Towards a standardized framework for AI-assisted, image-based monitoring of nocturnal insects.

Automated sensors have potential to standardize and expand the monitoring of insects across the globe. As one of the most scalable and fastest developing sensor technologies, we describe a framework for automated, image-based monitoring of nocturnal insects-from sensor development and field deployment to workflows for data processing and publishing. Sensors comprise a light to attract insects, a camera for collecting images and a computer for scheduling, data storage and processing. Metadata is important to describe sampling schedules that balance the capture of relevant ecological information against power and data storage limitations. Large data volumes of images from automated systems necessitate scalable and effective data processing. We describe computer vision approaches for the detection, tracking and classification of insects, including models built from existing aggregations of labelled insect images. Data from automated camera systems necessitate approaches that account for inherent biases. We advocate models that explicitly correct for bias in species occurrence or abundance estimates resulting from the imperfect detection of species or individuals present during sampling occasions. We propose ten priorities towards a step-change in automated monitoring of nocturnal insects, a vital task in the face of rapid biodiversity loss from global threats. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.

B Cell Synovitis and Clinical Phenotypes in Rheumatoid Arthritis: Relationship to Disease Stages and Drug Exposure.

OBJECTIVE: To define the relationship of synovial B cells to clinical phenotypes at different stages of disease evolution and drug exposure in rheumatoid arthritis (RA). METHODS: Synovial biopsy specimens and demographic and clinical data were collected from 2 RA cohorts (n = 329), one of patients with untreated early RA (n = 165) and one of patients with established RA with an inadequate response to tumor necrosis factor inhibitors (TNFi-IR; n = 164). Synovial tissue was subjected to hematoxylin and eosin and immunohistochemical staining and semiquantitative assessment for the degree of synovitis (on a scale of 0-9) and of CD20+ B cell infiltrate (on a scale of 0-4). B cell scores were validated by digital image analysis and B cell lineage-specific transcript analysis (RNA-Seq) in the early RA (n = 91) and TNFi-IR (n = 127) cohorts. Semiquantitative CD20 scores were used to classify patients as B cell rich (≥2) or B cell poor (<2). RESULTS: Semiquantitative B cell scores correlated with digital image analysis quantitative measurements and B cell lineage-specific transcripts. B cell-rich synovitis was present in 35% of patients in the early RA cohort and 47.7% of patients in the TNFi-IR cohort (P = 0.025). B cell-rich patients showed higher levels of disease activity and seropositivity for rheumatoid factor and anti-citrullinated protein antibody in early RA but not in established RA, while significantly higher histologic synovitis scores in B cell-rich patients were demonstrated in both cohorts. CONCLUSION: We describe a robust semiquantitative histologic B cell score that closely replicates the quantification of B cells by digital or molecular analyses. Our findings indicate an ongoing B cell-rich synovitis, which does not seem to be captured by standard clinimetric assessment, in a larger proportion of patients with established RA than early RA.

Identification of the novel HLA-C*07:315 allele.

The HLA-C*07:315 allele is mostly identical to HLA-C*07:09 but has a non-synonymous substitution of C to G in exon 2.

[Removal of the laryngeal mask airway in the post-anesthesia care unit. A means of process optimization?]. / Geplante Entfernung der Kehlkopfmaske im Aufwachraum. Mittel zur Prozessoptimierung?

