Attitudes to children's pain: exploding the 'pain myth'

Previous research has identified healthcare professionals' belief in myths about children's experience of pain as a cause of inadequate pain treatment. In this study, 47 doctors and 36 nurses involved in paediatric care completed a detailed questionnaire on 'pain myths'. The findings indicate a more informed awareness among healthcare professionals regarding childhood pain than previously suggested and that unconditional belief in 'pain myths' is not widespread.

Holding children still for procedures

The attitudes and concerns of 394 paediatric nurses about the practice of restraining children during clinical procedure were surveyed. The majority believed that restraint rather than pain was the most likely cause of distress. Age of the child, degree of urgency and type of procedure were all relevant to the decision whether to hold the child still. Nurses were unsure about the legal position and the majority reported that they had no formal training in holding techniques. These findings indicate the need for more training and guidelines about when to hold children and for the legal position to be clarified.

Mental health. Back from the brink

Mental healthcare in Wolverhampton had sunk to such depths that two years ago the purchasing authority was openly discussing commissioning its services from another town. Today the situation is transformed. David Jolley and colleagues explain how such marked progress was achieved.

Potent antitumour activity of a new class of tumour-specific killer cells

Two approaches to the antibody-directed targeting of toxic or cytolytic activity and augmentation of cellular immune responses have been explored for tumour immunotherapy, but so far success has been limited. Obstacles facing immunotherapy are the limited accessibility of antibodies or antibody conjugates to solid tumours and the difficulty in obtaining tumour-specific cytotoxic lymphocytes. Here we generate a new class of tumour-specific killer cells by genetically modifying lymphocytes to produce and secrete a targeted toxin against an oncoprotein overexpressed on breast and other tumour cells. The transduced lymphocytes were shown to have potent and selective cytotoxicity to tumours in culture and nude mouse models. The potent in vivo antitumour activity is probably a result of the migration of the lymphocytes to tumours as a targeted toxin carrier, and production and accumulation of the targeted toxins inside tumours as a producer. Our approach, which has features of both antibody-directed and cell-mediated immunotherapy, may have application in a gene therapy context.

Endothelial "stunning" following a brief exposure to endotoxin: a mechanism to link infection and infarction?

BACKGROUND

There is an association between infection, inflammation and acute cardiovascular events. In an attempt to explore the mechanism of this association we have developed a model to examine the effects on endothelial function of a brief exposure to endotoxin.

METHODS AND RESULTS

Endotoxin was instilled into isolated superficial hand veins of healthy volunteers. The vein was isolated by means of two wedges and endotoxin instilled into the isolated segment. After 1 h the contents of the vein were aspirated and the wedges removed. Dose-response curves to bradykinin (a stimulator of nitric oxide synthesis), arachidonic acid (the precursor of prostanoid production) and GTN (a nitric oxide donor) were constructed before and 1 h after endotoxin. Endotoxin caused a glucocorticoid-inhibitable attenuation in the dose-response curves to bradykinin and arachidonic acid (P < 0.05). This effect persisted for 48 h and took 7 days to recover. Exposure of saphenous vein to endotoxin in vitro also caused selective impairment of endothelium-dependent relaxation (P < 0.05) yet microscopy of the vessels exposed to endotoxin showed no endothelial denudation or structural damage.

CONCLUSION

The results demonstrate that a brief local exposure to endotoxin caused endothelial dysfunction that persists for 48 h and takes up to 7 days to recover. The endothelial dysfunction is not due to expression of the inducible isoform of nitric oxide synthase and persists for far longer than the effects of endotoxin on vascular smooth muscle function. We have coined the term endothelial "stunning" to describe the transient endothelial dysfunction and suggest it might provide a mechanism underpinning the association between infection or inflammation and increased cardiovascular risk. Endothelial stunning appears to provide a novel, transient, variable and modifiable potential cardiovascular risk factor.

Local venous responses to endotoxin in humans

BACKGROUND

Septic shock is characterized by arterial and venous dilatation and decreased responsiveness to vasoconstrictors. We have developed a method to explore the effects and mechanisms of action of administration of endotoxin into a blood vessel in vivo.

