Effect of hypertonic saline solution and dextran on ventricular blood flow and heart-lung interaction after hemorrhagic shock

BACKGROUND: Hypertonic saline solutions may have beneficial hemodynamic effects in the resuscitation of hemorrhagic shock. The effects on cardiac function and potential interaction with lung function are controversial and served as the basis for this study. METHODS: Domestic swine were resuscitated from hemorrhagic shock with equivalent sodium loads of lactated Ringer's solution (LR) or 7.5% NaCl plus 10% dextran (HSD). Hemodynamic data were obtained at baseline, shock, and after resuscitation. Right ventricular ejection fraction and left ventricular change in pressure with respect to time (dP/dt) were used to index contractility. Regional myocardial blood flow was determined with microspheres. Lung water was determined gravimetrically. RESULTS: There were no differences in the ability to restore hemodynamic parameters with equivalent sodium loads of LR and HSD resuscitation. Right ventricular ejection fraction and left ventricular change in pressure with respect to time were only transiently affected by shock and resuscitation. Regional myocardial blood flow was increased above baseline values after HSD. The total resuscitation volumes were 1958 +/- 750 mL and 140 +/- 31 mL with LR and HSD, respectively. CONCLUSIONS: Although LR and HSD were equally effective in the early resuscitation of hemorrhagic shock, this occurred at the expense of significantly greater volume requirements for resuscitation with LR. This may contribute to cardiac dysfunction in this setting. Enhanced regional myocardial blood flow after HSD resuscitation may be beneficial against ongoing myocardial stress.     

Prolonged pregnancy. Labor induction versus intensified monitoring]

This study was made in order to evaluate the effect of a policy of induction of labour at 42 weeks of gestation in post-term pregnancies. A group of 139 women with uncomplicated post-term pregnancies, who gave birth at the maternity ward at Herlev Hospital in 1993 was compared to a group of 145 women, who gave birth in 1996 at the same location. In 1993 spontaneous labour was awaited with twice weekly surveillance tests, and labour was only induced if there was evidence of foetal or maternal compromise, while in 1996 labour was induced at 42 weeks of gestation. There were at 20.1% inductions of labour in 1993 compared to 44.8% in 1996. The perinatal morbidity and birth complication rates were similar in the two groups.     

Effect of hypotension preceding death on the function of lungs from donors with nonbeating hearts

BACKGROUND: A shortage of suitable brain-dead donors continues to severely limit lung transplantation. Use of donors with nonbeating hearts has been suggested as a solution. Lungs are unique, in that aerobic metabolism can continue in the absence of blood circulation because oxygen is present in airways and alveoli. Animal studies have shown reasonable cadaveric graft function up to several hours after sudden death by drug administration. However, hemodynamic instability before death may worsen lung function through activation and pulmonary sequestration of neutrophils and release of inflammatory mediators. Because many potential cadaveric donors experience hypotension before death, this study was undertaken to assess the effect of hypotensive shock on cadaveric lung viability. METHODS: A rat isolated lung reperfusion model was used to assess pulmonary function over 3 hours of reperfusion or until gross pulmonary edema developed. Twenty-five rats were randomly allocated to the following study groups, which were based on status before lung harvest: (1) control: no interventions; (2) hypotensive: 1 hour of hypotension by exsanguination to a mean blood pressure of 30 to 40 mm Hg; (3) cadaver: death by cervical dislocation followed by 3 hours of in situ lung ischemia; (4) hypotensive + 3 hours cadaver: 1 hour of hemorrhagic shock, followed by death and 3 hours of in situ ischemia; (5) hypotensive + 2 hours cadaver: similar to group 4, except the in situ ischemia was abbreviated to 2 hours. RESULTS: No significant differences were found among group 1, 2, or 3 lungs with regard to wet to dry weight ratios, gas exchange, and pulmonary arterial or airway pressures. However, all group 4 lungs became grossly hemorrhagic and developed severe pulmonary edema within 10 minutes of reperfusion. Group 5 lungs fared only marginally better, with two of five lungs tolerating 3 hours of reperfusion. CONCLUSIONS: A period of hypotension before death severely impairs cadaveric lung viability.     

Looking toward the twenty-first century. The role of nursing research in care of children and families affected by HIV

Although there has been extensive research concerning pediatric infection and disease, most of this work has focused on medical and basic science issues. Additional research is needed to provide an empirical basis for nursing interventions. Nursing research can also contribute to the development of health care delivery systems and public policy decisions. This article provides an overview of research related to nursing management of children and families affected by HIV infection. It discusses strategies and considerations for conducting research as well as implications for future needs.     

Dental team''s role in tobacco cessation

In rat experiments new imidazoline derivatives caused a pain-relieving effect and inhibited a rise in arterial pressure in pain. Fluoride derivatives of imidazoline in doses of 1, 2, and 4 mg/kg induced long-term analgesia, had no effect on the background arterial blood pressure (AP), and significantly reduced its nociceptive pressor responses. The bromide derivatives of imidazoline showed no noticeable pain-relieving activity but reduced the nociceptive AP shifts. The background AP parameters did not change in this case. The prospects of directed chemical modification of imidazoline derivatives to obtain new analgesics capable of reducing the undesirable hemodynamic manifestations of pain are discussed.     

Effects of calcitonin and parathyroid hormone on calcification of primary cultures of chicken growth plate chondrocytes

Few studies have been directed toward elucidating the action of calcitonin (CT) and parathyroid hormone (PTH) on growth plate chondrocytes, cells directly involved in longitudinal bone growth and provisional calcification. In this study, primary cultures of avian growth plate chondrocytes that calcify without the supplement of beta-glycerophosphate were used to investigate the effects of synthetic human CT and 1-34 bovine PTH on (1) cell division and growth; (2) the deposition of Ca2+ and inorganic phosphate (Pi); (3) the activity of alkaline phosphatase (AP), an enzyme long associated with the mineralization process; (4) the levels of proteoglycans; and (5) the synthesis of collagens. Added continually to preconfluent cultures from day 6 until harvest, CT (1-30 nM) and PTH (0.1-1.0 nM) increased mineral deposition; the maximal increase was seen between days 18-21 at 10 nM CT (175-260%) and 0.5 nM PTH (approximately 170-280%), both p < 0.001. CT had no significant effect on cellular protein, or AP-specific activity, whereas PTH increased cellular protein, DNA, proteoglycan, and collagen content of the cultures in a dosage-dependent manner. AP activity and levels of Type II and X collagens and fibronectin in the culture medium showed a biphasic response to PTH; maximal increases were seen at 0.5 nM between days 15-18. Longer exposure (days 21-27) to PTH at higher levels (5-10 nM) caused a marked decreased in AP activity but a lesser decrease in the collagens. These results indicate that CT and PTH can act directly on chondrocytes to stimulate mineralization, but that PTH specifically stimulated cell division and synthesis of cellular and extracellular proteins by growth plate chondrocytes. The implications of these findings with regard to Ca2+ homeostasis and bone formation are discussed.