A newly developed recovery-enhancing device improves recovery scores during emergence from general anesthesia in horses: a randomized trial

OBJECTIVE

To compare the quality of recovery in horses emerging from general anesthesia with or without the assistance of a novel device (recovery-enhancing device [RED]) designed to minimize high-energy falls.

ANIMALS

20 mixed-breed horses, between July 1, 2023, and January 24, 2024.

METHODS

A computer-controlled belay system designed to slow the acceleration of a horse during a fall was evaluated in this study. Horses were randomly assigned to 1 of 2 treatment groups: RED (belay, assisted) or FREE (unassisted). An inertia-measuring unit was fitted to all horses and data were live streamed and recorded onto a computer for further analysis. Recoveries were scored using the composite grading scale (CGS; 0 to 100) by 3 independent observers. Two additional unitless recovery scores (RS and RS'), based on accelerometry values (high accelerations, less desirable), were calculated for each recovery. All the recovery scores were compared between the 2 treatment groups.

RESULTS

Composite grading scale scores were 26 ± 10 and 46 ± 13 in the RED and FREE groups, respectively (P = .001). The RS was 120 ± 79 and 198 ± 34 for the RED and FREE treatment groups, respectively (P = .015). The RS' was 32 (7 to 50) and 46 (28 to 44) for the RED and FREE treatment groups, respectively (P = .038).

CLINICAL RELEVANCE

The RED improves the recovery scores compared with unassisted recoveries. This device may lead to a potential reduction in the number and severity of injuries in horses and personnel involved during the recovery period.

Ventilation strategies for front of neck airway rescue: an in silico study

BACKGROUND

During induction of general anaesthesia a 'cannot intubate, cannot oxygenate' (CICO) situation can arise, leading to severe hypoxaemia. Evidence is scarce to guide ventilation strategies for small-bore emergency front of neck airways that ensure effective oxygenation without risking lung damage and cardiovascular depression.

METHODS

Fifty virtual subjects were configured using a high-fidelity computational model of the cardiovascular and pulmonary systems. Each subject breathed 100% oxygen for 3 min and then became apnoeic, with an obstructed upper airway. When arterial haemoglobin oxygen saturation reached 40%, front of neck airway access was simulated with various configurations. We examined the effect of several ventilation strategies on re-oxygenation, pulmonary pressures, cardiovascular function, and oxygen delivery.

RESULTS

Re-oxygenation was achieved in all ventilation strategies. Smaller airway configurations led to dynamic hyperinflation for a wide range of ventilation strategies. This effect was absent in airways with larger internal diameter (≥3 mm). Intrapulmonary pressures increased quickly to supra-physiological values with the smallest airways, resulting in pronounced cardio-circulatory depression (cardiac output <3 L min^-1 and mean arterial pressure <60 mm Hg), impeding oxygen delivery (<600 ml min^-1). Limiting tidal volume (≤200 ml) and ventilatory frequency (≤8 bpm) for smaller diameter cannulas reduced dynamic hyperinflation and gas trapping, preventing cardiovascular depression.

CONCLUSIONS

Dynamic hyperinflation can be demonstrated for a wide range of front of neck airway cannulae when the upper airway is obstructed. When using small-bore cannulae in a CICO situation, ventilation strategies should be chosen that prevent gas trapping to prevent severe adverse events including cardio-circulatory depression.

Seizure-like movements caused by residual sevoflurane inside the anesthesia machine: A case report

RATIONALE

Sevoflurane-induced seizures are most often caused by high concentrations of sevoflurane during anesthesia induction. However, in this case, we found a rare case of seizure-like movements caused by residual sevoflurane inside the anesthesia machine. Therefore, we propose that the detection of residual anesthesia-inhaled drugs should be included in pre-anesthesia checkout procedures.

PATIENT CONCERNS

An 11-year-old girl with a history of epilepsy was scheduled for emergency appendectomy under general anesthesia. The patient presented with seizure-like movements caused by residual sevoflurane inside the anesthesia machine after pre-oxygenation during rapid sequence induction.

DIAGNOSES

Based on the clinical presentation and previous history of seizures, sevoflurane-induced seizures were diagnosed.

INTERVENTIONS

A washout procedure was performed by turning the oxygen flow up to 10L/min to wash out the residual sevoflurane from the anesthesia machine.

OUTCOMES

The seizures ceased spontaneously, and the vital signs of the patient were stable during the washout procedure. Rapid sequence anesthesia induction and total intravenous anesthesia maintenance were uneventful. Surgery was performed as planned, and there were no postoperative problems. The patient was discharged after 4 days without complications and was well on follow-up.

LESSONS

The check-up procedure of residual anesthesia-inhaled drugs inside the anesthesia machine should be included in the checkout design guidelines, or else the washout procedure should be performed in the pre-anesthesia checkout procedures.

Development of a prediction model for hypotension after induction of anesthesia using machine learning

Arterial hypotension during the early phase of anesthesia can lead to adverse outcomes such as a prolonged postoperative stay or even death. Predicting hypotension during anesthesia induction is complicated by its diverse causes. We investigated the feasibility of developing a machine-learning model to predict postinduction hypotension. Naïve Bayes, logistic regression, random forest, and artificial neural network models were trained to predict postinduction hypotension, occurring between tracheal intubation and incision, using data for the period from between the start of anesthesia induction and immediately before tracheal intubation obtained from an anesthesia monitor, a drug administration infusion pump, an anesthesia machine, and from patients’ demographics, together with preexisting disease information from electronic health records. Among 222 patients, 126 developed postinduction hypotension. The random-forest model showed the best performance, with an area under the receiver operating characteristic curve of 0.842 (95% confidence interval [CI]: 0.736-0.948). This was higher than that for the Naïve Bayes (0.778; 95% CI: 0.65-0.898), logistic regression (0.756; 95% CI: 0.630-0.881), and artificial-neural-network (0.760; 95% CI: 0.640-0.880) models. The most important features affecting the accuracy of machine-learning prediction were a patient’s lowest systolic blood pressure, lowest mean blood pressure, and mean systolic blood pressure before tracheal intubation. We found that machine-learning models using data obtained from various anesthesia machines between the start of anesthesia induction and immediately before tracheal intubation can predict hypotension occurring during the period between tracheal intubation and incision.

Anesthetic Considerations for Automated High-Frequency Jet Ventilation During Electromagnetic Navigation Bronchoscopy

Newly advanced diagnostic bronchoscopic procedures, such as electromagnetic navigation bronchoscopy using navigation system technology (superDimension, Medtronic), provides computed tomography referenced and computerized 3-dimensional imaging. To increase accuracy and higher diagnostic biopsy yield, electromagnetic navigation bronchoscopy necessitates special anesthetic and ventilation techniques providing the interventional pulmonologist minimal respiratory lung motion. This anesthetic meets 2 important goals by limiting almost all interference from diaphragmatic and lung movement while allowing the anesthesia provider to achieve hands-free management. Proposed here is an anesthetic ventilation technique by automated high-frequency jet ventilation (HFJV) via double-lumen micro jet endotracheal tubes. This ventilation technique delivers consistent very low tidal volumes. Automated HFJV provides the pulmonologist the advantage of more accurate navigation and target alignment in this Global Positioning System-guided biopsy procedure. The technique offers essentially no chest motion, without interrupting ventilation. Additionally, HFJV allows the anesthetist better availability to attend to total intravenous anesthesia, adjustments, and interventions. The intention of this article is to detail an anesthetic method that provides a hands-free technique that requires only one anesthesia provider.