BACKGROUND: Removal of the laryngeal mask airway in the post-anesthesia care unit could potentially contribute to a faster turnover from one operation to the next. The aim of this study was, therefore, to obtain an insight into the potential time saving and the safety of planned removal of the ProSeal™-LMA (PLMA) in the post-anesthesia care unit. METHODS: In this study 120 adult patients with American Society of Anesthesiologists (ASA) classification I-II, age range 18-85 years, undergoing a surgical procedure under general anesthesia in which the PLMA was used were randomly assigned to one of two groups. In group I, the PLMA was removed in the awake patient in the operating room close to the end of the procedure. In group II, the anesthetised but spontaneously breathing patients were moved to the recovery room and the PLMA removed when the patient was awake. The anesthesia technique was standardized [balanced, sevoflurane, fentanyl, bispectral index-guided (BIS) target value=35±5] and identical in both groups until randomization. Patients were breathing room air during transport to the recovery room. Different time intervals as well as the incidence of critical incidents were compared between groups. An oxygen saturation (S(p)O(2)) value <95% was considered a clinically relevant and S(p)O(2) values <90% as clinically critical O(2)-desaturation. RESULTS: Removal of the PLMA took place after an average of 4.9±5.1 min in group I and after 19.5±9.6 min in group II. There was no difference in the availability of the anesthetist in the operating room for the following procedure between groups (group I: 12±5.6 min vs. group II: 10.7±4.2 min, p>0.05) despite the fact that patients of group II left the operating room faster (4.9±3.9 min) than patients of group I (7.1±5.1 min, p<0.01). In group II patients were ready for discharge (White score=12) from the recovery room later (13.2±8.2 min) than in group I (3.6±4.8 min, p<0.01). There were no significant differences in other process related time intervals between group I and group II: duration of the operation (113.2±45.9 min vs. 105.3±42.6 min), duration of dressing (5.1±3.7 min vs. 4.6±2.8 min), duration of transport to the recovery room (3.9±1.3 min vs. 3.6±1.3 min) and information at end of surgery by the surgeon (22.5±9.3 min vs. 22.4±10.5 min). The incidence of clinically relevant as well as clinically critical O(2) desaturation at the time of recovery room arrival (S(p)O(2)≤90%) was increased in group II with 33.3% vs. 56.6% and 13.3% vs. 6.7%, p<0.01, respectively. CONCLUSION: Planned PLMA removal in the recovery room after BIS-guided balanced anesthesia did not enable the anesthetist to be available earlier for induction of anesthesia in the following patient. Hence the anesthetist could not contribute to a faster turnover of cases. Obviously, with the type of close communication between surgeon and anesthetist dictated by the study protocol (announcement of expected end of surgery by the surgeon 20 min before end of surgery) it is possible for the patient to regain consciousness within a very small time window following the end of surgery. Following this kind of protocol, postponement of removal of the LMA in the recovery room does not seem to be attractive neither from a clinical nor an economic point of view. In contrast, removal of LMA in the recovery room should be restricted to occasional cases with an abrupt end of the operation or prolonged emergence from anesthesia. The obvious risk of hypoxemia necessitates continuous O(2) application and S(p)O(2) monitoring during transport to the recovery room.

[ProSeal™laryngeal mask in normal weight and obese patients : oxygenation under pressure-controlled ventilation and different end-expiratory pressures]. / ProSeal®-Kehlkopfmaske in normalgewichtigen und adipösen Patienten : Oxygenierung unter druckkontrollierter Beatmung mit verschiedenen endexspiratorischen Drücken.

BACKGROUND: Most of the data on combining pressure-controlled ventilation (PCV) with positive end-expiratory pressure (PEEP) come from studies with an endotracheal tube (ETT) whereas data on utilization of PEEP with a laryngeal mask airway (LMA) are limited. The LMA-ProSeal® (PLMA) forms a more effective seal of the airway than the LMA-Classic™ (CLMA). The application of PEEP when PCV is used with the PLMA could have an impact on oxygenation in adult patients. METHODS: For this study 148 patients with an mean age of 44 years (range18-65 years) and mean weight of 86 kg (range 49-120 kg) were recruited in 2 groups: group N ((Normal)): body-mass index (BMI) <30 kg/m(2) and group O ((Obesity)) BMI ≥30 and <36 kg/m(2). Cardiovascular and pulmonary disease and a history of smoking were exclusion criteria in addition to the usual LMA contraindications. The bispectral index-guided (BIS) anesthesia technique was used with propofol, fentanyl, and remifentanil without muscle relaxants. Measurement of PLMA seal pressure served as recruitment maneuver and PCV was randomly combined with 0 cmH(2)O, 5 cmH(2)O or 8 cmH(2)O PEEP. An arterial blood gas sample was taken 50 min after induction of anesthesia under an inspiratory oxygen fraction (F(I)O(2)) of 0.3. In the first part partial oxygen pressure (p(a)O(2)) under 0 cmH(2)O was compared with p(a)O(2) under 5 cmH(2)O and in the second part p(a)O(2) under 5 cmH(2)O was compared with p(a)O(2) under 8 cmH(2)O. A significant difference was set as p<0.025. RESULTS: The PLMA could be placed after 3 attempts in 147 patients. The mean seal pressure was in the range of 24-30 cm H(2)O. Application of randomized PEEP was possible in all patients and ventilation was comparable between corresponding groups. In group N no differences were found in part 1 (139±28 vs. 141±28 mmHg, p=0.88) or part 2 (127±24 vs. 134±26 mmHg, p=0.35). In group O there was a significant difference in p(a)O(2) in part 1 (75±12 vs. 94±18 mmHg, p=0.02) but not in part 2 (92±21 vs. 103±18 mmHg, p=0.04). CONCLUSIONS: The application of PEEP when PCV is used with the PLMA results in improved oxygenation in obese patients with a BMI ≥30 and <36 kg/m(2) but not in normal weight patients. Alveolar recruitment produced by seal pressure measurements below 30 cm H(2)O was sufficient to produce a clinically significant improvement in oxygenation in most obese patients and there was a significant improvement of oxygenation with PEEP=5 cmH(2)O. Both findings are in contrast to findings of studies using an ETT which suggests that higher pressures (40 cmH(2)O) are needed for recruitment of collapsed alveoli and higher PEEP (10 cmH(2)O) is needed to produce a clinically significant improvement in oxygenation in obese patients. The results of this study support data showing that the consequences of bronchopulmonary airway reactions known to occur with an ETT are less pronounced or absent when an LMA is used.

