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At least 1,711 records · Page 95Linked to original sources
PubMed2000

Ease of tracheal intubation through the intubating laryngeal mask during manual in-line head and neck stabilisation.

We studied 40 anaesthetised and paralysed patients, in a randomised manner, to compare the ease of tracheal intubation either using a Macintosh laryngoscope and gum elastic bougie (group C) with the ease of tracheal intubation through the intubating laryngeal mask using a fibreoptic bronchoscope (group L), during manual in-line stabilisation of the patient's head and neck. In both groups, a maximum of 120 s was allowed for attempts at tracheal intubation. The ease of placement of the intubating laryngeal mask or tracheal intubation was assessed using a 100-mm visual analogue scale (VAS). In patients in whom tracheal intubation succeeded, time for intubation was measured. The intubating laryngeal mask was placed successfully in 19 of 20 patients, with the median VAS of 18 mm (95% CI: 13-32 mm). The success rate of tracheal intubation in group L (17 patients) was significantly higher than in group C (nine patients) (p < 0.01), tracheal intubation in group L was significantly easier than intubation in group C (p < 0.001; 95% CI for difference in VAS: 18-68 mm) and time taken for tracheal intubation was significantly shorter in group L than in group C (95% CI for difference: 8-50 s).

Adult↗
PubMed2000

Visible and occult blood contamination of laryngeal mask airways and tracheal tubes used in adult anaesthesia.

The purpose of this study was to compare visible and occult blood contamination of 50 laryngeal mask airways and 50 tracheal tubes following routine anaesthesia for procedures not involving the oropharyngeal or nasal cavities. All airway devices were examined visually for the presence of blood before washing in 100 ml of water. A semiquantitative dipstick was used to test for the presence of blood in the washings. Laryngeal mask airways were examined visually by both authors to test agreement. The results show that occult blood contamination occurred in 78% of tracheal tubes and 76% of laryngeal mask airways, while visible blood contamination was 16% and 12%, respectively. Other studies reporting visible blood contamination of airway devices probably underestimate the true incidence of blood contamination. Oral secretions following the use of these devices should be considered as high risk for transmission of blood-born viruses. Anaesthetic and recovery staff should be protected against the risks of occupational exposure to oral secretions following the use of airway devices.

Adult↗
PubMed2000

A comparison of the intubating laryngeal mask tracheal tube with a standard tracheal tube for fibreoptic intubation.

We conducted a prospective randomised study to compare the intubating laryngeal mask tracheal tube with a standard tube, for ease of tracheal intubation over a fibrescope. Thirty-six patients were investigated, using a sequential analysis technique. Ease of intubation was improved when the intubating laryngeal mask tracheal tube was used compared with the standard tube (p = 0.0009). Median (interquartile range [range]) intubation times (time from the tube's tip being level with the patient's teeth to successful placement) were 1.5 (1-2.3 [1-3]) s when the intubating laryngeal mask tracheal tube was used and 5 (3-7.3 [3-13]) s when the standard tube was used (p < 0.0001).

Adolescent↗
PubMed2000

Supplementary oxygenation with the laryngeal mask airway: a comparison of four devices.

The provision of supplementary oxygen via the laryngeal mask airway used in the recovery room is important for patient safety. Several devices have been described for this purpose, but these studies have not included an accurate measurement of the most clinically important variable, the end-tidal oxygen concentration. We constructed an artificial model of spontaneous ventilation to compare the efficacy and safety of four devices; a circuit filter, a Hudson mask, the 'T-bag' device and a T-piece. We combined the use of oximetry with a pneumotachograph to provide a continuous picture of the oxygen delivery characteristics of the devices at flow rates of 2, 4 and 8 l.min-1. The performances of the T-bag and the T-piece were superior to those of the filter and Hudson mask, with end-tidal oxygen concentrations of 46.1%, 45.8% and 35.4%, 34.8%, respectively, at 8 l.min-1. Single point assessments of oxygen delivery, such as peak inspired oxygen concentration, may overestimate the efficacy of test devices.

Anesthesia Recovery Period↗
PubMed2002

Monitoring pollution by proton-transfer-reaction mass spectrometry during paediatric anaesthesia with positive pressure ventilation via the laryngeal mask airway or uncuffed tracheal tube.