Impact of supraglottic device with assist ventilation under general anesthesia combined with nerve block in uniportal video-assisted thoracoscopic surgery

BACKGROUND

With the improvement of anesthesia and surgical techniques, supraglottic device with assist ventilation under general anesthesia (GA) combined with nerve block is gradually applied to video-assisted thoracoscopic surgery. However, the safety of assist ventilation has not been fully confirmed, and a large number of samples should be studied in clinical exploration.

METHODS

The subjects included 120 patients, undergoing elective thoracoscopic GA, with American Society of Anesthesiologists (ASA) physical status I or II, were randomly divided into 3 groups, 40 cases in each group. Group T: received double-lumen bronchial intubation, Group I: received intercostal nerve block using a supraglottic device, Group P: received paravertebral nerve block using a supraglottic device. Mean arterial pressure, heart rate, saturation of pulse oximetry and surgical field satisfaction, general anesthetic dosage and recovery time were recorded before induction of GA (T0), at the start of the surgical procedure (T1), 15 minutes later (T2), 30 minutes later (T3), and before the end of the surgical procedure (T4). Static and dynamic pain rating (NRS) and Ramsay sedation score were recorded 2 hours after surgery (T5), 12 hours after surgery (T6), 24 hours after surgery (T7), time to get out of bed, hospitalization time and cost, patient satisfaction and adverse reactions.

RESULTS

There was no significant difference with the surgical visual field of the 3 groups (P > .05). The MAP, HR and SpO2 of the 3 groups were decreased from T2 to T3 compared with T0(P < .05). Compared with group T: the total dosage of GA was reduced in group I and group P, the recovery time was shorter, the time to get out of bed was earlier (P < .05), the hospitalization time was shortened, the hospitalization cost was lower, and the patient satisfaction was higher (P < .05). The static and dynamic NRS scores were lower from T5 to T7 (P < .05). Ramsay sedation scores were higher (P < .05), and the incidence of adverse reactions was lower (P < .05). Comparison between group I and group P: Dynamic NRS score of group P was lower from T6 to T7 (P < .05).

CONCLUSION

Supraglottic device with assist ventilation under general anesthesia combined with nerve block in uniportal video-assisted thoracoscopic surgery is safe and feasible.

RETRACTED: The accuracy of continuous temporal artery thermometers during general anesthesia

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief for inappropriate authorship. The Editor-in-Chief decision was based on the investigation by the Japanese Society of Anesthesiologists which concluded that the corresponding author, Dr. Ueshima presented the names of the individuals not involved or only partially involved in research as lead authors, presented the names of the individuals not involved in research as co-authors and submitted papers without the agreement of the co-authors. The investigation report can be found here.

Cobra-PLA provides higher oropharyngeal leak pressure than LMA-Classic and LMA-Unique: A meta-analysis with 22 studies

Cobra Perilaryngeal Airway (Cobra-PLA) is a relatively new single-use supraglottic device employed during general anesthesia. This meta-analysis includes randomized controlled trials (RCTs) yielding extensive comparison results among Cobra-PLA, Laryngeal Mask Airway (LMA)-Classic, and LMA-Unique.Two authors performed searches in EMBASE, CENTRAL, PubMed, and ScienceDirect to identify RCTs that compared Cobra-PLA with LMA-Classic and with LMA-Unique in patients undergoing general anesthesia. Both random- and fixed-effects models were used. Begg's funnel plot was used to evaluate publication bias.Twenty-two RCTs with a total of 1845 patients were included. Cobra-PLA offered significantly higher oropharyngeal leak pressure than LMA-Classic [mean difference (MD) = 3.56 (1.56, 5.55), P = .0005] and LMA-Unique [MD = 4.44 (2.12, 6.76), P = .0002]. First-insertion success rate, ease of insertion, insertion time, and reported complications among Cobra-PLA, LMA-Classic, and LMA-Unique were similar.Compared with the commonly used LMA-Classic and LMA-Unique, Cobra-PLA provides superior airway sealing.

Laryngeal mask airway for general anesthesia in interventional neuroradiology procedures

Objectives:

To evaluate whether using laryngeal mask airway (LMA) made a difference in terms of airway security, hemodynamic changes, complications, and recovery times compared to tracheal intubation during the procedure in patients undergoing general anesthesia for endovascular treatments of unruptured cerebrovascular aneurysms.

Methods:

The electronic medical records database, patient files, and anesthesia charts were examined between May 2008 and September 2016 to identify patients with the following inclusion criteria: 1) aged 18-70 years; 2) American Society of Anesthesiologists (ASA) classification I-III; 3) diagnosis of unruptured CVA; 4) Glasgow coma scale of 15 without neurological deficit; and 5) underwent elective EVT under general anesthesia.

Results:

Tracheal tube (TT) was used in 46 patients (group TT, n=46) and LMA in 42 patients (group LMA, n=42). Mean arterial pressure (MAP) levels were increased to >20% of baseline in 14 patients (30.4%) after intubation and in 6 (13%) after extubation in group TT. All LMA patients remained within normal MAP limits (p<0.05). Six patients (13%) displayed coughing or straining at extubation in group TT whereas none in group LMA (p<0.05). Recovery and discharge times were similar (p>0.05).

Conclusion:

Laryngeal mask airway and TT provided comparable airway security during procedure. Laryngeal mask airway attenuated stress response in hemodynamic parameters at intubation and extubation and smoother emergence compared to TT without delay in recovery.

AuraGain and i-Gel laryngeal masks in general anesthesia for laparoscopic cholecystectomy. Performance characteristics and effects on hemodynamics

Objectives:

To evaluate and compare the performances of new types of supraglottic airway devices (SADs) with endotracheal intubation regarding their ease of insertions, perioperative complications, and effects on hemodynamic parameters and peak airway pressures in laparascopic cholecystectomy (LC).

Methods:

One hundred and fourteen patients with ASA 1-2 physical status scheduled for elective LC were recruited for this prospective randomized controlled trial. The study was completed between January 2016 and January 2017 in Adiyaman University Research and Educational Hospital, Adiyaman, Turkey. The patients were divided into AuraGain^™ (Ambu, Ballerup, Denmark) (n=38), i-Gel® (Intersurgical Ltd, UK) (n=35), and endotracheal tube (ETT) (n=32) groups. Ease of insertion, airway pressures, complications, and hemodynamic variables were compared.

Results:

The trial was completed with 105 patients. Ease of insertion for SADs which was evaluated with insertion procedure duration, attempts, first insertion success rates, and oropharyngeal leak pressures were similar between the groups. Heart rate, systolic and diastolic arterial pressures, and peak airway pressures were significantly lower in the AuraGain and i-Gel® groups, compared with the ETT, p<0.017.

Conclusion:

Both AuraGain and i-Gel® SADs are comparable with ETT used for airway control in general anesthesia for LC, regarding application ease and perioperative complications. Favorable hemodynamic responses to AuraGain and i-Gel® SADs may put them in a better place than ETT.

