Second generation extraglottic airway devices with gastric access and separate breathing channels have ushered in a new era where their use is increasingly prevalent in surgical patients who would have been traditionally intubated for general anesthesia. New innovations like the i-gel, which is constructed of a thermoplastic elastomer, provide an airtight seal around patient's perilaryngeal anatomy without the inflatable cuff mechanism found in the laryngeal mask airway supreme (LMAS).
We conducted a randomized controlled trial comparing the LMAS with the i-gel in 70 anesthetized paralyzed patients undergoing laparoscopic female sterilization. Our primary outcome measure was the oropharyngeal leak pressure (OLP). We studied secondary outcomes of successful first attempt insertion rates, time and ease of the airway and gastric tube insertion, leak fractions and pharyngeal morbidity.
We found no difference in the OLP between LMAS and i-gel, 25.9 (4.2) versus 24.4 (4.3) s, P=0.153. Both devices had similar first attempt insertion rates (LMAS 94% vs. i-gel 91%) with similar ease and comparable times to achieve an effective airway, LMAS 14.7 (2.7) versus i-gel 16.5 (9.6) s, P=0.306, although gastric tube insertion was easier and faster for the LMAS, 7.9 (1.9) versus i-gel 14.8 (7.7) s, P<0.005. Intraoperatively, there was a significantly greater leak fraction with the i-gel of 0.06 (0.03) versus 0.04 (0.02) with the LMAS, P=0.013. Three patients (8.6%) with LMAS had mild sore throat; one patient (2.9%) had mucosal injury. No complications were documented in the i-gel group.
Both these extraglottic airway devices offer similar OLPs, high insertion success rates at the first attempt with similar ease and insertion times (albeit longer gastric tube insertion with i-gel). Both provided effective ventilation despite a higher leak fraction with i-gel that was clinically inconsequential.
Extraglottic airway devices; i-gel; laparoscopic surgery; laryngeal mask airway supreme; leak fraction; leak pressures
The conventional sequence when using supraglottic airway devices is insertion, cuff inflation and fixation. Our hypothesis was that a tighter fit of the cuff and tip could be achieved with a consequently lower incidence of air leak, better separation of gastrointestinal and respiratory tracts and less airway morbidity if the device were first affixed and the cuff then inflated.
Our clinical review board approved the study (public registry number DRKS00003174). An LMA Supreme® was inserted into 184 patients undergoing lower limb arthroscopy in propofol-remifentanil anaesthesia who were randomly assigned to either the control (inflation then fixation; n = 92) or study group (fixation then inflation; n = 92). The cuff was inflated to 60 cmH2O. The patients’ lungs were ventilated in pressure-controlled mode with 5 cmH2O PEEP, Pmax to give 6 ml kg-1 tidal volume, and respiratory rate adjusted to end-tidal CO2 of 4.8 and 5.6 kPa. Correct cuff and tip position were determined by leak detection, capnometry trace, oropharyngeal leak pressure, suprasternal notch test, and lube-tube test. Bowl and cuff position and the presence of glottic narrowing were assessed by fiberscopic examination. Postoperative dysphagia, hoarseness and sore throat were assessed with a questionnaire. Ventilatory impairment was defined as a tidal volume < 6 ml kg-1 with Pmax at oropharyngeal leak pressure, glottic narrowing was defined as an angle between the vocal cords under 16 degrees.
The incidence of incorrect device position (18% vs. 21%), failed ventilation (10% vs. 9%), leak pressure (24.8 vs. 25.2 cmH2O, p = 0.63), failed lube-tube test (16.3% vs. 17.6%) and glottic narrowing (19.3% vs. 14.1%, p = 0.35) was similar in both groups (control vs. study, resp.). When glottic narrowing occurred, it was more frequently associated with ventilatory impairment in the control group (77% vs. 39%; p = 0.04). Airway morbidity was more common in the control group (33% vs. 19%; p < 0.05).
Altering the sequence of cuff inflation and device fixation does not affect device position, oropharyngeal leak pressures or separation of gastrointestinal and respiratory tracts. It reduces the incidence of glottic narrowing with impaired ventilation and also perioperative airway morbidity.
Supraglottic airway; Insertion sequence; Malposition; Endoscopic evaluation; Glottic narrowing; Ventilatory impairment; Airway morbidity
The main responsibility of an anesthesiologist is to safely maintain an open airway and preserve sufficient gas exchange in the lungs. This role becomes more significant when managing children especially those with difficult airways (DA). In such cases, a quick appropriate action can decrease the related mortality and morbidity. Laryngeal mask airway (LMA) is a device used in cases with difficult airways. Its placement is much more difficult in children especially those with DA. There is a greater risk of malpositioning and its insertion with routine techniques is sometimes impossible. In this article, we introduce a new method for replacement of LMA in difficult pediatric airways (DPA).
