Norepinephrine causes a pressure‐dependent plasma volume decrease in clinical vasodilatory shock

Background: Recent experimental studies have shown that a norepinephrine‐induced increase in blood pressure induces a loss of plasma volume, particularly under increased microvascular permeability. We studied the effects of norepinephrine‐induced variations in the mean arterial pressure (MAP) on plasma volume changes and systemic haemodynamics in patients with vasodilatory shock. Methods: Twenty‐one mechanically ventilated patients who required norepinephrine to maintain MAP ≥70 mmHg because of septic/postcardiotomy vasodilatory shock were included. The norepinephrine dose was randomly titrated to target MAPs of 60, 75 and 90 mmHg. At each target MAP, data on systemic haemodynamics, haematocrit, arterial and mixed venous oxygen content and urine flow urine were measured. Changes in the plasma volume were calculated as 100 × (Hct_pre/Hct_post?1)/ (1?Hct_pre), where Hct_pre and Hct_post are haematocrits before and after intervention. Results: Norepinephrine doses to obtain target MAPs of 60, 75 and 90 mmHg were 0.20±0.18, 0.29±0.18 and 0.42±0.31 μg/kg/min, respectively. From 60 to 90 mmHg, increases in the cardiac index (15%), systemic oxygen delivery index (25%), central venous pressure (CVP) (20%) and pulmonary artery occlusion pressure (33%) were seen, while the intrapulmonary shunt fraction was unaffected by norepinehrine. Plasma volume decreased by 6.5% and 9.4% (P<0.0001) when blood pressure was increased from 60 to 75 and 90 mmHg, respectively. MAP (P<0.02) independently predicted the decrease in plasma volume with norepinephrine but not CVP (P=0.19), cardiac index (P=0.73), norepinephrine dose (P=0.58) or urine flow (P=0.64). Conclusions: Norepinephrine causes a pressure‐dependent decrease in the plasma volume in patients with vasodilatory shock most likely caused by transcapillary fluid extravasation.     

Intrarenal detection of nitric oxide using electron spin resonance spectroscopy in hypertensive lipopolysaccharide-treated rats

The inhibition of nitric oxide (NO) synthesis by chronic administration of NG-nitro-l-arginine methyl ester (l-NAME) in rats is responsible for systemic hypertension. However, the mechanisms involved in this hypertension remain unclear. The effects of chronic l-NAME on kidney and blood NO production were studied in rats in a state of endotoxic shock due to lipopolysaccharide (LPS). A nitric oxide spin trapping technique using electron spin resonance (ESR) spectroscopy has been used to identify and measure the production of NO in the kidney. This method is based on the trapping of nitric oxide by a metal-chelator complex consisting of N-methyl-d-glucamine dithiocarbamate (MGD) and reduced iron (Fe2+) forming a water-soluble NO-FeMGD complex detected by ESR. After LPS injection (14 mg/kg, IV, 6 h before the sacrifice) to rats pretreated with l-NAME (10 mg/kg/d over 14 days), the NO-FeMGD complex was evaluated in the kidney (arbitrary units [AU]/g of kidney) and the density of polynuclear neutrophils was counted by light microscopy. Chronic inhibition of NO synthase by l-NAME, a nonspecific inhibitor, was responsible for a decrease of the NO-FeMGD complex levels in the kidney (24.9 +/- 1.6 AU versus 13.8 +/- 1.3 AU). LPS administration was responsible for a large increase in both NO-FeMGD complex and neutrophil levels in the kidney of normotensive rats (332.6 +/- 12.8 AU versus 24.9 +/- 1.6 AU for NO-FeMGD complex and 1.36 +/- 0.41 versus 0.11 +/- 0.03 for neutrophils). Conversely, LPS administration in hypertensive, l-NAME-pretreated rats was linked to a smaller increase in the NO-FeMGD complex (85.1 +/- 7.9 AU versus 332.6 +/- 12.8 AU) and a larger increase in glomerular neutrophils (2.48 +/- 0.36 versus 1.36 +/- 0.41) compared with normotensive rats. These results are in agreement with a direct implication of NO during LPS-and l-NAME-induced kidney injuries.     

