High‐frequency ventilation with the Dräger Babylog 8000plus: measuring the delivered frequency

Background: Ventilator frequency is one of the determinants of tidal volume delivery during high‐frequency ventilation. Clinicians increasingly use data on ventilator displays to inform their decisions. Aim: To measure the frequencies delivered by the Dräger Babylog 8000plus ventilator when used in high‐frequency mode. Methods: Ventilator waveforms using a test lung were recorded at the full range of settings 5–20 Hz using Spectra software at 1000 Hz. The changes in frequency produced by a 1‐ Hz change in set frequency were calculated. Actual and displayed frequencies were compared. Results: For settings up to 12 Hz, median (range) difference between set and delivered frequencies was 0 (?0.4 to +0.1) Hz. Above 12 Hz, delivered frequency varied by ?0.3 (?1.9 to +0.3) Hz. For 1‐ Hz changes in frequency settings, in the range 5–12 Hz, 1‐ Hz changes produced a change in delivered frequency of 1.0 (0.6–1.4) Hz. Above 12 Hz, the corresponding changes were 0.7 (0–2.9) Hz. The ventilator displays the set frequency during operation rather than the delivered frequency. Conclusion: At 12 Hz and below, the differences between set and delivered frequencies were relatively small compared with those at 13 Hz and higher. Above 13 Hz, the difference between set and delivered frequencies was up to 2.9 Hz. Some frequency setting changes did not result in a change in delivered frequency.     

Density of γ/δ+ T cells in the jejunal epithelium of patients with coeliac disease and dermatitis herpetiformis is increased with age

Increased density of γ/δ T cell receptor (TCR)⁺ intraepithelial lymphocytes is the only characteristic in the jejunum of patients with coeliac disease and dermatitis herpetiformis which is not normalized on a gluten-free diet. We explored the age-dependent changes in intraepithelial γ/δ and α/β TCR⁺ cells from 137 biopsies from patients with coeliac disease and dermatitis herpetiformis and from controls. Biopsy specimens from 100 patients with coeliac disease and dermatitis herpetiformis and from 37 controls were studied with an immunohistochemical method using MoAbs to T cell receptors and peroxidase staining. An increase in the density of intraepithelial γ/δ T cells above the mean +2 s.d. of the density in controls was present in 97 of 100 specimens from patients with coeliac disease and dermatitis herpetiformis. The density of γ/δ⁺ cells of patients with coeliac disease and dermatitis herpetiformis on a normal gluten-containing diet showed a positive correlation with age (r = 0.45, P< 0.0001). In controls, the density of γ/δ⁺ cells remained low throughout the age-range studies, from age 0.6–57 years. In controls, α/β⁺ cells increased with age (r = 0.57, P< 0.001). The increase in density of intraepithelial lymphocytes with age is in agreement with their thymus-independent character and local proliferation.     

Adenosine triphosphate treatment for meconium aspiration-induced pulmonary hypertension in pigs

To investigate the pulmonary haemodynamic effects of meconium aspiration and subsequent adenosine triphosphate (ATP) treatment, 12 anaesthetized and ventilated pigs (wt 24-28 kg) received either ATP or an equal volume of saline into the right heart in doses of 0.02 to 0.80 lmol kg^-1 min^?1 after intratracheal administration of 2 mL kg^?1 of human meconium. Meconium instillation induced significant increases in pulmonary vascular pressures and total and postarterial resistances calculated from pulmonary artery occlusion studies, but did not affect the systemic haemodynamics, except for a fall in heart rate and increase in central venous pressure. Infusion of ATP at the lowest doses (0.02 and 0.08 µmol kg^?1 min^?1) selectively decreased the pulmonary arterial pressure and vascular resistance and at 0.32 and 0.80 µmol kg^?1 min^?1 reduced both the pulmonary and systemic resistances. In the lung circulation the increasing doses of ATP reduced preferably the arterial, but also the postarterial resistance. Withdrawal of ATP infusion led to a significant rebound effect especially in the postarterial segment of the lung circulation. Meconium aspiration thus induces an acute, predominantly postarterial obstruction in the lung circulation and infusion of ATP at low doses selectively dilates the pulmonary vascular bed and may help to preclude elevation of capillary pressures in meconium aspiration-induced pulmonary hypertension.     

