Dan Med Bull
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The mechanism of central nervous side effects of lumbar puncture is reviewed on the basis of the literature. The most frequent adverse effect of lumbar puncture remains the postdural puncture headache; dysfunction of certain cranial nerves occurs less frequently. Laboratory studies have shown that the production rate of CSF. ⋯ There are no reports of measurement of the intracranial pressure in patients with postdural puncture headache, but there are several indications of a reduced CSF pressure that may explain postdural puncture headache and vestibulocochlear dysfunction following lumbar puncture. Recent audiometric studies suggest that hearing loss may be a sensitive indicator of CSF leakage, and larger series indicate that the needle size and the shape of the needle tip are important determinants of the incidence of central nervous side effects. Epidural blood patch may give immediate relief of postdural puncture headache and cranial nerve dysfunction after lumbar puncture, but the reason for the rapid and impressive effect of epidural blood patch has not been fully elucidated.
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K+ channels play a key role in regulation of membrane potential and cell excitability. Several different types of K+ channels have been identified and the presence, characteristics and functions of these channels vary among different tissues. The 3 most important K+ channels in smooth muscle are the KATP (activated by a fall in intracellular ATP and a rise in nucleotide diphosphates and blocked by glibenclamide), BKCa (activated by a rise in intracellular Ca2+) and Kv (activated by depolarization). ⋯ Additional to the antagonistic action against K+ channel openers the sulfonylurea KATP blockers and phentolamine at higher concentrations relaxed airway smooth muscle by yet unknown mechanisms that seemed unrelated to KATP. 3) Cromakalim and pinacidil inhibited nerve-mediated e-NANC contractile responses in guinea-pig bronchi. Such responses are due to release of SP and related tachykinins from sensory nerve endings. These neuropeptides cause bronchoconstriction and airway inflammation and may possibly play an important role in the pathophysiology of asthma.
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Review Comparative Study
Monitoring of neuromuscular transmission by electromyography during anaesthesia. A comparison with mechanomyography in cat and man.
In this study the applicability of the electromyographical method for monitoring neuromuscular transmission during anaesthesia has been investigated. The purpose was to determine the stability and temperature dependence of the EMG and to evaluate and compare EMG area, amplitude and duration during a non-depolarizing neuromuscular block in the tibialis anterior muscle preparation of the cat. Further, in clinical studies the purpose was to investigate differential hand muscle sensitivity to non-depolarizing neuromuscular blocking agents based on the EMG and the standard adductor pollicis mechanomyogram, and to establish the agreement between the electromyographical and the mechanomyographical methods and their relationship to clinical parameters of residual neuromuscular block. ⋯ However, due to the range of deviations between the EMG and the mechanomyogram, EMG TOF ratios down to 0.55 or up to 0.90 in some patients were found to be compatible with adequate recovery of a mechanomyographical TOF ratio of 0.75. Differences between electromyographical and mechanomyographical TOF ratios in their relation to 5 s sustained headlift were only revealed when the TOF ratio was below 0.50-0.60. More patients were then able to perform the test if the TOF ratio was measured from the EMG.(ABSTRACT T
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The objective of the study was to evaluate neonatal survival and subsequent disabilities in infants with extremely low gestational age in relation to perinatal events and neonatal treatment. A retrospective follow-up study was performed based on medical records, questionnaires to parents and recordings of contact with health authorities. All infants with a gestational age 28 completed weeks or less, who were admitted to the Department of Neonatology, Rigshospitalet, within 24 hours of age during the period January 1, 1987 - December 31, 1990 were included. ⋯ Sixty infants (31%) needed medical or surgical closure of a persistent ductus arteriosus. In 11 infants (6%) cystic periventricular leucomalacia occurred, 10 infants (5%) developed retinopathy of prematurity stage 3-4, and 35 infants (24%) received supplementary oxygen at 28 days of age. Risk factors present at birth for adverse outcome were: Apgar score <7 at five minutes, birth weight <1000 g, male sex and birth in another hospital than Rigshospitalet, For adverse outcome in surviving infants only, ICH grade II-IV was the only significant risk factor.