Randomized Evaluation of the Single-use SoftSeal™ and the Re-useable LMA Classic™ Laryngeal Mask

A number of laryngeal masks are available, including both re-usable and single-use masks. Single-use laryngeal masks may decrease the risk of transmitting prion infections. We performed a single-blind randomized trial in 200 spontaneously breathing female patients under general anaesthesia with nitrous oxide, to compare a new single-use laryngeal mask, the SoftSeal™ (Portex Ltd, U.K.), with a re-usable laryngeal mask, the LMA Classic™ (Laryngeal Mask Company Ltd., Cyprus). The primary outcome was successful insertion at the first attempt. Size 4 single-use (n=99) or re-usable (n=100) laryngeal masks, inserted by experienced anaesthetists, were equivalent for successful placement at the first attempt (90% versus 91% respectively). The single-use mask was less easy to insert (47% difficult versus 9%, P<0.001). Clinical and anatomical tests of position and function were similar. The cuff pressure of the re-usable mask increased significantly compared with the single-use mask (median +10 cm versus –2 cm H 2 O, P<0.001). Forty per cent of patients allocated the single-use mask and 20% of those allocated the re-usable mask experienced sore throat at 24 hours postoperatively (P<0.05). An estimation of cost per patient use was greater for the re-usable mask.

We conclude that the SoftSeal™ single-use laryngeal mask and the LMA Classic™ re-usable laryngeal mask airway are of similar clinical utility in terms of successful insertion and airway maintenance. The re-usable laryngeal mask was easier to insert and associated with less postoperative sore throat, but costs were higher.

The ProSeal™ Laryngeal Mask Airway is an Effective Alternative to Laryngoscope-Guided Tracheal Intubation for Gynaecological Laparoscopy

We tested the hypothesis that the ProSeal™ laryngeal mask airway is superior to laryngoscope-guided tracheal intubation for gynaecological laparoscopy. One-hundred and eighty consecutive patients (ASA grade 1-2, aged 18-80y) were divided into two equal-sized groups for airway management with the ProSeal™ laryngeal mask airway or tracheal tube. Induction was with fentanyl/propofol, maintenance with sevoflurane and muscle relaxation with atracurium. The following primary variables were tested: time to achieve an effective airway, ventilatory capability, peak airway pressure before and after pneumoperitoneum, duration of surgery and pneumoperitoneum and haemodynamic responses. Data about gastric size, airway trauma and sore throat were collected. The number of attempts for successful insertion were similar, but effective airway time was shorter for the ProSeal™ laryngeal mask airway (20±2s vs 37±3s, P<0.001). All devices were successfully inserted within three attempts. There was no episode of failed ventilation or hypoxia. The haemodynamic stress responses to insertion and removal were greater for the tracheal tube than the ProSeal™ laryngeal mask airway. The duration of surgery, duration of pneumoperitoneum and intraabdominal pressures were similar. Gastric size was similar at the start and end of surgery. There were no differences in the frequency of complications or sore throat.

We conclude that the ProSeal™ laryngeal mask airway is a similarly effective airway device to conventional laryngoscope-guided tracheal intubation for gynaecological laparoscopy, but is more rapidly inserted and associated with an attenuated haemodynamic response to insertion and removal.

Anesthetic Management of Pleurectomy/Decortication Under Differential Lung Ventilation

A 64-year-old male (a building demolition worker) was diagnosed with malignant left-sided pleural mesothelioma, and left-sided pleurectomy/decortication was scheduled. Differential lung ventilation (DLV) was performed during the removal of the visceral pleura by connecting the affected lung to a ventilator and the healthy lung to an anesthesia machine, and then separately ventilating the left and right lungs. Anesthetic management using DLV was successfully established without causing significant changes in oxygenation or circulatory dynamics.

A Comparison between the i-gel® and air-Q® Supraglottic Airway Devices Used for the Patients Undergoing General Anesthesia with Muscle Relaxation

OBJECTIVES

The aim of the present study was to compare two supraglottic airway (SGA) devices (i.e., the i-gel® © Intersurgical Ltd and air-Q® (Reusable) Cookgas company) in terms of the insertion time, amount of leak during ventilation with maximum positive pressure, and postoperative complications in patients referring to Modarres Hospital in Tehran.

METHOD

The present double-blind clinical trial was performed on 60 patients undergoing elective surgeries that required general anesthesia with muscle relaxation. Patients were randomly assigned to either i-gel® (n = 30) or Air-Q® (n = 30) groups.

RESULTS

The mean age, body mass index, duration of surgery, duration of anesthesia, and gender ratio were not significantly different between the two groups. Mean ± SD values of the SGA devices' insertion time (in seconds) in the air-Q® and i-gel® groups were 4.87 ± 1.6 and 6.80 ± 1.2, respectively (P < 0.001). The mean OLP in the Air-Q® group was significantly higher than that of the i-gel® group (35.9 ± 9.6 versus 24.8 ± 3.7, p < 0.001). The frequency of complications occurred after the supraglottic airway insertion was higher in the i-gel® group. However, only in terms of sore throat, the difference between the two groups was statistically significant: 6 (20%) had sore throat (P = 0.024) in the i-gel groups, but in in the Air-Q® groups no one had this side effect after surgery.

CONCLUSION

It was concluded that the Air-Q® supraglottic airway was placed faster and easier with fewer complications than the i-gel in general anesthesia with muscle relaxation. The frequency of the occurrence of all three complications, cough, sore throat, and blood, on the cuff (6 (20%) was higher in the i-gel group than that in the air-Q® group (cough3 (10%), sore throat 0 (0%), and blood on the cuff 3 (10%) (P < 0.05).

Cuffed versus uncuffed endotracheal tubes for general anaesthesia in children aged eight years and under

BACKGROUND

Since the introduction of endotracheal intubation in paediatrics, uncuffed endotracheal tubes (ETTs) have been the standard of care for children under eight years old, based on the presumption that complications, particularly postoperative stridor, are higher with cuffed ETTs. The major disadvantages of uncuffed ETTs cited for this shift in procedure include the difficulty in achieving tidal volumes due to leakage around an uncuffed ETT. To seal the airway adequately, uncuffed tubes may need to be exchanged for another tube with a larger diameter, which sometimes requires several attempts before the appropriate size is found. Uncuffed tubes also allow waste anaesthetic gases to escape, contributing significantly to operating room contamination and rendering the anaesthetic procedure more expensive. Our review summarizes the available data, to provide a current perspective on the use of cuffed versus uncuffed endotracheal tubes in children of eight years old or less.

OBJECTIVES

To assess the risks and benefits of cuffed versus uncuffed endotracheal tubes during general anaesthesia in children up to eight years old.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS and Google Scholar databases from their inception until March 2017. We also searched databases of ongoing trials, and checked references and citations. We imposed no restriction by language.

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials in which the effects of using cuffed and uncuffed tubes were investigated in children up to eight years old undergoing general anaesthesia. We excluded studies conducted solely in newborn babies.

DATA COLLECTION AND ANALYSIS

We applied standard methodological procedures, as defined in the Methodological Expectations of Cochrane Intervention Reviews (MECIR).

