Reference ranges for thromboelastography (TEG(®) ) and traditional coagulation tests in term parturients undergoing caesarean section under spinal anaesthesia*.

There has been little published work defining 'normal' thromboelastography (TEG(®) ) values in healthy parturients, and few large studies defining reference ranges for traditional coagulation tests in this patient group. Our aim was to establish peri-operative reference ranges for TEG and for standard laboratory coagulation tests in our pregnant population. Fifty healthy term parturients presenting for elective caesarean section under spinal anaesthesia had blood samples taken pre-operatively, on arrival in the recovery room and, in a subset of 33 women, 4 h after routine thromboprophylaxis with enoxaparin 40 mg. All three samples had TEG analysis, the first and second having standard laboratory coagulation tests in addition. Reference ranges for our pregnant population were established, demonstrating a hypercoagulable state in term parturients and a significant effect of enoxaparin. The standard coagulation reference ranges were within 98% of the local non-pregnant ranges. These reference ranges provide a useful comparator for peri-operative TEG and routine coagulation analysis in term parturients.

Safe initiation of oral diets in hospitalized patients based on passing a 3-ounce (90 cc) water swallow challenge protocol.

BACKGROUND: Safe and timely oral alimentation is crucial for optimum patient care. OBJECTIVE: To determine the short-term success of recommending specific oral diets, including drinking thin liquids, to acute care hospitalized patients at risk for dysphagia based on passing a 3-ounce water swallow challenge protocol. DESIGN: Prospective single group consecutively referred case series. SETTING: Large, urban, tertiary care, teaching hospital. PARTICIPANTS: 1000 hospitalized patients. INTERVENTION: 3-ounce (90 cc) water swallow challenge protocol. MEASUREMENTS: Specific diet recommendations and volume (in cc) of liquid ingested at the next day's meal 12-24 h after passing a 3-ounce challenge protocol were accessed electronically from oral intake information entered on each participant's daily care logs. Eating and drinking success, clinically evident aspiration events and compliance with ordering the recommended diet were recorded. Care providers were blinded to the study's purpose. RESULTS: Of 1000 patients, 907 met the inclusion criteria of stable medical, surgical or neurological conditions 12-24 h after passing a 3-ounce water swallow challenge protocol. All 907 were both eating and drinking thin liquids successfully and without overt signs of dysphagia. Median volume of liquid ingested was 340 cc [interquartile range (IQR), 240-460]. Specific diet recommendations were followed with 100% accuracy. CONCLUSION: A 3-ounce water swallow challenge protocol successfully identified patients who can be safely advanced to an oral diet without subsequent identification of overt signs of aspiration within 12-24 h of testing. Importantly, when a clinical 3-ounce challenge protocol administered by a trained provider is passed, specific diet recommendations, including drinking thin liquids, can be made safely and without the need for additional instrumental dysphagia testing.

Maternal anti-factor Xa activity following subcutaneous unfractionated heparin after Caesarean section.

Unfractionated heparin is widely used for prophylaxis against venous thromboembolism after Caesarean section. We performed a survey of thromboprophylactic methods after elective Caesarean section in 50 maternity units in the United Kingdom. We found that a variety of regimens were used. Thirteen (26%) used subcutaneous unfractionated heparin at standard (non-pregnant) doses. We then studied anti-Xa activity in women following elective Caesarean section under regional anaesthesia. Initially, eight women were given 5000 U unfractionated heparin subcutaneously after surgery and anti-Xa activity was measured 1, 2, 3, 4, 5, 6, 8 and 10 h after administration. There was no detectable anti-Xa activity in any of the samples so the dose was increased to 7500 U in a further five women and a single anti-Xa assay performed at 3 h when peak activity should occur. Again, no activity was detected so the dose was increased to 10 000 U heparin in a final group of 10 women and anti-Xa activity measured at 0.5, 1, 1.5, 2, 3, 4, 5 and 6 h. Although there was some activity after 10 000 U heparin, the level was below that accepted for prophylaxis. If anti-Xa activity is an appropriate monitor of prophylactic unfractionated heparin, doses up to 10 000 U are inadequate. Since there is evidence that enoxaparin is effective at producing adequate prophylactic anti-Xa activity following Caesarean section, we suggest abandoning the use of unfractionated heparin in favour of enoxaparin for this purpose.

Enhancement of dopamine-mediated behaviour by the NMDA antagonists MK-801 and CPP: similarities with repeated electroconvulsive shock.

