OBJECTIVETo evaluate the effectiveness of two training methods for avoiding excessive inflation of laryngeal mask airway(LMA)Supreme.

METHODSTotally 41 anesthesiologists were randomly divided into hand touch group(H group,n=20)and short-term pressure gauge training group(G group,n=21). Before training,subjects were asked to inflate the cuff of LMA Supreme to two target pressures,30 cmH(2)O and 60 cmH(2)O, according to their own experiences. The actual cuff pressures were recorded as baseline pressures. Subjects in H group then received the training of hand touch:touch the vermilion of the lip and apex nasi with the left ring finger and feel the hardness. A cuff pressure with hardness similar to the vermilion of the lip was defined as 30 cmH(2)O, and similar to the apex nasi as 60 cmH(2)O. Subjects in G group were asked to inflate the cuff with a pressure gauge and feel the hardness of the cuff when the pressure reached 30 cmH(2)O and 60 cmH(2)O. After one-week training,two groups of subjects repeated the cuff inflation test. Actual cuff pressures after training were also recorded and compared with the baseline pressures. Results Actual cuff pressures after training[Group H:(39.7±15.7) cmH(2)O(P=0.00);Group G:(26.2±13.2) cmH(2)O(P=0.03)]were significantly lower than baseline pressures in both groups when the target cuff pressure was 30 cmH(2)O, and the differences were not statistically significant between these two groups(P=0.06). When the target pressure was 60 cmH(2)O,the actual cuff pressure of H group [(91.1±24.3)cmH(2)O] was significantly higher than that of G group [(58.1±15.4) cmH(2)O (P=0.01)]. However,the actual cuff pressure of G group was similar to the target pressure.

CONCLUSIONThe two training methods are equally effective when the target pressure is 30 cmH(2)O, while short-term pressure gauge training method is superior when the target pressure is 60 cmH(2)O.

This paper describes to design and to examine the mechanical characteristics of high frequency jet ventilator. The device consists of Phase lock loop (PLL) system, solenoid valve driving control part and Air regulating system. This study is carried out by changing several factors such as endotracheal tube (E.T. tube) diameter, injector cannula diameter, 1%, and frequency (breaths/min.) having direct effects on the gas exchange as well as parameters of the entrained gas by venturi effect, so as to measure the tidal volume and minute volume. This system characteristics were as follows: 1) Frequency: 6-594 bpm 2) Inspiration time: 1-99% 3) Variance of input air pressure: 1-30 PSI
Air Pressure ; Catheters ; Tidal Volume ; Ventilators, Mechanical*

OBJECTIVETo establish a method for determining brodifacoum in workplace air by high-performance liquid chromatography (HPLC).

METHODSBrodifacoum in workplace air was collected with a polytetrafluoroethylene filter and desorbed by mixed solution of methanol and dichloromethane (20:80, V:V), and was then separated using an ODS column and determined by an ultraviolet detector; retention time was used for identification, and peak area was used for quantification.

RESULTSThe concentration of brodifacoum showed a linear relationship with peak area within 0.2∼10.0 µg/ml; the elution efficiency was 91.6%∼95.1%; the detection limit was 0.08 µg/ml (injection volume: 20 µl eluate); the minimum detectable concentration was 0.000 67 mg/m(3) (calculated by 240 L air sample).

CONCLUSIONThis HPLC method is convenient and simple for air collection and sample preparation and meets the methodological requirements. Therefore, this method can be used for the determination of brodifacoum in workplace air.

OBJECTIVETo develop a method for determination of 2, 4-dichlorophenoxyacetic acid (2, 4-D) in the air of workplace by high-performance liquid chromatography.

METHODS2, 4-D was collected by ultrafine glass filters, desorbed by methanol, separated by a C18 column, and detected by a UV detector. Identification and quantification of 2, 4-D were performed by retention time and peak areas, respectively.

RESULTSThe linear range of the test was 2∼200 µg/ml; the elution efficiency was 94.6%- 95.9%; the limit of detection (S/N = 3) was 0.034 µg/ml (injection volume of 20 µl eluant); the lower limit of quantification (S/N = 10) was 0.11 µg/ml; the minimum detectable concentration was 0.011 mg/m(3); the minimum quantifiable concentration was 0.037 mg/m(3) (with sampled air volume of 45 L).

CONCLUSIONThis method is convenient and simple in sample collection and preparation, and satisfies all methodological requirements. Therefore, this method is useful for the determination of 2, 4-D in the air of workplace.

