[Infusion of mivacurium and atracurium guided by manual tactile evaluation]

INTRODUCTION

The aim of this investigation was to compare the use of a continuous infusion of mivacurium or atracurium guided by tactile evaluation of the neuromuscular block.

MATERIALS AND METHODS

Forty-five patients were randomly allocated to three groups of patients. Group M and MN received a bolus dose of mivacurium 0.15 mg/kg followed by a continuous infusion and group AN a bolus dose of atracurium 0.4 mg/kg followed by an infusion.

RESULTS

The neuromuscular blockade recovered spontaneously in group M and was antagonised in group MN and AN. The level of block was quantified by tactile evaluation. The time to full recovery was significantly shorter in patients receiving mivacurium compared to patients given atracurium, 14.5, 12.0 and 18.0 min, respectively. Further, reversal with neostigmine significantly enhanced recovery following mivacurium.

CONCLUSION

A continuous infusion of mivacurium and atracurium can easily be performed, guided by tactile evaluation of the neuromuscular block and the effect can be reversed by neostigmine.

The effect of succinylcholine on atracurium-induced neuromuscular block

BACKGROUND

The interaction between prior succinylcholine and atracurium has been found only after full recovery of succinylcholine block. We investigated whether the effect of succinylcholine on atracurium block may depend on the level of recovery from succinylcholine.

METHODS

Fifty patients in 4 groups received atracurium 0.2 mg/kg when first response (T1) in train-of-four (TOF) after succinylcholine 1 mg/kg had recovered to 5%, 25%, 75% or 100%. A control group received only atracurium. The following indices were compared: the time from injection of atracurium to maximum block (onset time) and to return of T1 to 25% (duration 25%), maximal depression of T1, time from 25% to 75% recovery of T1 (interval 25-75%) and time from injection of atracurium to a TOF ratio of 0.75 (duration TOF 0.75).

RESULTS

Onset time was shorter, max T1 depression was greater and duration 25% increased the more succinylcholine recovery progressed. Neither interval 25-75% nor duration TOF 0.75 varied with the level of recovery from succinylcholine. The control group showed a shorter latency and onset time compared to the early (5%) recovery group and a longer onset time and less depressed T1 compared to the late (100%) recovery group. There was no difference between the control group and the early or late recovery groups, respectively for duration 25% or duration TOF 0.75.

CONCLUSION

The effect of prior administration of succinylcholine on atracurium block depends on the state of recovery from succinylcholine and concerns both its potency, onset and duration characteristics.

The high-pressure phase of zincite

Synchrotron-radiation X-ray diffraction studies of ZnO have been performed with special emphasis on the rock-salt-type high-pressure phase. The wurtzite (B4) to rock salt (B1) phase transformation is accompanied by a volume collapse of 18%, which is a very large effect. The lattice constant of the B1 phase at ambient pressure is a(0) = 4.280 (4) A, and the bulk modulus is B(0) = 170 (10) GPa. Comparisons are made with a recently published theoretical equation of state obtained from ab initio perturbed-ion calculations.

X-ray diffraction investigations of CaF2 at high pressure

Synchrotron-radiation X-ray diffraction studies of CaF2 at high pressures have been performed on a powder sample up to 45 GPa and on a single-crystal sample up to 9.4 GPa. The bulk modulus of the low-pressure phase was determined to be B 0 = 87 (5) GPa. A phase transition was observed at about 9.5 GPa. The transition is accompanied by a volume contraction of 11%. The high-pressure phase is orthorhombic PbCl2 type (space group Pbnm). The sample only partially reverts to the low-pressure phase upon release of pressure.

[Quality assurance of results of clinical chemical analyses in Danish hospital laboratories]

During the past 35 years, voluntary professional assessment of quality of the results of analyses in Danish hospital laboratories has been undertaken under the auspices of the Danish Society of Clinical Chemistry. The analytical quality of the laboratories is described by their "imprecision" and "accuracy" as expressed by "coefficient of variation" and "bias", respectively. The participation in these programmes was 90%. During the period between 1968 and 1987, inter-laboratory variation decreased markedly where all analyses were concerned. To ensure the necessary and adequate quality, establishment of specifications of quality based on clinical/biological goals of quality has proved necessary. The commonest reasons for large imprecision and bias from the target values are less specific methods of analysis, errors in calibration and sporadic "outliers". As the result of a stable organisation for ensuring quality, Denmark is well equipped for the introduction of the great demands in documentation of quality which may be anticipated from the Common Market during the immediate future.