Materials and Methods
In this before and after, pre and post design clinical trial, we evaluated 30 children with congenital anomalies and difficult airways who were candidates for elective eye surgery (short term). A written consent was obtained from the parents or the legal guardians of those who met the inclusion criteria. Inhalation anesthesia was induced by sevoflurane. The patients had assisted spontaneous respiration. No muscle relaxant was administered. LMA was inserted using the classic method in the anesthesia depth of BIS = 35-40. After 2 unsuccessful attempts according to the criteria for adequate function of LMA, we tried placing the LMA using our innovated method after meeting the primary requirements and reaching the anesthesia depth of 35-40. In this method, the index finger of the left hand was placed on the tongue pushing it downwards (towards the floor of the mouth) when inserting the LMA. This way, we assisted LMA passing down the pharynx resulting in its adequate positioning. Criteria for adequate function of LMA in both classic and innovated insertion methods included monitoring of easy ventilation, no resistance during exhalation, adequate chest movement, no air leakage, optimal airway pressure, optimal lung compliance, level of oxygenation of arterial blood and level of CO2 at the end of exhalation. In case of presence of air leakage with bag pressure below 15 cm of water, lack of chest movement during inhalation, upper airway pressure over 20 cm of water, SPO2 lower than 90% and low compliance of the lung, LMA placement would be considered a failure. In such cases, LMA would be immediately extracted and the required depth of anesthesia would be reached using an oxygen mask and required inhalations. Complications occurring during the procedure and after LMA extraction would be recorded.
Our understudy population included 30 children in the age range of 1.5 months to 10 yrs (11 girls and 19 boys) who had clear DA criteria due to syndromes and severe congenital anomalies and were candidates for elective eye surgery. Duration of the operation was 30 to 60 minutes. In all 30 cases, LMA placement with the classic method was not successful after 2 attempts by an expert. LMA was successfully inserted for all cases by the same person using the innovated method after meeting the required criteria (BIS = 35-40). All ventilation indices were met and the operation was performed successfully with no complication.
There is always a risk of unsuccessful LMA placement in difficult pediatric airways using the classic method of insertion. The innovated method recommends pushing down the tongue by the index finger of the left hand. Considering the hypersensitivity of children to hypoxia and risk of unsuccessful LMA placement by the classic method, the innovated placement method is advised in children suffering from anomalies associated with macroglossia.
Difficult pediatric airway; LMA; Sevoflurane; Muscle relaxant; Hypoxia
To compare two different supraglottic airway devices, the laryngeal mask airway (LMA) and the I-gel, regarding easiness of insertion of the device, leak pressure, gastric insufflation, end tidal CO2, oxygen saturation, hemodynamic and postoperative complications in anesthetized, spontaneously ventilated adult patients performing different non-emergency surgical procedures.
Materials and Methods:
The study was carried out as a prospective, randomized, clinical trial among 80 patients who underwent different surgical procedures under general anesthesia with spontaneous ventilation in supine position. They were equally randomized into two groups: I-gel and LMA groups. Both the devices were compared with regard to heart rate, arterial BP, SPO2, end-tidal CO2, number and duration of insertion attempts, incidence of gastric insufflation, leak pressure and airway assessment after removal of the device.
No statistically significant difference was reported between both the groups, regarding heart rate, arterial BP, SPO2 and end-tidal CO2. The mean duration of insertion attempts was 15.6±4.9 seconds in the I-gel group, while it was 26.2±17.7 seconds in the LMA group. The difference between both the groups regarding duration of insertion attempts was statistically significant (P=0.0023*), while the number of insertion attempts was statistically insignificant between both the study groups (P>0.05). Leak pressure was (25.6±4.9 vs. 21.2±7.7 cm H2O) significantly higher among studied patients of the I-gel group (P=0.016*) and the incidence of gastric insufflation was significantly more with LMA group 9 (22.5%) vs. I-gel group (5%) (P=0.016).
Both LMA and I-gel do not cause any significant alteration in the hemodynamic status of the patients, end tidal CO2, and SPO2. The postoperative complications were not significantly different except nusea and vomiting was statistically significant higher in LMA group (P=0.032). among both LMA and I-gel patients. Insertion of I-gel was significantly easier and more rapid than insertion of LMA. Leak pressure was significantly higher with I-gel than LMA and thus incidence of gastric insufflation was significantly lower with I-gel.
Classical laryngeal mask airway; I-gel; supraglottic airway devices
This study compared the safety and efficacy of the Supreme Laryngeal Mask Airway (S-LMA) with that of the ProSeal-LMA (P-LMA) in laparoscopic cholecystectomy.
Material and Methods:
Sixty adults were randomly allocated. Following anaesthesia induction, experienced LMA users inserted the airway devices.
Oropharyngeal leak pressure was similar in groups (S-LMA, 27.8±2.9 cmH2O; P-LMA, 27.0±4.7 cmH2O; p=0.42) and did not change during the induction of and throughout pneumoperitoneum. The first attempt success rates were 93% with both S-LMA and P-LMA. Mean airway device insertion time was significantly shorter with S-LMA than with P-LMA (12.5±4.1 seconds versus 15.6±6.0 seconds; p=0.02). The first attempt success rates for the drainage tube insertion were similar (P-LMA, 93%; S-LMA 100%); however, drainage tubes were inserted more quickly with S-LMA than with P-LMA (9.0±3.2 seconds versus 14.7±6.6 seconds; p=0.001). In the PACU, vomiting was observed in five patients (three females and two males) in the S-LMA group and in one female patient in the P-LMA group (p=0.10).
