A prospective comparison of invasive and non-invasive blood pressure in children undergoing cardiac catheterization

BACKGROUND

Blood pressure measurement is a standard of monitoring during general anesthesia. Invasive measurement is considered the gold standard but is less commonly used than non-invasive. Automated oscillometric blood pressure devices measure the mean arterial pressure (MAP) and use an algorithm to determine the systolic and diastolic pressures. Few devices have been validated in children, particularly during anesthesia. Few studies have assessed the agreement between invasive and non-invasive blood pressure measurements in children.

METHODS

This was a multi-center prospective observational study of children under 16 years undergoing cardiac catheterization with general anesthesia. Paired invasive and non-invasive blood pressure measurements were recorded for each patient during stable periods of the procedure. Correlation within and between sites was assessed with Pearson's correlation coefficient, and agreement was examined using Bland-Altman methodology to determine bias. Agreement during episodes of hypotension and for age and weight was also determined. Bias greater than 5 mmHg and standard deviation greater than 8 mmHg was considered clinically significant. The primary end point was agreement of MAP measurements.

RESULTS

A total of 683 paired blood pressure values were collected from 254 children in three pediatric hospitals. Median [IQR] age and weight were 3 [1-7] years and 13.9 [8-23] Kg. The overall bias (SD) for mean arterial pressure values was 7.2 (11.4) mmHg. During hypotension (190 readings), the bias (SD) was 15 (11.0) mmHg. The non-invasive MAP was frequently higher than invasive MAP during infancy, and lower in older children.

CONCLUSION

Automated oscillometric blood pressure measurement is unreliable in anesthetized children during cardiac catheterization. Invasive pressure measurement should be considered for high-risk cases.

Preparation of Entangled States through Hilbert Space Engineering

We apply laser fields to trapped atomic ions to constrain the quantum dynamics from a simultaneously applied global microwave field to an initial product state and a target entangled state. This approach comes under what has become known in the literature as "quantum Zeno dynamics" and we use it to prepare entangled states of two and three ions. With two trapped ^{9}Be^{+} ions, we obtain Bell state fidelities up to 0.990_{-5}^{+2}; with three ions, a W-state fidelity of 0.910_{-7}^{+4} is obtained. Compared to other methods of producing entanglement in trapped ions, this procedure can be relatively insensitive to certain imperfections such as fluctuations in laser intensity.

Salvia lavandulaefolia essential oil inhibits cholinesterase in vivo

The essential oil of Salvia lavandulaefolia at two dosage levels was administered orally to rats for five days. Choline esterase activity was measured post mortem in three areas of the brain, both in the absence and presence of TEPP, a specific butylcholine esterase inhibitor, and was found to be significantly reduced in the striatum with both doses and also in the hippocampus at the higher dose. The activity of the enzyme in the cortex was not significantly reduced even at the higher dose. Thus it appears that S. lavandulaefolia oil, shown to inhibit choline esterase in vitro, also has an in vivo effect and this may help explain its traditional use for ailing memory.

Workplace performance effects from chronic depression and its treatment

Utilizing data from a clinical trial and an econometric model incorporating the impact of a medical intervention and regression to the mean, we present evidence supporting the hypotheses that for chronically depressed individuals: (i) the level of perceived at-work performance is negatively related to the severity of depressive status; and (ii) a reduction in depressive severity improves the patient's perceived work performance. Improvement in work performance is rapid, with about two-thirds of the change occurring already by week 4. Those patients having the greatest work improvement are those with both relatively low baseline work performance and the least severity of baseline depression.

Case payment: a New South Wales perspective

This paper addresses the role of casemix systems within the NSW public health system. In NSW, Areas and Regions are funded according to a casemix modified population-based funding formula (Resource Allocation Formula). The RAF is compared with case payment as a means of funding hospitals. It is argued that because of the current shortcomings in casemix funding, including output orientation, inapplicability to ambulatory and non-acute inpatients, and limited scope for global expenditure control, case payment should not be introduced as the mechanism for funding hospitals. However, it is recognised that there is scope to combine population-based funding at area/region level, with case payment to individual agencies.

