The Laryngeal Tube Sonda® (LTS) and the ProSeal® Laryngeal Mask Airway (PLMA) are two new devices introduced for maintaining the airway during controlled ventilation under general anaesthesia. The present investigation compared their performance in a randomized controlled study.

One hundred ASA I–II patients, aged 18–60 yr undergoing elective minor surgery, were randomized to receive either an LTS (n = 50) or PLMA (n = 50) for airway management. After induction of general anaesthesia, the devices were inserted, its correct placement was verified and airway leak pressure was measured. Ease of insertion, quality of airway seal, fibre-optic view and postoperative pharyngeal morbidity were examined.

There were no differences in patient characteristics for both groups. First-time and second-time success rates were comparable for both groups (86 vs. 88% and 96 vs. 98% in LTS and PLMA groups, respectively). The airway of one patient in each group could not be managed with these devices after three attempts. Time until delivery of first tidal volume for LTS and PLMA was 24.5 ± 6.9 and 28.8 ± 10.3 s. Fixation and manipulation time was 54.9 ± 15.2 and 73.2 ± 25 s, respectively (P < 0.05). Airway seal pressure (cm H2O) for LTS and PLMA was 20 ± 8.6 and 24.1 ± 10.8, respectively (P = 0.04). Patients were questioned on a variety of postoperative pharyngeal morbidities. Only hoarseness was more frequent in the LTS group.

Both devices provide a secure airway, are similar in clinical utility and are easy to insert. Better airway seal was detected in the PLMA group.

The objective of the study was to determine regional pulmonary filling characteristics in 20 mechanically ventilated patients with acute lung injury.

Regional filling characteristics were calculated from tracings of regional tidal volumes vs. global tidal volumes measured by electrical impedance tomography (EIT). These plots were fitted to a polynomial function of the second degree. Regional polynomial coefficients of the second degree characterized the curve linearity of the plots. Near-zero values of the polynomial coefficient indicated a homogeneous increase in regional tidal volumes during the whole inspiration. Positive values hinted at initial low regional tidal volume change suggesting lung volume recruitment. Negative values indicated late low regional tidal volume change implying hyperinflation of this lung region.

We found a broad heterogeneity of regional lung filling characteristics. The minimal regional polynomial coefficients varied from −2.80 to −0.56 (median −1.16), while the maximal regional polynomial coefficients varied from 0.58 to 3.65 (median 1.41).

Measurements of regional filling characteristics by EIT may be a helpful tool to adjust the respiratory settings during mechanical ventilation to optimize lung recruitment and to avoid overdistension. It applies a non-pressure-related assessment to the mechanics of lung inflation and gives a view of the real problems underlying ventilatory strategies dependent on global characteristics.

Propofol is reported to have protective effects on cerebral ischaemia-induced neuronal death. The aim of this study was to explore whether propofol and halothane can protect hippocampal neuronal function from ischaemic injury during general anaesthesia in rats.

Rats were divided into 2-vessel occlusion (incomplete cerebral ischaemia) and 4-vessel occlusion (complete cerebral ischaemia) groups consisting of three subgroups each (sham-operated, propofol and halothane groups). One hour after starting propofol 1 mg kg−1 min−1 with 30% O2 and N2 or halothane 0.8% in 30% O2 and N2 rats with or without bilateral vertebral artery occlusion had bilateral common carotid arteries occluded by vessel clips for 10 min. Anaesthesia was maintained for another 1 h. Seven days after ischaemia–reperfusion, hippocampal long-term potentiation in the perforant path–dentate gyrus synapse was determined as an index of cerebral outcome.

In the propofol groups, the formation of long-term potentiation was significantly impaired in the 2-vessel and 4-vessel occlusion groups compared to the respective sham-operated groups (P < 0.01 and P < 0.05, respectively). Impaired formation of long-term potentiation in propofol groups was comparable to that in halothane groups. The formation of long-team potentiation in the propofol and halothane 2-vessel group was not significantly different from that in the awake 2-vessel group.

Propofol and halothane administered during ischaemia do not possess protective effects against hippocampal neuronal dysfunction induced by cerebral ischaemia–reperfusion as evaluated by our transient ischaemic rat models.