Twenty children aged 2-66 months were randomly allocated for airway management with either the laryngeal mask airway or uncuffed tracheal tube using intermittent positive pressure ventilation with a tidal volume of 8 ml.kg-1 and a respiratory rate adjusted to maintain end-expiratory carbon dioxide concentration at 5.3 kPa. Induction was with fentanyl/propofol and maintenance was with sevoflurane 2.5% in oxygen/air. The airway device was removed when the patients were awake and the patients were transferred to the postanaesthesia care unit 10 min later. Air was sampled from a point 1.5 m above the floor at a location remote from the ventilation outlet and analysed using a proton-transfer-reaction mass spectrometer capable of continuous trace gas analysis at the parts per billion volume (ppbv) level. The concentration of sevoflurane was recorded every minute during three consecutive phases: for 5 min before the introduction of sevoflurane (background); after introduction of sevoflurane until removal of the airway device (intra-operative); and every minute after removal until the concentration returned to background levels. Median (interquartile range [range]) intra-operative sevoflurane concentrations were 200-400 times higher than background values for the laryngeal mask airway 1 (1-2 [0-3]) ppbv vs. 404 (278-523 [83-983]) ppbv, respectively, and the tracheal tube 2 (1-3 [0-5]) ppbv vs. 396 (204-589 [107-1735]) ppbv (both p < 0.0001), and returned to background values within 5 min of removal. There were no differences in sevoflurane concentration between devices intra-operatively or after removal. The performance of the proton-transfer-reaction mass spectrometer was identical at the start and end of the 30-day study. We conclude that peri-operative sevoflurane concentration in a modern operating theatre is similar for the laryngeal mask airway and the uncuffed tracheal tube in paediatric patients receiving intermittent positive pressure ventilation. Intra-operative sevoflurane concentrations are five times lower than occupational safety limit requirements, and 1000 times lower 5 min after removal of the airway device with the patient awake. The proton-transfer-reaction mass spectrometer has potential for monitoring air quality in the operating theatre.

Air Pollutants, Occupational↗
PubMed1996

Low-flow and minimal-flow anaesthesia using the laryngeal mask airway.

This study was designed to investigate whether the advantages of low- and minimal-flow anaesthesia can be combined with the laryngeal mask airway (LMA). Seventy female patients undergoing routine gynaecological surgery were investigated. After induction of anaesthesia and after positioning a laryngeal mask airway nos 3 and 4, patients were ventilated for 20 min with a fresh gas flow of 6 L min-1. Thereafter, the flow was reduced to 1 L min-1 in 50 patients and to 0.5 L min-1 in 20 patients. Once in the proper position, the LMA allowed flow reduction in all patients, indicating that no gas leakage occurred. It is concluded, that the application of low-flow and even minimal-flow anaesthesia is an alternative to high-flow anaesthesia. It can result in high annual savings and minimization of pollution. However, its use should be restricted to those anaesthesiologists who are experienced with the laryngeal mask airway and minimal-flow anaesthesia.

Adolescent↗
PubMed1999

Removal of the laryngeal mask airway: factors affecting the incidence of post-operative adverse respiratory events in 300 patients.

The purpose of this study is to compare the incidence of undesirable respiratory events when the laryngeal mask airway is either removed from patients who are fully awake or from patients who are deeply anaesthetized. Three-hundred patients aged 1.5-81 years were randomly assigned to have their laryngeal mask airway removed either when deeply anaesthetized or after airway reflexes had returned. The occurrence of adverse respiratory events (coughing, oxygen desaturation and airway obstruction) was recorded. Airway obstruction after laryngeal mask airway removal was evident in 20% of patients in the deep anaesthesia group and in 8% of patients in the awake group (P = 0.007). In spite of this finding, oxygen desaturation in children of less than 6 years of age (SaO2 < 96%) occurred most frequently after awake removal (31.3%) compared with deep anaesthesia removal (4.5%) (P = 0.023).

Adolescent↗
PubMed1999

Arterial to end-tidal carbon dioxide tension difference in anaesthetized adults mechanically ventilated via a laryngeal mask or a cuffed oropharyngeal airway.