MAIN RESULTS

We included three trials (2804 children), comparing cuffed with uncuffed ETTs. We rated the risks of bias in all three trials as high. Outcome data were limited. The largest trial was supported by Microcuff GmbH, who provided the cuffed tubes used. The other two trials were small, and should be interpreted with caution. Based on the GRADE approach, we rated the quality of evidence as low to very low.Two trials comparing cuffed versus uncuffed ETTs found no difference between the groups for postextubation stridor (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.65 to 1.33; 2734 children; quality of evidence very low). However, those two trials demonstrated a statistically significantly lower rate of endotracheal tube exchange in the cuffed ETT group (RR 0.07, 95% CI 0.05 to 0.10; 2734 children; quality of evidence very low).One trial with 70 participants found that costs per case were lower in the cuffed ETT group (mean difference (MD) EUR 19.0 lower; 95% CI 24.23 to 13.77 lower; quality of evidence low), since the higher cost of the cuffed tubes may be offset by the savings made with anaesthetic gases.No clear evidence emerged to suggest any difference between cuffed and uncuffed tubes for outcomes such as the need to treat postextubation stridor with tracheal re-intubation (RR 1.85, 95% CI 0.17 to 19.76; 115 children; 2 trials; quality of evidence very low), epinephrine (RR 0.70, 95% CI 0.38 to 1.28; 115 children; 2 trials; quality of evidence very low) or corticosteroid (RR 0.87, 95% CI 0.51 to 1.49; 102 children; 1 trial; quality of evidence very low), or need for intensive care unit (ICU) admission to treat postextubation stridor (RR 2.77, 95% CI 0.30 to 25.78; 102 children; 1 trial; quality of evidence very low).None of the trials included in this review evaluated the ability to deliver appropriate tidal volume.

AUTHORS' CONCLUSIONS

Implications for practiceWe are unable to draw definitive conclusions about the comparative effects of cuffed or non-cuffed endotracheal tubes in children undergoing general anaesthesia. Our confidence is limited by risks of bias, imprecision and indirectness. The lower requirement for exchange of tubes with cuffed ETTs was very low-quality evidence, and the requirement for less medical gas used and consequent lower cost was low-quality evidence. In some cases, tracheal re-intubation is required to guarantee an open airway when adequate oxygenation is difficult after removal of the tube, for a variety of reasons including stridor, muscle weakness or obstruction. No data were available to permit evaluation of whether appropriate tidal volumes were delivered. Implications for researchLarge randomized controlled trials of high methodological quality should be conducted to help clarify the risks and benefits of cuffed ETTs for children. Such trials should investigate the capacity to deliver appropriate tidal volume. Future trials should also address cost effectiveness and respiratory complications. Such studies should correlate the age of the child with the duration of intubation, and with possible complications. Studies should also be conducted in newborn babies. Future research should be conducted to compare the effects of the different types or brands of cuffed tubes used worldwide. Finally, trials should be designed to perform more accurate assessments and to diagnose the complications encountered with cuffed compared to uncuffed ETTs.

Comparison of a curved forceps with a conventional straight forceps for nasogastric tube insertion under videolaryngoscopic guidance: A randomized, crossover manikin study

BACKGROUND

Nasogastric tube (NGT) insertion is an easy procedure that can be routinely performed under general anesthesia. However, for difficult cases, there are limited insertion techniques available in routine clinical practice, considering the flexibility of NGTs. The SUZY curved forceps are designed for the removal of pharyngolaryngeal foreign bodies under guidance of the McGRATH MAC (McG) videolaryngoscope. Because McG enables clear visualization of the esophageal inlet, we hypothesized that the SUZY forceps can facilitate easier NGT insertion compared with the conventional Magill forceps under McG guidance and designed a randomized, crossover manikin study to test this hypothesis.

MATERIALS AND METHODS

Ten anesthesiologists participated in this study. Each participant was instructed to insert an NGT using either the SUZY or the Magill forceps under McG guidance. Both types of forceps were used by each participant in a computer-generated random order. The primary outcome measure was the number of "strokes" (1 stroke was defined by a specific sequence of participant actions) required to advance the NGT 30 cm from the starting point. Data are expressed as medians (interquartile ranges [ranges]).

RESULTS

The number of strokes required for NGT insertion was fewer in the SUZY group than in the Magill group {7 [7.0-12.5 (5-14)] vs 16.5 [13.5-20.3 (7-22)]; P <.05}. The time required for NGT insertion was also lesser in the SUZY group than in the Magill group {15.4 [13.7-20.0 (7.0-38.3)] seconds vs 30.3 [22.0-42.3 (12.8-47.5) seconds]; P <.05}.

CONCLUSIONS

The SUZY curved forceps facilitated NGT insertion more effectively than the Magill straight forceps under McG guidance. Our results suggest that NGT insertion using the SUZY forceps under McG guidance is a secure and easy procedure.

The effect of lidocaine jelly on a taper-shaped cuff of an endotracheal tube on the postoperative sore throat: a prospective randomized study: A CONSORT compliant article

BACKGROUND

Postoperative sore throat (POST) following general anesthesia with endotracheal intubation is a common complication. We hypothesized that lidocaine jelly applied to the tapered cuff of the endotracheal tube (ETT) might decrease the incidence of POST most commonly arising from endotracheal intubation.

METHODS

A total of 208 patients under general anesthesia were randomly assigned into 1 of 2 groups. In the lidocaine group (n = 104), the distal part of ETTs with tapered-shaped cuff was lubricated with lidocaine jelly. In the control group (n = 104), the distal part of ETTs with tapered-shaped cuff was lubricated with normal saline. The incidence of POST, hoarseness, and cough in the postanesthesia patients was compared.

RESULTS

The overall incidence of POST was higher in the lidocaine group than in the normal saline group [60 (58%) vs 40 (39%), P = .006]. The incidence of POST at 1 hour postoperatively was higher in the lidocaine group than in the normal saline group [53 (51%) vs 32 (31%), P = .003]. The overall incidence of hoarseness for 24 hours postoperatively was comparable (P = .487). The overall incidence of cough for 24 hours postoperatively is higher in the lidocaine group (P = .045).

CONCLUSION

The lidocaine jelly applied at the distal part of ETT with tapered-shaped cuff increased the overall incidence of POST in patients undergoing general anesthesia.

The EasyTube during general anesthesia for minor surgery: A randomized, controlled trial

BACKGROUND

The EasyTube (EzT) is a supraglottic airway device that is used for emergency airway situations. Ventilation during general anesthesia should also be feasible, but literature on the EzT is scarce. We evaluated the EzT in comparison with the endotracheal tube (ETT) in its use during general anesthesia in a comparative study.

METHODS

A total of 400 patients with American Society of Anesthesiologists (ASA) physical status I to II scheduled for minor surgery in 4 centers were randomized for ventilation via the ETT or EzT.

RESULTS

In all patients, the EzT and the ETT could be inserted within 3 attempts. In all EzT patients, the inspiratory and expiratory minute volumes (6.64 ± 0.71 and 6.34 ± 0.69 L/min) were sufficient to reach target oxygenation values, similar to ETT patients (P  =  .59). Mean peak pressure, mean plateau pressure, and mean dynamic compliance did not differ between the groups. Sore throat and blood on the cuff after removal were the most frequent complications in both groups.

CONCLUSION

Ventilation for up to 1 hour during general anesthesia in patients with ASA physical status I to II with the EzT is feasible and safe.

