We wanted to study the effects of a 600 micrograms inhaled salbutamol dose on the cardiovascular and respiratory autonomic nervous regulation in eight children suffering from bronchial asthma.
In this randomized, double-blind, placebo-controlled, crossover study we continuously measured electrocardiogram, finger systolic arterial pressure (SAP) and flow-volume spirometry at baseline as well as 20 min and 2 h after the drug inhalation. The R-R interval (the time between successive heart beats) and SAP variabilities were assessed by using spectral analysis. Baroreflex sensitivity was assessed by using cross-spectral analysis.
Salbutamol significantly decreased the total and low frequency (LF) variability of R-R intervals as well as the high frequency (HF) variability of R-R intervals and of SAP. Salbutamol significantly increased the LF/HF ratio of R-R intervals and of SAP, minute ventilation, heart rate and forced pulmonary function in comparison with placebo. The weight of the subjects significantly correlated positively with baroreflex sensitivity and negatively with heart rate after the salbutamol inhalation.
We conclude that the acute salbutamol inhalation decreases cardiovagal nervous responsiveness, increases sympathetic dominance in the cardiovascular autonomic balance, and has a tendency to decrease baroreflex sensitivity in addition to improved pulmonary function.
Correlation between clinical features and magnetic resonance imaging (MRI) findings is essential in low-back-pain patients. Most previous studies have analyzed concordance in the interpretation of lumbar MRI among a few radiologists who worked together. This may have overestimated concordance.
To evaluate intra- and interobserver agreement in the interpretation of lumbar MRI performed in an open 0.2 T system.
Seven radiologists from two different geographic settings in Spain interpreted the lumbar MRIs of 50 subjects representative of the general Danish population aged 40 years. The radiologists interpreted the images in routine clinical practice, having no knowledge of the clinical and demographic characteristics of the subjects and blinded to their colleagues' assessments. Six of the radiologists evaluated the same MRIs 14 days later, having no knowledge of the previous results. Data on the existence of disc degeneration, high-intensity zones, disc contour, Schmorl nodes, Modic changes, osteophytes, spondylolisthesis, and spinal stenosis were collected in the Nordic Modic Consensus Group Classification form. Intra- and interobserver agreement was analyzed for variables with a prevalence >or=10% and
Lateral radiographs of the airways were taken in 20 men and 24 women lying supine with the neck in the normal position. The mean configuration of the airways for men and women is presented in a standard coordinate system. The results (contours of the airways) are compared to those of a Swedish study since the same method was applied in order to find out, if the established model is valid for other populations. Significant differences were found between the two population groups as well as between males and females. This indicates both inter-racial and inter-sexual modification of the anatomical shape of the airways.
We assessed the convergent validity of commonly applied metrics of cerebral autoregulation (CA) to determine the extent to which the metrics can be used interchangeably. To examine between-subject relationships among low-frequency (LF; 0.07-0.2 Hz) and very-low-frequency (VLF; 0.02-0.07 Hz) transfer function coherence, phase, gain, and normalized gain, we performed retrospective transfer function analysis on spontaneous blood pressure and middle cerebral artery blood velocity recordings from 105 individuals. We characterized the relationships (n = 29) among spontaneous transfer function metrics and the rate of regulation index and autoregulatory index derived from bilateral thigh-cuff deflation tests. In addition, we analyzed data from subjects (n = 29) who underwent a repeated squat-to-stand protocol to determine the relationships between transfer function metrics during forced blood pressure fluctuations. Finally, data from subjects (n = 16) who underwent step changes in end-tidal P(CO2) (P(ET)(CO2) were analyzed to determine whether transfer function metrics could reliably track the modulation of CA within individuals. CA metrics were generally unrelated or showed only weak to moderate correlations. Changes in P(ET)(CO2) were positively related to coherence [LF: ß = 0.0065 arbitrary units (AU)/mmHg and VLF: ß = 0.011 AU/mmHg, both P