Bleeding after cardiac surgery correlates with morbidity and mortality. The aim of this study was to determine the influence of antiplatelet therapy on bleeding and transfusion rates in coronary artery bypass grafting.

Forty patients receiving aspirin and/or clopidogrel/ticlopidine within 7 days prior to surgery were retrospectively compared to 40 control patients lacking antiplatelet therapy for at least 8 preoperative days. Blood loss was assessed as chest-tube drainage during the first 12 h after surgery. Units transfused were recorded intraoperatively and during stay in the intensive care unit.

Both groups were comparable for pre- and intraoperative data. Irrespective of single or combined antiplatelet therapy, treated patients demonstrated lower fractions of the creatine-kinase isoenzyme MB (5.8 ± 3.1 vs. 8.2 ± 4.1%; P = 0.004) and infarction rates (0 vs. 3; P = 0.240) than control patients, but had significantly more haemorrhages (940 ± 861 mL vs. 412 ± 590 mL; P = 0.002) and transfusion requirements (red cells: 4.5 ± 4.9 vs. 1.5 ± 2.3, plasma: 4.9 ± 6.4 vs. 1.3 ± 2.5, platelets: 1.5 ± 1.3 vs. 0.1 ± 0.2; all P ⩽ 0.001). The differences to control patients were more pronounced for only short antiplatelet therapy free intervals or ongoing antiplatelet therapy (P⩽2 days ⩽ 0.019). For antiplatelet therapy free intervals longer than 2 days, bleeding and transfusion rates (except for platelets) were nonsignificantly higher as compared to control patients (P ⩾ 0.058).

To overcome increased blood loss and transfusion rates, antiplatelet therapy should be discontinued for at least 2 days before elective coronary surgery. Whether patients at high risk for myocardial infarction might benefit from ongoing antiplatelet therapy remains to be investigated.

Antithrombin levels during cardiac surgery critically decrease, due to both hemodilution and consumption. This factor prompted the question of whether improved attenuation of hemostatic activation can be achieved by high dose treatment with antithrombin. The aim of this review is to present the currently available pre-clinical and clinical data on the use of antithrombin in cardiac surgery.

Review of the available literature searched using the terms ‘AT’ or ‘Antithrombin’ and ‘Cardiac surgery’ or ‘CPB’ or ‘Cardiopulmonary bypass’.

Antithrombin has been proposed in cardiac operations both as purified concentrates and as recombinant human preparations. The main clinical field where antithrombin supplementation is proposed is in case of heparine resistance (failure to achieve adequate anticoagulation following a standard heparin dose). However, other clinical scenarios have been investigated (modulation of inflammatory reaction; pulmonary vasodilation; prevention of thromboembolic complications).

Many studies suggest that antithrombin supplementation during and after cardiac surgery may be beneficial to correct abnormally low values. One article found an association between low values of antithrombin activity at the end of the operation and adverse postoperative outcomes. However, a large prospective, randomized trial is still needed to finally set the role of antithrombin supplementation in cardiac surgery.

Pain on injection is still a problem with propofol. The purpose of the study was to compare the effectiveness of diphenhydramine and lidocaine on pain caused by propofol at the site of injection.

One hundred and eighty ASA I–II adults undergoing elective surgery were randomly assigned into three groups of 60 each. Group I (placebo) received 2 mL normal saline, Group II received 2 mL (40 mg) 2% lidocaine and Group III received 2 mL (20 mg) diphenhydramine intravenously (i.v.) during a 1-min venous occlusion, followed by propofol into a cephalic forearm vein of the antecubital fossa. Pain assessment was made immediately after propofol injection.

In the placebo group 25 (41.7%) patients experienced pain during propofol injection as compared to 2 (3.3%) and 3 (5.0%) in the lidocaine and diphenhydramine groups, respectively. The prevalence of pain and pain score were significantly less in both the lidocaine and diphenhydramine groups than in the placebo group (P= 0.00). No difference was found between the diphenhydramine and lidocaine groups (P = 0.60).

Previous injection of diphenhydramine with venous occlusion can be considered as an alternative to lidocaine for reducing the prevalence of pain caused by injection of propofol into peripheral veins.

