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At least 1,225 records · Page 68Linked to original sources
PubMed2002

[Fiber-optic intubation with non-invasive ventilation with an endoscopic facial mask].

OBJECTIVES: To assess the feasibility and safety of a new technique of fiberoptic bronchoscopy (FOB) tracheal intubation (TI) with noninvasive ventilation (NIV) via an endoscopic full facial mask with two openings, in case of acute respiratory failure (ARF) temporally improved by NIV, but requiring a mechanical ventilation. STUDY DESIGN: Clinical, prospective, open, noncomparative trial of feasibility with direct individual profit. PATIENTS: Sixteen patients with ARF (age: 60 +/- 17 years, PaO2 = 59 +/- 16 mmHg, PaCO2 = 64 +/- 26 mmHg, PaO2/FIO2 = 142 +/- 70 before NIV) (m +/- SD), requiring TI. Including were: TI necessity (SpO2 < 90% or hypercapnic despite NIV, dependence of NIV, exhaustion, septic syndrome), clinical and SpO2 improvement with NIV. METHODS: After i.v. injection of 5 mg midazolam and topical anesthesia (TA) of the nose, the endoscopic mask (modified Fibroxy, Péters) was applied to the face, fixed with elastic straps, then connected to the ventilatory support system with IPAP = 20 cmH2O, EPAP = 5 to 12 cmH2O, FIO2 = 1. A tube was slid on the FOB. As soon as SpO2[[[nbsp] 94%, the extremity of the FOB, was inserted through the lower opening of the mask, slid in the nostril, positioned in front of the glottis for AL, then pushed in the trachea authorizing AL and i.v. injection of 0.15 mg.kg-1 of etomidate (Ramsay[[[nbsp]3). The tube was then slid in the trachea, then, FOB was removed from trachea. RESULTS: The FOB intubation was easy at the patient's, without any failure or any complication. The procedure was 6.7 +/- 2 min. SpO2 significantly improved during TI, from 84 +/- 5% (FIO2 = 0.6 +/- 3) to 97 +/- 1 (FIO2 = 1 +/- 0), without decrease in oxygen saturation off 90%. Arterial pressure decreased only after the 5th min. The quantities of midazolam and of etomidate used were 4.6 +/- 2 mg and 12 +/- 4 mg. Three patients benefited from EPAP > 10 cmH2O. CONCLUSION: Fiberoptic tracheal intubation with NIV via an adapted endoscopic facial mask is a safe technique in patient with ARF temporally improved by NIV. This procedure requires TA and conscious sedation.

Bronchoscopy↗
PubMed2002

[Evaluation of the learning curve of a new intubation technique: intubating laryngeal mask].

OBJECTIVE: Assessment of the learning curve of a new device for blind orotracheal intubation: Intubating laryngeal mask. STUDY DESIGN: Prospective clinical study. METHODS: Ten persons practicing anaesthesia (specialist, fellow, nurse) underwent videotape learning and manikin training required with the device. Each person had to carry out a tracheal intubation in ten consecutive patients undergoing scheduled surgery. No patient presented history or clinical sign of difficult airway management. Results were expressed as mean +/- SD. Main percentages were provided with their 95% confidence interval; the percentage comparison were performed using Chi 2 test. The significance level for overall analysis was p < 0.05. RESULTS: One hundred patients were included. The overall success rate of tracheal intubation with the intubating laryngeal mask was 88%. An easy learning curve was obtained according to the low failure rate that was observed. No failure was noticed after eight procedures. Significant diminution of the delay for tube insertion was observed during the practice (3 +/- 1.30 min for the first procedure and 1.16 +/- 0.60 min for the tenth procedure). Circumstances of the oral intubation were improved with muscle relaxation. Finally, all failure with the intubating laryngeal mask were followed by successful intubation using direct laryngoscopy. CONCLUSION: The intubating laryngeal mask is a new device for blind orotracheal intubation with an easy learning curve in patients without difficulty in airway management, even for non-selected operators.

Aged↗
PubMed2003

[Laryngeal mask airway in paediatrics: when? How?].