CONTEXT: High resting blood pressure (BP) is among the best studied and established risk factors for cardiovascular disease. However, little is known about the relationship between BP under acute stress, such as in acute chest pain, and subsequent mortality. OBJECTIVE: To study long-term mortality related to supine BP in patients admitted to the medical intensive care unit (ICU) for acute chest pain. DESIGN, SETTING, AND PARTICIPANTS: Data from the RIKS-HIA (Registry of Information and Knowledge About Swedish Heart Intensive Care Admissions) was used to analyze the mortality in relation to supine admission systolic BP in 119,151 participants who were treated at the ICU for the symptom of chest pain from 1997 through 2007. Results from this prospective cohort study were presented according to systolic BP quartiles: Q1, less than 128 mm Hg; Q2, from 128 to 144 mm Hg; Q3, from 145 to 162 mm Hg; and Q4, at or above 163 mm Hg. MAIN OUTCOME MEASURE: Total mortality. RESULTS: Mean (SD) follow-up time was 2.47 (1.5) years (range, 1-10 years). One-year mortality rate by Cox proportional hazard model (adjusted for age, sex, smoking, diastolic BP, use of antihypertensive medication at admission and discharge, and use of lipid-lowering and antiplatelet medication at discharge) showed that participants in Q4 had the best prognosis (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.72-0.80, Q4 compared with Q2; corresponding risks for Q1 were HR, 1.46; 95% CI, 1.39-1.52, and for Q3, HR, 0.83; 95% CI, 0.79-0.87). Patients in Q4 had a 21.7% lower absolute risk compared with Q2, patients in Q3 had a 15.2% lower risk than in Q2, and patients in Q1 had a 40.3% higher risk for mortality than in Q2. The worse prognosis in Q2 compared with Q4 was independent of body mass index and previous diagnoses and similar when analysis was restricted to patients with a final diagnosis of angina or myocardial infarction (HR, 0.75; 95% CI, 0.71-0.80, Q4 compared with Q2). CONCLUSION: Among patients admitted to the ICU for chest pain, there is an inverse association between admission supine systolic BP and 1-year mortality rate.
OBJECTIVE: To determine the contribution of prone sleeping, bed sharing, and sleeping outside an infant crib to sudden infant death syndrome (SIDS). METHODS: We conducted a retrospective descriptive study of all SIDS cases in Alaska from January 1, 1992, through December 31, 1997. Reviewed data sources included maternal and infant medical records, autopsy reports, birth and death certificates, police and state trooper death scene investigations, and occasionally home interviews. RESULTS: The death certificate identified SIDS as a cause of death for 130 infants (cause-specific infant mortality rate: 2.0 per 1000 live births). Among infants for whom this information was known, 113 (98%) of 115 were found in the prone position, sleeping outside an infant crib, or sleeping with another person. By contrast, 2 (1.7%) were found alone and supine in their crib (1 of whom was found with a blanket wrapped around his face). Of 40 infants who slept with a parent at the time of death, only 1 infant who slept supine with a non-drug-using parent on an adult nonwater mattress was identified. CONCLUSION: Almost all SIDS deaths in Alaska occurred in association with prone sleeping, bed sharing, or sleeping outside a crib. In the absence of other risk factors, SIDS deaths associated with parental bed sharing were rare.
We investigated the cardiovascular responses to active standing in Swedish and Japanese pre-pubertal children using non-invasive continuous beat-to-beat finger blood pressure (BP) monitoring. Seventy-eight Swedish (7-12 years) and 53 Japanese children (6-12 years) were examined. There were no significant differences in body weight or height between the two groups (total group). Finger blood pressure and heart rate were continuously recorded in the supine position and during standing. Supine BP was significantly higher in Swedish compared to Japanese children (115/65 vs 98/50 mmHg, P
Patients with cirrhosis often develop a systemic vasodilatation and a hyperdynamic circulation with activation of vasoconstrictor systems such as the renin-angiotensin-aldosterone system (RAAS), and vasopressin. Increased nitric oxide (NO) synthesis has been implicated in the development of this state of vasodilation and pulmonary dysfunction including increased exhaled NO concentrations. Circulating metabolites (NO(x)) may affect the systemic and pulmonary NO-generation. However, the relations of these abnormalities to the haemodynamic changes remain unclear.
