Propofol-air-oxygen anesthesia reduces the incidence of sore throat after laryngeal mask anesthesia

We investigated the effects of the presence or absence of N2O in propofol anesthesia using a laryngeal mask on the incidence of postoperative sore throat. In the N2O-combined anesthesia group (n = 25), score 0 (no sore throat) was observed in 11 patients; score 1 (slight pain and discomfort that improved on the next day of operation) in 9; and score 2 (persistent pain on the next day) in 5. In the non-N2O-combined anesthesia group (n = 25), score 0 was observed in 21 patients, score 1 in 3; and score 2 in 1, showing a significantly lower incidence of sore throat and milder sore throat than in the N2O-combined anesthesia group. These results suggest that propofol anesthesia using a laryngeal mask not combined with N2O reduces the incidence of postoperative sore throat.     

The laryngeal mask in pediatric anesthesia

We carried out a perspective study in order to assess the ease of insertion, the type and the incidence of perioperative complications connected with the use of the Laryngeal Mask Airway (LMA). We examined 300 consecutive patients, M/F 261/39, average age 4.2 yrs. (range 0.1-16), ASA I-II, who underwent surgical operations of short or average length not involving the pleural, the oropharyngeal or the peritoneum cavity. The choice about anesthesia was left to the discretion of the anesthesiologist. In 27 cases the position of the LM was controlled through a flexible fiberoptics. In 269 patients (89.6%) the LMA was correctly positioned during the first attempt. In 27 patients (9%), 2 or more attempts were necessary, and in 4 patients (1.4%) it was not possible to set the LMA. No differences of statistical significance were noticed between the different size of LMA, with regards to the facility of insertion. The control through fiberoptics showed a correct position, from an anatomical point of view, in 11 patients (41%), whereas in 13 patients (48%) some signs of partial obstruction were noticed (epiglottis interposing between the opening of LMA and larynx) and in 3 patients (11%) vocal cords are not visible. The following complications took place: laryngeal spasm on induction (2.3%), cough or movements on positioning (2.3%), hypoxia (4.3%), obstruction (1%), laryngeal spasm on awakening (1.7%), trauma (5%) and vomiting (0.3%). No connections were found between the size of LMA and total complications. Nevertheless, cough or movement during positioning and laryngeal spasm on awakening were significantly more frequent with LMA n. 3. In our experience, the LMA proved to be effectual and safe in the control of the airway during elective operations in pediatric surgery.     

The effect of cuff width on systolic blood pressure measurements in neonates

The width of the blood pressure cuff was found to have an effect on the accuracy of systolic blood pressure measured in the arm and thigh in neonates. Data were collected in 26 infants of a variety of birth weights and gestational ages. They show that the effect of cuff size can be minimized by selecting a cuff width equal to approximately 50% of the extremity circumference.     

Laryngeal mask airway performance: effect of cuff deflation during anaesthesia

We studied the effect of deflating the laryngeal mask airway (LMA) cuff in situ on recorded respiratory tidal ventilation in 30 spontaneously breathing anaesthetized patients. Another 26 patients were studied in whom the LMA cuff was undisturbed. Deflation of the cuff to a pressure of 22 mm Hg (below an estimated arteriolar perfusion pressure of the pharyngeal mucosa), by removing approximately 50% of the recommended cuff injection volume, had a minimal effect on tidal ventilation (P = 0.9). This manoeuvre may have a role in minimizing transmitted cuff pressure on the adjacent pharyngeal mucosa. Complete cuff deflation, however, resulted in a 17% decrease in mean tidal ventilation (P < 0.05), with two patients (6%) demonstrating a substantial leak around the cuff and airway obstruction. The practice of complete cuff deflation during the recovery period from anaesthesia cannot be recommended.     

The principles of pressure sore prevention

This article describes the main causes of pressure sore development and discusses the principles of pressure sore prevention. It relates to UKCC Professional Development categories: Reducing risk and Care enhancement.     