Since its introduction in 1981 by Brain, the laryngeal mask airway has achieved increased popularity in pediatrics. Despite widespread use, the definitive role of the laryngeal mask airway has yet to be established. We attempt to clarify the role of the laryngeal mask airway in airway management during anaesthesia by discussing the advantages and disadvantages as well as the indications and contra-indications of its use. The use in failed or suspected difficult endotracheal intubation was also described. Finally, we review the techniques of insertion, details of misplacement, the removal and complication associated with the use of laryngeal mask airway. Cleaning, pre-use checking and maintenance were also discussed.

Child↗
PubMed1992

[Difficult intubation managed by laryngeal mask and fibroscopy].

A case is reported of a patient due to undergo a combined kidney and pancreas transplant who proved to be difficult to intubate. This diabetic hypertensive 35-year-old male patient also had ankylosing spondylitis. Mouth opening was normal (more than fingers' breadth), the chin-sternum distance was 4 cm on full cervical flexion, and cervical extension was only slightly impaired. The Mallampati score was 1. Anaesthesia was induced with thiopentone, fentanyl and 6 mg of pancuronium. Mask ventilation was quite satisfactory. However, on laryngoscopy, the vocal cords could not be seen. Several attempts to carry out endotracheal intubation, including with a stylet, failed. A laryngeal mask (LM) was therefore applied to ventilate the patient correctly. It was not possible to pass a small endotracheal tube (6 mm diameter) through the LM tube, probably because of a small malposition of this latter. A paediatric fibroscope, passed through the LM tube, served as guide for the endotracheal tube. The mask was not removed, although its cushion was slightly deflated, so as not to extubate the patient. The benefits and usefulness of a laryngeal mask in predictable and unpredictable cases of difficult intubation are discussed.

Adult↗
PubMed2003

CT verification of isocentre relocatability using stereotactic mask fixation system.

AIMS: This study introduces a non-invasive method based on computed tomography (CT) verification to ensure patients are accurately positioned before fractionated stereotactic radiotherapy. It enables quality control of mask positioning with reference to the CT images of the treatment plan. MATERIALS AND METHODS: A mask system, together with a dental impression moulded mouth bite, was used for patient immobilisation. In order to facilitate relevant image comparison, special alignment during CT localisation was discussed in the study. The accuracy of patient set-up was studied by assessing the isocentre position in relation to the patient's anatomical structure. The planning CT images were applied as a reference and the study was applied to 261 cranial applications. RESULTS: The results show that the mean and the maximum overall displacements at the isocentre were 0.7 and 2.5 mm, respectively. The mean and the maximum rotational displacement in the axial plane were 0.56 degrees and 2 degrees, respectively. The mean translational displacement and rotational displacement were close to zero when considering the direction of movement. CONCLUSIONS: The results indicate that the systematic error of the mask system and the verification method are minimal. Advantages of this technique include the simple set-up, three-dimensional quantification and short study time (10-15 min). It is therefore practical to implement on a routine basis. Investigation of the ability to relocate the mask is also recommended to justify the required safety margin between the clinical and planning target volumes.

Dose Fractionation, Radiation↗
PubMed2006

Nasopharyngeal oxygen (NPO) as a safe and comfortable alternative to face mask oxygen therapy.

Nasopharyngeal oxygen (NPO) therapy is an emerging alternative to conventional face mask oxygen administration. It warrants consideration for treating hypoxaemia when face mask therapy is impractical or when patient intolerance or non-compliance regularly interrupt treatment. The effectiveness of the NPO route has been validated in post anaesthetic care and paediatric intensive care units (PICUs), but use in the adult ICU remains minimal. Recent research in the adult ICU setting has shown the nasopharyngeal route to be as effective as face mask oxygen administration in alleviating mild to moderate hypoxaemia, and is significantly more comfortable for patients. Therefore, NPO, administered via a fine catheter advanced into the nasopharynx, should be considered when face masks (FMs) or nasal prongs (NPs) are impractical or poorly tolerated and, because of its effectiveness and improved comfort, in patients for whom traditional non-invasive oxygen therapy is indicated. Implications for resource utilisation and costs also exist.

Adult↗
PubMedDate not supplied

[The use of water to seal facial mask for non invasive ventilation reduces the incidence of pressure ulcers].

