Nosocomial vs community-acquired pandemic influenza A (H1N1) 2009: a nested case-control study.

BACKGROUND: The characteristics of nosocomial influenza in children are not well described. AIM: To compare the characteristics of nosocomial and community-acquired pandemic influenza A (H1N1) 2009 (pH1N1) in Australian children. METHODS: In a nested case-control study, the clinical and epidemiological features of nosocomial vs community-acquired pH1N1 were compared among hospitalized children aged <15 years in six paediatric hospitals in Australia between 1 June and 30 September 2009. FINDINGS: Of 506 hospitalized children with pH1N1, 47 (9.3%) were of nosocomial origin. These 47 cases were compared with 141 gender- and age-matched controls. Cases had a significantly higher proportion of underlying medical conditions compared with controls (81% vs 42%, P < 0.001), and were more likely to be exposed to household smokers (36% vs 20%, P = 0.02). Fewer children with nosocomial influenza presented with classical symptoms of influenza, including subjective fever and lethargy. A higher proportion of children with nosocomial influenza received treatment with oseltamivir (77% vs 43%, P < 0.001), and they required a longer stay in hospital following the onset of influenza (mean 8.5 days vs 4.5 days, P = 0.006). Three children (2%) in the community-acquired group died of pH1N1, but there were no deaths in the nosocomial group. CONCLUSION: This study shows that children with pre-existing diseases and those who are exposed to household smokers are more susceptible to nosocomial pH1N1. They may have 'occult presentation' of influenza, but their course of illness is not markedly different from that of children with community-acquired influenza.

Rare childhood diseases: how should we respond?

Paradoxically, rare diseases are common, collectively affecting 6-10% of the population and have a huge impact on patients and families, health services, clinicians and the wider community. Accurate data are required to inform clinical practice, government policy and health service planning. We recommend a national approach, similar to that adopted in the USA and Europe, to support research and promote advocacy and equitable access to services for children with rare diseases.

Beyond counting cases: public health impacts of national Paediatric Surveillance Units.

Paediatric Surveillance Units (PSUs) have been established in 14 countries and facilitate national, prospective, active surveillance for a range of conditions, with monthly reporting by child health specialists. The International Network of Paediatric Surveillance Units (INoPSU) was established in 1998 and facilitates international collaboration among member PSUs and allows for sharing of resources, simultaneous data collection and hence comparison of data from different geographical regions. The impact of data collected by PSUs, both individually and collectively as members of INoPSU, on public health outcomes, clinical care and research is described.

Patients with dementia and their carers in general practice.

In 2004, 6.5% of Australians over 65 years of age were estimated to have dementia and the prevalence of dementia is rising as a result of our aging population. There is evidence to show that carer wellbeing is important for the wellbeing of the patient. Increasing burden of care may lead to depression, anxiety, and more frequent physical illness in the carer, and earlier institutionalisation of patients. The general practitioner's role includes recognising early dementia, undertaking assessments to confirm the diagnosis, managing the disease, health promotion and support for both patient and carer, and follow up. We initiated a project to explore the extent to which GPs currently fulfill this role for patients with dementia still living in the community (rather than in hostels or nursing homes).

A review of cerebral vasospasm. Part IV. Post-traumatic vasospasm.

Cerebral vasospasm is increasingly recognized as contributing to ischaemia after head injury. The reported incidence of post-traumatic vasospasm (PTV) varies between 10% and 90%, probably largely because of differences in patient selection, in definitions of vasospasm and in methods of detecting spasm. In severe head injury, based on studies with similar criteria, the incidence is approximately 40%. PTV is often associated with traumatic subarachnoid haemorrhage (tSAH), but has been reported without tSAH. These two factors are independently associated with poor outcome, but the direct links between tSAH, vasospasm and outcome are uncertain. There is evidence that calcium antagonists improve outcome in patients with head injury and tSAH; aminosteroids may also be effective here. Other strategies such as maintaining normocapnia and control of blood volume and pressure may also be useful. Further investigation of large cohorts is required to clarify fully the significance of PTV, its relationship with tSAH and outcome and possible treatment modalities.

[Evaluation of treatment outcome in patients after extremely severe head injury (GCS 3-4)]. / Ocena wyników leczenia pacjentów ze szczególnie ciezkimi urazami czaszkowo-mózgowymi (GCS 3-4).

