One hundred patients aged 18-49 yr, undergoing elective arthroscopy of the knee joint, were allocated randomly to either spinal anaesthesia using a 29-gauge spinal needle or general anaesthesia. Dural puncture was considered difficult in 18% of the patients receiving spinal anaesthesia. In three patients (6%) it was necessary to supplement the spinal anaesthetic with general anaesthesia. Spinal and general anaesthesia were otherwise uneventful in all patients. The incidence of postoperative headache was similar in the two groups. One patient developed post dural puncture headache following spinal anaesthesia. This headache was of short duration and disappeared without treatment. Spinal anaesthesia caused more backache than general anaesthesia, otherwise the frequency of postoperative complaints was the same or lower. Ninety-six percent of the patients receiving spinal anaesthesia would prefer the same anaesthetic for a similar procedure in the future.

The effect of three postoperative regimens of respiratory therapy on pulmonary complications and lung function was compared in high-risk patients. Fifty-one patients were randomized to: 1) conventional chest physiotherapy alone (PHYS), 2) chest physiotherapy and positive expiratory pressure (PEP), or 3) chest physiotherapy with both positive expiratory pressure and inspiratory resistance (RMT). Treatments were given twice daily by a physiotherapist and self-administered. The incidence of postoperative pulmonary complications (PPC) was respectively, 71%, 76% and 65% in the PHYS-, PEP- and RMT-groups. The incidence of PPC requiring treatment with antibiotic, bronchodilator or supplementary oxygen according to the existing clinical practice was 47%, 47% and 29%. The incidence of atelectasis was 65%, 64% and 60% and of pneumonia 29%, 35% and 6%. There was no difference between the groups, except for a tendency to a lower frequency of pneumonia in the RMT-group. Postoperatively forced vital capacity (FVC) decreased to mean 54%, forced expired volume in 1 s to 48% and functional residual capacity to 76% of preoperative values. Arterial oxygen tension (PaO2) declined to mean 8.1 kPa and arterial saturation (SaO2) to 89%. There was no difference between the groups except for FVC, PaO2 and SaO2 (P = 0.008, P = 0.008 and P = 0.002), which showed the least decrease in the RMT-group. None of the regimens could be considered as satisfactory concerning the prevention of PPC, but RMT seemed to be the most efficient. Insufficient self-administration of treatment was probably one of the causes of the overall high incidence of PPC in this study.

No abstract

Abstract--If anilinium ions are intercalated into Llano vermiculite, the stacking order of adjacent silicate layers is increased, resulting in a relatively sharp single crystal X-ray diffraction (XRD) pattern. The packing of intercalated organic members forms a superstructure and produces bonding from layer to layer which favors the stacking order. Superlattice reflections occur which, although sharp in the a'b* plane, are streaked along c*. Apparently there is little coherence between adjacent layers of ordered organic units.A three-dimensional set of XRD reflections for a triclinic sub-cell having the following lattice parameters was measured: a = 5.326(3), b = 9.264(4), c = 14.82(5) A, a = 90.31(7),/3 = 96.70(6), and 3' = 89.55(5) ~ In this unit cell (symmetry C1), ditrigonal cavities in adjacent silicate layers are approximately opposite. Differential Fourier analyses and least-squares refinements showed that the principal axes of the anilinium ions, i.e., N-C(1)-C(4), are nearly perpendicular to the silicate layers. The planes of the aromatic rings, however, are about +_ 30 ~ to X, neither parallel nor perpendicular to that direction, as indicated by earlier studies.Inorganic cations and water molecules are also present in the interlayer; the former and some of the latter occupy sites near the middle of the layer. Anilinium-rich and anilinium-poor domains coexist. In the latter, the cation-water system predominates and apparently conforms to the superstructure. Although the cation-water structure could not be uniquely established from the reflections produced by the subcell, possible positional coordinates were obtained. From structural data for the silicate layers, no evidence was found for long-range Si/A1 ordering in the tetrahedral sites.

In 20 patients a continuous block of the lumbar plexus was administered after knee-joint surgery, and the analgesic effect of two different concentrations of bupivacaine was compared. The same volume of bupivacaine was given to both groups of patients: a bolus dose of 0.4 ml/kg, 0.5% or 0.25%, followed by infusion of 0.14 ml/kg/h, 0.25% or 0.125%, respectively, via a catheter placed in the neurovascular fascial sheath of the femoral nerve according to the "3-in-1 block" technique. The median morphine consumption during the first 16 h postoperatively was 6.0 mg when bupivacaine 0.5/0.25% was used and 9.5 mg when 0.25/0.125% was used. This difference is not significant. The visual analogue pain scores were also similar in the two groups (P greater than 0.05). All plasma concentrations were below 4 micrograms/ml, the highest concentration measured being 3.6 micrograms/ml. It is concluded that when used for a continuous block of the lumbar plexus after knee-joint surgery, bupivacaine in a concentration of 0.125% offers the same pain relief as a concentration of 0.25%, and the risk of toxic reactions is reduced.