UNLABELLED: To demostrate that the use of water to seal facial mask for non invasive ventilation (NIV) reduces the incidence of facial pressure ulcers. METHODS: prospective study including 47 pacients who (according to their responsable physician) needs NIV. Intersurgical facial mask and Puritann Bennet 7200 ventilator are used. Facial mask interface is randomly filled with water or air. Risk factors for pressure ulcers, lenght oftime of NIV (TNIV) and when the facial ulcer appears (TUA) are recorded. Student's T test is used to compare menas (except by TUA, analized with Mann-Whitney test). For qualitative variables X2 is eused. Data are presented as mean standard desviation (for TUA mean [range]). RESULTS: We studied 23 patients in the air group (AG) and 2 patients in the water group (WG), whose mean age was 73 years and APACHE II of 13. there where no differences studied in risk factors between groups (proteins 5.6 0.8 in AG vs 5.7 1.4 g/dl; PEEP 5 2 vs 6 1 cm of water; diabetes 11 vs 10; Nasogastric tube 7 vs 6; inotropics 9 vs 6 patients). TNIV was similar between groups (884 1,092 vs 875 1,107 minutes). 39% of patients in AG and 25% in WG developed facial ulcers (p = NS), with mean TUA of 847 minutes. CONCLUSIONS: The use of water to seal facial mask during invasive non ventilation dealays the appearance of facial ulcers. More studies are needed to demostrate significant reduction in the incidence of ulcers.

APACHE↗
PubMed2002

Airway management by physicians wearing anti-chemical warfare gear: comparison between laryngeal mask airway and endotracheal intubation.

BACKGROUND AND OBJECTIVE: To evaluate the ease with which successful insertion of a laryngeal mask airway can be performed in comparison with endotracheal intubation by medical personnel wearing chemical protective equipment. METHODS: Anaesthetists and non-anaesthetists (each n = 20) participated in the prospective comparative trial in an animal laboratory. The time and success rates of laryngeal mask airway vs. endotracheal tube insertions were measured as performed on anaesthetized monkeys. RESULTS: The results showed that the laryngeal mask airway was inserted more rapidly than the endotracheal tube by both groups (3.6 s and 28.6 s, P < 0.0001). Failed intubation occurred in 35% (anaesthetists) vs. 55% (non-anaesthetists) (P = 0.17). CONCLUSIONS: In view of the 100% success rate of insertion even in unfavourable conditions, the possible role of the laryngeal mask airway in the scenario of a toxic mass casualty event should be considered.

Anesthesia, Inhalation↗
PubMed2002

Cuffed oropharyngeal airway as a suitable alternative to the laryngeal mask airway for minor outpatient surgery.

BACKGROUND AND OBJECTIVE: To compare the application of the cuffed oropharyngeal airway and the laryngeal mask airway on anaesthetized adult patients undergoing minor outpatient surgery. METHODS: One hundred patients received intravenous fentanyl, propofol and N20 for the induction and maintenance of anaesthesia. The patients were randomly divided into two groups: a cuffed oropharyngeal airway group (n = 50) and a laryngeal mask airway group (n = 50). After insertion of the device, fibreoptic laryngoscopy was attempted and the degree of success scored. We then compared the first application success rate of both procedures while judging airway intervention requirement, fibreoptic scores, adverse airway events and haemodynamic tolerance. RESULTS: Both devices had an almost similar first-time placement rate (cuffed oropharyngeal airway 84% versus laryngeal mask airway 96%). The cuffed oropharyngeal airway required a higher number of airway interventions (P < 0.001). The laryngeal mask airway had a significantly better fibreoptic view compared with the cuffed oropharyngeal airway (P < 0.001). However, the number of adverse airway events was lower in the cuffed oropharyngeal airway group; there were no significant differences in adverse events and haemodynamic variables between the said two groups. CONCLUSIONS: The results suggest that the cuffed oropharyngeal airway was an effective alternative airway in spontaneously breathing patients during short procedures.

Adult↗
PubMed2002

Conditions for insertion of the laryngeal mask airway: comparisons between sevoflurane and propofol using fentanyl as a co-induction agent. A pilot study.