The aim of this study was to compare cardiac output measurements of the non-invasive cardiac output and the pulmonary artery catheter during repeat surgery for hip replacement.

In this prospective observational study, patients undergoing repeat hip surgery who needed a pulmonary artery catheter were included. A standard protocol was followed for induction, endotracheal intubation and maintenance of anaesthesia (sufentanil, etomidate, sevoflurane, cisatracurium). After endotracheal intubation, the non-invasive cardiac output was connected and a pulmonary artery catheter was inserted. Data were collected every 3 min until patients were extubated.

Ten patients were included and 2455 points of comparison recorded. Cardiac output from the pulmonary artery catheter varied from 1.7 to 8.9 L min−1 (mean 4.1 L min−1) and the non-invasive cardiac output (using averaging mode) from 1.7 to 8.0 L min−1 (mean 3.7 L min−1). There was a significant correlation between them (P < 0.01; bias 0.3 L min−1; limits of agreement +1.9 and –2.5 L min−1), although these differed between patients.

The perioperative bias was small and the non-invasive cardiac output slightly underestimated cardiac output intraoperatively compared to the pulmonary artery catheter. The bias was smaller when mean cardiac output was below 3 L min−1. Core temperature between 34.4°C and 37.6°C had no influence on the differences.

The effectiveness of the Cobra perilaryngeal airway as a routine airway device and as a conduit for tracheal intubation has not been prospectively studied to date. This study aimed to evaluate the Cobra perilaryngeal airway for its potential role in an emergency airway rescue, by analysing its use as a bridge to blind or fibre-optic-guided intubation.

In 49 patients, the procedure was carried out as follows: fibre-optic view through the Cobra perilaryngeal airway was assessed after the insertion of the Cobra perilaryngeal airway, then blind intubation through the Cobra perilaryngeal airway was attempted. After evaluating the success of blind intubation, fibre-optic-guided intubation was performed through the Cobra perilaryngeal airway. The endotracheal tube was removed after evaluating the success of fibre-optic-guided intubation, and then conventional laryngoscopy was carried out to evaluate the Cormack & Lehane grade and airway trauma.

In all, 95.9% (47/49) of patients had adequate ventilation using the Cobra perilaryngeal airway; the success rates for the blind and fibre-optic-guided intubation were 36.2% and 83.0%, respectively. The patients were divided into two groups according to the fibre-optic view. Group 1 included patients with an obstructed view by an anterior grill of the Cobra perilaryngeal airway head, and a view of the anterior epiglottis (downfolded epiglottis) with or without a visible larynx (16/47, 34.0%). Group 2 included the remaining patients (31/47, 66.0%). The success rates of the blind and fibre-optic intubations were different between the two groups (blind intubation: 12.5% vs. 48.4%, fibre-optic intubation: 62.5% vs. 93.6%, P < 0.05). The success rates of blind and fibre-optic-guided intubations were not different according to the Cormack & Lehane grading (P > 0.05). 42.6% of patients had blood staining after removing the device and complications such as trauma and oedema were confirmed under direct laryngoscopy.

This study suggests that the Cobra perilaryngeal airway could be a useful airway device as a vehicle for fibre-optic-guided intubation; however, it needs caution against airway trauma.

Electroencephalographic entropy is used to measure the degree of brain hypnosis and anaesthesia depth. Two parameters are displayed in the monitor, state entropy (SE) and response entropy (RE). Ageing leads to reduction in liver mass as well as hepatic blood flow, which decreases clearance of propofol and increases the risk of cardiovascular adverse effects. The aim of this study is to demonstrate the effect of electroencephalographic entropy on propofol requirement and haemodynamic parameters during induction of anaesthesia in elderly patients.

We studied 72 elderly patients. Standard monitoring was performed for all patients together with entropy monitor. Patients were allocated randomly either to the control group, which were given the recommended induction dose of propofol, or to the entropy group which was induced with propofol based on entropy reading where the end-point was SE 50 and SE-RE difference less than 10. Propofol induction doses and haemodynamic changes were recorded. Anaesthesia was maintained using sevoflurane and O2 air mixture.