Laryngeal Mask Airway Use in Morbidly Obese Patients Undergoing General Anesthesia

The use of laryngeal mask airways with morbidly obese patients remains controversial. A recent legal case involving the use of a laryngeal mask airway with a morbidly obese patient who aspirated during the anesthetic found the anesthesia providers negligent. We sought evidence examining the use of laryngeal mask airways with obese patients undergoing surgery. One Cochrane systematic review and a randomized controlled trial met our inclusion criteria. Subjects received general anesthesia with a laryngeal mask airway. Outcomes included the ability to successfully place a laryngeal mask airway, ease and time of insertion, ability to ventilate, hypoxemia, presence of laryngospasm/ bronchospasm, and/or evidence of aspiration. The trials had some methodologic concerns including the inability to blind anesthesia providers, not including exclusively morbidly obese subjects, not powered to detect all complications such as aspiration, and overall small sample sizes. The investigators reported few problems when using these devices with obese subjects. However, because of the limited amount and quality of the evidence and the catastrophic nature of potential complications, future research must be done before a recommendation can be made regarding the use of these devices with morbidly obese patients.

[General Anesthesia for Treatment of Arrhythmia under Magnetic Influence of Remote Magnetic Navigation System]

Catheter ablation is a common treatment for ar- rhythmia and the number of procedures is increasing. Takatsuki General Hospital introduced a remote mag- netic navigation system into clinical practice for the first time in Japan. This system produces- magnetic flux density of 0.08-0.1 Tesla. Catheter ablation is usu- ally performed under deep sedation at our facility ; however, general anesthesia is needed in some cases. Although many cases of general anesthesia for MRI have been reported, there has been no report of gen- eral anesthesia under the unique environment of a weak magnetic field. We use MRI-certified equipment such as an anesthesia machine and a patient monitor in the heart rhythm center. There is no contraindication for the selection of anesthetic agents. Analgesia, depending on pain or burning sensation by ablation, and immobilization are required. Anesthesiologists must be aware that there are some differences in gen- eral anesthesia in the MRI room compared with the heart rhythm center, including the environmental set- ting, limitations in the use of certain medical equipment and procedure-related knowledge.

[The Origins of the Words : Zenshin Masui and Kyokusho Masui.]

In 1850, Seikei Sugita coined the word "Masui" to describe a physical condition induced by ether inhala- tion. Therefore, the word"Masui"initially meant general anesthesia. After physical methods to produce local numbness were introduced to Japan, it was necessary to make a new phrase to express the methods and the physical condition produced by them, and "Kyokusho Masui" was made, in which "kyokusho" means local. Then,"Zenshin Masui", indicating general anesthesia, was made to form a set of "Kyokusho Masui" and "Zenshin Masui". It was 1876 when Tadanori Ishiguro published "Geka Tsujutsu", in which he described a clear definition of "Kyokusho Masui" and "Zenshin Masui". This is one of the earliest uses of "Kyokusho Masui" together with "Zenshin Masui" in Japan.

Closed-loop anesthesia

Automated anesthesia which may offer to the physician time to control hemodynamic and to supervise neurological outcome and which may offer to the patient safety and quality was until recently consider as a holy grail. But this field of research is now increasing in every component of general anesthesia (hypnosis, nociception, neuromuscular blockade) and literature describes some successful algorithms - single or multi closed-loop controller. The aim of these devices is to control a predefined target and to continuously titrate anesthetics whatever the patients' co morbidities and surgical events to reach this target. Literature contains many randomized trials comparing manual and automated anesthesia and shows feasibility and safety of this system. Automation could quickly concern other aspects of anesthesia as fluid management and this review proposes an overview of closed-loop systems in anesthesia.

[Combined Use of a Videolaryngoscope and a Transilluminating Device for Intubation with Two Difficult Airways]

Videolaryngoscope is useful in patients with difficult airways, but it may not be in some patients. We report the use of a lighted stylet to facilitate tracheal intubation in 2 patients in whom laryngoscopy with a videolaryngoscope was difficult. Case 1: A 52-year-old female with loose teeth and lockjaw presented for a scoliosis surgery under general anesthesia. Laryngoscopy using a blade 3 of a Glide-Scope® (Laerdal Medical Corporation, New York, NY, USA) videolaryngoscope (GVL) showed a Cormack-Lehanne grade 3 view. Bag mask ventilation was easily achieved. By using the Trachilight™ (Saturn Biomedical System Burnaby, BC, Canada) with the GVL, we could intubate the trachea succesfully. Case 2: A 16-year-old male with a history of difficult tracheal intubation due to a limited cervical spine movement presented for an external fixation of a femur under general anesthesia. After induction of anaesthesia, bag mask ventilation was easily achieved but the GVL laryngoscopy did not provide a good view of the glottis (Cormack-Lehanne grade 3). Combined use of the Trachilight™ with the GVL, facilitated tracheal intubation. The Trachilight™ is a recognized aid to facilitate trachal intubation but the device is now commercially not available. Neverthless, we believe that a lighted stylet is potentially useful for tracheal intubation when the view of the glottis with a videolaryngoscopy is not ideal.

Comparison of Second-Generation Supraglottic Airway Devices (i-gel versus LMA ProSeal) During Elective Surgery in Children

Second-generation supraglottic airway devices i-gel (Intersurgical Ltd) and LMA ProSeal (Teleflex Inc) are designed for a superior airway seal with a high success rate in adults. This study compared the efficacy of i-gel and LMA ProSeal (sizes 1, 1.5, and 2) as an airway device in a pediatric population, especially infants. The study included 163 ASA class 1 and 2 children, aged up to 10 years and weighing 2 to 25 kg, undergoing elective surgeries lasting less than 1 hour under general anesthesia on spontaneous respiration. Participants were randomly assigned to 2 groups: i-gel and LMA ProSeal. With each device, the ease of insertion, time of insertion, manipulations required for placement of the device, and oropharyngeal leak pressure were recorded. A lubricated gastric tube of the recommended size was passed through each device, and ease of insertion was noted. At the end of surgery, the device was removed and complications were noted, including laryngospasm, breath holding, and blood-stains. Mann-Whitney U test and χ2 tests were used to compare collected data. Both devices were found to be comparable in effectively securing the airway in children, even in infants. The insertion time was significantly faster with i-gel.

[Airway Management Utilizing an air-Q blocker in a Patient with Motor Neuron Disease and Soft Palate Paralysis]

A 67-year-old woman suffering from hoarseness or dysphagia was diagnosed with motor neuron disease. She was scheduled for laparoscopic cholecystectomy under general anesthesia for suspected gallbladder cancer. She was concerned about the exacerbation of her hoarseness or dysphagia from tracheal intubation. We therefore decided to perform airway management by using supraglottic device air-Q blocker, through which a gastric tube could be inserted. We first passed the gastric tube through the outer blocker hole and inserted it into the esophagus using Magill forceps. The air-Q blocker was placed position under the guidance of a McGrath videolaryngoscope. Sealing pressure was over 20 cmH2O and mechanical ventilation was performed uneventfully during artificial pneumoperitoneum. We were able to deflate the stomach and perform tracheal suction via the inner hole of the air-Q. Following the operation, the patient developed neither hoarseness nor pharyngeal pain.

[Measurement of the Minimum Pressure in the Bronchial Cuff during One-lung Ventilation Using a Capnometer]

BACKGROUND

It is recommended to avoid overinflation of the bronchial cuff, leading to ischemic pressure damages to the respiratory mucosa and bronchial rupture. We investigated the minimum bronchial cuff pressure of 35 Fr double lumen tubes (DLTs) during one lung ventilation using a capnometer.