Skin testing to evaluate oculo-respiratory syndrome (ORS) associated with influenza vaccination during the 2000-2001 season

A syndrome of red eyes and respiratory symptoms was noted following receipt of influenza vaccine in Canada during the 2000-2001 influenza season. We conducted intra-dermal skin testing to determine if oculo-respiratory syndrome (ORS) was related to failure of the splitting process during vaccine manufacturing, if it was associated with a particular viral strain and to identify individuals at risk for subsequent ORS reaction. Skin testing with minute quantities of vaccine antigen induced ORS symptoms at a higher rate amongst persons previously affected by this syndrome compared to previously unaffected persons. Skin test reaction size or quality could not identify persons at risk of ORS. Skin testing could not identify a specific strain or the stage in the manufacturing process during which the trigger may have been introduced.     

An analysis of the accessibility of video lottery terminals: the case of Montréal

Background  

Researchers and public health officials in Canada, the United States and Australia have for some time noted broader geographic accessibility to gambling establishments, above all in socioeconomically underprivileged communities. This increase in availability could lead to more and more gambling problems. This article focuses, in an ecological perspective, in particular on a spatial analysis of the geographic accessibility of sites possessing a VLT permit in the Montréal area, i.e. Montréal Island, the South Shore and Laval, from the standpoint of the development of an indicator of the vulnerability (socioeconomic components and demographic components) to gambling of populations at the level of certain neighbourhood units (dissemination areas). With the recent development of geographic information systems (GIS), it is now possible to ascertain accessibility to services much more accurately, for example by taking into account the configuration of the road network.     

Immunoautoradiographic determination of β1−G-globulin in the blood serum of patients with trophoblastic tumors

The results of determination of _1–G-globulin by immunoautoradiographic (IAR) and immunodiffusion (ID) methods in the blood serum of patients with trophoblastic tumors are compared. When negative results were obtained by the ID method, _1–G-globulin was found by means of the IAR method in seven of eight tests in chorionepithelioma of the uterus before treatment and in seven of 21 tests of the blood serum from patients of the same group after treatment. In the early stages of development of chorionepithelioma of the uterus (the state after hydatidiform mole, malignant hydatidiform mole) _1–G-globulin was found by the IAR method 4.5 times more frequently than by the ID method. This globulin was also found by the IAR method in testicular teratoblastoma with elements of chorionepithelioma. No -globulin could be found by the IAR method in the blood serum of other oncologic patients or donors.Department of Biochemistry, Problem Laboratory for Immunochemistry of Malignant and Embryonic Tissues, N. I. Pirogov Second Moscow Medical Institute. Laboratory of Immunochemistry of Tumors, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR. Institute of Experimental and Clinical Oncology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Kraevskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 80, No. 9, pp. 86–89, September, 1975.     

Managing disruptive behaviors with neuroleptics: treatment options for older adults in nursing homes

Disruptive behaviors are frequent among elderly individuals in long-term care centers. Neuroleptics remain the most common pharmacological treatment for controlling these challenging behavioral manifestations. However, their effectiveness is a subject of controversy and it is unclear what specific behaviors are more likely to be managed with neuroleptic medications. The objective of this study was to identify the types of disruptive behaviors for which neuroleptics are given to elderly individuals in long-term care facilities and determine if the frequency of these behaviors increases the risk of being prescribed neuroleptics. A cross-sectional study was conducted with 2,332 participants ages 65 or older living in 28 long-term care facilities. Among them, 27.8% had taken at least one neuroleptic drug in the prior week. The administration of neuroleptics was not linked to the presence of any one specific disruptive behavior. However, a significant finding was that the greater the frequency of disruptive behavior exhibited by an elderly individual, the greater the risk of them being administered a neuroleptic medication. A multi-dimensional approach to the assessment of disruptive behaviors is recommended to facilitate the identification of the underlying causes of those behaviors. Accordingly, it is suggested that non-pharmacological treatment plans be adapted to each situation and then implemented to potentially reduce the use of neuroleptics.