Advances in the diagnosis and treatment of severe head injured patients (GCS < = 8) have led to major improvement in outcome, but have not eliminated high mortality rates, which range between 38 and 80% as reported in the literature. The aim of this study was to evaluate the outcome of patients with GCS 3 and 4 and to evaluate the role of early and late hypotension (systolic blood pressure SBP < 90 mmHg) in outcome. Sixty two patients with severe head injury were divided into two groups. In Group I-22 patients with GCS 3-4, and in Group II-40 patients with GCS 5-8. There was no significant difference between mortality (p = 0.5), poor outcome (p = 0.36), and the very best outcome in the groups (p = 0.06). There was a statistically significant difference in death rate (p = 0.0012), when hypotension was present at the scene. Our data suggest that patients with extremely severe head injury do not necessarily have a worse outcome, if prompt diagnosis and appropriate aggressive treatment is implemented.

The importance of traumatic subarachnoid haemorrhage.

Post-traumatic cerebral vasospasm is being increasingly recognised as a possibly significant complication after head injury. To assess the relationship between post-traumatic subarachnoid haemorrhage (tSAH) and post-traumatic vasospasm, 63 patients with severe head injury (GCS 3-8) were studied. Forty-seven patients had cerebral contusion on the initial CT scan. In 25 of these (Group I) there were only contusions, while 22 (Group II) also had tSAH. All patients had daily measurements of blood flow velocity in the basal cerebral arteries using transcranial Doppler ultrasound (TCD). The incidence of vasospasm detected by TCD was significantly higher in Group II. Furthermore there were significantly fewer good outcomes (GOS 1 and 2) in this group. These results suggest that the presence of subarachnoid blood in patients with severe head injury is associated with a risk of vasospasm, and with poorer outcome.

Incidence and effects of increased cerebral blood flow velocity after severe head injury: a transcranial Doppler ultrasound study I. Prediction of post-traumatic vasospasm and hyperemia.

Cerebral blood flow velocity was monitored in 50 patients with severe head injury (GCS 8 or less) within 24 h of injury and at least once daily thereafter, using transcranial Doppler ultrasonography (TCD). Delayed post-traumatic vasospasm occurred in 20, and cerebral hyperemia in another 15. Doppler velocities were higher in vasospasm, which also lasted significantly longer than hyperemia. The presence of visible blood on an early CT scan was of some value in predicting vasospasm only (accuracy 59%). Xenon-133 cerebral blood flow (CBF) was also measured within 24 h of injury. An abnormal early cerebral blood flow level, either above or below a narrow central range, was more effective than CT in predicting vasospasm or hyperemia (accuracy 80%), while the combination of an abnormal blood flow and hemorrhagic findings on CT scan helped to determine which of these would occur later. Patients with an abnormal early cerebral blood flow and hemorrhagic findings on CT were more likely to develop vasospasm--accuracy for prediction of vasospasm 73%. This distinction may be of great importance, since these different groups of patients may well need different management.

Incidence and effects of increased cerebral blood flow velocity after severe head injury: a transcranial Doppler ultrasound study II. Effect of vasospasm and hyperemia on outcome.

Cerebral blood flow velocities were measured in 50 severely head injured (Glasgow Coma Scale (GCS) 8 or less) patients using transcranial Doppler ultrasonography (TCD). Abnormally high TCD velocities were recorded in 35 patients; in 20 this was deemed to be due to vasospasm and in the other 15 to hyperemia. Patients who developed hyperemia also had the highest intracranial pressure (ICP) and the lowest cerebral perfusion pressure (CPP) of the three groups. Outcome was assessed at six months after injury using the Glasgow outcome scale and the disability rating scale. In the normal velocity group 87% of patients had a good outcome, compared with 47% of those with hyperemia and 40% of those with vasospasm. The highest velocity (HVEL), GCS, age, ICP and CPP were entered into a logistic regression analysis. HVEL, age and CPP were found to be the most significant predictors of outcome (chi 2 = 29.5; p < 0.0001). These factors predicted outcome with 82% accuracy, 86% sensitivity and 76% specificity. Routine monitoring of TCD velocity may be useful in detecting hyperemia and vasospasm after severe head injury, allowing appropriate treatment to be started as early as possible.