To evaluate arterial (PaCO2), end-tidal (PETCO2) and carbon dioxide tension difference during mechanical ventilation with extratracheal airways, 60 patients ASA physical status I-II, receiving general anaesthesia for minor extra-abdominal procedures were randomly allocated to receive either a cuffed oropharyngeal airway (group COPA, n = 30) or a laryngeal mask (group LMA, n = 30). The lungs were mechanically ventilated by IPPV using a 60% nitrous oxide and 1-1.5% isoflurane in oxygen mixture (VT = 8 mL kg-1; RR = 12 b min-1; l/E = 1/2). After PETCO2 had been stable for at least 10 min after airway placement, haemodynamic variables and PETCO2 were recorded and an arterial blood sample was obtained for measurement of PaCO2. No differences in anthropometric parameters, smoking habit, haemodynamic variables and incidence of untoward events were observed between the two groups. Airway manipulation, to maintain adequate ventilation, was required in only nine patients in the cuffed oropharyngeal airway group (30%) (P < 0.0005); however, in no case was it necessary to remove the designated extratracheal airway due to unsuccessful mechanical ventilation. The mean difference between arterial and end-tidal carbon dioxide partial pressure was 0.4 +/- 0.3 KPa in the laryngeal mask group (95% confidence intervals: 0.3-0.5 KPa) and 0.3 +/- 0.26 KPa in the cuffed oropharyngeal airway group (95% confidence intervals: 0.24-0.4 KPa) (P = NS). We conclude that in healthy adults who are mechanically ventilated via the cuffed oropharyngeal airway, the end-tidal carbon dioxide determination is as accurate an indicator of PaCO2 as that measured via the laryngeal mask, allowing capnometry to be reliably used to evaluate the adequacy of ventilation.

Adolescent↗
PubMed2000

Modification of the Penlon Nuffield 200 series ventilator and IPPV with a laryngeal mask airway.

There is a risk of regurgitation if a laryngeal mask airway is used with intermittent positive pressure ventilation. The lower the pressure gradient between airway and stomach, the less will be the likelihood of stomach insufflation with gas and consequent regurgitation. A flow generator ventilator, such as the Penlon Nuffield 200 which achieves a peak pressure at the end of inspiration at any given tidal volume, is likely to produce a higher peak airway pressure than a pressure generator. Replacing the expiratory valve by a venturi gives a preferable flow pattern with an inspiratory pressure plateau. At equal tidal volumes, the venturi modification provided a 10% lower inflation pressure (standard deviation 6%, P < 0.01) and a 1.8% smaller leak (P < 0.05) past the laryngeal mask airway. The same comparison but using identical inflation pressures, gave 8% larger tidal volumes (standard deviation 5.1%, P < 0.01) and a 2% smaller leak (P < 0.01) past the laryngeal mask airway.

Air Pressure↗
PubMed2000

The laryngeal mask airway in the difficult paediatric airway: an assessment of positioning and use in fibreoptic intubation.

The laryngeal mask airway (LMA) was used in 34 children who presented with difficult airways and difficulty in intubation. All 34 children were a grade 3 or grade 4 Cormack and Leehane view at conventional laryngoscopy. The laryngeal mask airway was used as part of the anaesthetic technique. It was either used as the method of airway maintenance during a short procedure or as an aid to fibreoptic intubation. The results of its use in this group of patients showed that overall a good airway was obtained in 73% of patients and an adequate airway in 27%, and in no patient was a poor airway obtained. The fibreoptic positioning of the LMA, taken from the distal aperture of the laryngeal mask airway showed that, overall, in 29.5% of patients a full view of the glottis (grade 1) was obtained, in 29.5% of patients a partial view of the glottis (grade 2) was obtained and in 41% a view of the epiglottis only (grade 3) was obtained. In no patient was a view excluding the epiglottis obtained. In children with a mucopolysaccharide disorder, the number of children who had a grade 3 view increased to 54%. Children with a disorder other than mucopolysaccharidosis had a grade 3 view in only 17% of cases. Children with mucopolysaccharidoses had a grade 1 view in only 14% of cases compared with 58% in the group with other disorders. Of the 34 patients, 21 patients were intubated on 31 separate occasions. There were no failures. The complications of the fibreoptic intubation technique described are outlined.

Anesthesia, Endotracheal↗
PubMed2002

The rotational technique with a partially inflated laryngeal mask airway improves the ease of insertion in children.

BACKGROUND: This study compared the ease of insertion of the laryngeal mask airway (LMA) with a partially inflated cuff using the standard 'nonrotational' technique versus the rotational technique. METHODS: One hundred and forty-five children undergoing anaesthesia using the LMA were randomly assigned to either method. The cuff was partially inflated in both groups. The ease of insertion was assessed by the time taken to complete the LMA insertion, the number of attempts before successful placement and the occurrence of complications. RESULTS: The success rate of insertion at the first attempt was higher in the rotational technique group (99% versus 79%, P < 0.05). All patients in the rotational group had the mask inserted within two attempts. On the other hand, three patients had the mask inserted on the first attempt with the rotational technique after three unsuccessful attempts by an anaesthesiologist with the standard 'nonrotational' technique. Insertion technique made no difference on insertion time. CONCLUSIONS: The rotational technique was associated with a higher success rate for insertion and a lower incidence of complications in children. Using the rotational technique with a partially inflated cuff could be the first-choice approach in paediatric patients.