BACKGROUND AND OBJECTIVE: To compare the conditions for insertion of the laryngeal mask airway using sevoflurane or propofol plus fentanyl. We evaluated the haemodynamic changes and cost of induction of anaesthesia in both groups. METHODS: Sixty patients were equally and randomly divided into two groups. Both groups received fentanyl 1 microg kg(-1). Patients in the sevoflurane group were induced with 8% sevoflurane and those in the propofol group with propofol 2.5 mg kg(-1). Conditions for insertion were graded on a three-point scale using six variables. Overall, conditions were assessed as excellent, satisfactory or poor based on the total score in each group. Systolic and diastolic arterial pressure and heart rate were recorded for 6 min after mask insertion. The financial cost of induction in both groups was calculated. RESULTS: The mean (+/- SD) time taken from induction to successful laryngeal mask insertion was significantly shorter with propofol (68.70 +/- 22.60 s) compared with sevoflurane (149.83 +/- 55.25 s). Excellent or satisfactory conditions were observed in 30 (100%) patients in the propofol group and in 29 (96.66%) in the sevoflurane group. Systolic and diastolic arterial pressures were significantly lower in the propofol group. The cost of sevoflurane used was 3.95 euros +/- 1.48 (Rs 216.23 +/- 64.66) (P < 0.05) compared with that of propofol, which was 3.23 euros +/- 0.65 (Rs 141.00 +/- 28.20). CONCLUSIONS: Although there was a faster induction with propofol-fentanyl, conditions for insertion of the laryngeal mask airway were similar in both groups. Haemodynamic stability was better with sevoflurane-fentanyl. The propofol-fentanyl combination was more cost-effective.

Adult↗
PubMedDate not supplied

Assessment of pulmonary mechanics and gastric inflation pressure during mask ventilation.

INTRODUCTION: Mask ventilation is a procedure routinely used in emergency medicine. Potential hazards are inadequate alveolar ventilation and inflation of the stomach with air, leading to subsequent regurgitation and aspiration. The aim of this study was to measure lung function and gastric inflation pressures during mask ventilation. METHODS: For this purpose, 31 patients scheduled for routine urological procedures were studied during induction of anesthesia. Lung function was assessed by recording respiratory flow and pressure directly at the face mask. Gastric inflation was observed with a microphone taped to the epigastric area. RESULTS: Gastric inflation occurred in 22 of the 31 patients. Mean gastric inflation pressure was 27.5 +/- 6.55 cm H2O, mean compliance was 67 +/- 24.1 ml/cm H2O, mean resistance was 17.4 +/- 6.41 cm H2O/L/sec, and the mean respiratory time constant was 1.1 +/- 0.26 seconds. CONCLUSIONS: These data suggest that inspiratory pressure be limited to 20 cm H2O, and that an inspiratory time of at least four times the respiratory time constant be allowed. Monitoring airway pressure and gastric inflation is a simple technique that may improve the safe-ty of patients during mask ventilation.

Adult↗
PubMed1999

An alternative method to intubate with laryngeal mask and see-through-bougie.

BACKGROUND: Different ways of managing the difficult airway is an important issue for the anaesthetist. We have investigated a technique with a see-through-bougie and laryngeal mask for intubation. METHODS: We report our experience with intubation of 30 patients using a see-through-bougie guided through a laryngeal mask with a fibreoptic bronchoscope. The bougie is then used as a guidance for a tracheal tube. RESULTS: In 29 of the 30 investigated patients, this method could be used. In one patient the method had to be abandoned because of a tortuous trachea. Seventeen patients were intubated within 2 min, 11 between 2 and 5 min and 1 required 10 min. The time was mainly dependent on the endoscopic experience of the anaesthetist. No patient sustained arterial desaturation. CONCLUSION: We conclude that intubation using a see-through-bougie and a laryngeal mask is a valuable method in the difficult intubation situation, when a temporary airway can be achieved with laryngeal mask, since it permits continuous ventilation and visual control throughout the procedure.

Adult↗
PubMed1994

"Unconscious anxiety": phobic responses to masked stimuli.

We tested the hypothesis that an unconscious preattentive perceptual analysis of phobic stimuli is sufficient to elicit human fear responses. Selected snake- and spider-fearful Ss, as well as normal controls, were exposed to pictures of snakes, spiders, flowers, and mushrooms. A separate forced-choice recognition experiment established backward masking conditions that effectively precluded recognition of experimental stimuli both for fearful and nonfearful Ss. In the main experiment, these conditions were used to compare skin conductance responses (SCRs) to masked and nonmasked phobic and control pictures among fearful and nonfearful Ss. In support of the hypotheses, snake- and spider-fearful Ss showed elevated SCRs to snake and spider pictures as compared with neutral pictures and with responses of the nonfearful Ss under both masking conditions. Ratings of valence, arousal, and dominance indicated that the fearful Ss felt more negative, more aroused, and less dominant in relation to both masked and nonmasked phobic stimuli.

