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At least 19 recordsLinked to original sources
PubMed1999

Airway management during cardiopulmonary resuscitation--a comparative study of bag-valve-mask, laryngeal mask airway and combitube in a bench model.

Gastric inflation and subsequent regurgitation are a potential risk of ventilation during cardiopulmonary resuscitation (CPR). In respect of recent investigations, principal respiratory components such as respiratory system compliance, resistance and lower esophageal sphincter pressure were adapted according to CPR situations. The purpose of our study was to assess lung ventilation and gastric inflation when performing ventilation with bag-valve-mask, laryngeal mask airway, and combitube in a bench model simulating an unintubated cardiac arrest patient. Twenty-one student nurses, without any experience in basic life support measures, ventilated the bench model with all three devices. Mean ( +/- S.D.) gastric inflation with the laryngeal mask airway (seven cases) was significantly lower than with the bag-valve-mask (0.6 +/- 0.8 vs 3.0 +/- 2.11 min(-1), P < 0.01). There was no gastric inflation when ventilation was performed with the combitube. Only seven of 21 volunteers exceeded 1-min lung volumes of > 5 1 when using the bag-valve-mask, whereas mean (+/-S.D.) 1-min lung volumes with both laryngeal mask airway and combitube were significantly higher (laryngeal mask airway 15.0+/-6.61, combitube 16.6 +/- 6.81 vs bag-valve-mask 4.8 +/- 2.71, P < 0.01). The time for insertion was significantly faster with both bag-valve-mask and laryngeal mask airway compared with the combitube (median: bag valve mask 22 s, laryngeal mask airway 37 s vs combitube 70 s, P < 0.01). This may tip the scales towards using the laryngeal mask airway during basic life support airway management. In conclusion, our data suggests that both laryngeal mask airway and combitube may be appropriate alternatives for airway management in the first few minutes of CPR.

Adult↗
PubMed2003

[Airway equipment and its maintenance for a non difficult adult airway management (endotracheal intubation and its alternative: face mask, laryngeal mask airway, laryngeal tube)].

The airway equipment for a non difficult adult airway management are described: endotracheal tubes with a specific discussion on how to inflate the balloon, laryngoscopes and blades, stylets and intubation guides, oral airways, face masks, laryngeal mask airways and laryngeal tubes. Cleaning and disinfections with the maintenance are also discussed for each type of airway management.

Adjuvants, Anesthesia↗
PubMed1998

Physiological dead space/tidal volume ratio during face mask, laryngeal mask, and cuffed oropharyngeal airway spontaneous ventilation.

OBJECTIVE: To compare the physiological dead space/tidal volume ratio and arterial to end-tidal carbon dioxide tension (ETCO2) difference during spontaneous ventilation through a face mask, a laryngeal mask (LMA), or a cuffed oropharyngeal airway. DESIGN: Prospective, randomized, cross-over study. SETTING: Inpatient anesthesia at a university department of orthopedic surgery. PATIENTS: 20 ASA physical status I and II patients, without respiratory disease, who underwent ankle and foot surgery. INTERVENTIONS: After a peripheral nerve block was performed, propofol anesthesia was induced and then maintained with a continuous intravenous (i.v.) infusion (4 to 6 mg/kg/h). A face mask, a cuffed oropharyngeal airway, or an LMA were placed in each patient in a random sequence. After 15 minutes of spontaneous breathing through each of the airways, ventilatory variables, as well as arterial, end-tidal, and mixed expired CO2 partial pressure, were measured, and physiological dead space/tidal volume ratio was calculated. MEASUREMENTS AND MAIN RESULTS: Expired minute volume and respiratory rate (RR) were lower with LMA (5.6 +/- 1.2 L/min and 18 +/- 3 breaths/min) and the cuffed oropharyngeal airway (5.7 +/- 1 L/min and 18 +/- 3 breaths/min) than the face mask (7.1 +/- 0.9 L/min and 21 +/- 3 breaths/min) (p = 0.0002 and p = 0.013, respectively). Physiological dead space/tidal volume ratio and arterial to end tidal CO2 tension difference were similar with the cuffed oropharyngeal airway (3 +/- 0.4 mmHg and 4.4 +/- 1.4 mmHg) and LMA (3 +/- 0.6 mmHg and 3.7 +/- 1 mmHg) and lower than with the face mask (4 +/- 0.5 mmHg and 6.7 +/- 2 mmHg) (p = 0.0001 and p = 0.001, respectively). CONCLUSION: Because of the increased dead space/tidal volume ratio, breathing through a face mask required higher RR and expired minute volume than either the cuffed oropharyngeal airway or LMA, which, in contrast, showed similar effects on the quality of ventilation in spontaneously breathing anesthetized patients.