Regional differentiation of cortical activity in schizophrenia: a complementary approach to conventional analysis of regional cerebral blood flow.

This study examines an alternative to a narrow locus-of-dysfunction cortical pathophysiology in schizophrenia, which in turn suggests a modified approach to the analysis of data from regional cerebral blood flow studies. The results provide qualified support for a model of impaired differentiation of cortical activity in schizophrenia. As an index of the differentiation of cortical fields, regional gradients of cortical blood flow were examined. Medicated patients (n = 15) failed to show the differentiation of networks in frontal areas during a verbal memory recognition task observed in normal comparison subjects (n = 15). Unmedicated patients (n = 15) at rest tended to lose normal lateralization and had increased gradients in the right frontal area compared with normal comparison subjects.

A survey of personal and professional attitudes of intensivists to organ donation and transplantation.

A questionnaire survey was carried out to examine the attitudes and practices of Australian and New Zealand intensivists with regard to brain death and organ donation. A return rate of 82.5% was achieved. Fifty-eight per cent had written evidence of their own wishes to donate organs and 94% would agree to donation from a dependent. At least one intensivist is involved in certifying brain death on 95% of occasions. Intensivists are involved in the request for organ donation over 90% of the time although one-third do not believe that it is their role to request organ donation. Although two-thirds believe that the family should always be approached for organ donation, another 52 out of 254 indicated that it was their (the intensivist's) role to decide if families should be asked for organ donation. Possible reasons for not requesting are language or other communication problems, perceptions of cultural differences and degrees of family distress. Twenty per cent of respondents do not provide haemodynamic support before brain death confirmation. Australian and New Zealand intensivists overwhelmingly support the concept of brain death, current methods of confirmation of brain death, organ donation and transplantation. Possible reasons behind loss of potential donors include decisions not to resuscitate both before and after brain death is confirmed. Perceptions of family grief and cultural differences clearly inhibit requests for organ donation. A very few units have an effective policy on approaching families about organ donation. Intensivists have almost exclusive control over requests for organ donation and thus bear a full professional responsibility for this element of hospital practice.

The significance of traumatic intraventricular haemorrhage in severe head injury.

Since the advent of computed tomography (CT) traumatic intraventricular haemorrhage (IVH) has been diagnosed more often. It has reportedly been associated with a poor prognosis, but pure or solitary IVH is rare, suggesting that other lesions occurring concurrently with it may contribute to the poor outcome. In a series of 65 patients with severe head injury (GCS < or = 8), 14 (22%) had IVH on initial CT. Death rate in these 14 was 21%, not significantly different from that in patients without IVH (14%), although a significantly higher proportion of patients without IVH had a good outcome. These results suggest that mortality is related to other lesions associated with IVH rather than to IVH alone and that the presence of IVH does not necessarily lead to a poor outcome.

Transcranial Doppler ultrasound in brain death: experience in 140 patients.

The interpretation of clinical tests for brain death is often complicated by the presence of facial trauma, or the use of barbiturate therapy for reduction of intracranial pressure. We propose a non-invasive technique--transcranial Doppler (TCD) sonography for the diagnosis of brain death. One hundred and forty comatose patients, 111 of whom were believed to be brain dead underwent TCD examinations. TCD assessments of the middle cerebral arteries (MCAs) and the basilar artery were performed before formal clinical testing for brain death. The TCD spectra recorded in the brain dead (BD) patients consisted of short, sharp systolic peaks followed by retrograde flow during diastole or just systolic peaks with absent flow in either direction. There were no survivors among patients who displayed these two TCD patterns. The 29 comatose control patients always showed flow throughout the cardiac cycle--no retrograde flow was ever recorded in these patients all of whom survived. Of particular interest were the basilar artery results. In nine BD patients no MCA signals could be obtained while good quality signals were recorded from the basilar artery. The TCD results agreed essentially with 100% accuracy with clinical testing and four vessel cerebral angiography. This paper illustrates the usefulness of TCD examination of the MCAs and especially the basilar artery in the diagnosis of brain death.

Neuropsychological assessment and brain imaging technologies in evaluation of the sequelae of blunt head injury.

