The haemodynamic responses during extubation can cause complications after open-heart surgery. In this study, we aimed to examine the effect of esmolol and magnesium before extubation on these haemodynamic responses.

Following the approval of local Ethics Committee, 120 patients having coronary artery bypass grafting with extubation in the intensive care unit were included in the study. Patients were allocated to receive esmolol 1 mg kg−1 (group I, n = 40), magnesium 30 mg kg−1 (Group II, n = 40) or normal saline (Group III, n = 40). Study medication was administered as a 20-min infusion in a volume of 20 mL. Patients were extubated just after termination of the infusion. Heart rate, blood pressure and central venous pressure were recorded prior to drug administration, before extubation, during extubation and 1 min after extubation.

Heart rate was lower in Group I than in Groups II (P < 0.05) and III (P < 0.001) and lower in Group II than in Group III (P < 0.05) during extubation. It was also lower in Group I than in Group III (P < 0.05) after extubation. Systolic blood pressure was lower in Group I than in Groups II and III (P < 0.001) during extubation. Diastolic blood pressure was higher in Group III than in Groups I and II during extubation (P < 0.001) and after extubation (P < 0.05). Mean arterial pressure was lower in Group I than in Groups II and III (P < 0.001) during extubation, lower in Group II than in Group III (P < 0.05) during extubation and lower in Group I than in Group III (P < 0.05) after extubation.

We found that using esmolol before extubation following coronary artery bypass graft surgery prevents undesirable haemodynamic responses while magnesium reduces undesirable haemodynamic responses but does not prevent them.

Arterial pulse waveform analysis has been proposed for cardiac output (CO) determination and monitoring without calibration or thermodilution (FloTrac™/Vigileo™; Edwards Lifesciences, Irvine, CA, USA). The accuracy and clinical applicability of this technology has not been fully evaluated. We designed this prospective study to compare the accuracy of the FloTrac™ system (COFT) vs. pulmonary artery catheter standard bolus thermodilution (COPAC) in patients undergoing coronary artery bypass grafting.

We studied 11 patients referred for coronary artery bypass grafting. COFT and COPAC were determined at six time points in the operating room including before and 5 min after volume expansion (500 mL 6% hetastarch). Measurements were performed on arrival in the intensive care unit and every 4 h afterwards. Bland–Altman analysis was used to assess the agreement between COFT and COPAC.

COPAC ranged from 2.0 to 7.6 L min−1 and COFT ranged from 1.9 to 8.2 L min−1. There was a significant relationship between COPAC and COFT (r = 0.662; P < 0.001). Agreement between COPAC and COFT was −0.26 ± 0.87 L min−1. Volume expansion induced a significant increase in both COPAC and COFT (from 3.4 ± 0.8 to 4.4 ± 1.0 L min−1; P < 0.001 and from 3.9 ± 1.2 to 5.0 ± 1.1 L min−1; P < 0.001, respectively) and there was a significant relationship between percent change in COPAC and COFT following volume expansion (r = 0.722; P = 0.01).

We found clinically acceptable agreement between COFT and COPAC in this setting. This new device has potential clinical applications.

The death of patients treated by ventricular assist device is usually related to multiorgan failure for which a disorder of splanchnic circulation is blamed. Gastric tonometry (measurement of gastric intra-mucosal pressure of CO2) has already been studied in many fields and especially in cardiac surgery. The aim of this study was to investigate the prognostic value of gastric tonometry monitoring after implantation of a ventricular assist device.

In this prospective study, all consecutive patients scheduled for a ventricular assist device were included. Gastric tonometry was added to standard monitoring. Data were collected (lactate, gastric CO2 (PgCO2) during cardiopulmonary bypass, at admission to ICU, 24 and 48 h later and when norepinephrine was stopped. Preoperative biologic and haemodynamic data were also collected. The primary endpoint was death.

Fifty-six patients (50 men and 6 women) were included. In 91% of the cases, the mechanical assistance was biventricular. The objective of the assistance was a bridge to transplant in 93% (n = 27). Twenty-seven deaths (48%) occurred during the study, 59% (n = 16) of them took place before the cardiac transplantation (mean time = 18 ± 16 days after assist device insertion). Many factors were found to be associated with death: weight (P = 0.018), red cells administration (P = 0.025), length of surgery (P = 0.016), PgCO2 on admission to ICU (P = 0.040) and norepinephrine dose at 24 h.

Gastric tonometry has a prognostic value in the early postoperative hours after the implantation of a ventricular assist device.

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 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.

A number of algorithms for the prevention of postoperative nausea and vomiting have been proposed. Their efficacy and efficiency remains unclear.

We assumed that four antiemetic interventions were similarly effective and achieved additive effects when combined. We applied published and hypothetical algorithms for the prevention of postoperative nausea and vomiting to patient populations with different baseline risks. As indicators of efficacy and efficiency we computed for each baseline risk and each algorithm the total number of patients receiving prophylaxis, the total number of administered interventions, the cumulative 24 h incidence of postoperative nausea and vomiting, and an Efficiency Index (i.e. the number of administered interventions divided by the achieved absolute risk reduction). This was done for cohorts of 100 patients.

