Minimum and optimum light requirements for laryngoscopy in paediatric anaesthesia: a manikin study.

Direct laryngoscopy is performed regularly in paediatric anaesthetic practice for the purpose of intubating a patient's trachea. A minimum illumination of 700 lux at a distance of 20 mm has been suggested in a draft standard for laryngoscopes from the International Organization for Standardization. We investigated the minimum and optimum illumination required by anaesthetists during laryngoscopy. Fifty anaesthetists were recruited to perform laryngoscopy on a child manikin with a selection of laryngoscope blades and bulbs attached to a variable voltage supply. There was a large variation in the illumination range of different bulb and blade combinations. We demonstrated a large interindividual variability between anaesthetists for illumination requirements during laryngoscopy. Anaesthetists can see the larynx at very low light levels, but optimum illumination was significantly greater than minimum illumination. Two of the six combinations could produce more than 700 lux. In all, 78% and 54% of anaesthetists considered 700 lux too bright with a halogen and xenon bulb, respectively. Our study suggests that the proposed standard of 700 lux may possibly be too bright.

Choque inapropriado de cardioversor-desfibrilador implantável devido a duplo "sensing" específico da onda T / Inapropriate shock delivered by implantable cardioverter defibrillator during specific double counting of the T-wave

Introdução: apesar dos avanços tecnológicos dos cardioversores-desfibriladores implantáveis (CDIs), com o uso crescente de sistemas de dupla-câmara e algorítmos diagnósticos e de detecção mais sofisticados, os choques inapropriados continuam sendo a complicação...

Disfunção do eletrodo ventricular ocasionando "tempestade" de choques inapropriados e depleção precoce da bateria do cardioversor-desfibrilador implantável / Ventricular electrode dysfunction causing inappropriate

Paciente sexo masculino, com 54 anos de idade, portador de cardioversor-desfibrilador. Após dois anos e dez meses de evolução, apresentou "tempestade" de 80 choques inapropriados, de forma intermitente e persistente, em um período de três horas e meia. A análise eletrônica do sistema evidenciou disfunção do eletrodo de choque e desgaste da bateria, sendo realizada a troca do eletrodo e do gerador comprometidos...

The simultaneous determination of cerebrospinal fluid and plasma adenosine deaminase activity as a diagnostic aid in tuberculous meningitis.

The simultaneous determination of cerebrospinal fluid (CSF) and plasma adenosine deaminase (ADA) activity was evaluated as a diagnostic aid in tuberculous meningitis (TBM). CSF and plasma ADA activity were determined in four groups of patients: (i) a 'no meningitis' group of 174 children investigated for possible meningitis, but found to be uninfected; (ii) an aseptic meningitis group of 40 children; (iii) a bacterial meningitis group of 31 children; and (iv) a TBM group of 27 patients (24 children and 3 adults). CSF ADA alone was determined in a further 23 children with aseptic meningitis, 19 with bacterial meningitis and 13 children and 7 adults with TBM. Both the CSF/plasma ADA ratio and the absolute CSF ADA activity were raised in TBM (mean values 0,24 and 12,61 U/I respectively) and bacterial meningitis (mean values 0,59 and 15,43 U/I respectively), but not in the aseptic meningitis group (mean values 0,06 and 2,00 U/I) or the 'no meningitis' group (mean values 0,04 and 1,51 U/I). Both values will distinguish TBM from aseptic meningitis, but do not appear to hold any marked advantages over conventional CSF criteria in the diagnosis of TBM.

Adenosine deaminase levels in cerebrospinal fluid in the diagnosis of tuberculous meningitis.

The prognosis of tuberculous meningitis is closely linked to the stage at which treatment is started. At the same time the diagnosis will often have to be made on purely circumstantial evidence. Adenosine deaminase activity in the cerebrospinal fluid was evaluated as a diagnostic aid in 30 cases of tuberculous meningitis. Cerebrospinal fluid adenosine deaminase levels differentiated tuberculous meningitis cases from those with aseptic meningitis being higher than 4 U/l in all and higher than 6 U/l in 90% of cases of tuberculous meningitis, but lower than 6 U/l in aseptic meningitis and less than 4 U/l in normal controls. It could not distinguish bacterial meningitis from tuberculous or aseptic meningitis. In cases of low-cell-count bacterial meningitis, the mean cerebrospinal fluid adenosine deaminase level was significantly lower than in cases of tuberculous meningitis with a similar cell count, but considerable overlap of results in the two groups was still to be found.

Adenosine deaminase estimations in the differentiation of pleural effusions.

Adenosine deaminase (ADA) estimations were performed on the pleural fluid from 368 effusions. The mean (+/-SD) ADA concentration in tuberculous effusions was 92,11 +/- 37,05 U/l, and these values were found to be highly statistically different from the 23,23 +/- 13,15 U/l in secondary malignant tumours of the pleura, the 34,86 +/- 14,2 U/l in mesotheliomas, and the 23,81 +/- 15,07 U/l in pulmonary embolism. The ADA values of 64,3 +/- 44,95 U/l in lymphoproliferative disorders were less significantly different. No statistical difference could be found between values in the tuberculous group and the ADA levels of 97,57 +/- 82 U/l found in para-infective effusions, but these could be distinguished from each other by microscopic examination of the pleural fluid. The importance of ADA estimations in the diagnosis and differentiation of tuberculous effusions is discussed and the role of microscopy is emphasized.

Hormonal placental functions and intrauterine growth retardation in patients with positive contraction stress tests.

Human placental lactogen (HPL) and urinary and serum oestriol levels were studied in patients in whom the contraction stress test was positive. After birth the infants were assessed for growth retardation. Low HPL, serum oestriol and urinary oestrogen levels were found in 66%, 30% and 15% of patients respectively. Gestational ages were known in 148 patients, of whom 72 (49%) had infants whose weights were below the 10th percentile for gestational age. HPL values were low in 81% of mothers who gave birth to growth-retarded infants, but serum and urinary oestriol levels were low in only 43% and 21% respectively. When both a positive stress test and a low HPL value were present, 69% of infants were growth retarded. The incidence of growth retardation rose to 85% when both HPL and serum oestriol levels were abnormal in patients with positive contraction stress tests. In this study estimation of HPL levels was found to be superior to that of oestrogen levels in detecting growth-retarded infants.

Urinary porphyrins and porphyrin precursors in normal pregnancy. Relationship to urinary total oestrogen excretion,.

The relationship between urinary excretion of porphyrins, porphyrin precursors and total oestrogens in normal pregnancy was investigated. Significant increases in total oestrogen, delta-aminolaevulinic acid (ALA) and coproporphyrin (COPRO) excretion were noted. However, no close correlation was found between total oestrogen excretion and urinary output of ALA and COPRO. The results suggest that the observed increases in ALA and COPRO excretion during pregnancy may not simply be the result of steroid-mediated induction of hepatic haem biosynthesis, as has been proposed.