A randomised, non-crossover study of the GuardianCPV Laryngeal Mask versus the LMA Supreme in paralysed, anaesthetised female patients.

We investigated the hypothesis that the oropharyngeal leak pressure would differ between the GuardianCPV™ and the LMA Supreme™ in anaesthetised patients. We randomly assigned 120 patients to receive either the GuardianCPV or the LMA Supreme for airway management. Oropharyngeal leak pressure was measured during cuff inflation from 0 to 40 ml in 10-ml steps. In addition, intracuff pressure, fibreoptic position of the airway and drain tube, device insertion success, ventilation success, blood staining and airway morbidity were determined. Mean (SD) oropharyngeal leak pressures for clinically acceptable cuff volumes of 20-40 ml were 31 (7) cmH2O for the GuardianCPV and 27 (7) cmH2O for the LMA Supreme (p < 0.0001); mean (SD) intracuff pressures were 68 (33) cmH2O and 88 (43) cmH2O (p < 0.0001), respectively. We found no differences in device insertion success, ventilation success, fibreoptic position of the airway and drain tube, blood staining or airway morbidity. We conclude that the oropharyngeal leak pressure is better for the GuardianCPV than for the LMA Supreme in anaesthetised patients.

LMA ProSeal(TM) vs. i-Gel(TM) in ventilated children: a randomised, crossover study using the size 2 mask.

BACKGROUND: The Laryngeal Mask Airway (LMA) ProSeal(TM) and the i-Gel(TM) are two extraglottic devices with either an inflatable cuff or a non-inflatable cuff. AIM: We test the hypothesis that oropharyngeal leak pressure and fiberoptic position of the airway tube differ between the size 2 LMA ProSeal(TM) and the i-Gel(TM) in non-paralysed ventilated children. METHODS: Fifty-one children aged 1.5-6 years weighing 10-25 kg were studied using a crossover design. Anaesthesia was with remifentanil/propofol mixture. The LMA ProSeal(TM) and the i-Gel(TM) were inserted into each patient in random order. RESULTS: Oropharyngeal leak pressure for the LMA ProSeal(TM) and the i-Gel(TM) was similar at 22 (5) and 21 (5) cm H(2) O, respectively. Fiberoptic position of the airway tube for the LMA ProSeal(TM) and the i-Gel(TM) was similar, with the vocal cords visible from the distal airway tube in 94% and 96%, respectively. CONCLUSION: We conclude that oropharyngeal leak pressure and fiberoptic position of the airway tube are similar for the size 2 LMA ProSeal(TM) and i-Gel(TM) in non-paralysed ventilated children.

Directly measured mucosal pressures produced by the i-gel™ and Laryngeal Mask Airway Supreme™ in paralysed anaesthetised patients.

The i-gel™ and LMA Supreme™ are extraglottic airway devices with non-inflatable and inflatable cuffs, respectively. We hypothesised that directly measured mucosal pressures would differ between these devices in anesthetised paralysed patients. Thirty patients were randomly allocated to receive one of these two devices. Four pressure sensors were attached to all airway devices used to measure mucosal pressure at the base of the tongue, the distal oropharynx, the hypopharynx and the pyriform fossa. At these four places, median (IQR [range]) i-gel mucosal pressures were 8.0 (2.7-10.7 [0-26.7]), 5.0 (2.7-7 [1.0-37.3]), 9.3 (2.7-13.3 [0-22.7] and 8.0 (2.7-10.7 [0-25.3]) cmH(2)O, respectively, and for the LMA Supreme, these were 5.0 (0.5-8.0 [0-33]), 4.0 (1.3-9.3 [0-24]), 10.7 (4-17.3 [0-26.7]) and 8.0 (0-10.7 [0-36]) cmH(2)O, respectively. Mucosal pressures were low and similar for both devices. The LMA Supreme mucosal pressures were higher in the hypopharynx than in the distal oropharynx (p = 0.04) and base of the tongue (p = 0.011). There were no pressure differences between the locations for the i-gel.

Lung function after total intravenous anaesthesia or balanced anaesthesia with sevoflurane.