After induction of anaesthesia, the systolic, diastolic, mean arterial pressure, RE and SE were significantly lower in the control group (P value < 0.05). Total dose of propofol and the dose kg−1 were significantly reduced by 37.1% and 31.8%, respectively, in the entropy group (P value < 0.01).

The use of electroencephalographic entropy during induction of anaesthesia in elderly patients reduces propofol requirements and maintains cardiovascular stability.

Dynamic balance involving movement of the centre of gravity is important for the evaluation of street fitness after sedation. The purpose of this study was to compare the recovery of dynamic balance after intravenous sedation with propofol or midazolam, and to investigate the usefulness of simple dynamic balance tests in evaluating the recovery.

Fourteen young male volunteers underwent intravenous sedation with propofol and midazolam for 1 h each at an interval of more than 1 week. Computerized dynamic posturography using a multi-axial tilting platform, the 10-m maximum-speed walking test and the timed ‘up & go’ test (subjects stand up from a chair, walk 5 m and back with maximum speed and sit down again) were performed before and after sedation. The increase in each variable of the tests described above represents a reduction of function.

The score of the computerized dynamic posturography was significantly lower in propofol sedation than that in midazolam sedation until 40 min after the end of sedation (P = 0.006). The scores of maximum-speed walking test and timed ‘up & go’ test were significantly lower in propofol sedation than those in midazolam sedation till 60 min after the end of sedation, respectively (P = 0.035 and 0.042). The timed ‘up & go’ and maximum-speed walking tests were well and significantly correlated with computerized dynamic posturography in midazolam sedation (timed ‘up & go’ test vs. computerized dynamic posturography: r = 0.66, P < 0.01; and maximum-speed walking test vs. computerized dynamic posturography: r = 0.53, P < 0.01).

The timed ‘up & go’ and maximum-speed walking tests are useful simple dynamic balance tests well correlated with precise computerized dynamic posturography for the evaluation of the recovery of dynamic balance from midazolam sedation in younger adults.

Epidural and intravenous analgesia are widely used for postoperative pain management. Efficacy and safety is enhanced with the establishment of acute pain services. We studied the terms of application of these techniques in Greek hospitals and compared practices between anaesthetic departments with or without acute pain services.

We performed a postal survey regarding departmental policy on the application of epidural and intravenous analgesia, patient monitoring, audit and educational activities, acute pain service teams and proposals for improvement. Pain services were classified according to predetermined quality criteria. Hospitals with or without acute pain services were compared.

Response rate was 46.3% (51 of 110 departments). Epidural analgesia was used in 49 departments, equally applied as intermittent boluses or continuous infusion. Twenty-two of the 39 departments that were using continuous infusion, used exclusively a lumbar approach. Intravenous analgesia was used by 42 (82%) departments; 13 used exclusively continuous infusion. All eight departments that had an established acute pain service fulfilled the predefined quality criteria compared with only ten of the remaining 43 (P < 0.001).

Our study discloses important issues regarding the use of intravenous and epidural analgesia and postoperative patient monitoring in Greek hospitals. Implementation of acute pain services that are satisfying the quality criteria may help to improve patient care.

An increased risk of awareness during general anaesthesia in patients receiving tramadol has been reported. We studied whether tramadol affects the amount of propofol required for induction of anaesthesia.

In this prospective controlled study, we evaluated 46 patients, half of whom used tramadol regularly. Entropy indices, state entropy and response entropy, were used to assess the level of hypnosis. Patients were anaesthetized with a propofol infusion (1 mg kg−1 min−1) until they first became unconscious, and further until they developed a burst suppression pattern in the electroencephalogram. The doses of propofol needed to reach these end-points were recorded.

The amount (median, (range)) of propofol required for loss of consciousness was 2.0 (1.0–5.5) mg kg−1 and 2.4 (0.9–8.3) mg kg−1 (P = 0.95) in the tramadol users and controls, respectively. The amount of propofol required for burst suppression was 5.8 (3.9–12.7) mg kg−1 and 6.4 (2.9–15.1) mg kg−1 (P = 0.89) in the tramadol users and controls. There was no difference between the groups in state entropy and response entropy during different stages of induction of anaesthesia.