METHODS AND RESULTS

Endotoxin was instilled into a dorsal hand vein for 1 hour and then removed. A dose-response curve to norepinephrine was constructed before and 1, 2, 3, and 4 hours after endotoxin. In a separate study, dose-response curves to norepinephrine were constructed in two separate veins on the same hand, only one of which received endotoxin. Sympathetic-mediated venoconstrictor responses were also studied. Cyclooxygenase inhibitors, nitric oxide synthase inhibitors, and hydrocortisone were used to explore the mechanisms of the effects seen. Endotoxin caused a rightward shift in the dose-response curve to norepinephrine. The effect was greatest at 1 hour (maximal constriction: before endotoxin, 87 +/- 4%; after endotoxin, 52 +/- 8%; occlusion n = 4; P < .05) and returned to normal by 4 hours. In addition, deep-breath venoconstrictor responses were abolished in the endotoxin-treated vein. Instillation of endotoxin daily for 3 days resulted in the development of tolerance (maximal constriction to norepinephrine after endotoxin; day 1, 39 +/- 6%; day 2, 67 +/- 7%; day 3, 85 +/- 7%). Cyclooxygenase and/or nitric oxide synthase inhibitors did not alter the response to endotoxin, whereas prior administration of hydrocortisone abolished the effects.

CONCLUSIONS

Instillation of endotoxin caused a glucocorticoid-inhibitable hyporesponsiveness to the constrictor effects of norepinephrine and abolished sympathetically induced and drug-induced venoconstriction. This acute response does not appear to be mediated by nitric oxide or prostanoids. Direct vascular tolerance to endotoxin occurs on repeated administration.

Characterization of hepatic nitric oxide synthase: identification as the cytokine-inducible form primarily regulated by oxidants

Induction of hepatic nitric oxide synthase (NOS) by tumor necrosis factor-alpha (TNF alpha), interleukin-1 beta (IL-1 beta), interferon-gamma (IFN gamma), interleukin-6 (IL-6), and lipopolysaccharide was assessed as activity and immunoreactive protein. Hepatic NOS activity was cytosolic and had cofactor requirements consistent with inducible nitric oxide synthase (NOS2). NOS induction by TNF alpha was dose dependent from concentrations of 0.06 to 60 nM and was increased 2-3-fold by IFN gamma. NOS induction was reflective of total TNF alpha binding to hepatocyte receptors. Hepatocyte TNF alpha binding fit a biphasic curve with high affinity (K(d) = 1.4 nM, Bmax = 3157 sites) and low affinity (K(d) = 157 nM, Bmax = 204,948 sites) elements. NOS2 activity was induced by lipopolysaccharide, IL-1 beta, TNF alpha, and IFN gamma but not by IL-6. All cytokine stimuli were inhibited by antioxidants. Oxygen radical generation was directly measured as dichlorofluoroscein fluorescence in isolated mitochondria. Mitochondria from TNF alpha-treated hepatocytes generated more oxygen radicals than did controls. Antioxidants reduced mitochondrial generation of oxygen radicals. Activation of the transcription factor nuclear factor-kappa B by TNF alpha, IFN gamma, and IL-1 beta was assessed by gel shift analysis. Cytokine treatment increased nuclear factor-kappa B binding, and the addition of antioxidants or rotenone inhibited cytokine activation. Taken together, these data suggest that oxygen radicals, possibly generated by mitochondria, play a major role in NOS2 induction by cytokines.

Distress and radiological investigations of the urinary tract in children

The distress associated with radiological investigations may be related to the information and style of parental explanation given to the child and the parents own coping style. In a questionnaire survey we assessed distress in relation to investigations of the urinary tract using the Groningen Distress Rating Scale and the Utrecht Coping List. We found the micturating cystourethrogram (MCUG) to be significantly more distressing than radionuclide investigations. MCUG distress was adversely correlated with passive and palliative parental coping styles. Results suggested that cognitive coping styles modelled by the parents ameliorated distress on dimercaptosuccinic acid scintigraphy.

