David Littlewood

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In an unblinded study 50 patients undergoing cystoscopic procedures received a spinal anaesthetic of plain 0.5% bupivacaine 4 ml administered in the sitting position at the L3-4 space. There was a correlation between the height of blockade assessed by pinprick analgesia and the degree of obesity of the patients measured by weight, weight/height, and(More)
Various concentrations of lignocaine, etidocaine and bupivacaine in 10-ml doses of plain solutions were studied in a double-blind manner as agents for extradural analgesia to relieve the pain of labour. In 67 patients in established labour the onset time and duration of analgesia were assessed by the abolition and recurrence of the pain of uterine(More)
A double-blind study was carried out using hyperbaric solutions of bupivacaine to compare the effects of varying the concentration of bupivacaine and the volume of solution administered intrathecally. Fifty-seven patients were studied. Ten patients received each volume of each concentration: 0.5% bupivacaine in 8% dextrose, 2 ml, 3 ml or 4 ml and 0.75%(More)
In this study, the problem of updating a printer characterization in response to systematic changes in print-device characteristics is addressed with two distinct approaches: the creation of corrective models used in conjunction with an existing device model, and the re-evaluation of regression-model parameters using an augmented characterization data set.(More)
The effect of adding 0.1, 0.2, or 0.3 ml of 1:1000 epinephrine to 1.5 ml of 5% lidocaine in 7.5% dextrose for spinal anesthesia was assessed in 40 patients in a double-blind study. The addition of epinephrine produced little or no clinically useful prolongation of block. There was a small reduction in the speed of decay of nerve block, but this only reached(More)
The effects of intrathecal injection of 0.5% bupivacaine in solutions containing various concentrations of glucose have been studied in four groups of 20 patients. When solutions containing 0.8% glucose were injected at the L3-4 interspace the median maximum extent of block was higher, and the range of blocks wider, with the 8% solutions. All patients(More)
Blood-gas tensions, FRC and volume of trapped gas (VTG) in the lung were measured in patients on the day before lower abdominal gynaecological surgery, and twice on the day following surgery, before and after establishing lumbar extradural block (EDB) using 0.5% bupivacaine to provide analgesia after operation. FRC and VTG were measured with the(More)
We develop and analyze an optimization–based method for the coupling of nonlocal and local diffusion problems with mixed volume constraints and boundary conditions. The approach formulates the coupling as a control problem where the states are the solutions of the nonlocal and local equations, the objective is to minimize their mismatch on the overlap of(More)
An elasto-viscoplastic constitutive model and corresponding finite-element implementation are presented for Al 7075-T651. The material model is informed by microscale mechanisms and is suitable for providing heterogeneous stress and strain data at the grain scale to formulations for crack initiation and fatigue failure. A precipitation hardening model was(More)
The effect of adding 0.2 ml of 1:1000 epinephrine or 0.5 ml of 1% phenylephrine to 1.5 ml of 1% tetracaine for spinal anesthesia was assessed in 30 patients in a double-blind study. Phenylephrine but not epinephrine produced a significant prolongation of sensory loss in the T12 dermatome. Both vasoconstrictors produced a significant prolongation of the(More)