[Clinical use of the ProSeal™ laryngeal mask in infants, children and adolescents : prospective observational survey]. / Klinischer Einsatz der ProSeal®-Kehlkopfmaske bei Säuglingen, Kindern und Jugendlichen : Prospektive Anwendungsbeobachtung.

BACKGROUND: In contrast to the adult population scientific data on ProSeal™-LMA (PLMA) usage in infants, children, and adolescents are rather limited. Most data have been generated by expert users in studies on small numbers of patients. The aim of this study was to gather comprehensive data about the characteristics, efficacy and safety of its routine use in children at a teaching institution. METHODS: Using a standardized reporting form the following data were collected in the course of a prospective survey on PLMA usage in patients aged up to 18 years: user characteristics, patient characteristics, type and duration of operation, details of airway management and anesthetic technique, details of PLMA usage-related critical incidents and postoperative status of the patient. RESULTS: Use of the PLMA was documented in 512 patients by 61 anesthesiologists (32% staff grade, 68% trainees). The average age, height and weight of the patients was 8 years (range 0-17 years), 130 cm (range 54-193 cm) and 29 kgBW (range 5-130 kgBW), respectively. Anesthesia was induced intravenously in 458 patients (89.5%) and by inhalation in 54 patients. Maintenance of anesthesia was by total intravenous anesthesia (propofol) in 184 patients (36.5%) and by an inhalational agent (sevoflurane or desflurane) in 320 patients (63.7%). Neuromuscular blocking agents were used in 7 patients (1.4%). The patients were anesthetized for an average of 80 min (range 15-270 min) and insertion success rate was 99% with a maximum of 3 attempts. The average initial airway leak pressure was 27cm H(2)O (range 12-40 cm H(2)O); however, lower pressures were recorded for smaller size masks (size 1.5-2.5) without a dorsal cuff than for larger size masks (size 3-5; p<0.01). Ventilation was controlled in 96% and combined with PEEP in 39% of cases. Critical incidents associated with PLMA were documented in a total of 8.4% of cases, the majority being minor trauma, evidenced by blood on the PLMA on removal, followed by some form of airway obstruction. In 3.3% of cases these incidents were judged as clinically relevant of which 0.6% were classified as serious. Twice as many problems occurred during induction of anesthesia as in the maintenance phase and emergence phase of anesthesia (p=0.037). In 1.6% the PLMA was abandoned in favor of the endotracheal tube. In 7 patients the PLMA was exchanged in the induction room whereas in 1 patient this took place intraoperatively. Failure of ProSeal™ laryngeal mask use correlated with the level of PLMA use experience with 75% of failures caused by users with an experience of less than 50 uses and no failure in users with an experience of more than 100 uses. Failure did not correlate with the size of the mask. In 2 cases the PLMA was successfully used after failed endotracheal intubation. In 6 patients drainage of regurgitated gastric fluid through the drain tube was documented. No long-term adverse sequelae resulted in any patient. CONCLUSION: This survey demonstrates that the PLMA can be used effectively in infants, children and adolescents in the routine university clinical practice setting. However, this study does not confirm the extremely high success and low complication rates reported in controlled studies. The results support the assumption that with the PLMA regurgitated gastric fluid can be drained away from the larynx through the drain tube.