Both airway devices can be used safely in laparoscopic cholecystectomies with suitable patients and experienced users. However, further studies are required not only for comparing both airway devices in terms of postoperative nausea and vomiting but also for yielding definitive results.
Laparoscopic cholecystectomy; supraglottic airway devices; laryngeal mask airway; proseal; supreme
Background. This study was designed to assess and compare the effect of head and neck position on the oropharyngeal leak pressures and cuff position (employing fibreoptic view of the glottis) and ventilation scores between ProSeal LMA and the I-gel. Material and Methods. After induction of anesthesia, the supraglottic device was inserted and ventilation confirmed. The position of the head was randomly changed from neutral to flexion, extension, and lateral rotation (left). The oropharyngeal leak pressures, fibreoptic view of glottis, ventilation scores, and delivered tidal volumes and end tidal CO2 were noted in all positions. Results. In both groups compared with neutral position, oropharyngeal leak pressures were significantly higher with flexion and lower with extension but similar with rotation of head and neck. However the oropharyngeal leak pressure was significantly higher for ProSeal LMA compared with the I-gel in all positions. Peak airway pressures were significantly higher with flexion in both groups (however this did not affect ventilation), lower with extension in ProSeal group, and comparable in I-gel group but did not change significantly with rotation of head and neck in both groups. Conclusion. Effective ventilation can be done with both ProSeal LMA and I-gel with head in all the above positions. ProSeal LMA has a better margin of safety than I-gel due to better sealing pressures except in flexion where the increase in airway pressure is more with the former. Extreme precaution should be taken in flexion position in ProSeal LMA.
The Laryngeal Mask Airway (LMA) is a frequently-used efficient airway device, yet it sometimes seals poorly, thus reducing the efficacy of positive-pressure ventilation. The Perilaryngeal Airway (CobraPLA) is a novel airway device with a larger pharyngeal cuff (when inflated). We tested the hypothesis that the CobraPLA was superior to LMA with regard to insertion time and airway sealing pressure and comparable to LMA in airway adequacy and recovery characteristics. After midazolam and fentanyl, 81 ASA I-II outpatients having elective surgery were randomized to receive an LMA or CobraPLA. Anesthesia was induced with propofol (2.5 mg/kg, IV), and the airway inserted. We measured 1) insertion time; 2) adequacy of the airway (no leak at 15-cm-H2O peak pressure or tidal volume of 5 ml/kg); 3) airway sealing pressure; 4) number of repositioning attempts; and 5) sealing quality (no leak at tidal volume of 8 ml/kg). At the end of surgery, gastric insufflation, postoperative sore throat, dysphonia, and dysphagia were evaluated. Data were compared with unpaired t-tests, chi-square tests, or Fisher’s Exact tests; P<0.05 was significant. Patient characteristics, insertion times, airway adequacy, number of repositioning attempts, and recovery were similar in each group. Airway sealing pressure was significantly greater with CobraPLA (23±6 cm H2O) than LMA (18±5 cm H2O, P<0.001). The CobraPLA has insertion characteristics similar to LMA, but better airway sealing capabilities.
Airway: Sealing. Cuff Pressure. Insertion. Leak. Pharynx; Equipment: Laryngeal mask airway. Perilaryngeal airway; Ventilation: Controlled. Spontaneous; Anesthesia
i-gel™ is a new single-use supraglottic airway device without an inflatable cuff. This study was designed to compare the usefulness of i-gel™ versus a classic laryngeal mask airway (cLMA) in small children.
Sixty-three children (age range : 4-72 months) were randomly assigned to an i-gel™ or cLMA group. We evaluated hemodynamic data, airway sealing ability, the success rate of insertion, and adverse events including an inadvertent sliding out during ventilation.
Demographic data and hemodynamic data obtained immediately after the insertion of these devices did not differ between the two groups. The success rates for insertion on the first attempt were 77 and 84% for i-gel™ and cLMA, respectively (P = 0.54), and the overall success rates were 87 and 100% respectively (P = 0.14). There were no significant differences in terms of airway leak pressure. The inserted i-gel™ inadvertently slid out in 8 of 31 patients but only one sliding out case occurred in the cLMA group (P = 0.02). There were no differences between the groups in terms of other side effects (e.g., coughing, bleeding) associated with the use of i-gel™ and cLMA (P = 0.75 and 0.49, respectively).
Oropharyngeal leak pressure and insertion success rate of i-gel™ are similar to those of cLMA. However, i-gel™ is prone to inadvertent sliding out of the mouth in small children. Therefore, it is recommended that the i-gel™ should be secured more tightly to avoid displacement of the device.
Laryngeal mask airway; i-gel™
Objective: To compare the postoperative complications between Laryngeal Mask Airway (LMA) and endotracheal tube (ETT) during low-flow anesthesia with controlled ventilation.