The pressure-induced transformation B1 to B2 in actinide compounds

The phase transformation from NaCl structure (B 1) to CsCl structure (B2) in actinide compounds has been studied using X-ray powder diffraction in the pressure range up to about 60 GPa. It is shown that the transition is sluggish, has a strong hysteresis and is accompanied by a volume change in the range 8–12%. These features are similar to those of the corresponding transition in the alkali halides and other B1 compounds, indicating a common mechanism for the transformation as concerns the lattice geometry.

A high-pressure study of Ti3O5 by X-ray diffraction and synchrotron radiation. 1. Pressures up to 38.6 GPa

High-pressure X-ray diffraction studies have been performed on powder samples of β-Ti3O5 (C2/m) for pressures up to 38.6 GPa using synchrotron radiation and a diamond-anvil cell. The compressibility is highly anisotropic. Thus, the compression Δl/l 0 for the maximum pressure investigated is 5.4, 0.8 and 6.7% for the unit-cell axis directions a, b and c, respectively. The anisotropy is reasonable, considering the crystal structure. The bulk modulus B 0, determined from the Murnaghan equation, is 173(10) GPa and B′0 is 7(1).

Crystal structure and the equation of state of thorium monophosphide for pressures up to 50 GPa

High-pressure X-ray diffraction studies have been performed on ThP using synchrotron radiation and a diamond-anvil cell. The bulk modulus B 0 and its pressure derivative B′0 have been determined (B 0 = 137 GPa; B′0 = 5.1). A phase transition from the NaCl structure to the CsCl structure was observed at about 30 GPa.

Danish very-low-dose aspirin after carotid endarterectomy trial

The effect of very-low-dose aspirin as an antithrombotic agent was evaluated blindly in 301 patients who had recently undergone carotid endarterectomy. After randomization, 150 patients received aspirin and 151 received placebo. The two groups were comparable with regard to age, sex, blood pressure, previous cerebrovascular events, and smoking habits. The effect of the study medication on platelet aggregation was measured twice in each patient during the first 2 months and at each follow-up visit; the dose was individually adjusted. In 76% of the patients receiving aspirin, 50 mg/day gave satisfactory platelet inhibition, 13% needed 60 mg/day, 8% needed 70 mg/day, and 3% needed 100 mg/day. Platelet aggregation was found to be inhibited in only 1.2% of the measurements in the patients receiving placebo. Observation during treatment averaged 21 months; total intention-to-treat follow-up averaged 25 months. For the combined outcome events of transient ischemic attack, stroke, acute myocardial infarction, and vascular death, aspirin reduced risk by 11% (95% confidence limits: -38% to 48%, p greater than 0.1). Thus, there was no significant effect of very-low-dose aspirin in our trial.

Ritodrine in the treatment of preterm labor: second Danish Multicenter Study

In a randomized trial intramuscular ritodrine followed by oral ritodrine treatment and bed rest was compared with placebo and bed rest in the treatment of 99 cases of preterm labor. The ritodrine treatment did not have a statistically significant effect on birth weight, gestational age, or the incidence of low birth weight. However, it did inhibit preterm labor in the initial stage, resulting in a gain of a few days to a few weeks in length of gestation. This gain may be valuable. Where necessary, advantage can be taken of it to transfer the mother before delivery to a more specialized hospital with a neonatal intensive care unit or to administer steroid treatment to promote fetal lung maturation. No serious side effects were recorded. The intramuscular route is recommended because large fluid infusions are avoided and treatment can easily be started before the patient is transported from home to hospital.