METHODS

We studied 50 patients who were scheduled to undergo thoracic surgery. General anesthesia was induced and the patients were intubated with 35 Fr left DLT. With a fiberoptic bronchoscope, the DLT was positioned appropriately. The bronchial cuff was inflated first with air 3-3.5 ml. Lung isolation was confirmed by auscultation. Measurements were performed with the patient in the lateral position. Ventilating one lung isolatedly for 5 minutes, we confirmed non ventilated condition with a capnometer displaying flat line. The bronchial cuff was deflated 0.5-ml steps just before displaying the respiratory pattern by the capnogram. The bronchial cuff pressure and volume were recorded at this point

RESULTS

The minimum pressures of bronchial cuff (volume) for one lung ventilation are for male 5.46 ± 0.6 cmH2O (2.33?0.1 ml) and for female 1.5?0.5 cmH20 (1.09 ± 0.3 ml). These values are smaller than the recommended value (< 25 cmH2O). There was no case in which the collapse of the operated lung was insufficient.

CONCLUSIONS

In this study, the bronchial pressure higher than 12 cmH2O was not necessary for one lung ventilation. If high intracuff pressure is necessary to seal the bronchus, there are possibilities of the incompatibility of the size of DLT and the herniation of the bronchial cuff to the proximal side. The method of confirmation of OLV using a capnometer can display the non ventilated condition on the monitor objectively. We can thus decrease troubles during operations.

[Airway Obstruction Caused by Heat and Moisture Exchange Filter Used during General Anesthesia: A Case Report and an In Vitro Study]

BACKGROUND

A previously healthy 54-year-old woman underwent a resection of the acoustic tumor. Following induction of general anesthesia and tracheal intubation, volume-controlled ventilation was started and the patient was placed in the left park bench position. The heat and moisture exchange filter (HMEF) was placed within the ventilatory circuit and positioned below the patient's head to avoid unintentional extubation. Six hours after the start of surgery, peak inspiratory pressure gradually rose, and 2 hours later ventilation of the patient's lung became increasingly difficult. When the HMEF was replaced, normal breathing was promptly restored.

METHODS

We reproduced this scenario with a similar HMEF under the same ventilator settings by adding 0-8 g of normal saline into the HMEF housing, and measured the inspiratory pressure and tidal volume across the HMEF.

RESULTS

When instilling 4 g of saline, an increase in inspiratory pressure occurred.

CONCLUSIONS

This case shows a potential risk of unexpectedly early occurrence of obstruction of the HMEF due to accumulation of condensed water within the device when the HMEF was positioned below the patient's head. We recommend selection of the appropriate HMEF and suitable mounting to avoid this problem.

[Rapid Sequence Intubation with the McGRATH MAC Videolaryngoscope in the Sitting Position for a Patient with Restricted Mouth Opening]

Here we report successful rapid-sequence inubation with the McGRATH MAC videolaryngscope (McGRATH) in the face to face sitting position for a patient with severe ileus and restricted mouse opening. A 46-year-old woman with advanced bladder cancer had developed ileus. Ileus tube and octreotide did not relieve her symptoms, and emergency colostomy was planned. Due to the invasion of cancer to the spine and interior of the pelvis, she could not keep supine position and always kept sitting position. We decided to perform rapid-sequence intubation in the sitting position. First an anesthesiologist stood at face to face position to the patients, and the second anesthesiologist kept the head of the patient from the cranial side. After thiamylal and fentanyl administration, cricoid pressure was applied by the third anesthesiologist. Under the guide of the McGRATH's monitor, we could successfully insert the 7.0 mm internal diameter tracheal tube with a stylet uneventfully in the face to face sitting position.

The comparison of ProSeal and I-gel laryngeal mask airways in anesthetized adult patients under controlled ventilation

OBJECTIVES

To compare the insertion time, ease of device insertion, ease of gastric tube insertion, airway leakage pressure, and complications between the laryngeal mask airway (LMA) ProSeal (P-LMA) and I-gel (I-gel) groups.

METHODS

Eighty patients with age range 18-65 years who underwent elective surgery were included in the study. The study took place in the operation rooms of Haydarpaşa Numune Hospital, Istanbul, Turkey from November 2013 to April 2014. Patients were equally randomized into 2 groups; the I-gel group, and the P-LMA group. In both groups, the same specialist inserted the supraglottic airway devices. The insertion time of the devices, difficulty during insertion, difficulty during gastric tube insertion, coverage of airway pressure, and complications were recorded.

RESULTS

The mean insertion time in the I-gel group was significantly lower than that of the P-LMA group (I-gel: 8±3; P-LMA: 13±5 s). The insertion success rate was higher in the I-gel group (100%, first attempt) than in the P-LMA group (82.5%, first attempt). The gastric tube placement success rate was higher in the I-gel group (92.5%, first attempt) than in the P-LMA group (72.5%, first attempt). The airway leakage pressures were similar.

CONCLUSION

Insertion was easier, insertion time was lower, and nasogastric tube insertion success was higher with the I-gel application, and is, therefore, the preferred LMA.

Detection of endobronchial intubation by monitoring the CO2 level above the endotracheal cuff

Early detection of accidental endobronchial intubation (EBI) is still an unsolved problem in anesthesia and critical care daily practice. The aim of this study was to evaluate the ability of monitoring above cuff CO2 to detect EBI (the working hypothesis was that the origin of CO2 is from the unventilated, but still perfused, lung). Six goats were intubated under general anesthesia and the ETT positioning was verified by a flexible bronchoscope. The AnapnoGuard system, already successfully used to detect air leak around the ETT cuff, was used for continuous monitoring of above-the-cuff CO2 level. When the ETT distal tip was located in the trachea, with an average cuff pressure of 15 mmHg, absence of CO2 above the cuff was observed. The ETT was then deliberately advanced into one of the main bronchi under flexible bronchoscopic vision. In all six cases the immediate presence of CO2 above the cuff was identified. Further automatic inflation of the cuff, up to a level of 27 mmHg, did not affect the above-the-cuff measured CO2 level. Withdrawal of the ETT and repositioning of its distal tip in mid-trachea caused the disappearance of CO2 above the cuff in a maximum of 3 min, confirming the absence of air leak and the correct positioning of the ETT. Our results suggest that measurement of the above-the-cuff CO2 level could offer a reliable, on-line solution for early identification of accidental EBI. Further studies are planned to validate the efficacy of the method in a clinical setup.

The application of single-lumen endotracheal tube anaesthesia with artificial pneumothorax in thoracolaparoscopic oesophagectomy

Double-lumen endotracheal tube (DLET) anaesthesia is the commonly used method in minimally invasive oesophagectomy (MIE). However, DLET intubation does have its disadvantages. Firstly, the placement of the DLET needs a skilled anaesthetist with familiarity of the technique and subsequent ability to perform a fibre-optic bronchoscopy for confirmation. Secondly, DLET intubation and one-lung ventilation are associated with numerous complications, including hoarseness, tracheobronchial injury and vocal injury. In this report, a retrospective analysis was performed on 42 consecutive patients who underwent MIE using single-lumen endotracheal tube (SLET) anaesthesia with CO2 artificial pneumothorax compared with 81 patients who underwent the same procedure with DLET intubation. Our findings showed that SLET intubation with artificial pneumothorax by CO2 insufflation is a feasible and safe method for MIE procedures.

[GlideScope Cobalt: assessment of performance in 50 children]

BACKGROUND

GlideScope Cobalt video laryngoscope is a new type of GlideScope series. A reusable camera baton is inserted into a disposable plastic curved blade. The blade has 5 choices of size and can be used from infants to adults. The aim of the current study was to evaluate the efficacy of GlideScope Cobalt in children.

