Digital palpation of the pilot balloon vs. continuous manometry for controlling the intracuff pressure in laryngeal mask airways.

This study compared two methods of controlling the intracuff pressure in laryngeal mask airways. One hundred and eighty patients were randomly assigned into two groups. In the first group (n = 90), after training, the intracuff pressure was controlled using digital palpation of the pilot balloon. In the second group (n = 90), continuous manometry was used to control the intracuff pressure. An upper pressure limit of 60 cmH2 O was set. The median (IQR [range]) intracuff pressure in the palpation group was 130 (125-130 [120-130]) cmH2 O compared with 29 (20-39 [5-60]) cmH2 O in the manometry group (p < 0.001). In the palpation group, 37% of patients experienced pharyngolaryngeal complications vs. 12% in the manometry group (p < 0.001). We conclude that the digital palpation technique is not a suitable alternative to manometry in controlling the intracuff pressure in laryngeal mask airways.

[Continuous cuff pressure measurement during laryngeal mask anesthesia : An obligatory measure to avoid postoperative complications]. / Kontinuierliche Cuff-Druck-Messung bei Larynxmaskennarkosen : Eine obligatorische Maßnahme zur Vermeidung postoperativer Komplikationen.

BACKGROUND: Inflation of laryngeal masks is often performed only with regard to the clinical impression and without any objective measurement of cuff pressure. As a result the use of laryngeal masks frequently leads to postoperative complications, such as sore throat, dysphonia, dysphagia and nerve palsy. In this study the influence of continuous measurement of cuff pressure on the incidence of postoperative sore throat was investigated in patients who underwent laryngeal mask anesthesia. PATIENTS/MATERIAL AND METHODS: In the context of a retrospective audit all patients who underwent laryngeal mask anesthesia were asked to complete a questionnaire on anesthesia. The primary endpoint of the study was the postoperative occurrence of a sore throat. For analysis the patients were divided into two groups. In the first group the cuff pressure was controlled only by clinical means and in the second group the cuff pressure was controlled using continuous manometry. The study covered a 10-month period of observation for each group. RESULTS: During the observation period laryngeal mask anesthesia was performed in 4169 patients. Of these 917 patients (manometry group n = 433 and control group n = 484) voluntarily completed the questionnaire. In the group without cuff pressure measurement 36 % of patients complained of sore throat postoperatively but only 12 % of the patients in the group with cuff pressure measurement (p < 0.001). Postoperative nausea and vomiting occurred in 16 % of the patients and 13 % complained of severe pain in the area of the operation. No differences between the two groups were found. While 97 % of patients in the group with continuous measurement of cuff pressure were satisfied with the anesthesia, this applied to only 79 % of patients in the control group (p = 0.006). CONCLUSION: In terms of the results of this study and with respect to data from the literature, measurement of cuff pressure should be compulsory during laryngeal mask anesthesia.

Acute and chronic effects of marathon running on the retinal microcirculation.

OBJECTIVE: Previous studies indicate an association between marathon running and premature atherosclerosis. Retinal vessel diameter alterations, in particular narrower arterioles and wider venules, reflect early stages of atherosclerosis, but the influence of marathon on the retinal microcirculation is unknown. METHODS: Retinal vessel diameters were measured in 85 male runners (age 31-60 years; previous marathons 0-56) and in 45 age-matched healthy controls using a static vessel analyzer. In runners, diameters were also measured immediately and 24h after a marathon. Cardiovascular risk profiles, clinical chemistry and, in a subgroup of 46 runners, peripheral arterial wave reflections were also assessed. RESULTS: Runners had larger arterioles (median 196 µm (IQR 25) vs. 190(25); p = 0.068) and smaller venules (222(25) vs. 224(18); p = 0.063) than controls, resulting in a significantly increased arteriolar-to-venular ratio (AVR; 0.89(0.08) vs. 0.85(0.07); p < 0.001). In runners, retinal vessel diameters were not associated with body mass index, blood pressure, smoking, lipids or training history, and no differences were observed between the lowest (0.71-0.84) and highest (0.95-1.06) AVR quintiles. The marathon run induced a significant increase of AVR (0.91 (0.09); p = 0.007) due to larger arteriolar than venular dilatations, correlating weakly to race duration (r = 0.32; p = 0.003) and to a lower increase in leucocytes (r = -0.35; p = 0.001). Vessel diameters normalized 24h after the race. Augmentation index and pulse pressure decreased significantly after the race, but no associations with retinal vessel diameters were observed. CONCLUSION: Marathon running is not associated with an impairment of the retinal microcirculation. These findings contrast previous reports on atherosclerotic alterations of peripheral vessels.

Effects of contralateral speech competition on the late auditory evoked potential in children.

Researchers recently reported evidence of a possible electrophysiologic correlate of impaired binaural processing or attention in elderly subjects. This experiment found that the presence of speech competition in the contralateral nontest ear produced significantly greater decreases in the peak-to-peak amplitude of the N1-P2 component of the late auditory evoked potential (LAEP) in an older group of subjects (50 to 80 years of age) than in a younger group (20 to 49 years). The present study used this same test paradigm with groups of children ranging in age from 7.5 to 14.9 years of age to investigate whether a comparable age-related effect might be found at the other end of the normal age spectrum in younger children. While the present children did exhibit statistically significant reductions in LAEP amplitude in the presence of speech competition, the magnitude of this effect did not differ among the different age groups.

Multinuclear metal nucleobase complexes.

Of all properties of metal nucleobase complexes, formation of multinuclear species appears to be an outstanding feature. After a brief introduction into well known polymeric metal nucleobase complexes, three aspects recently Studied in our laboratory will be dealt with in more detail: (i) Heteronuclear complexes derived from trans-[(amine)(2)Pt(1-MeC)(2)](2+) (1-MeC=1-methylcytosine). They form, e. g. with Pd(II) or Hg(II), upon single deprotonation of the exocyclic amino group of each 1-MeC ligand, compounds of type trans-[(amine)(2)Pt(1-MeC-)(2)MY](n+), displaying Pt-M bond formation. (ii) Cyclic nucleobase complexes derived from cis-a(2)Pt(II). A cyclic compound of composition {[(en)Pt(UH-N(1),N(3))](4)}(4+) (UH=monoanion of unsubstituted uracil) is presented and the analogy with organic calix-[4]-arenes is pointed out. (iii) Cyclic nucleobase complexes from trans-a(2)Pt(II). Possible ways for the preparation of macrocyclic nucleobase complexes containing trans-a(2)Pt(II) linkages are outlined and precursors and intermediates are presented.