The aims of the present study were to measure changes in exhaled NO in relation to circulating NO(x), RAAS, and haemodynamics.
Twenty patients (eight child class A and 12 class B patients) underwent a liver vein catheterization with determination of splanchnic and systemic haemodynamics. Circulating NO(x) and exhaled NO were determined in the supine and sitting positions and related to haemodynamics, RAAS and lung diffusing capacity (D(L)CO). Eight matched healthy individuals served as controls.
All patients with cirrhosis had portal hypertension. We found no significant difference in exhaled NO between patients and controls and no changes from the supine to the sitting position. Exhaled NO in the patients correlated significantly with plasma volume, heart rate and D(L)CO. NO(x) concentrations were not significantly increased in the patients. NO(x) correlated with portal pressure and haemodynamic indicators of vasodilatation, but not with exhaled NO concentrations.
In patients with moderate cirrhosis, exhaled NO is normal. Circulating NO(x) do not seem to reflect pulmonary and systemic NO release, but NO(x) seems to reflect systemic and splanchnic haemodynamic changes in cirrhosis.
With Image-Guided Radiation Therapy (IGRT) rapidly gaining acceptance in the clinic it is timely to commence an assessment of its potential outcome benefit versus costs.
Using Activity-Based Costing we have calculated the incremental cost of adding Image-Guided Patient Repositioning (IGPR), a significant component of IGRT, to both Intensity-Modulated Radiation Therapy (IMRT) and Three-Dimensional Conformal Radiation Therapy (3DCRT) for prostate cancer. The dosimetric outcome benefit resulting from the implementation of IGPR is estimated from a publication describing the improvement in set-up accuracy using each of four correction protocols. In our study outcome is quantified using a metric based on the Equivalent Uniform Dose. Our discussion is limited to image-guided corrective translations of the patient and does not specifically address margin reduction, rotations, organ deformation or major equipment failure modes, all of which are significant additional justifications for implementing an IGRT program.
Image guidance used solely for translational patient repositioning for prostate cancer adds costs with relatively little improvement in dosimetric quality. Full exploitation of the potential of IGRT, particularly through margin reduction, can be expected to result in a reduction in the cost-outcome ratios reported here.
IMRT benefits more than 3DCRT from IGPR with the Weekly Shrinking Action Level approach yielding the lowest cost-outcome ratio.
Chronic cerebrospinal venous insufficiency (CCSVI) has been proposed as a major risk factor for multiple sclerosis (MS). The aim of this study was to assess inter-observer agreement between two ultrasound examiners and to compare findings in MS patients and control participants.
A prospective, blinded, controlled study of MS patients diagnosed within 2 years (MS = 2, n = 39), patients diagnosed more than 10 years ago (MS > 10, n = 43) and age- and sex-matched control participants (n = 40). Ultrasound examinations were performed by two independent examiners. CCSVI criteria 1, 3, 4 and 5 as proposed by Zamboni were explored: (1) reflux in the internal jugular (IJV) and vertebral veins (VV), (3) IJV cross-sectional area (CSA) =0.3 cm(2), (4) absence of flow in IJV and VV, and (5) reverted postural control of venous outflow.
Criteria 1, 4 and 5 were met in less than 10% of the MS patients and control participants as studied by both examiners. The level of inter-observer agreement was poor for all parameters except assessment of the CSA of IJV at the thyroid level. Findings meeting CCSVI criterion 3 (CSA = 0.3 cm(2)) were observed in 18/40 (45%) of the control participants, in 24/37 (65%) of MS = 2 patients (p = 0.09 vs. control participants) and in 30/43 (70%) of the MS > 10 patients (p = 0.022 vs. control participants).
The feasibility of the CCSVI criteria for common use is questionable because of low inter-observer agreement. Small-calibre IJVs meeting the CCSVI criterion 3 appear common in both Finnish control participants and MS patients, but the clinical significance of this finding is questionable.