BACKGROUND: We investigated the effects of total i.v. anaesthesia (TIVA) and balanced anaesthesia (BAL) with sevoflurane on postoperative lung function in patients undergoing surgery in the prone position. METHODS: Sixty patients, aged 21-60 yr, undergoing elective lumbar disc surgery in the prone position were randomly allocated to undergo TIVA (propofol-remifentanil) or BAL (fentanyl-nitrous oxide-sevoflurane). Forced vital capacity (FVC), forced expiratory volume in 1 s, mid-expiratory flow (MEF 25-75), and peak expiratory flow were measured before and after general anaesthesia. RESULTS: Both groups were similar with respect to patient characteristic data and preoperative lung function parameters. Irrespective of the type of anaesthesia administered, lung function parameters decreased after operation, with the decrease in FVC being greater after TIVA than after BAL with sevoflurane. CONCLUSIONS: In patients emerging from general anaesthesia, postoperative reduction in FVC is greater after TIVA than after BAL with sevoflurane.

Lornoxicam characteristically modulates cerebral pain-processing in human volunteers: a functional magnetic resonance imaging study.

BACKGROUND: Lornoxicam like other non-steroidal anti-inflammatory drugs (NSAIDs) is widely used for postoperative pain therapy. Evaluation of the effect of lornoxicam on cerebral processing of surgical pain was thus the aim of the present functional magnetic resonance imaging (fMRI) study. METHODS: An fMRI-compatible pain model that mimics surgical pain was used to induce pain rated 4-5 on a visual analogue scale (VAS) at the anterior margin of the right tibia in volunteers (n=22) after i.v. administration of saline (n=11) or lornoxicam (0.1 mg kg(-1)) (n=11). RESULTS: Lornoxicam, which significantly reduced pain sensation [VAS: mean (sd) 4.6 (0.7) vs 1.2 (1.5)], completely suppressed pain-induced activation in the SII/operculum, anterior cingulate cortex, insula, parietal (inferior), prefrontal (inferior, medial), temporal (inferior, medial/superior) lobe, cerebellum, and contralateral (e.g. left-sided) postcentral gyrus (SI). Only the hippocampus and the contralateral superior parietal lobe (BA 7) were activated. CONCLUSIONS: As compared with saline, lornoxicam typically suppressed pain-induced brain activation in all regions except the hippocampus. Furthermore, de novo activation was found in the contralateral, superior parietal lobe (BA 7).

Bacterial contamination of anaesthetists' hands by personal mobile phone and fixed phone use in the operating theatre.

Following hand disinfection, 40 anaesthetists working in the operating room (OR) were asked to use their personal in-hospital mobile phone for a short phone call. After use of the cell phone, bacterial contamination of the physicians' hands was found in 38/40 physicians (4/40 with human pathogen bacteria). After repeating the same investigation with fixed phones in the OR anteroom 33/40 physicians showed bacterial contamination (4/40 with human pathogen bacteria). The benefit of using mobile phones in the OR should be weighed against the risk for unperceived contamination. The use of mobile phones may have more serious hygiene consequences, because, unlike fixed phones, mobile phones are often used in the OR close to the patient.

Effect of total intravenous anaesthesia and balanced anaesthesia on the frequency of coughing during emergence from the anaesthesia.

BACKGROUND: The effects of total intravenous anaesthesia (TIVA) and balanced anaesthesia (BAL) on coughing during emergence from the general anaesthesia have not yet been compared. METHODS: Fifty patients, aged 18-60 yr, undergoing elective lumbar disk surgery were randomly allocated to undergo TIVA (propofol-remifentanil) or BAL (fentanyl-nitrous oxide-sevoflurane). Extubation was performed in the knee-elbow position, documented on video, and subsequently evaluated by blinded examiners. RESULTS: There was no difference between TIVA and BAL patients with respect to patient characteristics, proportion of smokers, surgical time, or time of emergence. The median number of coughs was significantly lower in the TIVA group (1, range 0-9) than in the BAL group (4, range 0-20, P = 0.007). Mean maximal heart rate and mean maximal arterial pressure measured during emergence were also significantly lower in the TIVA group (P = 0.009 and P = 0.006, respectively). CONCLUSIONS: During emergence from anaesthesia in the knee-elbow position, TIVA is associated with significantly less coughing and reduced haemodynamic response when compared with BAL.