The behavioural effect of dopamine D1-like receptor agonists (SKF 38393, SKF 81297) and a D2-like receptor agonist (quinpirole), administered alone and in combination, was tested in rats pretreated with a single injection of an NMDA antagonist (MK-801, CPP) or vehicle. Agonist-induced behaviour was monitored by automated activity meters and direct observation using a checklist scoring method. Pretreatment with MK-801 (0.05 mg/kg, SC, 30 min) had no significant effect (compared to controls) on the behavioural response to SKF 38393 (7.5 mg/kg SC), SKF 81297 (0.2 mg/kg SC) or quinpirole (0.1 and 0.25 mg/kg SC) administered alone. In contrast, MK-801 markedly increased locomotion (activity counts and scores) induced by co-administration of a D1-like plus a D2-like agonist [SKF 38393 (7.5 mg/kg) plus quinpirole (0.25 mg/kg), SKF 81297 (0.2 mg/kg) plus quinpirole (0.1 mg/kg)]. The behavioural response to the non-selective dopamine agonist apomorphine (0.5 mg/kg SC) was also enhanced by MK-801. Pretreatment with CPP (0.1 mg/kg SC, 30 min) also significantly increased the locomotor response to co-administration of SKF 38393 plus quinpirole administered alone, but had no effect on the behavioural response to separate injection of these agonists. MK-801 (0.05 mg/kg SC, 30 min) also enhanced the behavioural response to bilateral injection into the nucleus accumbens of SKF 38393 plus quinpirole (1.0 plus 0.4 microgram/side, respectively). These data suggest that in the intact rat, the enhancement of dopamine-mediated behaviour by either MK-801 or CPP requires concomitant stimulation of D1-like and D2-like receptors, possible located within the nucleus accumbens. The effect of these NMDA antagonists on dopamine function is similar to that of repeated electroconvulsive shock (ECS), indicating that one of the actions of ECS may be to reduce NMDA receptor function.

The yohkoh mission for high-energy solar physics.

The Japanese Yohkoh satellite is now in orbit observing the sun with a set of x-ray imagers and x-ray and gamma-ray spectrometers. The data from this successful mission provide new information on solar flares and the sun's corona. This paper discusses the Yohkoh observations and presents a sample of the first scientific results from the mission.

Ergometrine and 5-hydroxytryptamine binding sites in rat brain and myometrium.

Functional studies suggest that ergometrine is a partial agonist involving 5-hydroxytryptamine (5-HT) receptors in rat uterus. Ergometrine displaced [3H]5-HT from specific binding sites in rat brain, but did not displace [3H]5-HT at functionally important concentrations in rat myometrium. These binding studies indicate that the agonist and antagonist actions of ergometrine in rat uterus arise from its initial interaction with binding sites other than those for 5-HT.

X-ray Photographs of a Solar Active Region with a Multilayer Telescope at Normal Incidence.

An astronomical photograph was obtained with a multilayer x-ray telescope. A 4-centimeter tungsten-carbon multilayer mirror was flown as part of an experimental solar rocket payload, and successful images were taken of the sun at normal incidence at a wavelength of 44 angstroms. Coronal Si-XII emission from an active region was recorded on film; as expected, the structure is very similar to that observed at O-VIII wavelengths by the Solar Maximum Mission flat crystal spectrometer at the same time. The small, simple optical system used in this experiment appears to have achieved a resolution of 5 to 10 arc seconds.

Large-aperture high-resolution x-ray collimator for the Solar Maximum Mission.

A description is presented of a flight-qualified large-aperture 12 x 12-sec of arc angular resolution multigrid x-ray collimator developed for the Solar Maximum Mission (SMM) flat crystal spectrometer. This collimator, designed for the 1.4-22.4-A wavelength range, utilizes an optical bench/metering structure to align and support prealigned grid subassemblies. One advantage of this scheme is to provide ready access to the grid subassemblies for inspection and/or servicing. The optical bench is a lightweight, rigid, and stable aluminum honeycomb structure. Aluminum is a viable material choice in this application because of the good thermal control expected in the SMM instrument package. The grids are of a compound and bimetallic design, having 63.5-microm square holes on an 88.9-microm spacing in 8-microm thick gold, which is in turn supported by a 76-microm thick Invar grid having 600-microm square holes on a 739-microm spacing. The small apertures in the gold provide the 12-sec of arc collimation with the Invar grids providing wide angle off-axis blocking out to an ~35-min of arc view angle. The collimator has seven individual channels, four of a 5.1- x 10-cm area and three of a 1.3- x 10-cm area. Laboratory measurements gave an average angular resolution of 12.5-sec of arc FWHM with 0.259 transmission for the large area channels and 12.0 sec of arc and 0.200 transmission for the small area channels. A hypothetical perfectly aligned collimator would have 12.5-sec of arc resolution and 0.300 transmission. A thermal filter composed of two layers of ~1000-A thick aluminum prevents solar heating of the front collimator grids by absorbing longer wavelength radiation while passing most of the x radiation in the band of interest. The filter was flight qualified by passing a protoflight acoustic test environment of 147-dB total sound level, 20-microN/M(2) reference, for 1-min duration.

Diffraction properties of hydrogen-phthalate-crystals in the 0.1-2-nm region.

By means of single- and double-crystal spectrometers, the integrated and the percent reflectivities and the halfwidth of the KAP, NaAP, RbAP, and NH(4)AP crystals have been measured in several orders within the (0.147-1.76-nm) spectral range. The reflection plane for all crystals is the 001 plane, which is also the cleavage plane. Among the selected crystals RbAP shows the highest reflectivity. Comparison with the theory leads in a first approximation to the conclusion that all these crystals are of nearly perfect and not of a mosaiclike structure.