The laryngeal mask airway and positive-pressure ventilation

BACKGROUND: The utility of the laryngeal mask airway during positive-pressure ventilation has yet to be determined. Our study was designed to assess whether significant leaks occurred with positive-pressure ventilation and if leaks were associated with gastroesophageal insufflation. METHODS: Forty-eight patients undergoing elective surgery were studied. After induction of anesthesia and paralysis, controlled ventilation was used with four different peak pressure settings in each patient (15, 20, 25, and 30 cmH2O). The order of ventilator pressure settings was assigned from a randomized block schedule. Data collected included inspiratory and expiratory volumes, qualitative assessments of gastroesophageal insufflation, and leak at the neck. After data collection during laryngeal mask use, the anesthesiologist intubated the trachea and measurements were repeated for tracheal tube ventilation. Leak was calculated by subtracting the expiratory from the inspiratory volume and expressed as a fraction of the inspiratory volume. RESULTS: Ventilation with the laryngeal mask airway was adequate at all ventilation pressures and comparable with tracheal tube ventilation. Leak fraction (mean +/- SD) at 15, 20, 25, and 30 cmH2O for laryngeal mask ventilation were 0.13 +/- 0.15, 0.21 +/- 0.18, 0.25 +/- 0.16 and 0.27 +/- 0.17, respectively, and 0.03 +/- 0.03, 0.05 +/- 0.03, 0.05 +/- 0.03 and 0.04 +/- 0.03, respectively, for tracheal tube ventilation. Leak fractions for ventilation with the laryngeal mask were consistently greater than those measured for tracheal tube ventilation at similar ventilation pressures. Leak fraction with laryngeal mask ventilation increased with increasing airway pressures, whereas leak with tracheal tube ventilation remained unchanged. The frequency of gastroesophageal insufflation ranged from 2.1% at a ventilation pressure of 15 cmH2O to 35.4% at 30 cmH2O. CONCLUSIONS: Ventilation using the laryngeal mask appears to be adequate if airway resistance and pulmonary compliance are normal. Gastroesophageal insufflation of air will become a problem in the presence increased ventilation pressure.     

The laryngeal mask airway in paediatric practice

Computed tomography (CT)-guided percutaneous needle biopsy is often necessary to evaluate small intrathoracic lesions. Not infrequently, an overlying structure such as a rib or vessel precludes insertion of the biopsy needle within the CT slice containing the lesion. Insertion and angulation of the needle at a site within an adjacent CT slice is then required. In order to determine the optimal skin-entry site and degree of angulation for biopsy needle insertion, we analyzed the geometric relationship between lesion depth, needle length, and needle angulation.     

Apropos of transsectioned laryngeal mask

While controversy about the role of private clinics in Canada's health care system continues, a Vancouver physician has been running a private medicine centre for overseas travellers since 1991, and its popularity has been growing. For a $25 fee, the clinic provides vaccinations and disease-prevention information. More than 8000 patients used the service in 1994.     

The importance of the laryngeal mask in the difficult intubation and early experience with the intubating laryngeal mask airway--ILMA--Fastrach

The conventional laryngeal mask airway ("Standard" laryngeal mask airway SLMA is of outstanding importance in the management of the difficult airway. The intubating laryngeal mask airway (ILMA, commercial name Fastrach) has become available recently. First results indicate that the excellent ventilation characteristics of SLMA are maintained, but in addition blind intubation is successful in more than 90% of patients with normal anatomy as well as with difficult intubation. PURPOSE: We present the use of ILMA, compare the potential of the two laryngeal mask types in difficult intubation by own results, present the results of a first symposium on the ILMA held at Jersey in December 1996, the role of the SLMA in difficult intubation as proposed by the American and the French Societies of Anaesthesiology, as well as an outlook on possible uses of the ILMA in the light of the available results. METHODS: The SLMA was prospectively used between 1992 and 1997 for 66 operations in 55 patients with difficult intubation (laryngoscopic view Cormack grade IV, n = 24; grade III, n = 35; grade < III, n = 7). 48 operations were performed after resection of a facial carcinoma, 14 on patients without carcinoma who could not be intubated conventionally, 5 on patients with periglottic pathology, and on 50 normals. The ILMA was used on 150 patients between 11/1996 and 11/1997, 106 had normal anatomy, 33 were difficult to intubate (Cormack grade IV, n = 12; grade III, n = 21), 24 had a reduced mouth opening of < or = 2.5 cm awake, 14 of these also were difficult to intubate. RESULTS: Ventilation was superior to a face mask (FM): (SLMA: ventilation not sufficient (SaO2 < 90% > 30 sec) with a FM in 22 operations compared to 5 with a SLMA; ILMA: ventilation not sufficient with a FM in 7 operations compared to 3 with an ILMA). Blind intubation through a SLMA had a success rate of 50% and 34% in 50 normals and in 32 operations with difficult intubation after a mean of 2.6 intubation attempts each. The success rate per intubation attempt for the SLMA was 22% in normals and 13% in difficult intubation. Through an ILMA, blind intubation was successful in 92% of normals, 5 of them with immobile spine, in 91% in patients with difficult intubation, and in 83% in patients with reduced mouth opening. The success rate per intubation attempt was 60% in normals, 46% in difficult intubation, and 46% in reduced mouth opening, with a success rate for the first intubation attempt of 57%. This compares favourably with results presented at the Jersey symposium in 554 patients. CONCLUSION: The ILMA maintains the superb ventilation potential of a SLMA in difficult intubation but doubles the success rate of blind intubation irrespective of anatomical difficulties, with a 50% success rate during the first intubation attempt. Possible uses of the ILMA may be in difficult intubation situations including immobile spine, in cannot ventilate--cannot intubate situations comparable to a SLMA with an improved chance of successful intubation, and perhaps as a device for ventilation and intubation for untrained people. The use of the ILMA can be trained during everyday practice. Expert assessment of successful endotracheal tube position is mandatory.     