Methodology: Eighty adult Patients with ASA class I or II were randomly allocated into two forty-patient groups (ETT or LMA). Cuff pressure was monitored during anesthesia. After high uptake period, fresh gas flow (FGF) was decreased to 1 lit/min and isoflurane set to 1%. Monitoring during anesthesia included non-invasive blood pressure, ECG, ETCO2 and pulse oximetry. System leakage (>100 ml/min), rebreathing and any attempt to increase FGF to overcome the leak were monitored during anesthesia. Later, patients were extubated and transferred to Post Anesthesia Care Unit (PACU). In PACU, the incidence of sore throat, cough, difficulty in swallowing and shivering was monitored for all patients.
Results: Leakage was observed in two and three cases in ETT and LMA groups respectively (P>0.05). Postoperative cough, sore throat and difficulty in swallowing were significantly less in LMA than ETT group. No significant difference was observed regarding ETCo2 values between 2 groups.
Conclusion: If careful measures regarding insertion techniques, correct LMA position and routine monitoring of LMA cuff pressure are taken, LMA can be used as a safe alternative with lower incidence of post operation complication compared with ETT during low-flow controlled anesthesia with modern anesthetic machines.
Laryngeal Mask Aiway; Endotracheal Tube; Low-flow anesthesia; Complications; Controlled ventilation
Supraglottic airway devices play an important role in ophthalmic surgery. The flexible laryngeal mask airway (LMA™) is generally the preferred airway device. However, there are no studies comparing it with the Cobra perilaryngeal airway (CobraPLA™) in pediatric ophthalmic procedures.
To analyze the intraoperative device stability and ability to maintain normocarbia of CobraPLA™ and compare it to that with flexible LMA™.
Materials and Methods:
Ninety children of American Society for Anesthesiologists physical status 1 and 2, aged 3–15 years scheduled for elective ophthalmic surgeries were randomly assigned to either the CobraPLA™ or the flexible LMA™ group. After placement of each airway device, oropharyngeal leak pressure (OLP) was noted. Adequate seal of the devices was confirmed at an inspired pressure of 15 cm H2O and pressure-controlled ventilation was initiated. Device displacement was diagnosed if there was a change in capnograph waveform, audible or palpable gas leak, change in expired tidal volume to <8 ml/kg, end-tidal carbon-dioxide persistently >6 kPa, or need to increase inspired pressure to >18 cm H2O to maintain normocarbia.
Demographic data, duration, and type of surgery in both the groups were similar. A higher incidence of intraoperative device displacement was noted with the CobraPLA™ in comparison to flexible LMA™ (P < 0.001). Incidence of displacement was higher in strabismus surgery (7/12). Insertion characteristics and ventilation parameters were comparable. The OLP was significantly higher in CobraPLA™ group (28 ± 6.8 cm H2O) compared to the flexible LMA™ group (19.9 ± 4.5 cm H2O) (P < 0.001). Higher surgeon dissatisfaction (65.9%) was seen in the CobraPLA™ group.
The high incidence of device displacement and surgeon dissatisfaction make CobraPLA™ a less favorable option than flexible LMA™ in ophthalmic surgery.
Airway complication; CobraPLA™; flexible laryngeal mask airway; pediatric ophthalmic surgery
The newest variation of the i-gel supraglottic airway is a pediatric version.
This study was designed to investigate the usefulness of the size 2 i-gel compared with the ProSeal laryngeal mask airway (PLMA) and classic laryngeal mask airway (cLMA) of the same size in anesthetized, paralyzed children.
Settings and design:
A prospective, randomized, single-blinded study was conducted in a tertiary care teaching hospital.
Ninety ASA grade I–II patients undergoing lower abdominal, inguinal and orthopedic surgery were included in this prospective study. The patients were randomly assigned to the i-gel, PLMA and cLMA groups (30 patients in each group). Size 2 supraglottic airway was inserted according to the assigned group. We assessed ease of insertion, hemodynamic data, oropharyngeal sealing pressure and postoperative complications.
There were no differences in the demographic and hemodynamic data among the three groups. The airway leak pressure of the i-gel group (27.1±2.6 cmH2O) was significantly higher than that of the PLMA group (22.73±1.2 cmH2O) and the cLMA group (23.63±2.3 cmH2O). The success rates for first attempt of insertion were similar among the three devices. There were no differences in the incidence of postoperative airway trauma, sore throat or hoarse cry in the three groups.
Hemodynamic parameters, ease of insertion and postoperative complications were comparable among the i-gel, PLMA and cLMA groups, but airway sealing pressure was significantly higher in the i-gel group.
Classic laryngeal mask airway; i-gel; pediatric patients; ProSeal laryngeal mask airway
The newest variation of the i-gel supraglottic airway is a pediatric version.
This study was designed to investigate the usefulness of the size 2 i-gel compared with the classic laryngeal mask airway (cLMA) of the same size in anesthetized, paralyzed children.
Settings and Design:
A prospective, randomized, single-blinded study was conducted in tertiary care teaching hospital.