CONCLUSION

The high level of MCUG associated distress and presence of traumatised children in the MCUG sample, along with the potential for parental contribution to distress reduction, suggests that both children and parents would benefit from more active preparation programmes prior to MCUG testing.

Gastric intramural pH in mechanically ventilated patients

BACKGROUND

The hypothesis that gastric intramural pH (pHi) is predictive of outcome in haemodynamically stable, mechanically ventilated patients was tested in 25 patients on assisted mechanical ventilation for respiratory failure.

METHODS

Simultaneous samples of arterial blood and gastric juice were obtained from patients on assist control, synchronised intermittent and pressure control ventilation during the first 48 hours of mechanical ventilation. Gastric pHi was calculated from the equation: pHi= 6.1 + log HCO3/(gastric PCO2 X 0.03). The outcome was survival or death due to respiratory or circulatory failure within 45 days of admission.

RESULTS

Gastric pHi proved to be a better predictor of outcome than all presently utilised parameters. Although all patients included in this study were haemodynamically stable and were similar for all laboratory indices, the only variable capable of accurately predicting outcome was gastric pHi. Patients with a normal arterial pH but a gastric intramural pH of less than 7.25 had an observed mortality of 66%. Standard severity of illness scores grossly underestimated mortality rates. The sensitivity and specificity of a gastric pHi value of less than 7.25 in predicting death were 86% and 83%, respectively. A receiver operator curve for all variables exaggerates the superiority of gastric pHi as a predictor of outcome.

CONCLUSION

Low gastric pHi, a marker of gastrointestinal ischaemia, may occur in the presence of normal haemodynamics and may be used to predict severity of illness and mortality accurately.

Isolated reduction in single-breath diffusion capacity in young, healthy, asymptomatic women

The clinical significance of an isolated reduction in the carbon monoxide diffusing capacity (DLCO) in nonsmoking, asymptomatic individuals is not known. Whether a reduced DLCO despite otherwise normal pulmonary function tests warrants further investigation remains unanswered. In this article, the authors describe five healthy, asymptomatic, young women who had isolated, reduced DLCO and subsequent follow-up examinations over a span of 6 years. This case series lends support to the contention that an isolated low DLCO in asymptomatic subjects is not clinically significant and does not necessitate additional medical inquiry.

Vasodilatation to arachidonic acid in humans. An insight into endogenous prostanoids and effects of aspirin

BACKGROUND

Human endothelial and vascular smooth muscle cells synthesize prostanoids. Several of these have been implicated in the physiological and pathophysiological regulation of vascular tone; however, there is no direct evidence that human blood vessels synthesize sufficient prostanoid to alter vessel tone.

METHODS AND RESULTS

We explored the effects of local infusions of arachidonic acid on the tone of preconstricted superficial hand veins in healthy volunteers. Aspirin was used to assess the contribution of prostanoids to the responses seen. Local infusion of arachidonic acid produced a dose-dependent dilatation of preconstricted veins. This was abolished by local infusion of aspirin. Oral aspirin was also effective: a high (anti-inflammatory) dose of aspirin (1 g) taken 2 hours before the experiment blocked the arachidonic acid-induced venodilatation; however, a low (cardioprotective) dose of aspirin (75 mg) did not. Unlike the responses to arachidonic acid, responses to glyceryltrinitrate and bradykinin were unaltered by aspirin (1 g). Ex vivo platelet aggregation was inhibited by aspirin in both high and low doses. Aspirin (1 g) inhibited arachidonic acid-induced venodilatation for up to 5 days. The time course was similar for vascular and platelet effects.

CONCLUSIONS

The present findings demonstrate that local generation of prostanoids in a human vessel in vivo alters vascular tone. The predominant prostanoid synthesized is a dilator and its synthesis can be blocked by an anti-inflammatory but not a cardioprotective dose of aspirin. The results suggest that selective inhibition of platelet aggregation by oral aspirin might be a function of dose rather than the interval between doses.