Serum cholesterol and high density lipoprotein cholesterol distributions in patients with acute myocardial infarction and in the general population of Kuopio Province,Eastern Finland

Abstract. As part of the FINMONICA project, serum total cholesterol (TC) and high density lipoprotein cholesterol (HDLC) concentrations were determined in 1216 AMI patients (937 men. 279 women) aged 35–64 years in the province of Kuopio in eastern Finland during the 5-year period 1983–87. The distributions were compared with the corresponding distributions in a representative sample of the general population of the same area (1026 men, 1021 women). The mean serum TC levels did not differ between the AMI patients and the normal population. Only the prevalence of a very high serum TC level (> 8.0 mmol l^?1) among women was significantly higher in the AMI group than in the population sample. On the other hand, in both sexes the age-adjusted mean HDLC was significantly lower in the AMI group than in the population sample. Our findings emphasize the importance of HDLC measurement as a part of the assessment of the lipid risk factor profile in patients with AMI.     

Effect of hepatic and renal dysfunction on disposition of bupropion in rats

Disposition of bupropion after oral administration was investigated in carbon tetrachloride (CCl4) and gentamicin treated rats. Bupropion exhibits extensive first-pass effect and is mainly cleared by hepatic route. In rats with hepatic damage, maximum plasma concentration (Cmax) was approximately 3 times higher and area under the plasma concentration-time curve up to 6 h (AUC 0-6) and AUC 0-infinity increased on an average 4 and 5 times respectively compared to the control. The half-life was doubled with hepatic dysfunction. These findings suggest that hepatic impairment in rats causes a decrease in first pass effect as well as an increase in the half-life of the drug. Rats with renal impairment, exhibited a significant increase in Cmax, AUC 0-6 and AUC 0-infinity of bupropion approximately 3-fold as compared to the control, no change in half life of the drug was observed. This indicates that rats with renal impairment show less efficient first-pass effect which may lead to increase in systemic bioavailability. The time to peak observed in all treated animals was not significantly different from the control. The percentage of bound bupropion did not differ either in CCl4 or gentamicin treated plasma as compared to the control.     

Sequential Bilateral Bundle Branch Block During Dofetilide, A New Class III Antiarrhythmic Agent, In a Patient with Atrial Fibrillation

Sequential Bilateral BBB During Dofetilide. Introduction: I in mechanism of wide QRS complex tachycardias during dofetilide infusion was studied in a patient with atrial fibrillation.
Methods and Results: Endocardial recording from the intraventricular conduction system showed that dofetilide caused "classic" aberrant conduction (Ashman phenomenon, typical QKS morphology) at high prematurity ratios (preceding interval = 1.78 X coupling interval 290), thus mimicking ventricular ectopy. In addition, there was frequent sequential bilateral bundle branch block, caused by a significant difference in preceding bundle-to-bundle intervals (mean difference ± 1 SD: 74 ± 26 msec).
Conclusion: The present findings may prove helpful in the clinical assessment of wide QKS complex rhythms after dofetilide and possibly other "pure" Class III antiarrhythmics.     

