Ropivacaine vs. levobupivacaine combined with sufentanil for epidural analgesia after lung surgery.

BACKGROUND AND OBJECTIVES: There are no clinical studies that compare epidural infusion of ropivacaine and levobupivacaine in patients undergoing lung surgery. The aim of this prospective, randomized double-blind study was to evaluate the efficacy and safety of two commercially available solutions of ropivacaine (0.2% w/v) and levobupivacaine (0.125% w/v) when administered by continuous epidural infusion together with sufentanil in patients undergoing lung surgery. METHODS: After obtaining informed consent, 54 patients, ASA physical status I-III undergoing lung resection, were enrolled. Patients were randomly assigned to two groups in which analgesia was performed by continuous thoracic epidural infusion of ropivacaine 0.2% w/v (Group R) or levobupivacaine 0.125% w/v (Group L) with or without sufentanil 1 microg mL(-1). After a test and a loading dose of each drug for the respective group, continuous epidural infusion, set at 5 mL h(-1), began. General anaesthesia was standardized. In the recovery room, patients were provided with intravenous morphine patient-controlled analgesia. Visual analogue scale at rest and when coughing, rescue patient-controlled analgesia morphine amount, haemodynamics, sensory and motor block, sedation, nausea and vomiting, patient satisfaction score, were evaluated within 48 h. RESULTS: The two groups were similar regarding patient characteristics, quality of analgesia, level of sensory block, morphine consumption and satisfaction score. Postoperative haemodynamic profile was stable in all the patients. Minor side-effects occurred with a similar incidence. Motor block was not seen. CONCLUSIONS: Equivalent volumes of ropivacaine (0.2% w/v) and levobupivacaine (0.125% w/v) provided similar static and dynamic analgesia with similar incidence of minor side-effects after thoracotomy.

Changes in hemodynamics during isoflurane and propofol anesthesia: a comparison study.

OBJECTIVES: Volatile anesthetics are thought to impair cerebral autoregulation more than i.v. anesthetics. However, few comparative studies have been carried out in humans. The aim of our study was to evaluate the differences in cerebral hemodynamic changes after introduction of isoflurane (a volatile anesthetic) and propofol (an i.v. anesthetic). METHODS: Eighteen consecutive patients submitted to laparoscopic cholecystectomy were selected. After the induction, anesthesia was maintained by isoflurane (one minimum alveolar anesthetic concentration) during the first part of the surgical operation, and then by propofol (5 mg/kg/hour i.v.). Ventilation was adjusted to maintain a constant end-tidal CO(2). Middle artery flow velocity was assessed by means of transcranial Doppler ultrasonography. Arterial blood pressure, heart rate (HR), capnometry, pulse oxymetry, inspired fraction of O(2), and body temperature, were monitored. RESULTS: Cerebral artery velocity, HR, and mean arterial pressure all significantly increased from baseline after the introduction of isoflurane (p<0.05); the HR and mean arterial blood pressure showed no significant difference between the isoflurane and propofol phases. Isoflurane anesthesia induced a significant increase in cerebral blood velocity. Propofol introduction led to a significant decrease in cerebral artery velocity (p<0.05). CONCLUSIONS: Propofol but not isoflurane decreased cerebral blood velocity thus restoring cerebral autoregulation and the coupling between cerebral blood flow and cerebral metabolism.

Hepatic resections in normothermic ischemia.

BACKGROUND: Reduction of operative blood transfusions is a primary goal in resective surgery of the liver. Temporary vascular inflow occlusion is an effective method to decrease hemorrhage during hepatic resection. This study was performed to assess the impact of normothermic ischemia on intraoperative bleeding and outcome after hepatic resection. METHODS: Sixty-one hepatic resections were performed by using pedicle clamping alone or associated with total vascular exclusion of the liver. The mean duration of normothermic ischemia was 40 +/- 18 minutes (range, 7 to 98 minutes). Major resections were performed in 32 cases (52.5%). RESULTS: Operative mortality was nil. Major complications occurred in 11.5% of cases. Twenty-five patients (41%) received intraoperative blood transfusions; mean +/- SD of transfused blood units was 2.4 +/- 1.3. Twelve major resections (37.5%) did not require any transfusion. Postoperative changes in liver function test results were moderate and transient. CONCLUSIONS: The results of this study confirm the benefit of vascular occlusion techniques in reducing intraoperative bleeding and postoperative complications. The routine use of these techniques during hepatic resections, if applied properly and with the necessary precautions, is not associated with severe adverse effects on liver function.

An attempt to control cerebrospinal fluid acidosis in coma due to head injury.