Subject and Methods:
Sixty ASA grade I–II patients undergoing lower abdominal, inguinal, and orthopedic surgery were included in this prospective study. The patients were randomly assigned to i-gel and cLMA groups (30 patients in each group). Size 2 supraglottic airway was inserted according to the assigned group. We assessed ease of insertion, hemodynamic data, oropharyngeal sealing pressure, and postoperative complications.
Statistical Analysis Used:
Parametric data were analyzed with the unpaired t-test and non-parametric data were analyzed with the Chi-square test. Unless otherwise stated, data are presented as mean (SD). Significance was taken as P < 0.05.
There were no differences in the demographic and hemodynamic data among the two groups. The airway leak pressure of the i-gel group (26.1 ± 2.4 cm H2O) was significantly higher than that of the cLMA group (22.64 ± 2.2 cm H2O). The success rates for first attempt of insertion were similar among the two devices. There were no differences in the incidence of postoperative airway morbidity among the two groups.
Hemodynamic parameters, ease of insertion, and postoperative complications were comparable between the i-gel and cLMA groups, but airway sealing pressure was significantly higher in i-gel group.
Classic laryngeal mask airway; i-gel; pediatric patients
Fiberoptical assisted intubation via a placed laryngeal mask airway (LMA) has been described as save and easy procedure to manage a difficult airway. The laryngeal tube (LT) is a promising alternative to the LMA as supraglottic airway device. Fiberoptical assisted intubation via LT is possible, however considered more difficult. The aim of this study was to compare the fiberoptical assisted intubation via LT and LMA.
Materials and Methods:
A total of 22 anesthesiologists with different levels of experience participated in the study performed on an adult airway model. Primarily the supraglottic device was placed and correct position was confirmed by successful ventilation. A 5 mm internal diameter tracheal tube was loaded onto a flexible 3.6 mm fiberscope and the so prepared device was inserted into the proximal lumen of the LMA or the LT. The glottis was passed under visual control and the tube advanced into the trachea. After removal of the fiberscope, ventilation was examined clinically by inspection. Success rates, procedure time and observed complications of LMA versus LT were compared (U-test; P < 0.05).
Placement of the endotracheal tube was successful in all attempts using both the LMA and LT. There was no difference in the time needed for the placement procedure (33 [26-38] s LMA; 35 [32-38] s LT). Only minor technical complications were observed in both groups.
A fiberoptical assisted intubation via LT can be considered as a relevant alternative in advanced airway management.
Difficult airway; fiberoptic intubation; laryngeal mask; laryngeal tube
To reduce the incidence of postoperative pharyngolaryngeal adverse events, laryngeal mask airway (LMA) manufacturers recommend maximum cuff pressures not exceeding 60 cmH2O. We performed a prospective randomised study, comparing efficacy and adverse events among patients undergoing laparoscopic surgical procedures who were allocated randomly into low (limiting 25 cmH2O, L group) and high (at 60 cmH2O, H group) LMA cuff pressure groups with LMA Supreme. Postoperative pharyngolaryngeal adverse events were evaluated at discharge from postanaesthetic care unit (PACU) (postoperative day 1, POD 1) and 24 hours after discharge from PACU (postoperative day 2, POD 2). All patients were well tolerated with LMA without ventilation failure. Before pneumoperitoneum, cuff volume and pressure and oropharyngeal leak pressure (OLP) showed significant differences. Postoperative sore throat at POD 2 (3 versus 12 patients) and postoperative dysphagia at POD 1 and POD 2 (0 versus 4 patients at POD 1; 0 versus 4 patients at POD 2) were significantly lower in L group, compared with H group. In conclusion, LMA with cuff pressure limiting 25 cmH2O allowed both efficacy of airway management and lower incidence of postoperative adverse events in laparoscopic surgical procedures. This clinical trial is registered with KCT0000334.
The aim of this study was to compare size 2 Laryngeal Mask Airway ProSeal and size 2 Laryngeal Mask Airway Supreme in spontaneously breathing children undergoing lower abdominal elective surgery of <1 hour duration.
Randomized clinical trial.
Material and Methods:
Sixty children aged 1–7 years, weighing 10–20 kg, ASA I physical status were randomly allocated to the Laryngeal Mask Airway ProSeal and Laryngeal Mask Airway Supreme.
There were no differences in demographic variables, ease of gastric tube placement, ease of insertion and ventilation, number of insertion attempts, hemodynamic changes on insertion, postoperative complications and bloodstaining between the groups. Gastric insufflation was detected and gastric tube was placed in all patients except one in LMA Supreme. Postoperative cuff volumes were comparable with the preoperative values in group itself. Oropharyngeal leak pressures were higher in Laryngeal Mask Airway ProSeal (24.6±5.5 vs 21.3±4.2, respectively; p<0.01).
As a result Laryngeal Mask Airway ProSeal and Laryngeal Mask Airway Supreme can safely be used in spontaneously breathing pediatric population undergoing lower abdominal elective surgery.
Laryngeal mask; proseal; supreme; children; oropharyngeal leak pressure
The objective of the study was to compare the performance of i-gel supraglottic airway with cLMA in difficult airway management in post burn neck contracture patients and assess the feasibility of i-gel use for emergency airway management in difficult airway situation with reduced neck movement and limited mouth opening.