Prolongation of bleeding time and inhibition of platelet aggregation by low-dose acetylsalicylic acid in patients with cerebrovascular disease

Platelet aggregation and bleeding time was measured in 43 cerebrovascular patients participating in a controlled double-blind study of low-dose acetylsalicylic acid. In 19 patients with satisfactory inhibition of the platelet aggregation obtained by 50 to 70 mg acetylsalicylic acid per day the bleeding time averaged 11.2 minutes in contrast to 7.0 minutes in the placebo group, p less than 0.001. This study confirms our previous findings of platelet inhibition by low-dose acetylsalicylic acid in patients with cerebrovascular disease. The prolongation of the bleeding time demonstrates that we are dealing not merely with an in vitro phenomenon but with a significant in vivo effect. The study provides the rationale for clinical evaluations of low-dose acetylsalicylic acid in stroke prophylaxis.

The rabbit cornea lacks cholinergic receptors

Cholinergic receptors were studied in membranes prepared from rabbit cornea, iris-ciliary body, and retina, using 3H-quinuclidinyl benzilate (3H-QNB) to identify muscarinic receptors and 125I-alpha-bungarotoxin (125I-BGT) to identify nicotinic receptors. Muscarinic cholinergic receptors were not found in the cornea. As a positive control, muscarinic cholinergic receptors were characterized in preparations of the iris-ciliary body. Specific binding of 3H-QNB to iris-ciliary body membrane preparations was saturable, with a Kd of 1.3 nM QNB. Specificity of the assay for muscarinic receptors was confirmed by the relative abilities of the following compounds to displace 3H-QNB: atropine greater than pilocarpine greater than hexamethonium. Nicotinic cholinergic receptors were not found in the cornea. As a positive control, nicotinic cholinergic receptors were characterized in preparations of the retina. Specific binding of 1252-BGT to retinal membrane preparations was saturable with both high and low affinity receptors (Kd values of 1.0 nM and 93 nM BGT, respectively). Specificity of the assay for nicotinic receptors was confirmed by the relative abilities of the following compounds to prevent 125I-BGT binding: curare greater than or equal to nicotine greater than hexamethonium greater than atropine. The lack of cholinergic receptors in the cornea, which has high levels of acetylcholine and related enzymes, suggests either an extraordinary use or a lack of function for acetylcholine in this tissue.

Spontaneous slow potentials and spreading depression in amphibian retina

1. In frog and mudpuppy eye cups perfused with low-chloride solution, two types of slow potential phenomena were studied. One type, "spontaneous slow potentials" (SSPs), appeared both in the dark and during light stimuli. The other type, the slow potential change (SPC) of spreading depression (SD), appeared at termination of long-duration light stimuli. 2. The SSPs were analyzed by depth-profile studies, pharmacologic studies, and the use of potassium-specific electrodes. Results indicated that SSPs may represent spontaneous d-waves that travel across the retina. The SSPs are associated with potassium activity, and the main response is probably generated by Müller cells. Initiation and/or propagation appear to require chemically mediated synaptic transmission and impulse activity. 3. Depth-profile studies were also done of the SPC of SD induced by termination of long-duration light stimuli. Results indicated that the SPC is not an exaggerated d-wave. The SPC consists of two components, the second of which reverses more superficially than the d-wave. The main SPC response is probably generated by Müller cells. Although impulse activity does not appear to be necessary for SD, it may contribute to this complex response.

Bacteriology and antibiotics in acute suppurative otitis media

One hundred and forty-seven patients with acute suppurative otitis media, were divided into three groups and treated with antibiotics (azidocillin, ampicillin, and cephalexin). The therapeutic effect was assessed bacterioloically by swabbing from the aural discharge and from the nasopharynx on the first, second, third, and seventh day after initiation of treatment. In addition, the concentration of antibiotic in the aural discharge and in the nasopharynx was determined. As compared with other published materials, there was a common occurrence of Haemophilus influenzae and S. Aureus. Hemolytic streptococci are less common than prior to the advent of antibiotics. Pneumococci disappeared in all cases from the aural discharge in the course of the first three days. The effect upon Haemophilus was slower. In the nasopharynx the effect was questionable, and no effect was obtained upon other bacteria. The clinical course could not be correlated to the bacterial findings except that resistant bacteria were found in all cases with persisting discharge.