Tramadol did not affect the dose of propofol required to achieve loss of consciousness or burst suppression pattern in electroencephalogram during induction of general anaesthesia. However, there was a ninefold inter-individual variation in propofol dose requirement for loss of consciousness and a fivefold variation for reaching burst suppression. Due to extensive inter-individual variability, monitoring the level of hypnosis during general anaesthesia using propofol may enhance the correct dosage.

The aim of this prospective, randomized, double-blind, placebo-controlled study was to evaluate the efficacy of phrenic nerve infiltration with ropivacaine 0.2% on the incidence and severity of ipsilateral shoulder pain after thoracotomy in patients receiving continuous thoracic epidural analgesia.

Fifty ASA physical status II–III patients, receiving thoracic epidural analgesia for post-thoracotomy pain, were randomly allocated to receive infiltration of the ipsilateral phrenic nerve with either ropivacaine 0.2% 10 mL (ropivacaine, n = 25), or saline 0.9% (control, n = 25) just before lung expansion and chest closure. A blinded observer recorded the incidence and severity of ipsilateral shoulder pain 6, 12, 24, 36 and 48 h after surgery. Postoperative respiratory function was also evaluated with blood gas analyses.

The cumulative incidences of ipsilateral shoulder pain during the first 24 h after surgery were 8/25 in the ropivacaine and 16/25 in the control groups (P = 0.047), with median (range) onset times for shoulder pain of 2 (2–24) h with ropivacaine and 0.5 (0.5–24) h in controls (P = 0.005). No differences were reported on the second postoperative day. The areas under the curves of the amount of pain over time were 0 (0–2760) mm h for the ropivacaine and 350 (0–1900) mm h for the control groups (P = 0.06). Postoperatively, similar reductions in indices of oxygenation were observed in both groups.

Phrenic nerve infiltration with ropivacaine 0.2% 10 mL reduced the incidence and delayed the onset of ipsilateral shoulder pain during the first 24 h after open lung resection, with no clinically relevant effects on respiratory function.

Delayed recovery of cognitive function is a well-recognized phenomenon in older patients. The potential for the volatile anaesthetic used to contribute to alterations in postoperative cognitive function in older patients following minor surgical procedures has not been determined. We compared emergence from isoflurane and sevoflurane anaesthesia in older surgical patients undergoing urological procedures of short duration.

Seventy-one patients, 60 yr of age or older, undergoing anaesthesia expected to last less than 60 min for ambulatory surgery, were randomly assigned to receive isoflurane or sevoflurane. A standardized anaesthetic protocol was used, with intravenous fentanyl 1 μg kg−1 and propofol 1.5–2.0 mg kg−1 administered to induce anaesthesia. Anaesthesia was maintained with either sevoflurane or isoflurane in 65% nitrous oxide and oxygen. Early and intermediate recovery times were recorded. The mini mental state examination and digit repetition forwards and backwards were administered at baseline, and at 1, 3 and 6 h postoperatively, to assess cognitive function.

There were no between-group differences in (sevoflurane vs. isoflurane, mean ± standard error of the mean) times to removal of the laryngeal mask airway (7.7 ± 0.6 vs. 7.1 ± 0.4 min), verbal response time (10.1 ± 0.7 vs. 9.9 ± 0.7 min) and orientation (12.1 ± 0.7 vs. 12.1 ± 0.7 min). Intermediate recovery, as measured by time to readiness for discharge from the post anaesthesia care unit (44.9 ± 1.5 vs. 44.3 ± 1.5 min), was similar in the two groups. Postoperative indices of cognitive function and attention were comparably reduced at 1 h, but returned to baseline in both groups at 6 h.

Isoflurane and sevoflurane anaesthesia resulted in similar clinical and neurocognitive recovery profiles in older patients undergoing ambulatory surgical procedures of short duration.

The objective of the study was to assess the safety of training fibre-optic intubation performed under propofol light general anaesthesia in patients with an anticipated difficult intubation.