Prospective, crossover, randomized controlled trial was performed amongst forty eight post burn neck contracture patients with limited mouth opening and neck movement. i-gel and cLMA were placed in random order in each patient. Primary outcome was overall success rate. Other measurements were time to successful ventilation, airway leak pressure, fiberoptic glottic view, visualization of square wave pattern.
Success rate for the i-gel was 91.7% versus 79.2% for the cLMA. i-gel required shorter insertion time (19.3 seconds vs. 23.5 seconds, P=0.000). Airway leak pressure difference was statistically significant (i-gel 21.2 cm H20; cLMA 16.9 cm H20; P=0.00). Fiberoptic view through the i-gel showed there were less epiglottic downfolding and better fiberoptic view of the glottis than cLMA. Overall agreement in insertion outcome for i-gel was 22/24 (91.7%) successes and 2/24(8.3%) failure and for cLMA, 19/24 (79.16%) successes and 5/24 (16.7%) failure in the first attempt.
The i-gel is cheap, effective airway device which is easier to insert and has better clinical performance in the difficult airway management of the airway in the post burn contracture of the neck. Our study shows that i-gel is feasible for emergency airway management in difficult airway situation with reduced neck movement and limited mouth opening in post burn neck.
cLMA; difficult airway management; i-gel; post burn neck contracture
The relatively recently developed I-gel (Intersurgical Ltd., Workingham, England) is a supraglottic airway device designed for single-use that, unlike conventional LMAs, does not require an inflatable cuff. In addition, the I-gel, much like the Proseal LMA (PLMA), has a gastric drainage tube associated with an upper tube for decompression of the stomach, thereby avoiding acid reflux and decreasing the risk of pulmonary absorption. The purpose of this study was to compare PLMA and I-gel devices in patients undergoing gynecological laparoscopy based on sealing pressure before and during pneumoperitoneum, insertion time, and gas exchange.
Following Institutional Review Board approval and written informed consent, 30 adult patients were randomly allocated to one of two groups (the PLMA or I-gel group). In each case, insertion time and number of attempts were recorded. After successful insertion, airway leak pressure was measured.
Successful insertion and mechanical ventilation with both supraglottic airway devices was achieved on the first attempt in all 30 patients, and there were no significant differences with respect to insertion time. Likewise, leak pressure did not vary significantly either between or within groups after CO2 insufflation. In addition, differences between leak volume and leak fraction between groups were not significant.
The results of our study indicate that the I-gel is a reasonable alternative to the PLMA for controlled ventilation during laparoscopic gynecologic surgery.
Purpose. Hypoglossal nerve palsy after use of the laryngeal mask airway (LMA) is an exceptionally rare complication. We present the first case of unilateral hypoglossal nerve palsy after use of the LMA Supreme. Clinical Features. A healthy 67-year-old female was scheduled for a hallux valgus correction under general anesthesia combined with femoral and sciatic nerve blocks. A size 4 LMA Supreme was inserted successfully at the first attempt and the cuff was inflated with air at an intracuff pressure of 60 cmH2O using cuff pressure gauge. Anesthesia was maintained with oxygen, nitrous oxide (67%), and sevoflurane under spontaneous breathing. The surgery was uneventful and the duration of anesthesia was two hours. The LMA was removed as the patient woke and there were no immediate postoperative complications. The next morning, the patient complained of dysarthria and dysphasia. These symptoms were considered to be caused by the LMA compressing the nerve against the hyoid bone. Conservative treatment was chosen and the paralysis recovered completely after 5 months. Conclusion. Hypoglossal nerve injury may occur despite correct positioning of the LMA under the appropriate intracuff pressure. A follow-up period of at least 6 months should be taken into account for the recovery.
Background and Objective
Conflicting results were found between the I-gel™ and the LMA-Supreme™ during anesthesia, so we conducted a meta-analysis of randomized controlled trials (RCTs) to compare the effectiveness and safety of the I-gel™ vs. the LMA-Supreme™during anesthesia.
A comprehensive search was conducted using Pubmed, EMbase, ISI Web of Knowledge, the Cochrane Library, China Journal Full-text Database, Chinese Biomedical Database, Chinese Scientific Journals Full-text Database, CMA Digital Periodicals, and Google scholar to find RCTs that compare the LMA-S™ with the i-gel™during anesthesia. Two reviewers independently selected trials, extracted data, and assessed the methodological qualities and evidence levels. Data were analyzed by RevMan 5.0 and comprehensive meta-analysis software.
Ten RCTs were included. There were no significant differences in oropharyngeal leak pressures (mean difference [MD] 0.72, 95% confidence interval [CI] –1.10 2.53), device placement time (MD –1.3, 95%CI –4.07 1.44), first attempt insertion success (risk ratio [RR] 1.01, 95% CI 0.9 1.14), grade 3 and 4 fiberoptic view (RR 0.89, 95%CI 0.65 1.21), and blood on removal (RR 0.62, 95%CI 0.32 1.22) between the i-gel™ and the LMA-Supreme™, respectively. However, the LMA-Supreme™was associated with easier gastric tube insertion (RR 1.17, 95%CI 1.07 1.29), and more sore throat (RR 2.56, 95%CI 1.60 4.12) than the i-gel™ group.