Anesthesia↗
PubMed2003

The prolonged use of the laryngeal mask airway in a neonate with airway obstruction and Treacher Collins syndrome.

Upper airway obstruction and difficult tracheal intubation are often encountered in patients with Treacher Collins syndrome (mandibulofacial dysostosis). In this case report, the use of a laryngeal mask airway (LMATM) in a 10-day-old newborn with severe Treacher Collins syndrome and acute airway obstruction is described. It successfully relieved the airway obstruction and was left in situ for an exceptionally long period of 4 days. The difficult decisions with respect to the management of the airway and specifically the role of the laryngeal mask are described. In our opinion, in some newborns with severe mandibulofacial disorders and upper airway obstruction, where conservative airway management procedures have failed, the laryngeal mask can be considered not only to relieve the obstruction but also to buy time until there is full insight into the medical condition and its consequences.

Adult↗
PubMed2000

The use of sevoflurane in a 2:1 mixture of nitrous oxide and oxygen for rapid mask induction of anaesthesia in the cat.

An inhalational technique for rapid induction of anaesthesia in unsedated cats using sevoflurane and nitrous oxide is described. Using a pliable, tight-fitting, face mask, sevoflurane (7.5-8%) was delivered from an out-of-circuit precision vaporiser connected to a coaxial non-rebreathing system using a fresh gas flow of 1 l oxygen and 2 l nitrous oxide per min. Cats were restrained with gentle but firm pressure applied by scruffing the dorsal cervical skin until the righting reflex was lost and the patient could be positioned in lateral recumbency. Typically, cats could be positioned on their side in a light plane of anaesthesia within 1 min of applying the mask, at which time the sevoflurane concentration was reduced to 5% or less. A similar protocol, using a lower initial concentration of sevoflurane, is recommended for old or debilitated patients. Maintenance of light sevoflurane (2-4%) anaesthesia by mask permitted minor interventions to be performed readily, including blood collection, intravenous chemotherapy, abdominal palpation, radiography and ultrasonography. More painful procedures, such as bone marrow aspiration, required a deeper plane of anaesthesia. Cats were sufficiently deep to be intubated, if this was required, about 3 min after commencing the induction. Recovery from sevoflurane/nitrous oxide anaesthesia was smooth and rapid, with most cats being able to right within 5 min of discontinuing the agents. This protocol for rapid inhalational induction and recovery is particularly suited to feline practice, where rendering an uncooperative patient unconscious greatly facilitates the completion of many minor diagnostic and therapeutic procedures, especially when these must be performed on successive days or when peripheral vascular access is limited. For longer procedures, isoflurane may be substituted for sevoflurane for maintenance of anaesthesia in order to minimise cost.

Anesthesia Recovery Period↗
PubMed2001

Intraoperative wake-up procedure with propofol and laryngeal mask for optimal excision of brain tumour in eloquent areas.

This is the first thesis describing a new technique for awake craniotomy using a laryngeal mask. Awake craniotomy with propofol infusion has become increasingly popular for the optimal excision of brain tumours located in eloquent areas. During awake craniotomy, tracheal intubation is not performed and propofol infusion is limited to within doses which render the patient just sedated. This asleep-awake procedure is occasionally associated with difficulty in controlling brain volume, especially in patients with a significant mass effect of their brain tumours, since sufficient sedation with propofol tends to cause hypercapnea. We report an intraoperative wake-up procedure employing a laryngeal mask, which enables general anaesthesia to be performed at a sufficient dose of propofol and with control of the brain volume under mechanically assisted ventilation. Before the beginning of cortical mapping, propofol infusion is completely terminated, so allowing the patient to wake up within 5-15 min. Following completion of the tumour excision, general anaesthesia is re-induced at a sufficient dose of propofol. The laryngeal mask can be temporarily removed and repositioned with ease, if necessary. In our experience, this technique is applicable for the optimal excision of brain tumours, especially in patients who are very obese or those who have very large lesions.

Anesthetics, Intravenous↗
PubMed2001

[The ProSeal-LM, a new variant of the laryngeal mask: description and first clinical results].