[Airway leak pressure of the ProSeal laryngeal mask airway. Comparison with and without a gastric tube placed through the drain-tube]. / Leckagedruck der ProSeal-Kehlkopfmaske. Vergleich bei mit und ohne durch den Drainagekanal platzierter Magensonde.

BACKGROUND: The ProSeal laryngeal mask airway (PLMA) has been studied in numerous investigations and the airway leak pressure (P(leak)) is often used as a primary end-point, particularly in comparative studies with other supraglottic airway devices. The PLMA offers the opportunity to place a gastric tube through the drain-tube and P(leak) measurement can take place both with and without a gastric tube. With this study we tested the hypothesis that the use of a gastric tube influences the P(leak). METHODS: The P(leak) of the PLMA was studied in 98 patients under total intravenous anaesthesia with propofol (0.1-0.15 mg*kgBW-1*min-1) and remifentanil (0.1-0.3 microg*kgBW-1*min-1) before and after placement of a gastric tube through the drain-tube of the PLMA. RESULTS: There was no significant difference between the mean baseline P(leak) without a gastric tube in place (25+/-6.3 cm H(2)O) and the mean P(leak) after placement of a gastric tube (25+/-6.7 cm H2O; p=0.6). CONCLUSION: Placement of a gastric tube through the drain-tube of the PLMA does not influence the P(leak). Providing the same method of measurement has been used, P(leak) values from different studies obtained with or without a gastric tube in place are comparable.

[Anaesthesia education at german university hospitals: the teachers' perspective -- results of a nationwide survey]. / Die Weiterbildung für Anästhesiologie an deutschen Universitätskliniken aus Sicht der Ausbilder -- Ergebnisse einer bundesweiten Umfrage.

AIM OF THIS STUDY: The principle purpose of this study was to collect data on the conditions and practice of anaesthesia education as well as the teaching qualification of consultants at German university hospitals. Based upon the collected data, areas of weakness and strength as well as measures required to improve anaesthesia training are described. METHODS: A questionnaire containing 26 items was mailed to 607 consultants employed at 41 German university hospitals in June 2003. RESULTS: A total of 255 questionnaires was analysed (response rate: 43 %). Genuine training activities account for 14 % of the working hours of the participating consultants. On average, at the institutions of participating consultants, novices work for a duration of 1 month together with a consultant anaesthetist before they give anaesthetics without direct and constant supervision. When asked to describe the predominant method of training at their institution 71 % indicated "case-oriented teaching"; however, 53 % chose "see one, do one, teach one" and 49 % "learning by doing" as method of training as well (multiple choice). According to 63 % of respondents, departmental educational activities usually happen after their regular working hours. "Daily workload" (96 %), "time pressure" (96 %), "lack of time" (96 %) and "lack of personnel" (90 %) were indicated as the main obstacles of teaching. According to 80 % of respondents, a dedicated financial budget for education does not exist; instead, financial resources of third parties (industry) (58 %), of the state (for research und undergraduate education) (60 %) and of patients service (66 %) are used to ensure training of anaesthesia residents. CONCLUSION: Due to a lack of a dedicated financial budget for resident training and an increasing economic pressure, "lack of time" and "lack of personnel" are the main factors leading to the situation at German university hospitals that consultants can only spend 14 % of their working hours for teaching purposes despite of sufficient qualification and motivation. As a consequence, novice anaesthetists are faced with the situation to be working without direct and constant supervision after 1 month of training.

Use of the LMA-ProSeal in an experimental pig model -- a potential animal model for laryngeal mask airway research: results of a pilot study.