METHODS

Endotracheal intubation was performed in 50 surgical children undergoing general anesthesia. The length of time in intubation, percentage of glottic opening (POGO) score and optimizing procedures were recorded.

RESULTS

100% POGO score was obtained in 42 cases. Successful endotracheal intubation was performed in 47 cases and 37 patients were intubated within 1 minute. It took over 1 minute to intubate in 13 cases, because of the difficulty of tracheal tube maneuver. Particular children, mostly aged 6-8, had difficulty in matching the size of the blade because of the large difference between the sizes of blade 2 and that of blade 3.

CONCLUSIONS

GlideScope Cobalt is a useful tool in chidlren's airway management but it necessitates getting used to the tracheal tube maneuver and lacks the suitable blade size for 6-8 years old children.

Phonological outcome of laryngeal framework surgery by different anesthesia protocols: a single-surgeon experience

CONCLUSION

Similar to combined arytenoid adduction and medialization laryngoplasty (i.e. combined surgery) under local anesthesia, general anesthesia by intubation or by the laryngeal mask airway (LMA) method significantly improves phonological outcome. Thus, laryngeal framework surgery under general anesthesia is a promising surgical approach for selected patients with unilateral vocal cord paralysis (UVCP).

OBJECTIVE

The advantages of laryngeal framework surgery under local anesthesia have been described, but no studies exist concerning the difference in phonological outcome of laryngeal framework surgery performed under general anesthesia. To add new information, we retrospectively investigated the phonological outcome of the combined surgery performed under three different anesthesia protocols.

METHODS

Thirty-nine consecutive patients with severe UVCP underwent the combined surgery under three anesthesia protocols performed by a single surgeon: (1) under general anesthesia by intubation, (2) under general anesthesia using LMA, and (3) under local anesthesia.

RESULTS

Under all anesthesia protocols, the vocal cords of most patients could be positioned such that the best vocal outcome could be expected. Statistical analyses demonstrated improved maximum phonation time and mean airflow rate, and grade, roughness, breathiness, asthenia, and strain (GRBAS) scale in all patients, regardless of their anesthesia protocol. Furthermore, of the three protocols, local anesthesia had the shortest operation time.

ProSeal™ LMA increases safe apnea period in morbidly obese patients undergoing surgery under general anesthesia

BACKGROUND

Morbidly obese patients are at risk of hypoxemia at the time of induction of anesthesia. The aim of this study was to assess the possible increase in the safe apnea time with the use of ProSeal laryngeal mask airway (PLMA) as a conduit prior to laryngoscope-guided intubation in morbidly obese patients undergoing surgery under general anesthesia.

METHODS

Hundred patients with BMI greater than 35 kg/m2, undergoing surgery under general anesthesia, were randomly divided to receive either PLMA or facemask with oropharyngeal airway (FM) as the airway device. Following preoxygenation with 100% oxygen with continuous positive airway pressure of 10 cm H2O, in ramp position for 5 min the patients were made apneic. From start of apnea to the time to reach SpO2 to 92% was recorded as safe apnea time. Ventilation was initiated and time to reach SpO2 of 100% was recorded as recovery time.

RESULTS

The mean safe apnea time was 205 (96-320)s in FM vs. 337 (176-456) s in PLMA (P = 0.0000). The mean recovery period was 49 (36-68)s in FM vs. 42(30-56)s in PLMA groups (P = 0.0000). Arterial blood gas analysis showed significant difference in pO2 between the two groups.

CONCLUSION

The use of ProSeal laryngeal mask airway prior to laryngoscope-guided intubation is beneficial in increasing safe apnea period and achieving faster recovery from hypoxemia in morbidly obese patients.

Evaluation of multiwave pulse total-hemoglobinometer during general anesthesia

The purpose of this prospective study was to evaluate the accuracy and trending ability of a four-wavelength pulse-total hemoglobinometer that continuously and noninvasively measures hemoglobin in surgical patients. With IRB approval and informed consent, spectrophotometric hemoglobin (SpHb) was measured with a pulse-total hemoglobinometer manufactured by Nihon Kohden Corp (Tokyo, Japan) and compared to the CO-oximeter equipped with blood gas analyzer. Two hundred twenty-five samples from 56 subjects underwent analysis. Bland-Altman analysis revealed that the bias ± precision of the current technology was 0.0 ± 1.4 g/dl and -0.2 ± 1.3 g/dl for total samples and samples with 8 < Hb < 11 g/dl, respectively. The percentages of samples with intermediate risk of therapeutic error in error grid analysis and the concordance rate of 4-quadrant trending assay was 17 % and 77 %, respectively. The Cohen kappa statistic for Hb < 10 g/dl was 0.38, suggesting that the agreement between SpHb and CO-oximeter-derived Hb was fair. Collectively, wide limits of agreement, especially at the critical level of hemoglobin, and less than moderate agreement against CO-oximeter-derived hemoglobin preclude the use of the pulse-total hemoglobinometer as a decision-making tool for transfusion.

Supraglottic airway devices versus tracheal intubation for airway management during general anaesthesia in obese patients

BACKGROUND

The number of obese patients requiring general anaesthesia is likely to increase in coming years, and obese patients pose considerable challenges to the anaesthetic team. Tracheal intubation may be more difficult and risk of aspiration of gastric contents into the lungs is increased in obese patients. Supraglottic airway devices (SADs) offer an alternative airway to traditional tracheal intubation with potential benefits, including ease of fit and less airway disturbance. Although SADs are now widely used, clinical concerns remain that their use for airway management in obese patients may increase the risk of serious complications.

OBJECTIVES

We wished to examine whether supraglottic airway devices can be used as a safe and effective alternative to tracheal intubation in securing the airway during general anaesthesia in obese patients (with a body mass index (BMI) > 30 kg/m(2)).

SEARCH METHODS

We searched for eligible trials in the following databases: Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 8, 2012), MEDLINE via Ovid (from 1985 to 9 September 2012) and EMBASE via Ovid (from 1985 to 9 September 2012). The Cochrane highly sensitive filter for randomized controlled trials was applied in MEDLINE and EMBASE. We also searched trial registers such as www.clinicaltrials.gov and the Current Controlled Clinical Trials Website (http://www.controlled-trials.com/) for ongoing trials. The start date of these searches was limited to 1985, shortly before the first SAD was introduced, in 1988. We undertook forward and backward citation tracing for key review articles and eligible articles identified through the electronic resources.

SELECTION CRITERIA

We considered all randomized controlled trials of participants aged 16 years and older with a BMI > 30 kg/m(2) undergoing general anaesthesia. We compared the use of any model of SAD with the use of tracheal tubes (TTs) of any design.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. Two review authors independently assessed trial quality and extracted data, including information on adverse events. We contacted study authors for additional information. If sufficient data were available, results were presented as pooled risk ratios (RRs) with 95% confidence intervals (CIs) based on random-effects models (inverse variance method). We employed the Chi(2) test and calculated the I(2) statistic to investigate study heterogeneity.