Ten algorithms were tested in seven populations with different baseline risks. Algorithms were fixed (⩾ 1 intervention given to all patients, independent of baseline risk) or risk-adapted (⩾ 1 intervention administered depending on the presumed baseline risk). Risk-adapted algorithms were escalating (the greater the baseline risk, the more interventions are given) or dichotomous (a fixed number of interventions is given to high-risk patients only). With some algorithms, when applied to selected patient populations, the average postoperative nausea and vomiting incidence could be decreased below 15%; however, none produced consistent postoperative nausea and vomiting incidences below 20% across all populations. With all, the number of administered antiemetic interventions was the major factor for improved efficacy. Depending on the baseline risk, some algorithms offered potential towards improved efficiency.

Despite improved knowledge on risk factors and antiemetic strategies, none of the tested algorithms completely prevents postoperative nausea and vomiting and none is universally applicable. Anesthesiologists should try to identify the most useful antiemetic strategy for a specific setting. That strategy may be prophylactic or therapeutic or a combination of both, and it should consider institutional policies and individual baseline risks.

Diagnosis of brain death usually requires the absence of spontaneous respiratory movements during the apnoea test and an arterial carbon dioxide partial pressure above 60 mmHg. On the other hand, although capnography (end-tidal CO2) is currently monitored in intensive care unit patients, it has not been evaluated during the apnoea test in brain-dead patients. Therefore, the aim of this prospective study was first to investigate the usefulness of capnography monitoring, and secondly to evaluate the variation of the carbon dioxide partial pressure–end-tidal CO2 gradient during the apnoea test in clinically brain-dead patients.

After local Ethics Committee approval, 60 clinically brain-dead patients were investigated. End-tidal CO2 was continuously recorded before, during and after the apnoea test. Arterial blood gases were sampled immediately before and after the apnoea test for calculation of the carbon dioxide partial pressure–end-tidal CO2 gradient.

The apnoea test was clinically positive in 58 patients, whereas end-tidal CO2 was equal to 0 during the apnoea. During the 20-min apnoea test, carbon dioxide partial pressure increased from 40 ± 7 to 97 ± 19 mmHg (P < 0.001) with a rate of 2.8 ± 0.9 mmHg min−1, end-tidal CO2 increased from 31 ± 6 to 68 ± 17 mmHg (P < 0.001) and carbon dioxide partial pressure–end-tidal CO2 gradient increased from 9 ± 4 to 29 ± 10 mmHg (P < 0.001). In two patients, the apnoea test was clinically negative because of the occurrence of spontaneous respiratory movements, whereas capnography showed contemporaneously significant increases in end-tidal CO2.

End-tidal CO2 should be systematically monitored and recorded, at least for medico-legal considerations, during the apnoea test in brain-dead patients. The high variability in the carbon dioxide partial pressure–end-tidal CO2 gradient increase precludes any extrapolation of the carbon dioxide partial pressure from the end-tidal CO2 at the end of the apnoea test.

To the best of our knowledge, the value of the plasma effect site equilibration rate constant (ke0) of propofol has not been reported in Chinese patients. The aim of this prospective, randomized study was to examine the characteristics of the time to peak effect (TPEAK) of propofol, a pharmacokinetic-independent descriptor of blood–brain equilibration, and ke0 derived from TPEAK with A-line auditory-evoked potential monitor and Aspect A-2000 bispectral index monitor in Chinese patients.

Two-hundred ASA I patients received a submaximal bolus dose of propofol (1.5 mg kg−1). TPEAK was randomly measured by means of the A-line auditory-evoked potential monitor (Group AAI (auditory-evoked potential index), n = 100) or the Aspect A-2000 bispectral index monitor (Group BIS, n = 100). Using TPEAK and four previously validated pharmacokinetic parameter sets of propofol, the ke0 was estimated according to a method proposed recently.

The mean TPEAK was 145 ± 35 s (50–224 s) and 74±24 s (38–143 s) in Groups AAI and BIS, respectively (P < 0.01 between groups). There were no correlations between the patient’s age and TPEAKs (r = 0.147 and 0.031 for Groups AAI and BIS). The median ke0 in Group AAI was 0.64 min−1 with the model of Marsh, 0.17 min−1 with the Schnider model, 0.78 min−1 with the Tackley model and 0.93 min−1 with the Shafer model. The median ke0 in Group BIS was 1.87 min−1 with the model of Marsh, 0.83 min−1 with the Schnider model, 2.14 min−1 with the Tackley model and 2.48 min−1 with the Shafer model (P < 0.01 between groups and models).

The TPEAK of propofol measured by the A-line auditory-evoked potential monitor is different from that measured by the Aspect A-2000 bispectral index monitor. The TPEAKs of propofol from auditory-evoked potential index and bispectral index, and the values of ke0 calculated based on TPEAKs are different from previous reports and appear to be not affected by age. Further studies need to be taken to validate clinically the ke0 values of propofol.

The aim of this study was to determine which of two clinically applied methods, electromyography or acceleromyography, was less affected by external disturbances, had a higher sensitivity and which would provide the better input signal for closed loop control of muscle relaxation.

In 14 adult patients, anaesthesia was induced with intravenous opioids and propofol. The response of the thumb to ulnar nerve stimulation was recorded on the same arm. Mivacurium was used for neuromuscular blockade. Under stable conditions of relaxation, the infusion-rate was decreased and the effects of turning the hand were investigated.

Electromyography and acceleromyography both reflected the change of the infusion rate (P = 0.015 and P < 0.001, respectively). Electromyography was significantly less affected by the hand-turn (P = 0.008) than acceleromyography. While zero counts were detected with acceleromyography, electromyography could still detect at least one count in 51.1%.

Electromyography is more reliable for use in daily practice as it is less influenced by external disturbances than acceleromyography.