Alteration by prolactin of surface charge and membrane fluidity of rat 13762 mammary ascites tumor cells

Intraperitoneal injection of ovine prolactin (100 micrograms/d) in Fischer 344 rats bearing transplantable 13762 mammary ascites tumor (MAT) cells modifies the surface charge density and membrane fluidity of the tumor cells. In each of five experiments the mean electrophoretic mobility (epm) of MAT cells taken from prolactin-treated rats was significantly lower than that of cells from nonhormone-treated controls. Prolactin concentrations were increased in vivo by (a) direct intraperitoneal injection of ovine prolactin; (b) subcutaneous implantation of diethylstilbestrol-containing silastic capsules to produce pituitary prolactin secreting tumors; or (c) a single subcutaneous injection of polyestradiol phosphate, a long-acting estrogen. In an effort to establish that the prolactin effect was a direct one, two in vivo protocols were used: (a) MAT cells were coincubated with anterior pituitary halves obtained from nontumor-bearing littermates; or (b) rat or ovine prolactin was added to serum-free culture media containing MAT cells. In both protocols, the epm of the prolactin-treated cells was significantly lower. The isoelectric focusing pH of whole cells was increased by prolactin treatment from 4.93 to 5.12, consistent with a reduction in the number of surface carboxyl groups. The fluidity of membranes of treated cells was drastically increased, as measured by spin-label probe rotation rates. These combined results imply that the hormone exerts its effect by stimulating events in the cell that lead to a reduction of the average density of carboxylic acid residues on the tumor cell surface.

Effects of adamantane derivatives on the stability and assembly of bacteriophage PM2

1-Adamantanamine and several related compounds were tested for their effect on the lipid-containing bacteriophage PM2. 2-Adamantanol and 1-adamantane methanol were virucidal, while 1-adamantane acetic acid inhibited virus production in a highly pH-dependent manner.

Evaluation of a pilot program for rheumatic disability in an urban community

A program for the systematic detection and management of arthritis disability was developed for an urban population. A survey identified 601 persons with rheumatic disability in a population of 9,500-10,550. Seventy-eight persons were evaluated and given recommendations. An ombudsman assisted the clients in obtaining health services and coordinated care. An evaluation 6-8 months later showed increased utilization of and referrals to relevant services but, on the whole, little improvement in functional capacity was noted. However, the small numbers do not definite conclusions.

Interaction of divalent cations and proteins with phospholipid vesicles

The broadening of spin-label absorption lines resulting from spin-exchange reactions that occur during collision with paramagnetic Ni2+ is diminished when Ni2+ binds to phospholipid vesicles. Subsequent addition of non-paramagnetic ions that compete for binding sites releases Ni2+ into solution and restores the line-broadening. The concentrations of various ions required to achieve this effect was used to order the ions with respect to their binding to vesicles containing phosphatidylethanolamine and phosphatidylglycerol. The relative strengths of binding for those ions studied were: Ca2+ > Mg2+ > Zn2+ > Sr2+ > Ba2+. The spin-broadening assay was also used to study the effects of two proteins on the availability of Ni2+-binding sites on the vesicles. Ribonuclease, which is thought to associate electrostatically as an extrinsic protein on the surface of vesicles, completely blocked the Ni2+-binding sites at comparatively low protein concentrations. Quantitative considerations of these data suggest the possibility that Ni2+ may bind preferenetially to phosphatidylglycerol, and that these binding sites are aggregated in the ribonuclease-containing vesicles. In contract to ribonuclease, cytochrome c does not block Ni2+-bindings sites on the phospholipid vesicles, but rather contains sites of its own that bind Ni2+, both when the protein is in solution and when it is associated with the vesicles. These results are consistent with other studies which suggest that cytochrome c becomes partially embedded in membrane bilayers and associates with phospholipid molecules through hydrophobic interactions.

