 2LV (II, III), or after extubation (V). The only significant differences between the two groups were observed during 1LV (IV): the shunt fraction was 33.9 +/- 2.5% in A and 38.5 +/- 2.6% in B (P less than or equal to 0.05). Hypoxic pulmonary vasoconstriction was not inhibited in A, but was inhibited by 21.5% in group B during 1LV. Since no case of hypoxemia occurred in group A during 1LV (range of PaO2: 75.2-417.0 mmHg), but four patients developed hypoxemia in group B (Range of PaO2: 46.6-431.0 mmHg), regimen A might be of value in high-risk patients during thoracic surgery when 1LV is planned.
There is no evidence from randomized controlled trials of differences in patient outcomes for anaesthesia maintained by intravenous versus inhalational anaesthesia during one-lung ventilation. This review highlights the need for continued research into the use of intravenous versus inhalation anaesthesia for one-lung ventilation. Future trials should have standardized outcome measures such as death, adverse postoperative outcomes and intraoperative awareness. Dropouts and losses to follow up should be reported.