Laryngeal mask airway cuff pressure and position during anaesthesia lasting one to two hours

The cuff of the laryngeal mask airway (LMA) is highly permeable to nitrous oxide (N2O), and cuff pressure increases during N2O/O2 anaesthesia. The extent of these changes and their effect on LMA position have previously only been investigated for short procedures. The current study was designed to investigate the effects of nitrous oxide-oxygen (N2O/O2) anaesthesia lasting one to two hours on cuff pressure, LMA positioning and pharyngeal morbidity. Twenty-four male patients underwent spontaneous ventilation anaesthesia with 66% N2O in oxygen and isoflurane. Following insertion and inflation of a #4 LMA with 30 ml air, mean (SD) cuff pressures immediately increased from 107 (9) to 145 (12) mmHg and then at a decreasing rate for 90 min to peak at 215 (12) mmHg. There was a correlation between N2O concentration and final cuff volume (P < 0.001). There was no displacement of the LMA cuff in any patient. Three of 19 patients had a mild sore throat. This study demonstrates that the increase in LMA cuff pressure is self limiting over a one-to-two-hour period and does not cause displacement of the LMA. There is no evidence that cuff pressure monitoring and pressure limitation is necessary during LMA anaesthesia.     

The intubating laryngeal mask airway: an initial assessment of performance

A new prototype of the laryngeal mask airway (LMA), the intubating laryngeal mask airway (ILMA), was used to facilitate tracheal intubation in 100 fasted patients presenting for elective surgery. Alignment of the ILMA with the larynx was assessed fibreoptically before intubation without the investigator performing the intubation being aware of the view score. Ease of intubation correlated with the view obtained and with the degree of manipulation of the ILMA needed to achieve tracheal intubation. Intubation was successful in 93 patients. Of the seven intubation failures, five occurred in the first 20 patients. Conventional connection to the breathing system and ventilation of the lungs of the patients were possible throughout the intubation procedure.     

Timing of removal of the laryngeal mask airway

The course of experimental chlamydial infection of the male genital tract was studied. Inoculation of the Chlamydia psittaci agent of guinea pig inclusion conjunctivitis (GPIC agent) into the vas deferens of rats resulted in chlamydial infection of the epididymis, testis and the prostate gland. The inflammatory response was most prominent at 14 days after infection. Chlamydiae were recovered from the epididymides and the prostate glands for up to 90 and 60 days post inoculation, respectively. Histopathological changes associated with chlamydial infection of the epididymis or prostate gland were characterized by intratubular and interstitial purulent inflammation. Chlamydia-specific IgM- and IgG-antibodies were found in sera of nearly all infected animals. Results of this study indicate that this animal model may be useful to study the pathogenesis, immune responses and sequelae of chlamydial infections of the male genital tract.     

功能锻炼结合改良的封闭式负压引流Ⅳ期压疮的护理效果

目的:探讨Ⅳ期压疮治疗中功能锻炼的地位及应对方法.方法:对我科Ⅳ期压疮的病人进行功能锻炼的时机和方法.结果:Ⅳ期压疮治愈率88%,肢体康复47%,能下地活动60%,能坐轮椅40%.结论:通过本组病例的护理,认为功能锻炼对Ⅳ期压疮的治疗起到良好的辅助作用(应用封闭式负压引流的观察护理).     

The Finapres 2300e finger cuff. The influence of cuff application on the accuracy of blood pressure measurement

Blood pressure measurements associated with malapplication of a finger cuff were compared with contemporaneous intra-arterial pressure data in seven volunteers to determine the influence of cuff application on the accuracy of the Finapres 2300e. Systolic readings in all cuff positions differed from arterial line data by more than the recommended standard and tight and loose cuff applications under and over-read respectively, in all subjects. The results show the Finapres to be sensitive to small degrees of finger cuff malapplication which contribute to the bias on direct arterial comparison and limit the reliability of the instrument in clinical practice.