Analysis of Variance↗
PubMed2006

Comparison of airway management with the intubating laryngeal mask, laryngeal tube and CobraPLA by paramedical students in anaesthetized patients.

BACKGROUND: Because of the importance of airway management in emergency care, alternative methods with shorter learning curves for inexperienced personnel have been looked for as a substitute for endotracheal intubation (ETI). METHODS: We compared the success of insertion, oxygenation and ventilation of the intubating laryngeal mask (ILMA), laryngeal tube (LT) and CobraPLA (COB) in anaesthetized patients when used by paramedical students. After informed consent, 96 patients were monitored and anaesthetized for general surgery without the use of a muscle relaxant. After the induction of anaesthesia, 32 paramedical students inserted the ILMA, LT or COB in a random order and ventilated the patient for a 60-s period. The number of insertion attempts, the time needed for insertion, and oxygenation and ventilation parameters were recorded. The students gave a subjective evaluation of the airway devices after the test. RESULTS: Twenty-four of the 32 students (75%) successfully inserted ILMA at the first attempt, compared with 14 of 32 (44%) for LT and seven of 32 (22%) for COB (P<0.001, ILMA vs. COB). One student failed to insert ILMA after all three attempts, compared with seven of 32 (21%) using LT and seven of 32 (21%) using COB (P=not significant). Oxygenation and ventilation parameters did not differ between the groups after successful insertion. CONCLUSION: Clinically inexperienced paramedical students can successfully use ILMA in anaesthetized patients. Further investigations are warranted to study whether ILMA or LT can replace ETI in emergency airway management when used by inexperienced medical or paramedical staff.

Anesthesia, General↗
PubMed2000

Work of breathing during spontaneous ventilation in anesthetized children: a comparative study among the face mask, laryngeal mask airway and endotracheal tube.

Work of breathing (WOB) increases during general anesthesia in adults, but such information has been limited in pediatric patients. We studied WOB in 24 healthy children (mean age 2+/-1.9 yrs), during elective urogenital surgery under 1 minimum alveolar anesthetic concentration halothane-nitrous oxide anesthesia with a caudal block while breathing spontaneously. WOB was measured with an esophageal balloon, miniature flowmeter, and a computerized (Bicore) system. In each patient, WOB was computed under four conditions: a mask without oral airway (-AW), a mask with oral airway (+AW), a laryngeal mask airway (LMA), and an endotracheal tube (ETT). With each apparatus WOB was studied both with continuous positive airway pressure (CPAP) (5-6 cm H(2)O) and without CPAP (or zero end-expiratory pressure [ZEEP]). Under ZEEP, WOB (g x cm/kg) among the four apparatus were (mean +/- SEM): mask (-AW) (64 +/-19.2) > mask (+AW) (44+/-17.2), LMA (42+/-15.6) > ETT (25.4+/- 12.4) (P<0.05). WOB with CPAP significantly (P<0.05) decreased from WOB with ZEEP in three groups (mask [-AW], mask [+AW], and LMA), but not in the ETT group. Tidal volume (both ZEEP and CPAP) and end-tidal PCO(2) (with CPAP only) were significantly (P<0.05) decreased only in the ETT group, whereas no significant difference was found in respiratory rate or minute volume among the four airway apparatus groups, either with or without CPAP. The reduction in WOB, when breathing through ETT was primarily attributable to decreases in tidal volume and volume work. The finding that WOB decreases with CPAP in all groups except for the ETT group suggests that the decrease is a result of improved patency of the upper airway rather than of increases in functional residual capacity and lung compliance.