Studies with a hydrophobic, spin-labeled virucidal agent

A spin-labeled virucidal agent was synthesized, purified, and tested for its activity against the enveloped bacterial virus phi6 and herpes simplex virus. This compound, designated BPN, inactivated greater than 99% of phi6 and herpes simplex virus in vitro at concentrations as low as 0.1 mM. Detailed studies were carried out on the mechanism of inactivation of phi6 by BPN. These studies revealed that treatment of phi6 by BPN specifically removes a single envelope protein that is considered to be responsible for adsorption of the virus to the host cell. Related experiments with the phi6 host, Pseudomonas phaseolicola strain HB10Y, showed that this organism is insensitive to the effects of BPN. The basis for the differential sensitivity of phi6 to BPN, in comparison to the host cell, was investigated by electron spin resonance techniques. It was found that, for phi6, HB10Y, and their extracted phospholipids, BPN is localized in the hydrocarbon zones of the membrane bilayer. However, in the case of phi6, the rotational mobility of BPN is much reduced in comparison to that in HB10Y and the phospholipid preparations. Furthermore, an Arrhenius plot of rotational correlation time (tau(c)) showed a marked discontinuity in slope at 31 degrees C in the case of phi6, but not for the other samples studied. This suggests a strong interaction between the phi6 envelope proteins and the lipid domains in which BPN is localized. Calculations based on the known lipid and protein composition of phi6 indicate that there is an absence of "free-lipid" pools in the viral envelope. It is suggested that BPN localizes in free-lipid pools of cell membranes, where its presence is of little or no consequence, but that in phi6 the BPN perturbs the hydrophobic interactions between phospholipids and proteins in the envelope.

Inactivation of lipid-containing viruses by long-chain alcohols

This report describes the inactivation of lipid-containing viruses by several long-chain alcohols. A striking peak in antiviral activity was found for saturated alcohols having chain lengths from 10 to 14 carbons. Viruses having different membrane structure showed different susceptibilities to alcohols having different chain lengths and structural features. Decanol, dodecanol, and tetradecanol readily inactivated herpes simplex virus and the enveloped bacterial virus phi6. The lipid-containing virus PM2 was susceptible to decanol and dodecanol but comparatively unsusceptible to tetradecanol. The branched-chain alcohol phytol, a naturally occurring component of chlorophyll, was active against phi6 and herpes simplex virus but not against PM2. Polyoma virus and the bacteriophage phi23-1-a, which do not contain lipids, were not susceptible to inactivation by any of the alcohols tested. Experiments were also carried out to determine the effects of these compounds on cells. At 0.5 mM, decanol lysed human embryonic lung cells, erythrocytes, and the bacterial hosts for phi6 and PM2. Dodecanol, tetradecanol, and phytol at this concentration were less damaging to cells. At 0.05 mM, none of the alcohols caused observable cytopathic effects on human embryonic lung cells, although several of the alcohols at this concentration were active against herpes simplex virus. Our findings suggest that dodecanol, tetradecanol, and phytol may warrant further studies as potential antiviral agents, particularly for topical application to virus-infected areas of the skin.

Inactivation of the lipid-containing bacteriophage PM2 by butylate hydroxytoluene

Several factors have been investigated which are of significance in the inactivation of PM2, a lipid-containing bacterial virus, by butylated hydroxytoluene (BHT). Studies of the time dependence of inactivation during exposure to BHT showed that virus killing occurs rapidly, with the majority of the effect taking place in the first 5 min. The degree of inactivation is dependent upon the initial virus titer, the solvent from which BHT is added, and the presence of a variety of protective agents, including surfactants, bovine serum albumin, and bacterial cells. Sucrose gradient analysis of (32)P-labeled, BHT-treated virus was used to determine the degree to which the virion is disrupted by BHT. These experiments show that the (32)P-labeled molecules are converted into very slowly sedimentable material by BHT treatment, indicating complete destruction of the virus particle.