The ProSeal-LMA is a modification of the laryngeal mask airway (LMA) invented by AIJ Brain. It differs from the known models in three major respects: An additional lumen extending into the tip of the cuff allows insertion of a gastric tube. A pocket immediately behind the cuff accommodates a finger or a siliconated metal introducer and thus facilitates insertion. An additional cuff at the dorsal aspect of the mask pushes the mask into a ventral direction and thus improves the seal around the glottic opening. Our experience after 8 months of clinical use and first data from an international multi-center-study (24 ProSeal-LMA/24 Standard-LMA) are reported. With a ProSeal-LMA insertion of a gastric tube is much easier and more reliable than with a Standard-LMA (24/24 patients vs. 2/24 patients). Judged from visibility of the oesophagus during fibre-endoscopy the position of the ProSeal-LMA is superior to that of the Standard-LMA. Both are equally well tolerated and handled. Most remarkable is a better seal for the ProSeal-LMA (pressure for a leak of 3 L/min: 31 mbar compared to 20 mbar (mean) for the Standard-LMA). Therefore the ProSeal-LMA seems suitable for anaesthesia procedures with IPPV, which up to now are a domain of endotracheal intubation.

Adolescent↗
PubMed2003

Frameless stereotactic radiosurgery with mobile CT, mask immobilization and micro-multileaf collimators.

We present frameless stereotactic radiosurgery using mobile CT, thermal plastic mask fixation, a vacuum-form body immobilizer and micro-multileaf collimators. A linear accelerator and a self-moving helical CT scanner gantry were installed in the same room. The isocenter of irradiation can be also aligned with the center of the CT gantry by rotating the couch. A thermal plastic mask and vacuum-form body immobilizer was used for registration and immobilization. The advantages of this system are as follows: 1) Accurate and painless frameless fractionated irradiation can be performed smoothly, as the patient's head is fixed without exchanging the couch from CT scanning to irradiation system. 2) This mask system can be applied to children, infants or adults with a previous craniotomy bone flap that must have a fixation pin placed into it. This system can be also used for fractionated radiotherapy without painful skull pin-fixed frame. 3) 1 mm micro-multileaf collimators enable irregular contour irradiation. 4) Image fusion (among CT, MRI, angiography, and PET) and 3D images can be used for irradiation planning. 5) This system can be used on any part of the body. 6) This system can be installed in any irradiation room without any extension or new construction.

Brain Neoplasms↗
PubMed2005

[Severe ARDS following perioperative aspiration of gastric content associated with the use of a "ProSeal" laryngeal mask airway].

A ProSeal laryngeal mask airway was used for anaesthesia for laparoscopic surgery in a 26 y old male patient with acute appendicitis. Perioperative aspiration of gastric contents resulted in severe ARDS. Invasive therapeutic options including ECMO had to be used to obtain full recovery. After critical evaluation of the chain of causation it must be postulated that an improper airway was chosen for an intervention that comprises a high risk of aspiration per se. Further risk factors were a long period of fasting, untimely removal of the mask before the patient regained full consciousness, the late confirmation of the diagnosis and the hesitant initial therapy. Since PLMA provides a higher airway occlusion pressure compared to the classic laryngeal mask airway (CLMA), the use of this device may be justified for elective laparoscopic surgery. In emergency patients with increased risk of regurgitation endotracheal intubation still remains the gold standard.

Adult↗
PubMed1996

Use of a modified non-rebreathing mask during upper intestinal endoscopy.

BACKGROUND AND STUDY AIMS: Recently, attention has been drawn to the significant occurrence of respiratory and other complications during upper intestinal endoscopy. This prospective study was designed to compare the incidence and severity of oxygen desaturation when two different methods of oxygen delivery were used during elective oesophagogastroduodenoscopy. PATIENTS AND METHODS: After local medical ethics committee approval and written informed consent, one hundred patients undergoing elective oesophagogastroduodenoscopy were randomly allocated to receive supplemental oxygen at either four litres per minute via nasal specular or ten litres per minute through a specially modified non-rebreathing mask. Oxygen saturations during endoscopy facilitated by midazolam sedation were recorded, and non-parametric tests were used to compare the oxygen saturations in the two groups. RESULTS: The mean oxygen saturations were significantly better during the procedure for American Society of Anesthesiology (ASA) grade 2 and 3 patients who received oxygen with the modified mask than for those who received oxygen via nasal specular (98.6% vs. 97.0%, P = 0.004 for ASA grade 2 and 98.4% vs. 95.5, P = 0.006 for ASA grade 3). CONCLUSIONS: For ASA grade 2 and 3 patients, the modified non-rebreathing mask significantly improves oxygen saturations during upper intestinal endoscopy. This technique should be more widely used for patients at moderate and high risk.

Adult↗