Diagnostic features of acute myocardial infarction – changes over time from 1983 to 1990: results from the FINMONICA AMI register study

Abstract. Objectives . To examine, whether the acute myocardial infarctions (AMIs) are becoming smaller. Design . Analysis of electrocardiogram (ECG) and enzyme findings of community-based AMI registers in three geographical areas of Finland during the 8-year period 1983–90. Setting . In the FINMONICA AMI Register, all suspected coronary events in persons aged 25–64 years have been registered since 1983 according to the protocol of the WHO MONICA project in the provinces of North Karelia and Kuopio in eastern Finland and Turku/Loimaa area in south-western Finland. Subjects . Each consecutive case of suspected AMI originating from the monitored populations. During the study period, 11487 definite or possible AMIs were registered. Main outcome measures . Trends in ECG findings classified as definite or probable, and trends in enzyme findings classified as abnormal or equivocal. Results . Of the registered AMIs, 8439 (73.5%) reached the hospital alive and survived ≥ 24 h from the beginning of the symptoms. They were included in the analyses of this report and divided further, to first ever AMIs (n = 5392) and to recurrent AMIs (3047). During the study period, the proportion of ECG findings classified as definite on the basis of the serial Minnesota coding declined in men 3.1% year^?1 (P < 0.0001) on average for first AMIs and 1.9% year^?1 (P = 0.004) for recurrent AMIs. In women, the corresponding declines were 1.9% year^?1 (P = 0.007) and 1.6% year^?1 (P = 0.02), respectively. Also, the proportion of enzymes classified as abnormal declined amongst men 2.2% year (P < 0.0001) for first AMIs and 2.8% year^?1 (P < 0.0001) for recurrent AMIs. In women, the corresponding declines for abnormal enzymes was 1.3% year^?1 (P = 0.13) and 3.0% year^?1 (P = 0.02). These findings were consistent in all three areas with different registration teams and different laboratories. The proportion of definite ECG findings amongst patients hospitalized for AMI declined almost by half and the proportion of abnormal enzyme findings declined almost by one-third during the study period. Conclusions . Our findings are compatible with the clinical observation that the hospitalized AMIs are becoming smaller. The timing and magnitude of the changes suggest that they are mainly caused by decreased risk-factor levels in the population. Improved treatment of coronary heart disease and changed hospital admission policy are likely to be contributing factors.     

Client and information: a literature review

Summary

• ? This paper gives a brief review of existing research studies concerning patient information.
• ? The paper outlines two relevant perspectives on information giving and on the meaning of information to the individual patient: ideological and practical.
• ? From these two perspectives the knowledge structures of four patient groups: surgical patients, cancer patients, dialysis patients and psychiatric patients are looked at more closely.

     

Comparative bioavailability study of cefuroxime axetil (equivalent to 500 mg cefuroxime/tablet) tablets (Zednad® versus Zinnat®) in healthy male volunteers

This study was performed to investigate the bioequivalence of cefuroxime axetil tablets between a generic test product (A) Zednad? Tablet (500 mg cefuroxime/ tablet, Diamond Pharma, Syria), and the Reference Product (B) Zinnat? Tablet (500 mg cefuroxime/tablet, GlaxoSmithKline, Saudi Arabia). The bioavailability study was carried out for 24 healthy male volunteers. The subjects received 1 Zednad? Tablet (500 mg/ tablet) and 1 Zinnat? Tablet (500 mg/tablet) in a randomized, two-way crossover design fashion on 2 treatment days, after an overnight fast of at least 10 h, with a washout period of 7 days. 24 volunteers plus 2 alternatives completed the crossover. The bioanalysis of clinical plasma samples was accomplished by HPLC method, which was developed and validated in accordance with international guidelines. Pharmacokinetic parameters, determined by standard non-compartmental methods, and ANOVA statistics were calculated using SAS Statistical Software. The significance of a sequence effect was tested using the subjects nested in sequence as the error term. The 90% confidence intervals for the ratio between the test and reference product pharmacokinetic parameters of AUC0→t, AUC0→∞, and Cmax were calculated and found to be within the confidence limits of 80.00 - 125.00% for AUC0→t, AUC0→∞ and Cmax. The study demonstrated that the test product (A) was found bioequivalent to the reference product (B) following an oral dose of 500 mg tablet. Therefore, the two formulations were considered to be bioequivalent.