Air ; analysis ; Air Pollutants, Occupational ; analysis ; Chromatography, High Pressure Liquid ; methods ; Polycyclic Aromatic Hydrocarbons ; analysis ; Workplace

Air ; analysis ; Air Pollutants ; analysis ; Aldehydes ; analysis ; Chromatography, High Pressure Liquid ; methods

OBJECTIVES: Patients with bilateral vocal fold paralysis (BVFP) theoretically have difficulty producing voiceless consonants. However, perceptual studies have revealed clear production of voiceless consonants with good articulation scores in nontracheostomized patients. The purpose of this study was to clarify the production of voiceless stops during articulation in patients with BVFP compared to normal speakers. METHODS: The perceptual, acoustic, and aerodynamic characteristics of patients with BVFP and those with normal speech were investigated with special reference to voiceless stop consonants. Test words were prepared to place the stop consonants in different phonological environments, and were all nonsense words. RESULTS: The patients with BVFP perceptually produced the three types of stops successfully. However, they acoustically varied voice onset time to produce phonetically representative stops but decreased voice onset time of /ph/ and /p/ compared to those of normal speakers. These patients may properly control air pressure to produce the three types of stop consonants similar to normal speakers. CONCLUSION: The patients with BVFP realized the distinctions between the three types of stops similar to the normal speakers. Although vocal mobility was absent in the patients with BVFP, voice onset time, vowel duration, closure duration, and air pressure were similar to those of normal speakers.
Acoustics ; Air Pressure ; Humans ; Paralysis* ; Tracheotomy* ; Vocal Cords* ; Voice

Cerebral arterial air embolism (CAAE), although infrequent, is a complication that can occur at any time during an invasive medical procedure. We experienced two cases of CAAE during cerebral angiography accidentally. The author reports the two cases of CAAE wherein air emboli dissolved spontaneously and immediately under normal atmospheric pressure, not under therapeutic hyperbaric environment. One of the cases shows entire dissolution of the air embolus on the moving image. This report shows that arterial air embolus can be absorbed spontaneously, and air embolus size is one of the factors that influence air embolus dissolution besides hyperbaric oxygen condition.
Absorption* ; Atmospheric Pressure ; Cerebral Angiography ; Embolism* ; Embolism, Air ; Oxygen

Pneumocele is the pathologic expansion of an air-containing paranasal sinus that causes thinning of the bony sinus walls and displacement of nearby structures. This abnormality probably results from a physiological block in the rapid equilibration of intrasinus air pressure through the major sinus ostium and as a result of some abnormality producing a one-way valvular mechanism. A 41-year-old man had complained of headache, diplopia and periorbital pain on left side which aggravated after nose blowing. A computed tomographic scan showed a hyperlucent, expanded left ethmoid sinus. We treated the condition by endoscopic marsupialization of the anterior ethmoid sinus. Six months later, headache and periorbital pain have subsided, but diplopia has remained.
Adult ; Air Pressure ; Diplopia ; Ethmoid Sinus* ; Headache ; Humans ; Nose

BACKGROUND AND OBJECTIVES: The airway interruption method was developed as a combination of the measurement of expiratory pressure, mean air flow, intensity, and frequency. We evaluated the clinical usefulness of the airway interruption method in measuring vocal frequency, vocal intensity, mean air flow rate and expiratory air pressure. MATERIALS AND METHODS: We performed phonatory function tests in the patients with vocal nodule (n=380), vocal polyp (n=41), vocal sulcus (n=20), laryngitis (n=72), vocal paralysis (n=10) and glottic cancer, T 1 (n=5). And these results were compared with normal values which were reported previously. In 91 patients with vocal nodule and 5 patients with polyp, phonatory function test was followed up after laryngomicrosurgery and compared with preoperative test. RESULTS: In patients with vocal nodule and polyp, mean air flow rate was significantly increased (p<0.05). In polyp, these differences were greater than nodule group. In vocal paralysis, mean air flow rate was significantly increased than other groups. In glottic cancer (T1), expiratory air pressure was significantly increased than other groups. In laryngitis and sulcus vocalis, mean air flow rate was increased in some phonation methods. But their differences were less significant than other groups. After laryngomicrosurgery, mean air flow rate and expiratory air pressure were decreased in both groups. CONCLUSION: The aerodynamic test using the airway interruption method is a noninvasive, easy to perform and reliable for evaluation of aerodynamic conditions at the glottis. This research finds that the interruption method is effective both in evaluation of the treatment and in postoperative assessments of the laryngeal disorder patients.
Air Pressure ; Glottis ; Humans ; Laryngitis ; Paralysis ; Phonation ; Polyps ; Reference Values