Adult↗
PubMed1995

Forward and backward visual masking of contour by light in positive- and negative-symptom schizophrenia.

Forward and backward masking of contour by light was investigated with stimulus onset asynchronies from 20 to 180 ms in a group of 22 schizophrenic patients and 22 matched normal controls. Individuals with schizophrenia were selected using American Psychiatric Association (1987) criteria and were also assessed using the Andreasen scales for the presence of positive and negative symptoms (N.C. Andreasen, 1981, 1983). The Andreasen scales were used to divide schizophrenic patients into 2 subgroups (positive and negative symptoms). Positive-symptom schizophrenic patients showed no differences in their target duration thresholds or in their backward masking functions. Negative-symptom schizophrenic patients showed significantly longer target duration thresholds and experienced significantly more backward masking. There was no difference between schizophrenic patients and controls in forward masking.

Adult↗
PubMed1987

Retinal masking during pursuit eye movements: implications for spatiotopic visual persistence.

White (1976) reported that presentation of a masking stimulus during a pursuit eye movement interfered with the perception of a target stimulus that shared the same spatial, rather than retinal, coordinates as the mask. This finding has been interpreted as evidence for the existence of spatiotopic visual persistence. We doubted White's results because they implied a high degree of position constancy during pursuit eye movements, contrary to previous research, and because White did not monitor subjects' eye position during pursuit; if White's subjects did not make continuous pursuit eye movements, it might appear that masking was spatial when in fact it was retinal. We attempted to replicate White's results and found that when eye position was monitored to ensure that subjects made continuous pursuit movements, masking was retinal rather than spatial. Subjects' phenomenal impressions also indicated that retinal, rather than spatial, factors underlay performance in this task. The implications of these and other results regarding the existence of spatiotopic visual persistence are discussed.

Discrimination Learning↗
PubMed1977

Backward pattern masking can vary as a nonmonotonic function of target duration: on the influence of intratraget metacontrast.

The magnitude of backward masking is usually found to vary inversely with the amount of information about a target that is made available to the visual system. Contrary to these findings, we report a nonmonotonic relation between the magnitude of backward pattern masking and target duration. Specifically, masking decreased as target duration was increased to about 8 msec and, then, became more severe as target duration was further increased to a value of at least 40 msec. The occurrence of the nonmonotonic function depended on (a) the degree of definition of the target's edges, (b) the luminance levels within the target stimulus, and (c) the state of adaptation of the eye. It is hypothesized that the source of the nonmonotonic function was metacontrast interference that originated from within the target stimulus configuration. This hypothesis was supported by data that indicated that in the absence of any mask presentations, the apparent contrast between the target and its immediate background varied as a nonmonotonic function of target duration.

Adaptation, Ocular↗
PubMed1978

Age differences in peripheral perceptual processing: a monoptic backward masking investigation.

Peripheral processes in vision were investigated in two experiments involving monoptic backward masking with random noise. For young and old subjects, peripheral processing time (represented by stimulus onset asynchrony of target and mask) was characterized as a power function of target energy. Although processing time for both age groups showed a similar rate of decline with increasing target energy, old subjects processed targets more slowly at all energy levels. Results were independent of education, sex, and criterion differences between young and old. Target duration was related to critical interstimulus interval, such that stimulus onset asynchrony between target and mask was approximately constant for a given target energy within each age group. Evidence suggests that peripheral processing begins with target onset and that processing time is best characterized by a power function relating stimulus onset asynchrony of target and mask to target energy.

Adult↗
PubMed1979

Interaction of stimulus size and retinal eccentricity in metacontrast masking.

Metacontrast masking occurs both at the fovea and in the retinal periphery; foveally, the smallest stimulus elicited the strongest masking, whereas peripherally the reverse was the case. An analysis of variance showed a significant size effect, eccentricity effect, and size-eccentricity interaction. As stimulus size increased, the stimulus onset asynchrony of maximum masking shifted to greater values. Both foveal metacontrast and peak shifts contradicted predictions made by the hypothesis that metacontrast is mediated by an interaction of sustained and transient channels in the visual system. The data are consistent, however, with a lateral inhibitory model of metacontrast masking and stimulus coding.

Discrimination Learning↗