OBJECTIVE: In light of the increased use of the LMA-ProSeal (P-LMA) it seems desirable to consider the P-LMA for prolonged surgical cases or post-operative ventilation. Long-term use could carry the risk of serious complications. An experimental pig model could be used to gain basic knowledge about long-term use before conducting clinical trails. In this randomized controlled study we tested the hypothesis if prolonged positive pressure ventilation (PPV) with the P-LMA in the pig is possible. METHODS: The P-LMA was used for airway maintenance under general anaesthesia and PPV in 15 German country pigs. Randomised into 3 groups, the animals were ventilated for 90, 150 and 390 minutes, respectively. Arterial blood gas measurements were used to determine adequacy of ventilation. Airway leak pressure (P (leak)) and maximum tidal volume (TV) were measured in the supine, lateral and prone positions. A bronchoscopic examination was performed to detect signs of aspiration. RESULTS: Adequate ventilation was demonstrated both after 120 min (4.7 +/- 0.4 kPa) and 360 min (4.7 +/- 0.5 kPa). The corresponding PaO(2) at FiO(2) = 1.0 was 59 +/- 5 kPa and 64 +/- 10 kPa, respectively. The mean P (leak) was 34 +/- 7 cm H(2)O. Change of position did not result in any significant change in P(leak) or maximum TV kg (-1). There was no bronchoscopic evidence of aspiration in any pig. CONCLUSION: It was possible to ensure sufficient PPV with the P-LMA in the pig over different periods of time and in different body positions without any complications of airway management. The P-LMA can be used for PPV in the pig for durations of up to 390 minutes. We conclude that investigations into the long-term use of the LMA can be carried out in a pig model.

[Influence of neuromuscular blockade on the airway leak pressure of the ProSeal laryngeal mask airway]. / Auswirkung einer neuromuskulären Blockade auf den Leckagedruck der ProSeal-Kehlkopfmaske.

BACKGROUND: The ProSeal laryngeal mask airway (PLMA) is increasingly used for surgical procedures that might require the intraoperative use of neuromuscular blocking agents. The airway seal of the PLMA depends on the interplay of the surrounding soft tissue of the neck and the cuff of the mask. An intraoperative neuromuscular blockade could lead to a decrease of the airway leak pressure (P (leak)) secondary to the relaxation of the muscles of the neck. With this study we tested the hypothesis that a neuromuscular blockade can result in a decreased P (leak) of the PLMA. METHODS: The P (leak) of the PLMA was studied in 73 female patients under total intravenous anaesthesia with propofol (0.1 - 0.15 mg kg (-1) min (-1)) and remifentanil (0.1 - 0.3 microg kg (-1) min (-1)) before and after a complete neuromuscular blockade produced by intravenous injection of 0.6 mg kg (-1) Rocuronium. RESULTS: The P (leak) decreased by more than 10 % of the baseline P (leak) in 8 out of 73 patients (11 %); however, in the entire study population there was no significant difference between the mean baseline P (leak) (28.5 +/- 7.3 cm H(2)O) and the mean P (leak) after complete neuromuscular blockade (29.1 +/- 7.0 cm H(2)O); (p = 0.128). CONCLUSION: No general correlation between application of a neuromuscular blocking agent and a decrease of the mean P (leak) was found. However, the decrease of the P (leak) by more than 10 % in 11 % of the patients shows that in certain patients the application of neuromuscular blocking agents can result in a decreased P (leak) of the PLMA and indicates the necessity to control the P (leak) of the PLMA under complete muscle paralysis preoperatively when neuromuscular blocking agents are used.

[Video laryngoscopy for modified rapid sequence induction of anaesthesia: Sellick manoever with and without video laryngoscopic control]. / Videolaryngoskopie zur modifizierten "Rapid-sequence-Narkoseeinleitung" : Sellick-Manöver mit und ohne videolaryngoskopische Kontrolle.