Patients with ear, nose and throat cancer having at least two criteria for anticipated difficult intubation and scheduled for fibre-optic intubation were included prospectively. In 26 patients, intubation was performed by an anaesthesia resident (under senior supervision), whereas in 20 patients, it was performed by a senior anaesthesiologist. All patients received propofol light general anaesthesia adjusted to maintain both loss of consciousness and spontaneous ventilation.

Of the 46 patients, 45 had successful fibre-optic intubation, and one needed a rescue procedure because of hypoxaemia. Residents failed to intubate four patients, who were easily intubated by the senior. Episodic hypoxaemia (SPO2 < 90%) occurred in three patients in each group. No statistically significant difference was found between junior and senior neither on the duration of the procedure (9.3 ± 4.9 vs. 7.5 ± 4.0 min) nor on the propofol consumption (197 ± 130 vs. 193 ± 103 mg) or the ETCO2 at the end of the procedure (36 ± 6 vs. 38 ± 6 mmHg), respectively.

Teaching fibre-optic tracheal intubation in patients with anticipated difficult intubation and sedated with propofol did not increase morbidity significantly compared with an experienced anaesthesiologist. Fibre-optic intubation under propofol light general anaesthesia could be safely performed by a resident as long as a senior anaesthesiologist is permanently present, spontaneous ventilation is maintained and a rescue oxygenation technique is immediately available.

A positive effect of insulin–glucose–potassium infusion in severe bupivacaine-induced cardiovascular collapse has been described in vivo. It has been speculated that an antagonistic influence of insulin on sodium channel inhibition, transient outward potassium current, calcium-dependent adenosine triphosphatase or even improved myocardial energetics may be responsible for this effect. Using an isolated heart model, we therefore sought to further elucidate insulin effects in l-bupivacaine-induced myocardial depression.

An isolated rat heart constant-pressure perfused, non-recirculating Langendorff preparation was used. Hearts were exposed to l-bupivacaine 5 μg mL−1 and insulin 10 mIU mL−1. Heart rate, systolic pressure, the first derivative of left ventricular pressure (+dP/dt), coronary flow, double product, PR and QRS intervals were recorded. Hearts were freeze-clamped and high-performance liquid chromatography measurement of the total adenine nucleotide pool was performed.

l-Bupivacaine led to a significant decrease in heart rate, +dP/dt, systolic pressure, coronary flow and double product, and to an increase in PR and QRS. Insulin exerted a positive inotropic effect, significantly augmenting +dP/dt and systolic pressure in both l-bupivacaine-treated and control hearts. Heart rate, coronary flow, total adenine nucleotides, PR and QRS were not significantly changed by the insulin intervention.

Insulin did not have a significant effect on total adenine nucleotides in controls and in l-bupivacaine-treated hearts. However, it does exert a positive inotropic action in bupivacaine-induced myocardial depression. We conclude that the positive effect of insulin application lies in positive inotropic action and not in changes in total adenine nucleotides.

Purified antithrombin concentrates or human recombinant antithrombin have been proposed for treating heparin resistance in cardiac operations with cardiopulmonary bypass, and exert a beneficial effect in terms of haemostatic system activation control. However, little information is available with respect to antithrombin supplementation and clinical outcome in selected categories of patients. The aim of this study is to evaluate clinical outcome data in patients intraoperatively treated with purified antithrombin compared to a control population.

89 patients forming the AT-treated group received purified antithrombin to correct preoperatively low values of antithrombin activity or to treat heparin resistance. The Control group was retrospectively created with a propensity score analysis. After verifying the homogeneity of the two groups, various outcome variables were compared between groups.

Patients in the AT-treated group had a shorter Intensive Care Unit (2.6 ± 3 vs. 3 ± 2.7 days) and Hospital (7.5 ± 3.5 vs. 8.6 ± 4.5 days) stay, and a lower rate (relative risk 0.1, 95% confidence interval 0.01–0.81) of severe postoperative morbid events. Conversely, they demonstrated a significant, albeit clinically irrelevant, more pronounced postoperative bleeding tendency.

AT supplementation in patients at risk for inadequate thrombin suppression during the operation reduces postoperative complications and shortens the recovery time. However, a careful monitoring of the heparin requirements is recommended in order to avoid an undesired excessive postoperative bleeding.