The acid-base status of the arterial blood, jugular venous blood, peripheral venous blood and lumbar cerebrospinal fluid and the free amino acids in the cerebrospinal fluid have been studied in 12 patients suffering from coma due to head injury. They were given S adenosyl-methionine (10 mg/kg/day). Significant statistical differences of acid-base balance and CSF free amino acids have been obtained after the administration of te compound. The clinical and biochemical significance of the use of S adenosyl-methionine in severe brain injuries is discussed

Lysine hydrochloride for the control of metabolic alkalosis: a clinical report.

Many physiopathological states can produce metabolic alkalosis that must be promptly corrected as soon as it is dangerous. In our study we report the effectiveness of lysine hydrochloride to correct this condition in patients. This drug lowers the pH, reduces the bicarbonate stores, and leads to normal blood gases.

Liver resections with or without pedicle clamping.

BACKGROUND: Decreasing operative bleeding during liver resection, and thus extent of transfusions, has become a main criterion to evaluate operative results of hepatectomies. Hepatic pedicle clamping (HPC) is widely used for this purpose. The aim of the study was to evaluate safety, efficacy, technique, and contraindications of HPC during liver resections, comparing results of resections performed with or without HPC. METHODS: Data from 245 liver resections were analyzed. In all, 125 resections were performed with HPC (group A), continuous in 100 cases and intermittent in 25 cases. The average duration of ischemia in group A was 39 +/- 20 minutes (range 7 to 107). In 20 cases (16%) ischemia was prolonged for 60 minutes or more. A total of 120 resections were performed without HPC (group B). Major resections were 53.6% in group A (67 cases) and 38.3% in group B (46 cases). Cirrhosis was present in 36 cases, 19 in group A and 17 in group B. RESULTS: Operative mortality was nil. Postoperative mortality was 2.9%, morbidity 22.4%. Percentage of transfused cases (34.4% versus 60.0%; P <0.001) and number of blood units per transfused case (2 +/- 1 versus 4 +/- 3; P <0.001) were lower in group A versus group B. Similar figures were found by considering only major resections. Postoperative blood chemistries did not show important differences between the two groups, and postoperative alterations were related more to extent and complexity of the operation than to length of HPC. CONCLUSIONS: HPC during liver resection is a safe and effective technique. This is demonstrated in a context where HPC is used continuously in most cases, intermittently in cases with impaired liver function and for more prolonged ischemia, and avoided in cases with limited bleeding, jaundice, and simultaneous bowel anastomoses.

Changes in cerebral hemodynamics during laparoscopic cholecystectomy.

Laparoscopic surgery requires a series of procedures, including intraperitoneal CO2 insufflation, which can cause cardiovascular and hemogasanalytic modifications, potentially able to impair cerebral perfusion. The aim of this study was to evaluate changes in cerebral blood flow velocity during laparoscopic cholecystectomy. Eighteen patients undergoing laparoscopic cholecystectomy were studied. Middle cerebral artery blood flow velocity was monitored using transcranial Doppler ultrasonography. Electrical bioimpedance was employed to measure cardiac output, stroke volume and to calculate derived parameters. End-tidal CO2, mean arterial blood pressure, end expiratory anesthetic concentration and O2 saturation were monitored non-invasively. Cerebral artery blood flow velocity increased significantly after CO2 insufflation (p < 0.05) and remained stable. The highest values were reached after CO2 desufflation. A significant reduction in stroke volume and cardiac output (p < 0.05) associated with increased vascular systemic resistances (p < 0.001) was observed soon after CO2 insufflation. The decrease in cardiac output and the increase in vascular systemic resistances remained significant throughout abdominal insufflation. Heart rate and mean arterial pressure remained substantially unchanged with the exception of a significant decrease (p < 0.001) before CO2 insufflation. There was no significant change in end-tidal CO2 during abdominal insufflation. These findings suggest that the cerebrovascular system can undergo adaptive changes during all phases of laparoscopic surgery. However, the extent of cardio- and cerebrovascular variation indicates the need for careful preliminary evaluation of cerebral hemodynamics in patients with vascular disorders before laparoscopic surgery.

Interleukin-6 release in the hepatic blood outflow during normothermic liver ischaemia in humans.