BACKGROUND: There is evidence that cricoid pressure, one of the key elements of rapid sequence induction (RSI) in patients at risk of aspiration, can distort the glottic view obtained by direct laryngoscopy (DL) and consequently impair or delay endotracheal intubation (ETI). The fact that cricoid pressure is applied by an assistant "blindly", i.e. without any visual feedback, is believed to be a contributing factor. Video laryngoscopy (VIL) offers the advantage that both the anaesthetist and the assistant can follow laryngoscopy. This could be useful for ETI during RSI. METHODS: We used VIL for a simulated RSI in 170 adult patients randomised to either video laryngoscopy-guided application of cricoid pressure (group I) or conventional, i.e. "blind", application of cricoid pressure (group II). Time to ETI was compared between groups. The laryngoscopy view obtained by VIL was compared with the view of conventional DL obtained before, in all patients. RESULTS: Time to ETI did not differ between groups (p=0.2): 25.1+/-14.2 s (group I) vs. 23.7+/-12.1 s (group II). Laryngoscopy scores were significantly better for VIL than conventional DL (p<0.001). CONCLUSIONS: Visualisation of the larynx during RSI can be improved using VIL. Time to ETI is not decreased by use of video laryngoscopy-guided application of cricoid pressure.

Airway management practices at German university and university-affiliated teaching hospitals--equipment, techniques and training: results of a nationwide survey.

BACKGROUND: Until recently, Germany did not have national airway management guidelines. This survey collected comprehensive data on departmental airway management practices from German teaching institutions to identify weaknesses, and the results are presented here. German national airway guidelines were formulated by an expert group on the basis of these data and the current evidence in the literature. METHODS: Questionnaires were mailed to the directors of 452 university and university-affiliated anaesthesia departments. They were asked to respond to 39 questions on the use of particular equipment and techniques, management of the difficult airway and training in airway management. RESULTS: Two hundred and twelve questionnaires were returned. Many alternative devices for endotracheal intubation, such as the Bullard laryngoscope, the Bonfils laryngoscope and the Trachlight, are not used in the majority (80%) of departments. Thirty-six per cent of departments do not have difficult airway carts. No departmental difficult airway management plan is used in 22% of departments. Patients are not provided with written information on their personal airway management difficulties in 14% of departments. Structured training in the form of block rotation is offered in only 29-40% of departments. Although trainees perform fibreoptic intubation (FOI) in most departments, appropriate training in FOI is not available in some departments (8%). CONCLUSION: There are deficits in various areas of airway management, in particular training and the use of algorithms. International guidelines and recommendations are not followed by a large number of German teaching institutions. The provision of German national airway guidelines should improve this situation.

[Use of the size 3 ProSeal laryngeal mask airway in children. Results of a randomized crossover investigation with the Classic laryngeal mask airway]. / Einsatz der ProSeal-Kehlkopfmaske der Grösse 3 bei Kindern. Ergebnisse einer randomisierten Cross-over-Untersuchung mit der Classic-Kehlkopfmaske.

BACKGROUND: The low-pressure airway seal of the Classic laryngeal mask airway (CLMA) can be inadequate for positive pressure ventilation (PPV) in children. The ProSeal laryngeal mask airway (PLMA) forms a more effective seal of the airway than the CLMA and facilitates gastric tube placement in adults. The size 3 PLMA can be used in adults and children. METHODS: The CLMA and PLMA were studied in random order -- crossover -- in 30 anaesthetized, non-paralysed children (average age 10.6 years, average body weight 39 kg). Airway leak pressure, maximum tidal volume, ease of insertion, quality of initial airway and fiberoptic position were determined. Gastric tube placement was assessed for the PLMA. RESULTS: The mean airway leak pressure in neutral head position (27.0 vs. 16.8 cm H(2)O), maximum flexion (38.3 vs. 26.2 cm H(2)O) and maximum extension (21.1 vs. 14.2 cm H(2)O) as well as the mean maximum tidal volume (1432 vs. 1062 ml) were significantly higher (p<0.001) for the PLMA. Air insufflation into the stomach occurred with the CLMA but not with the PLMA. Gastric tube placement was possible in all patients. CONCLUSIONS: The high reliability of g-tube placement and the significantly increased airway leak pressure seem to make the size 3 PLMA a more suitable device for PPV in children than the same size CLMA.

Use of the ProSeal laryngeal mask airway for pressure-controlled ventilation with and without positive end-expiratory pressure in paediatric patients: a randomized, controlled study.