MAIN RESULTS

We identified two eligible studies, both comparing the use of one model of SAD, the ProSeal laryngeal mask airway (PLMA) with a TT, with a total study population of 232. One study population underwent laparoscopic surgery. The included studies were generally of high quality, but there was an unavoidable high risk of bias in the main airway variables, such as change of device or laryngospasm, as the intubator could not be blinded. Many outcomes included data from one study only.A total of 5/118 (4.2%) participants randomly assigned to PLMA across both studies were changed to TT insertion because of failed or unsatisfactory placement of the device. Postoperative episodes of hypoxaemia (oxygen saturation < 92% whilst breathing air) were less common in the PLMA groups (RR 0.27, 95% CI 0.10 to 0.72). We found a significant postoperative difference in mean oxygen saturation, with saturation 2.54% higher in the PLMA group (95% CI 1.09% to 4.00%). This analysis showed high levels of heterogeneity between results (I(2) = 71%). The leak fraction was significantly higher in the PLMA group, with the largest difference seen during abdominal insufflation－a 6.4% increase in the PLMA group (95% CI 3.07% to 9.73%).No cases of pulmonary aspiration of gastric contents, mortality or serious respiratory complications were reported in either study. We are therefore unable to present effect estimates for these outcomes.In all, 2/118 participants with a PLMA suffered laryngospam or bronchospasm compared with 4/114 participants with a TT. The pooled estimate shows a non-significant reduction in laryngospasm in the PLMA group (RR 0.48, 95% CI 0.09 to 2.59).Postoperative coughing was less common in the PLMA group (RR 0.10, 95% CI 0.03 to 0.31), and there was no significant difference in the risk of sore throat or dysphonia (RR 0.25, 95% CI 0.03 to 2.13). On average, PLMA placement took 5.9 seconds longer than TT placement (95% CI 3 seconds to 8.8 seconds). There was no significant difference in the proportion of successful first placements of a device, with 33/35 (94.2%) first-time successes in the PLMA group and 32/35 (91.4%) in the TT group.

AUTHORS' CONCLUSIONS

We have inadequate information to draw conclusions about safety, and we can only comment on one design of SAD (the PLMA) in obese patients. We conclude that during routine and laparoscopic surgery, PLMAs may take a few seconds longer to insert, but this is unlikely to be a matter of clinical importance. A failure rate of 3% to 5% can be anticipated in obese patients. However, once fitted, PLMAs provide at least as good oxygenation, with the caveat that the leak fraction may increase, although in the included studies, this did not affect ventilation. We found significant improvement in oxygenation during and after surgery, indicating better pulmonary performance of the PLMA, and reduced postoperative coughing, suggesting better recovery for patients.

High inspired carbon dioxide levels due to misplaced central tubing of the absorbent canister

The authors present a case of unusual rise in inspired carbon dioxide due to misplaced absorbent canister.

[Comparative a nimble of monitoring indicator, explore the superiority about Supreme dual-chamber laryngeal mask used for cesarean section anesthesia]

OBJECTIVE

Explore the feasibility and superiority about Supreme double-lumen laryngeal mask airway for cesarean section anesthesia.

METHODS

From March 2011 to March 2012, a total of 300 patients with American Society of Anesthesiologists (ASA) I or II foot of cesarean section in full-term pregnant women for the first time production of Quanzhou Women's and Children's Hospital were recruited, authenticated by Hospital Ethics Committee, they were randomly divided into three groups (Random number table), dual-chamber in the LMA group (A group of 100 cases), tracheal intubation group (B group of 100 cases) and spinal anesthesia group (C group of 100 cases). ECG, SpO2, MAP, heart rate, Narcotrend and Apgar scores were observed.

RESULTS

Before and after the LMA group inserted laryngeal mask HR,MAP no significant change in the performance of Narcotrend value remained at the level of anesthesia, intubation before and after HR, MAP significantly increased performance of Narcotrend values significantly increased, both compared to the obvious statistical difference (P < 0.05). The ventilation indicators of two groups compared to no significant difference (P > 0.05). LMA group cover required intubation time was significantly shorter than the time required for intubation of endotracheal intubation group (P < 0.01). Three groups of patient administration to the fetus at all times is in 5-10 min.Three groups similar to the Apgar score was no significant difference (P > 0.05).

CONCLUSION

The dual-chamber laryngeal mask airway for caesarean section anesthesia, fetal Apgar scores, feasibility, and its operation is easy, safe and comfortable anesthesia, compared tracheal intubation has obvious superiority.

[Intubating laryngeal mask efficacy in obese and overweight patients]

We evaluated the Intubating Laryngeal MAsk (ILMA Fastrach) efficacy for airway management, ventilation and blind intubation in obese and overweight patients. Methods. 50 adult patients (22 men and 28 women) with predicted difficult trachea intubation (PDTI), undergoing general anaesthesia with ILMA were included in this study. ILMA was selected according to gender: ILMA No 5 for men and No 4 for women. PREMEDICATION: diazepam and H,-blockers. Anaesthesia induction: midazolam 0. I - 0.15 mg/kg, propofol 1.6-2.5 mg/kg, fentanyl 0.1-0.15 microg/kg, rocuronii bromide or atracurii besilate 0.6 mg/kg.

RESULTS

21/2/3 patients had morbid obesity with BMI over 40/45/55 kg/m'. 5 and more difficult trachea intubation (TI) predictors were found in 48 patients. The ILMA was placed successfully at the first try for 7.2+/-2.9 sec in all patients. Ventilation was successful in 100% of cases; TI via ILMA - in 94% of cases (90% - at the first try). Total TI time was 7,5+/-4,8 sec, ILMA removal time - 9,2+1,5 sec. 2 patients had 2 or 3 DTI predictors, but conventional TI was unsuccessfild; TI via ILMA was performed at the first try. There was one "can't intubate, can't ventilate" case, TI via ILMA was made at the first try. TI via ILMA was unsuccessful in 3 patients, ILMA was replaced by Proseal LM or Supreme LM, TI was performed conventionally. There were no complications observed.

CONCLUSION

ILMA Fastrach was used successfiully in obese patients with PDTI for both ventilation and TI. Technique is simple in training, but a preliminary experience is essential for ILMA use in difficult cases.

A novel method for SLIPA™ size selection, for adult patients, on the basis of chamber length

PURPOSE

Nowadays the size of the streamlined liner of the pharynx airway (SLIPA™) is selected by matching the width of the thyroid cartilage of the patient to the widest dimension of the SLIPA™. The objective of this work was to improve the method of selection by matching the distance between the otobasion inferius and the most inferior margin of the cricoid cartilage (O-C) to the length of the SLIPA™ chamber.

METHODS

100 patients (ASAI-II) scheduled to undergo operations under general anesthesia were randomly divided into two groups, group A (size selected by matching O-C with SLIPA™ chamber length, n = 50) and group B (size selected by matching the width of the thyroid cartilage with the widest dimension of the SLIPA™, n = 50). We measured the distance between the nasopharynx and the interarytenoid fold (N-I) and investigated the correlation between O-C and N-I at the neutral head position. Number of attempts, insertion time, blood on the device, leakage, and the need to change sizes were assessed.

RESULTS

A positive correlation (r = 0.68, p < 0.05) was detected between N-I and O-C. Leakage was observed in 6 % (n = 3) of group A patients and in 20 % (n = 10) of group B patients (p < 0.05).

CONCLUSION

Compared with the classic size-selection method, matching the width of the thyroid cartilage with that of the SLIPA™, the size-selection method of matching SLIPA™ chamber length to O-C for adult patients is more accurate.