Anesthesia, Inhalation↗
PubMed2001

Laryngeal mask vs intubating laryngeal mask: insertion and ventilation by inexperienced resuscitators.

The laryngeal mask airway (LMA) has been shown to be useful in airway maintenance during resuscitation. The intubating laryngeal mask (ILM) is a modified LMA permitting both ventilation and rapid endotracheal intubation. We aimed to compare the LMA and the ILM with regard to ease of insertion and successful ventilation by inexperienced personnel. We have used anaesthetized, apnoeic, non-paralysed patients as a model to simulate resuscitation. Following standardized training, non-anaesthetic medical staff with no previous experience in laryngeal mask airway insertion (novices) inserted either the LMA or ILM in 55 patients following induction of anaesthesia. There were no differences between the two patient groups included in our study with regard to mean age and body mass index (BMI). The success rate for inserting the airway device and achieving a significant end-tidal CO2 recording within two minutes was 23/28 for the LMA (82.1%) and 22/27 for the ILM (81.5%). Reasons for failure included inability to insert the ILM past the teeth and insertion of the LMA upside down. There were no clinically relevant differences in the mean time to airway insertion and successful ventilation (62.6 vs 62 seconds) or expired tidal volume (781 vs 767 ml) for the LMA and ILM respectively. We conclude that the ILM is as easily inserted and effectively used as an LMA by novices and, because it allows the option offacilitating endotracheal intubation, may be the preferred device for maintaining an airway during resuscitation.

Adult↗
PubMed1993

Resistance to constant air flow imposed by the standard laryngeal mask, the reinforced laryngeal mask and RAE tracheal tubes.

The reinforced laryngeal mask airway (RLMA) has been introduced recently for head and neck surgery. Its resistance to constant air flow has been measured and compared with that of the standard laryngeal mask airway (LMA). The RLMA resistance has also been compared with that imposed by the standard oral Ring-Adair-Elwyn (RAE) tube of a corresponding size for a given patient. The resistance to gas flow of the new RLMA was approximately three to five times that of the LMA at two flow rates (0.5 and 1.0 litre s-1). The resistance of the RLMA 4 was intermediate between that of RAE tubes sizes 8 and 9 mm, and that of RLMA 2 intermediate between that of RAE tubes sizes 5 and 6 mm.

Air Pressure↗
PubMed2001

Fibreoptic views through the laryngeal mask and the intubating laryngeal mask.

BACKGROUND AND OBJECTIVE: The intubating laryngeal mask (intubating laryngeal mask airway) was designed to facilitate blind intubation. Its value as an adjunct to fibreoptic laryngoscopy has not been evaluated. This study compares the intubating laryngeal mask airway with the standard laryngeal mask airway as conduits for fibreoptic laryngoscopy. METHODS: The fibreoptic view of the laryngeal inlet was graded via both devices in 60 anaesthetized patients. The fibreoptic view through the intubating laryngeal mask airway was assessed after the central epiglottic elevator bar had been lifted out of the field of vision by an 8-mm Euromedical tracheal tube, which was inserted to a depth of 18 cm. The fibreoptic view from the aperture bars of the laryngeal mask was recorded. RESULTS: The vocal cords were viewed less frequently through the intubating laryngeal mask airway (52%) than through the laryngeal mask airway (92%) [difference = 40% (95% CI = 26% to 54%), P < 0.0001]. CONCLUSION: The view of the laryngeal inlet is better through the laryngeal mask airway than through a tracheal tube inserted to 18 cm in the intubating laryngeal mask.

Adolescent↗
PubMed2002

Positive pressure ventilation during fibreoptic intubation: comparison of the laryngeal mask airway, intubating laryngeal mask and endoscopy mask techniques.