BACKGROUND: Tracheal intubation and positive end-expiratory pressure (PEEP) are frequently used in children to avoid airway closure and atelectasis during general anaesthesia. Also, the laryngeal mask airway (LMA(dagger)) is frequently used. However, one of the limitations with its use in children is that its low-pressure seal is often inadequate for positive pressure ventilation with PEEP. The ProSeal LMA (PLMA) has been shown to form a more effective seal than the Classic LMA. The ability to apply PEEP with the PLMA might improve gas exchange during positive pressure ventilation in children when the LMA is used. METHODS: Twenty anaesthetized, non-paralysed children aged 55 (range 27-89) months, weighing 18 (sd 3) kg, were randomly allocated into two groups. Anaesthesia management and positive pressure ventilation were standardized. Size 2 and 2(1/2) PLMA were used. Artificial ventilation in Group I was with pressure controlled ventilation (PCV) and PEEP=5 cm H(2)O, in Group II with PCV without PEEP. A Fi(o(2)) = 1.0 was used for 20 min during induction of anaesthesia. Sixty minutes after induction of anaesthesia an arterial blood gas sample was taken under a Fi(o(2)) = 0.3. RESULTS: Groups were comparable with respect to demographic data. Pa(o(2)) in Group I [22.1 (1.6) kPa] was significantly (P=0.001) higher than in Group II [19.2 (1.7) kPa]. CONCLUSIONS: The PLMA can be used for PCV with PEEP in paediatric patients. Application of PEEP improves gas exchange.

[Use of the laryngeal mask airway at german university and university-affiliated hospitals -- results of a nationwide survey]. / Einsatz der Kehlkopfmaske in der anästhesiologischen Praxis deutscher Universitäts- und Lehrkrankenhäuser -- Ergebnisse einer bundesweiten Umfrage.

AIM OF THE STUDY: The aim of this study was to collect comprehensive data on the use of the laryngeal mask airway (LMA) under general anaesthesia at German university and university-affiliated hospitals. METHODS: Questionnaires were mailed to the directors of 452 German university and university-affiliated anaesthesia departments. Twenty-three questions related to the way and frequency of use of the LMA were asked. RESULTS: Data from 212 departments (47 %) could be included into the analysis. The LMA is used in all departments. Depending on the size of the department the LMA is used in 1 - 60 % of all anaesthetics. The LMA is used significantly more often (p > 0.001) in smaller departments providing up to 10 000 anaesthetics per year compared to larger departments providing up to, or more than, 20 000 anaesthetics per year. Controlled ventilation is the preferred mode of ventilation in more than 75 % of all departments. The LMA is used "routinely" or "always" for operations lasting more than 1 hour in more than 75 % of all departments. The LMA is used in the areas of ear, nose, and throat, maxillofacial, and eye surgery "routinely" or "always" only in 11 - 26 % of all departments. CONCLUSION: The role of the LMA in routine anaesthesia practice has clearly increased. Controversial aspects of use are reflected in the practice patterns of LMA use in different departments. The LMA has not been disseminated widely in the areas of ear, nose and throat-, maxillofacial- and eye surgery.

Size 2 ProSeal laryngeal mask airway: a randomized, crossover investigation with the standard laryngeal mask airway in paediatric patients.

BACKGROUND: One of the main concerns with the use of the standard laryngeal mask airway (SLMA) in small infants is that its low-pressure seal might be inadequate for positive pressure ventilation so that there is a risk of gas leakage into the stomach with the subsequent risk of regurgitation. The new ProSeal LMA (PLMA) has been shown to form a more effective seal than the SLMA and to facilitate gastric tube placement in adults. The first paediatric size PLMA became available recently. METHODS: Thirty anaesthetized, non-paralysed children aged 46 (19) months, weighing 16 (10-21) kg, were studied. The SLMA and PLMA were inserted in random order into each patient. Airway leak pressure and maximum tidal volume were measured. Ease of insertion, quality of initial airway and fibreoptic position were also determined. Gastric tube placement was assessed for the PLMA. RESULTS: The airway leak pressure and maximum tidal volume were significantly higher for the PLMA (P=0.001). Ease of insertion and quality of initial airway were similar for both devices. Air entry into the stomach occurred more frequently with the SLMA (P=0.005). Gastric tube placement was possible in all patients. CONCLUSIONS: The size 2 PLMA offered some advantages over the same size of SLMA in this crossover investigation. The high reliability of gastric tube placement and the significantly increased airway leak pressure might have important implications for use of this device for positive pressure ventilation in infants.