A 43 year old man with a traumatic amnesic syndrome experienced only a brief, if any, loss of consciousness following an injury to the head. Four years after this injury, his results on standard psychometric assessment were normal. Long-latency evoked response potentials results were normal, and the neurological examination and computed tomography scans were unhelpful in explaining his amnesic symptoms. He had no history of alcohol abuse, yet his neuropsychological profile was that of a Korsakoff-like amnesia with frontal lobe features. Magnetic-resonance images demonstrated evidence of extensive frontal lobe damage, while cerebral blood flow studies provided additional evidence of bilateral frontal lobe dysfunction. The case highlights the need for those giving opinions in medico-legal head trauma cases to go beyond a reliance on routine indicators, such as duration of coma, results of standard psychometric assessment and computed tomography scans, to more specialised neuropsychological evaluations and magnetic-resonance imaging scans.

The use of transcranial Doppler sonography in the diagnosis of brain death.

The diagnosis of brain death is important for many reasons. Clinical testing may not be feasible, so that cerebral angiography is needed to confirm circulatory arrest. Angiography is, however, cumbersome and expensive. We present the results of transcranial Doppler (TCD) studies on the middle cerebral arteries of 40 patients with brain death. In six, no cranial signals could be obtained. All except two of the remaining patients had typical TCD appearances, with a reverberating pattern and little or no net forward flow. One patient had this appearance on one side and a carotid-cavernous fistula on the other side, and another had preserved middle cerebral artery flow. Sixteen control patients all had quite different signals, with some showing evidence of raised intracranial pressure and some of vasospasm. There were thus few false-negative results, and more importantly no false-positives. Refinement of this technique, especially looking to a numerical value for the net flow velocity below which circulatory arrest is certain, is needed. The possibility of a changing pattern on serial studies, with prediction of brain death before it actually occurs, is also to be explored.

Regional cerebral blood flow measurements in the diagnosis of dementia.

The Xenon-133 regional cerebral blood flow technique (rCBF) was used to assess cortical perfusion in a group of 15 elderly patients (mean age = 79.1, SD = 8.7) with a probable diagnosis of Dementia of the Alzheimer type (DAT). Nine had mild DAT and six were in the moderate stages of DAT. These patients were compared with 15 age and sex matched normal elderly controls (mean age = 75.1, SD = 5.6). RCBF was measured in each patient and control at rest with eyes closed. The DAT patients had significantly lower mean global CBF than normal controls (t = -4.63, p less than 0.0001). In addition, a further 15 normal elderly subjects aged 60 to 92 were assessed and combined with the original 15 to allow calculation of a normal range of rCBF for elderly individuals. Seventy-three per cent of the DAT patients fell below the lower limit of the normal range (39.3 - 59.3 ISI units). These results show the possible usefulness of rCBF as an aid in the diagnosis of early DAT.

The P300 event-related potential and regional cerebral blood flow in patients with Alzheimer's disease.

A number of studies have reported that an abnormal delay in the latency of the P300 event-related potential (ERP) is characteristic of the majority of patients with a dementing process. Another body of research suggests regional cerebral blood flow (rCBF) is significantly reduced in Alzheimer's disease (AD). No previous study has compared the effectiveness of these 2 measures in identifying the same patients with AD. Furthermore, most of the studies on which the above findings are based examined patients in the moderate to severe stages of the disorder. In this study we examined P300 latency and rCBF in 10 patients with mild to moderate Alzheimer's disease, and compared their responses with those of normal subjects of similar age. The P300 component was not evident in 2 of the patients: the remaining 8 had a latency within normal limits for their age. On the other hand, 8 of the patients had abnormally reduced rCBF. These results suggest rCBF measures may be useful for identifying AD in its early stages.

Evoked response potentials and regional cerebral blood flow in somatization disorder.

Somatization disorder (SMD) is a chronic condition characterized by multiple complaints which are not due to any apparent organic illness but frequently involve pain. This study employs computer-aided imaging technologies to examine brain function in thousandths of a second (event-related brain potentials) and over a number of minutes (regional cerebral blood flow). Fourteen patients with SMD and 14 normal controls were investigated. Results from both studies suggest that patients with SMD have a dysfunction in the processes of attention, compared to normal controls.