BACKGROUND: The efficacy of delivery of mechanical ventilation through different airway devices during fibreoptic intubation is not known. METHODS: We compared the laryngeal mask airway (LMA), intubating laryngeal mask (ILM) and endoscopy mask for positive pressure ventilation (PPV) during fibreoptic intubation. In 80 adult paralysed patients, fibreoptic intubation was performed during PPV using a combination of a size 3 or 4 LMA with a 6.0 mm nasal RAE tracheal tube (LMA3/4 group; n=22), a size 5 LMA with a 7.0 mm nasal RAE tube (LMA5 group; n=18), an ILM with an 8.0 mm special reinforced tracheal tube (ILM group; n=20) or an endoscopy mask (Patil mask) with a 7.5 mm standard tracheal tube (Patil group; n=20). The inspiratory and expiratory tidal volumes (VI and VE) with a ventilation pressure of 20 cm H2O were measured using a pneumotachograph. RESULTS: Mean VE values during fibreoptic intubation in the LMA5 [5.3 (SD 1.5) ml kg(-1)] and ILM [7.1 (2.3) ml kg(-1)] groups were greater than in the LMA3/4 group [2.6 (1.0) ml kg(-1), P<0.0001]. The mean VE was greater in the Patil group [20.6 (4.9) ml kg(-1)] than in the other three groups (P<0.0001). Gastric insufflation during intubation was more frequent in the Patil group (30%) than in the other three groups (4.5-5.6%) (P<0.05). CONCLUSION: PPV is possible with the LMA, ILM or endoscopy mask during fibreoptic intubation. With an airway pressure of 20 cm H2O, ventilation during intubation using a size 3 or 4 LMA was almost insufficient, while ventilation using a size 5 LMA or an ILM was almost acceptable. Ventilation during intubation with the endoscopy mask was greater than that with the LMA or ILM, but gastric insufflation was more frequent.

Adult↗
PubMed2000

Comparison of laryngeal mask and intubating laryngeal mask insertion by the naïve intubator.

Seventy-five inexperienced participants were timed inserting the laryngeal mask airway (LMA) and the intubating laryngeal mask (ILM) in one of five cadavers. Adequacy of ventilation was assessed on a three-point scale depending on chest expansion and air leak. Participants were also asked to intubate the trachea via the ILM. The ILM was inserted faster than the LMA (P < 0.05) with a greater proportion achieving adequate ventilation after their first attempt (P < 0.05). Tracheal intubation via the ILM was completed successfully by 67% (52 of 75) of participants. In a questionnaire, participants stated that the ILM was easier to use and the preferred device in an emergency. The results suggest that inexperienced practitioners should use the ILM rather than the LMA for emergency ventilation.

Cadaver↗
PubMed1998

The incidence of regurgitation during cardiopulmonary resuscitation: a comparison between the bag valve mask and laryngeal mask airway.

The risk of gastric regurgitation and subsequent pulmonary aspiration is a recognised complication of cardiac arrest--a risk which may be further increased by the resuscitative procedure itself. The purpose of this study was to compare the incidence of gastric regurgitation between the bag valve mask (BVM) and laryngeal mask airway (LMA). The resuscitation data collection forms of 996 patients who underwent in-hospital cardiopulmonary resuscitation over a 3.5 year period were reviewed. Of these, 199 patients were excluded from the study because there was no airway management involving a BVM or LMA. The incidence and timing of regurgitation was studied in the remaining 797 patients. Regurgitation was recorded to have occurred at some stage in 180 of these patients (22.6%). However, 84 regurgitated prior to CPR (46.7% of those patients who regurgitated). These patients were excluded from further analysis as regurgitation could not have been affected by any form of ventilation. Of the remaining 713 patients, BVM ventilation was used in 636 cases. In 170 of these the LMA was also used following the BVM. Where the patient was ventilated with the BVM alone or BVM followed by ETT the incidence of regurgitation during CPR was 12.4%. The LMA was used during resuscitation in 256 cases of which 170 had BVM ventilation prior to the LMA. Where the patient was ventilated with the LMA alone or LMA followed by ETT the incidence of regurgitation during CPR was 3.5%. The study confirms experience reported in earlier studies that when an LMA is used as a first line airway device, regurgitation is relatively uncommon.