[Can sevoflurane save time in routine clincal use? A comparison with halothane in pediatric anesthesia]. / Kann Sevofluran im klinischen Alltag den zeitlichen Ablauf beschleunigen? Ein Vergleich mit Halothan bei Kinderanästhesien.

UNLABELLED: The volatile agent sevoflurane enables a rapid emergence from anaesthesia. The aim of this study was to investigate the possibility of increasing turnover in pediatric anaesthetic cases by use of sevoflurane in comparison with halothane. Often short cases or day cases need rapid turnover. METHODS AND PATIENTS: The pediatric patients aged 4-14 years (ASA I) presenting for elective ophthalmic surgery were randomised to either the halothane or the sevoflurane group. Standard monitoring was applied to all patients, in addition the pEEG was used to determine comparable anaesthetic depth. Sevoflurane or halothane were titrated to a SEF 90 of 8-12 Hz. Management of the airway was done with the RLMA (reinforced laryngeal mask). All patients were under controlled ventilation. At the end of surgery and anaesthesia 3 time intervals were measured: phase I) end of anaesthetic application--start of spontaneous respiration; phase II) start of spontaneous respiration--removal of RLMA. The SEF 90 interval was also assessed. RESULTS: 18 cases were included (halo n = 8/sevo n = 10, no significant differences concerning weight, age, anaesthesia time). There is a significant advantage for the Sevoflurane group in phase II of 6.8 minutes. No differences were seen in phase I and SEF 90 interval. CONCLUSION: Sevoflurane offers the potential for shortening turnover in pediatric anaesthesia.

Effects of anti-C5a monoclonal antibodies on oxygen use in a porcine model of severe sepsis.

METHODS: We analysed the effects of complement depletion and of C5a inhibition on haemodynamic parameters, oxygen delivery (DO2), oxygen consumption (VO2), oxygen extraction ratio (OER) and blood lactate levels after live bacteria infusion in pigs. RESULTS: In the first series of experiments, animals were decomplemented by cobra venom factor (CVF, 125 micrograms kg-1) and challenged with 1.3 x 10(9) Escherichia coli kg-1. In a second series, animals were treated with neutralizing anti-C5a monoclonal antibodies (mAb) T13/9 before infusion of an increased E. coli dosage (1 x 10(10) E. coli kg-1). Administration of Gram-negative bacteria resulted in hypotension, tachycardia, pulmonary hypertension and decreased cardiac output typical for severe sepsis. These alterations were more pronounced in animals challenged with a higher bacteria concentration (1 x 10(10) E. coli kg-1, n = 5) than with a lower dosage (1.3 x 10(9) E. coli kg-1, n = 4). Complement depletion by CVF injection 24 h before E. coli infusion (n = 4), or anti-C5a mAb T13/9 administration (n = 4) had no effect on the changes in haemodynamic parameters and in DO2 associated with E. coli challenge. Application of either 1.3 x 10(9) or 1 x 10(10) E. coli kg-1 resulted in a marked decrease in VO2 and an increase in blood lactate levels, whereas the OER did not change throughout the experiment. In contrast, pretreatment with CVF 24 h before low-dose E. coli (1.3 x 10(9) kg-1) administration resulted in a significant increase in VO2 (P < 0.05) and in OER (P < 0.05) compared with untreated septic animals (n = 4). No hyperlactaemia occurred in complement-depleted septic animals compared with complement-sufficient animals (P < 0.05). Animals challenged with a high E. coli dose (1 x 10(1) kg-1) and treated with anti-C5a mAbs showed a pronounced increase in VO2 and OER (P < 0.05) accompanied by an attenuated increase in lactate levels (P < 0.05) compared with untreated septic animals. CONCLUSION: The results demonstrate an improved oxygen use after complement depletion in this model of severe Gram-negative sepsis. Furthermore, a similar effect was seen after specifically neutralizing C5a by mAbs, indicating a role of C5a in the underlying mechanism.