The LMA-Supreme™ and i-gel™ were similarly successful and rapidly inserted. However, the LMA-Supreme™ was shown to be easier for gastric tube insertion and associated with more sore throat compared with the i-gel™.
The newest variation of i-gel is its pediatric version. This novel supraglottic airway device has the added advantage of a drain tube. In this study, we compared the effectiveness of size 2.5 i-gel with size 2.5 ProSeal LMA.
This study was designed to investigate the usefulness of the size 2.5 i-gel compared with the ProSeal laryngeal mask airway (PLMA) of the same size in anesthetized, paralyzed children.
Materials and Methods:
Sixty ASA grade I – II patients undergoing elective surgery were included in this prospective study and were randomly assigned to the i-gel and PLMA groups (30 patients in each group). A size 2.5 supraglottic airway was inserted according to the assigned group. We assessed the ease of insertion, hemodynamic data, oropharyngeal sealing pressure, and postoperative complications.
There were no differences in the demographic and hemodynamic data, success rates for the first attempt of insertion, or postoperative airway morbidity among the two groups. The airway leak pressure of the i-gel group (27.12 ± 1.69 cm H2O) was significantly higher than that of the PLMA group (22.75 ± 1.46 cm H2O).
Hemodynamic parameters, ease of insertion and postoperative complications were comparable between the i-gel and PLMA, but the nairway sealing pressure was significantly higher in the i-gel group.
I-gel; Pediatric patients; ProSeal laryngeal mask airway
Perfusion index (PI) is a non-invasive numerical value of peripheral perfusion obtained from a pulse oximeter. In this study, we evaluated the efficacy of PI for detecting haemodynamic stress responses to insertion of i-gel, laryngeal mask airway (LMA) and endotracheal tube and compare, its reliability with the conventional haemodynamic criteria in adults during general anaesthesia.
Sixty patients scheduled for elective general surgery under general anaesthesia were randomised to three groups. (i-gel, LMA and ET groups (n=20/group). Heart rate (HR) (positive if ≥10 bpm), systolic blood pressure (SBP), diastolic blood pressure (DBP) (positive if ≥15 mm Hg) and PI (positive if ≤10%) were monitored for 5 min after insertion. Main outcome measures: SBP, DBP, HR and PI were measured before induction of anaesthesia and before and after insertion of the airway device.
Insertion of airway devices produced significant increases in HR, SBP and DBP in LMA and ET groups. Moreover, PI was decreased significantly by 40%, 100% and 100% in the three groups. Using the PI criterion, the sensitivity was 100% (CI 82.4-100.0%). Regarding the SBP and DBP criterions, the sensitivity was 44.4% (CI 24.6-66.3%), 55.6% (CI 33.7-75.4%) respectively. Also, significant change in the mean PI over time (from pre-insertion value to the 1st min, 3rd min, until the 4th min after insertion without regard the device type), (P<0.001).
PI is a reliable and easier alternative to conventional haemodynamic criteria for detection of stress response to insertion of i-gel, LMA and ET during propofol fentanyl isoflurane anaesthesia in adult patients.
Airway management; classic laryngeal mask airway; endotracheal tube; equipment design; i-gel; intubation; laryngeal masks; perfusion index; stress response
Bystander resuscitation plays an important role in lifesaving cardiopulmonary resuscitation (CPR). A significant reduction in the "no-flow-time", quantitatively better chest compressions and an improved quality of ventilation can be demonstrated during CPR using supraglottic airway devices (SADs). Previous studies have demonstrated the ability of inexperienced persons to operate SADs after brief instruction. The aim of this pilot study was to determine whether an instruction manual consisting of four diagrams enables laypersons to operate a Laryngeal Mask Supreme® (LMAS) in the manikin.
An instruction manual of four illustrations with speech bubbles displaying the correct use of the LMAS was designed. Laypersons were handed a bag containing a LMAS, a bag mask valve device (BMV), a syringe prefilled with air and the instruction sheet, and were asked to perform and ventilate the manikin as displayed. Time to ventilation was recorded and degree of success evaluated.
A total of 150 laypersons took part. Overall 145 participants (96.7%) inserted the LMAS in the manikin in the right direction. The device was inserted inverted or twisted in 13 (8.7%) attempts. Eight (5.3%) individuals recognized this and corrected the position. Within the first 2 minutes 119 (79.3%) applicants were able to insert the LMAS and provide tidal volumes greater than 150 ml (estimated dead space). Time to insertion and first ventilation was 83.2 ± 29 s. No significant difference related to previous BLS training (P = 0.85), technical education (P = 0.07) or gender could be demonstrated (P = 0.25).
In manikin laypersons could insert LMAS in the correct direction after onsite instruction by a simple manual with a high success rate. This indicates some basic procedural understanding and intellectual transfer in principle. Operating errors (n = 91) were frequently not recognized and corrected (n = 77). Improvements in labeling and the quality of instructional photographs may reduce individual error and may optimize understanding.