Accidental intracerebroventricular injection of anaesthetic drugs during induction of general anaesthesia.

A 51-year-old patient scheduled for surgery under general anaesthesia was accidentally given remifentanil 150 microg and propofol 1% 10 ml through an intracerebroventricular totally implantable access port placed in the right infraclavicular region, which was mistakenly thought to be an intravenous line. Severe pain in the head and neck caused the mistake to be discovered rapidly, and 20 ml of a mixture of cerebrospinal fluid and the anaesthetic drugs were aspirated from the implantable access port. The patient suffered no apparent adverse neurological sequelae.

Touch sensitivity with sterile standard surgical gloves and single-use protective gloves.

The purpose of this study was to evaluate touch sensitivity and static two-point discrimination of the dominant index and middle finger in 20 anaesthetists wearing no gloves, single-use protective gloves or sterile standard surgical gloves. Semmes-Weinstein filaments were used to measure cutaneous pressure thresholds, and a Two-Point-Discriminator to estimate static two-point discrimination. Wearing gloves significantly reduced touch sensitivity (p < 0.01), but not two-point discrimination. No difference in touch sensitivity or two-point discrimination was found between different types of gloves. The results of our study suggest that the additional cost of sterile standard surgical gloves can not be justified in terms of touch sensitivity.

Intraocular pressure during lumbar disc surgery in the knee-elbow position.

Increased intraocular pressure is often implicated in the aetiology of postoperative visual impairment. Such an increase in intraocular pressure has been demonstrated in the prone position. We investigated intraocular pressure in seven patients undergoing lumbar disc surgery in the knee-elbow position with the head resting on a cushion and turned to the side. Measurements were performed in the supine position before induction of anaesthesia and in the knee-elbow position after surgery with the patient still anaesthetised. After a mean (SD) duration of prone positioning of 121 (18) min, mean (SD) intraocular pressure in the nondependent eye was unchanged when compared to the awake state (17.7 (2.4) mmHg vs 18.9 (5.5) mmHg), whereas the intraocular pressure in the dependent eye had significantly decreased (17.0 (3.6) mmHg vs 8.1 (1.8) mmHg; p < 0.01). These results may be important for choosing the optimal position for spinal surgery when an increase in intraocular pressure should be avoided.

Are leukocytes in salvaged washed autologous blood harmful for the recipient? The results of a pilot study.

To explore whether polymorphonuclear leukocytes (PMNL) are activated to the priming threshold through intraoperative blood salvage, and are thus able to induce endothelial damage, we investigated chemotactic response (n = 20) and respiratory burst (RB; n = 20) of PMNL without (basal respiratory burst, bPMNL-RB) and after in vitro stimulation with formyl-Met-Leu-Phe (fMLP-RB) and phorbol myristate acetate (PMA-RB). Blood was processed with a continuous autotransfusion device (CATS). Heparin (Heparin group) and sodium citrate (Citrate group) were used alternately as an anticoagulant for each half of the chemotaxis and RB studies. Comparison of measurements from the processed autologous erythrocyte concentrates (paEC) to pre- and intraoperative arterial blood samples showed no statistically significant difference for any test of PMNL functional responses in an orthopedic patient population. Analysis of intraindividual changes demonstrated a significantly increased bPMNL-RB (both groups, P = 0.0032; Heparin group, P = 0.0098), fMLP-RB (both groups, P = 0.0484; Citrate group, P = 0.0371), and PMA-RB (Citrate group, P = 0.002) in the paEC compared with intraoperative arterial samples, whereas the chemotactic response did not change. Nevertheless, median values of all RB measurements in the paEC were within the range of pre- and intraoperative values, indicating that PMNLs contained in the paEC are neither impaired nor activated to the priming threshold. The results confirm the clinical experience that intraoperative blood salvage is safe to use during major orthopedic surgery and questions the beneficial effect of special leukocyte-removing filters.