Cardiopulmonary Resuscitation↗
PubMed2000

Pharyngolaryngeal, neck, and jaw discomfort after anesthesia with the face mask and laryngeal mask airway at high and low cuff volumes in males and females.

BACKGROUND: There is controversy over (1) the relative incidence of sore throat between the face mask (FM) and laryngeal mask airway (LMA), (2) the efficacy of LMA intracuff pressure reduction as a mechanism for minimizing sore throat, and (3) the relative incidence of sore throat with the LMA between males and females. In a randomized double-blind study, the authors compared laryngopharyngeal, neck, and jaw discomfort with the FM and LMA at high and low cuff volumes in males and females. METHODS: Three hundred adult patients were randomly assigned to three equal-sized groups for airway management: (1) the FM, (2) the LMA with a fully inflated cuff (LMA-High), or (3) the LMA with a semi-inflated cuff (LMA-Low). Anesthesia was administered with propofol, nitrous oxide, oxygen, and isoflurane. In the FM group, a Guedel-type oropharyngeal airway and jaw thrust were used only if necessary. In the LMA groups, cuff inflation was achieved with either 15 or 30 ml for the size 4 (females) and 20 or 40 ml for the size 5 (males). The LMA was removed when the patient was awake. Patients were questioned 18-24 h postoperatively about surgical pain, sore throat, sore neck, sore jaw, dysphonia, and dysphagia, and about whether they were satisfied with their anesthetic. RESULTS: The incidence of sore throat was lower in the FM (8%) than the LMA-High (42%) and LMA-Low (20%) groups (both: P < or = 0.02). The incidence of sore neck was higher for the FM (14%) than the LMA-High group (6%; P = 0.05) but similar to the LMA-Low group (8%). The incidence of sore jaw was higher in the FM (11%) than the LMA-High (3%) and LMA-Low (3%) groups (both: P = 0. 02). There were no differences among groups for surgical pain or dysphonia. The incidence of dysphagia was lower in the FM (1%) than the LMA-High group (11%; P = 0.003), but similar to the LMA-Low group (1%). The incidence of sore throat and dysphagia was lower in the LMA-Low group than the LMA-High group for both males and females (all: P < or = 0.04). There were no differences in discomfort levels between males and females in any group. Two patients from the FM group and one from the LMA-High group were not satisfied with their anesthetic. These complaints were unrelated to postoperative morbidity. CONCLUSION: The LMA causes more sore throat and dysphagia but less jaw pain than the FM. Sore throat and dysphagia are more common with the LMA if the initial cuff volume is high. There are no differences in discomfort levels between males and females. However, these discomforts do not influence patient satisfaction after LMA or FM anesthesia.

Adult↗
PubMed1998

Gas leak and gastric insufflation during controlled ventilation: face mask versus laryngeal mask airway.

PURPOSE: To compare two airway management techniques, face mask (FM) with oropharyngeal airway and laryngeal mask airway (LMA), with respect to the effectiveness of positive pressure ventilation and airway maintenance. METHODS: After induction of anaesthesia, two airway management techniques (FM or LMA) and three peak pressures (20, 25 and 30 cm H2O) were randomly applied during controlled ventilation in 60 patients. Data collected included inspiratory and expiratory volumes and presence of gastro-oesophageal insufflation. Leak was calculated by subtracting the expiratory from the inspiratory volume, expressed as a fraction of the inspiratory volume. RESULTS: Expiratory volumes (mean +/- SD) at 20, 25 and 30 cm H2O for LMA ventilation were 893 +/- 260, 986 +/- 276 and 1006 +/- 262 respectively, and for FM ventilation 964 +/- 264, 1100 +/- 268 and 1116 +/- 261. Leak fractions at 20, 25 and 30 cm H2O for LMA ventilation were 0.21 +/- 0.15, 0.24 +/- 0.18 and 0.26 +/- 0.18 respectively, and for FM ventilation 0.14 +/- 0.09, 0.14 +/- 0.09 and 0.12 +/- 0.08. The frequency of gastro-oesophageal insufflation was 1.6%, 5% and 5% for the LMA and 5%, 15% and 26.6% for the FM for ventilation pressures of 20, 25 and 30 cm H2O respectively which was greater with LMA use. CONCLUSION: Ventilation was adequate in all patients using both techniques. Leak was pressure dependent and greater with LMA use. Most of the leak was vented to the atmosphere via the pharynx. Gastro-oesophageal insufflation was more frequent with ventilation using the face mask. LMA use with positive pressure ventilation would appear to be a better airway management method than the face mask.