The cuff of the laryngeal mask airway (LMA) is preferred to be partially inflated before insertion in pediatric cases. However, it is not known how much inflation is appropriate. In addition, intra-cuff pressure is not routinely monitored in many institutions despite the fact that a neglected high cuff pressure could cause several complications. This study was conducted to determine whether the cuff inflated with its resting volume before insertion could have a clinically tolerable intra-cuff pressure after insertion.
One hundred fifty unpremedicated children aged 0 to 9 yrs were enrolled. The pilot balloon valve was connected to a piston-free syringe to keep the valve open to the atmosphere and allowing the pressure within the cuff of to LMA to equalize to atmospheric pressure. Anesthesia was induced with 6 vol% of sevoflurane in oxygen. After insertion and final positioning of the LMA, the intra-cuff pressure was measured using a cuff pressure manometer.
The mean intra-cuff pressure was 50 ± 12.9 cmH2O; intra-cuff pressures were 39.1 ± 9.3, 51.6 ± 11.2, and 64.6 ± 12.5 cmH2O for LMAs of sizes 1.5, 2, and 2.5, respectively. Intra-cuff pressure of more than 60 cmH2O was measured in 26 patients, and the median value was 70 cmH2O. There was weak statistical correlation among age, height, and weight with intra-cuff pressure.
The cuff inflated by the resting volume before insertion may be a simple method for guaranteeing tolerable cuff pressure after insertion.
Children; Intra-cuff pressure; Laryngeal mask airway; Resting volume
Many tools have been developed to facilitate the insertion of the ProSeal laryngeal mask airway (LMA) insertion, which can be impeded by folding of its soft cuff. The aim of this study was to compare the efficiency of ProSeal LMA insertion guided by a soft, direct optical Foley Airway Stylet Tool (FAST) with the standard introducer tool (IT).
One hundred sixty patients undergoing general anesthesia using the ProSeal LMA as an airway management device were randomly allocated to either FAST-guided or IT-assisted groups. Following ProSeal LMA insertion, the glottic and esophageal openings were identified using a fiberoptic bronchoscope introduced through the airway and the drain tube. The primary outcomes were time taken to insert the ProSeal LMA and the success rate at the first attempt. Secondary end points included ease of insertion, hemodynamic response to insertion, and postoperative adverse events recorded in the recovery room and on the first postoperative morning.
One hundred forty patients were included in the final analysis: 66 in the FAST-guided group and 74 in the IT-assisted group. The success rate of FAST device-guided ProSeal LMA insertion (95.7%) was broadly comparable with IT-assisted insertion (98.7%). However, the time taken to insert the ProSeal LMA was significantly longer when the FAST technique was used (p <0.001). The incidence of correct alignment of the airway tube and the drain tube did not differ significantly between the groups. There were no significant differences in ease of insertion or hemodynamic responses to insertion, except that the incidence of postoperative sore throat was significantly higher in the FAST group on the first postoperative day (22.2% compared with 6.8% in the IT group; p =0.035).
Both FAST-guided and IT-assisted techniques achieved correct ProSeal LMA positioning, but the IT technique was significantly quicker and less likely to cause a sore throat.
ClinicalTrials.gov Identifier: NCT02048657
ProSeal laryngeal mask airway (LMA); Foley Airway Stylet Tool (FAST); Introducer tool (IT); Fiberoptic bronchoscope
Several publications have reported the successful, safe use of Laryngeal Mask Airway (LMA)-Classic devices in patients undergoing laparoscopic surgery. However, there have been no studies that have examined the application of volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) using a LMA during gynecological laparoscopy. The aim of this study is to compare how the VCV and PCV modes and using a LMA affect the pulmonary mechanics, the gas exchange and the cardiovascular responses in patients who are undergoing gynecological laparoscopy.
Sixty female patients were randomly allocated to one of two groups, (the VCV or PCV groups). In the VCV group, baseline ventilation of the lung was performed with volume-controlled ventilation and a tidal volume of 10 ml/kg ideal body weight (IBW). In the PCV group, baseline ventilation of the lung using pressure-controlled ventilation was initiated with a peak airway pressure that provided a tidal volume of 10 ml/kg IBW and an upper limit of 35 cmH2O. The end-tidal CO2, the peak airway pressures (Ppeak), the compliance, the airway resistance and the arterial oxygen saturation were recorded at T1: 5 minutes after insertion of the laryngeal airway, and at T2 and T3: 5 and 15 minutes, respectively, after CO2 insufflation.
The Ppeak at 5 minutes and 15 minutes after CO2 insufflation were significantly increased compared to the baseline values in both groups. Also, at 5 minutes and 15 minutes after CO2 insufflation, there were significant differences of the Ppeak between the two groups. The compliance decreased in both groups after creating the pneumopertoneim (P < 0.05).
Our results demonstrate that PCV may be an effective method of ventilation during gynecological laparoscopy, and it ensures oxygenation while minimizing the increases of the peak airway pressure after CO2 insufflation.
Lapraroscopic surgery; LMA; Pressure-controlled ventilation; Volume-controlled ventilation