BACKGROUND: Liver surgery techniques have consistently improved and normothermic ischaemia of the liver is considered to be a safe procedure to reduce intraoperative haemorrhage. Hepatic failure, however, remains a significant complication. In liver ischaemia-reperfusion injury, cytokines play a key proinflammatory role. Cytokines may be part of the intercellular signalling that leads to recovery or to failure after major surgery. Moreover, they could be potential predictors of the outcome. Modulation of the pattern of cytokine response in the early postsurgery period could represent a new approach to minimise the impact of these procedures. AIMS: The aim of our study was to analyse the cytokine pattern in the hepatic blood outflow in patients undergoing surgical intervention of partial liver resection with clamping of the hepatic pedicle and liver ischaemia, and to correlate the cytokine behaviour with clinical parameters. PATIENTS: We studied eight patients (mean age 55 years) who underwent surgical intervention of liver resection during vascular exclusion of the hepatic pedicle. Patients were monitored for haemodynamic and haematological parameters during the pre-, infra- and postoperative period. METHODS: IL-I alpha, IL-6, TNF-alpha and IFN-gamma were assayed from peripheral and central vein blood at different times. Blood samples for cytokine assays were also drawn from the supra-hepatic veins after clamping of the porta hepatis. RESULTS: We found a significant increase of the IL-6 levels in the supra-hepatic samples during liver ischaemia, while the trend with IL-1alpha was less clear; IFN-gamma and TNF-alpha were undetectable with the methods used. IL-6 levels appeared to correlate positively with bilirubin and gamma-GT levels and negatively with the degree of acidosis. CONCLUSIONS: Our study confirms that during surgical ischaemic stress there is an increase of IL-6 serum levels more relevant in supra-hepatic vein blood. Cytokines could contribute to modulate the inflammatory response to liver ischaemia.

Haemodynamic and metabolic changes during major liver resection with use of hepatic total vascular exclusion.

We evaluated haemodynamic changes during major liver resection that involved total hepatic vascular exclusion (HVE) carried out through clamping hepatic pedicle and inferior caval vein upper and above the liver. Fourteen patients, undergoing different procedures of major liver resection, were enrolled in this study which used complete cardiovascular monitoring. Haemodynamic parameters were measured and calculated at five different times during the operation. Changes such as reduction in cardiac output and increase in systemic vascular resistance, though significant, were well tolerated in all patients, allowing the execution of major liver surgery. HVE offers a significant reduction in haemorrhagic and air embolus risk, but it requires the use of complete haemodynamic monitoring to evaluate tolerance to clamping and correction of unavoidable cardiovascular changes.

[Somatosensory evoked potentials during isoflurane anesthesia]. / Les potentiels évoqués somatosensoriels pendant l'anesthésie à l'isoflurane.

Changes in Sensory Evoked Potentials (SEPs) produced by different concentrations of isoflurane with or without N2O have been studied. In all subjects the early components have always remained well defined. A significant increase of N 13 and N 20 latency and of the central conduction time has been noted. The amplitude of N 20 was not much modified by isoflurane, but was affected by the addition of N2O. Isoflurane may be used during SEP monitoring if its concentration remains below 1 MAC.

[A comparison of the hemodynamic effects of midazolam and propofol during anesthetic induction in patients at vascular risk]. / Comparaison des effets hémodynamiques du midazolam et du propofol à l'induction de l'anesthésie chez le sujet à risque vasculaire.

The haemodynamic effects of midazolam or propofol, with a low dose of fentanyl, were studied during induction of anaesthesia and tracheal intubation in 20 patients undergoing aortic reconstructive surgery. This study demonstrates that both drugs induce important modifications of haemodynamic parameters undesirable in elderly, high-risk patients.

A year in review in Minerva Anestesiologica 2013.

BACKGROUND: We organized a training program for oral fiber optic intubation (FOI) under conscious sedation. The efficacy of the program was evaluated by comparing the performances of experts and novices. METHODS: The training procedure was divided into two sessions: a theoretical session on difficult airways, the fiber optic bronchoscope (FOB), remifentanil, topical anesthesia and patient interactions; and a session involving simulations of the FOI technique on dummies. For in vivo FOI, we enrolled patients requiring orotracheal intubation for elective surgery. Electrocardiograms, mean arterial pressure was railroaded over the fiberscope, and tracheal intubati6 and 7) FOIs, respectively, joined the study. To reach ±23 bpm, P=0.02), and RR was decreased (from 16±3 to 12±4 bpm, P<0.05). No differences were recorded between the experts and less-experienced anesthesiologists. The average duration of FOI was 3.3±2.0 min for experts and 4.2±2.4 min for novices (P=0.03). Procedures were successful in both groups, with patients in each group being equally satisfied with the procedures. CONCLUSION: This study highlights the importance of a structured FOI training program, demonstrating that it is possible to learn to perform FOI proficiently by practicing on dummies.