Adult↗
PubMed2001

Intubating laryngeal mask airway, laryngeal tube, 1100 ml self-inflating bag-alternatives for basic life support?

Insufficient oxygenation, ventilation and gastric inflation with subsequent regurgitation of stomach contents is a major hazard of bag-valve-face mask ventilation during the basic life support phase of cardiopulmonary resuscitation (CPR). The European Resuscitation Council has recommended smaller tidal volumes of approximately 500 ml as an effort to reduce gastric inflation; furthermore, the intubating laryngeal mask airway and the laryngeal tube have been recently developed in order to provide rapid ventilation and to secure the airway. The purpose of our study was to examine whether usage of a newly developed medium-size self-inflating bag (maximum volume, 1100 ml) in association with the intubating laryngeal mask airway, and laryngeal tube may provide adequate lung ventilation, while reducing the risk of gastric inflation in a bench model simulating the initial phase of CPR. Twenty house officers volunteered for our study. When using the laryngeal tube, and the intubating laryngeal mask airway, respectively, the medium-size (maximum volume, 1100 ml) versus adult (maximum volume, 1500 ml) self-inflating bag resulted in significantly (P<0.05) lower mean+/-S.E.M. lung tidal volumes (605+/-22 vs. 832+/-4 ml, and 666+/-27 vs. 887+/-37 ml, respectively), but comparable peak airway pressures. No gastric inflation occurred when using both devices with either ventilation bag. In conclusion, both the intubating laryngeal mask airway and laryngeal tube in combination with both an 1100 and 1500 ml maximum volume self inflating bag proved to be valid alternatives for emergency airway management in a bench model of a simulated unintubated cardiac arrest victim.

Adult↗
PubMed2003

Resistive load of laryngeal mask airway and ProSeal laryngeal mask airway in mechanically ventilated patients.

BACKGROUND: The ProSeal Laryngeal Mask Airway (PLMA) ventilation tube is narrower and shorter than the standard Laryngeal Mask Airway (LMA) and is without the vertical bars at the end of the tube. In this randomized, crossover study, PLMA and LMA resistances were compared. METHODS: Respiratory mechanics was calculated in 26 anesthetized, mechanically ventilated patients with both LMA and PLMA. The laryngeal mask positioning was fiberoptically evaluated. Differences in the respiratory mechanics of the LMA and the PLMA were attributed to the differences between the laryngeal masks. RESULTS: In the total study population the airway resistance was 1.5 +/- 2.6 hPa.l-1.s-1 (P = 0.005) higher with the PLMA than with the LMA. During the PLMA use, the peak expiratory flow reduced by 0.02 +/- 0.05 l min-1 (P = 0.046), the expiratory resistance increased by 0.6 +/- 1.3 hPa.l-1.s-1 (P = 0.022), and the time constant of respiratory system lengthened by 0.09 +/- 0.18 s (P = 0.023). These differences doubled when the LMA was better positioned than the PLMA, whereas they disappeared when the PLMA was positioned better than the LMA. CONCLUSIONS: The standard LMA offers a lower resistive load than the PLMA. Moreover, the fitting between the laryngeal masks and the larynx, as fiberoptically evaluated, plays a major role in determining the resistive properties of these devices.

Adult↗
PubMed2003

Storage capacities of the laryngeal mask and laryngeal tube compared and their relevance to aspiration risk during positive pressure ventilation.

IMPLICATIONS: Supraglottic airways used for positive pressure ventilation run the occasional risk of regurgitated liquid entering the lungs (aspiration). A dynamic model described here shows that the laryngeal tube has a larger liquid storage capacity between the two cuffs than the bowl of the laryngeal mask, with a consequent smaller aspiration risk.

Intubation, Intratracheal↗