Electrical Impedance Plethysmography Versus Tonometry To Measure the Pulse Wave Velocity in Peripheral Arteries in Young Healthy Volunteers: a Pilot Study

The leading cause of health loss and deaths worldwide are cardiovascular diseases. A predictor of cardiovascular diseases and events is the arterial stiffness. The pulse wave velocity (PWV) can be used to estimate arterial stiffness non-invasively. The tonometer is considered as the gold standard for measuring PWV. This approach requires manual probe fixation above the artery and depends on the skills of the operator. Electrical impedance plethysmography (IPG) is an interesting alternative using skin surface sensing electrodes, that is miniaturizable, cost-effective and allows measurement of deeper arteries. The aim of this pilot study was to explore if IPG can be a suitable technique to measure pulse wave velocity in legs as an alternative for the tonometer technique. The PWV was estimated by differences in the ECG-gated pulse arrival times (PAT) at the a. femoralis, a. popliteal, a. tibialis dorsalis and a. dorsalis pedis in nine healthy young adults using IPG and the SphygmoCor tonometer as a reference. The estimated PWV results from bioimpedance and the tonometer were fairly in agreement, and the beat-to-beat variability in PAT was similar. This pilot study indicates that the use of IPG may be a good alternative for estimating PWV in the legs.

Determination of Total Dietary Fiber (CODEX Definition) by Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study

A method for the determination of total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official MethodsSM 985.29, 991.43, 2001.03, and 2002.02, the method quantitates high- and low-molecular-weight dietary fiber (HMWDF and LMWDF, respectively). In 2007, McCleary described a method of extended enzymatic digestion at 37C to simulate human intestinal digestion followed by gravimetric isolation and quantitation of HMWDF and the use of LC to quantitate low-molecular-weight soluble dietary fiber (LMWSDF). The method thus quantitates the complete range of dietary fiber components from resistant starch (by utilizing the digestion conditions of AOAC Method 2002.02) to digestion resistant oligosaccharides (by incorporating the deionization and LC procedures of AOAC Method 2001.03). The method was evaluated through an AOAC collaborative study. Eighteen laboratories participated with 16 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 11.57 to 47.83. Digestion of samples under the conditions of AOAC Method 2002.02 followed by the isolation and gravimetric procedures of AOAC Methods 985.29 and 991.43 results in quantitation of HMWDF. The filtrate from the quantitation of HMWDF is concentrated, deionized, concentrated again, and analyzed by LC to determine the LMWSDF, i.e., all nondigestible oligosaccharides of degree of polymerization 3. TDF is calculated as the sum of HMWDF and LMWSDF. Repeatability standard deviations (sr) ranged from 0.41 to 1.43, and reproducibility standard deviations (sR) ranged from 1.18 to 5.44. These results are comparable to other official dietary fiber methods, and the method is recommended for adoption as Official First Action.

Determination of Methylcellulose and Hydroxypropyl Methylcellulose Food Gums in Food and Food Products: Collaborative Study

A collaborative study was performed to determine the reproducibility of a method for the determination of methylcellulose (MC) and hydroxypropyl methylcellulose (HPMC) in food. These widely used food gums possess unusual solubility characteristics and cannot accurately be determined by existing dietary fiber methods. The new method uses the enzyme-digestion procedure of AOAC Official Method 991.43. Digestate solutions must be refrigerated to fully hydrate MC or HPMC. The chilled solutions are filtered and analyzed by size-exclusion liquid chromatography. Collaborating laboratories received 28 samples containing MC or HPMC in the range of 0100%. The sample set included blind duplicates of 5 food matrixes (bread, milk, fish, potato, and powdered juice drink). Cochran and Grubbs tests were used to eliminate outliers. For food samples containing MC, values for within-laboratory precision, repeatability relative standard deviation (RSDr), ranged from 4.2 to 16%, and values for among-laboratories precision, reproducibility relative standard deviation (RSDR), ranged from 11 to 20%. For HPMC samples, RSDr values ranged from 6.4 to 27%, and RSDR values ranged from 17 to 39%. Recoveries of MC and HPMC from the food matrixes ranged from 78 to 101%. These results show acceptable precision and reproducibility for the determination of MC and HPMC, for which no Official AOAC Methods exist. It is recommended that this method be adopted as AOAC Official First Action.

P1868Risk of arrhythmias after myocardial infarction in patients with left ventricular systolic dysfunction according to mode of revascularization: a CARISMA substudy

Introduction

The CARISMA trial was the first study to use continuous monitoring for documentation of long-term arrhythmias in post-infarction patients with left ventricular dysfunction. During the study duration (2000–2005), primary PCI (pPCI) as treatment of acute myocardial infarction was introduced approximately midway (2002) on the enrolling centres.

Purpose

The aim of this study was to describe the influence of mode of revascularization after myocardial infarction (AMI) on long-term risk of risk of new onset atrial fibrillation, ventricular tachyarrhythmias and brady arrhythmias.

Methods

The study is a sub-study on the CARISMA study population that consisted of patients with AMI and left ventricular ejection fraction ≤40%, which received an implantable loop recorder and was followed for 2 years. After exclusion of 15 patients who refused device implantation and 26 with pre-existing arrhythmias, 268 of the 312 patients were included. Choice of revascularization was made by the treating team independently of the trial and was retrospectively divided into primary percutaneous intervention (pPCI), subacute PCI (24 hours to 2 weeks after AMI), primary thrombolysis or no revascularization.

Endpoints were new-onset of arrhythmias and major cardiovascular events (MACE). The Kaplan-Meier (figure 1) and Mantel-Byar methods were used for time to first event risk analysis.

Results

A total of 77 patients received no revascularization, whereas 49 received thrombolysis only and 142 received PCI. At two-years follow up patients treated with any PCI had a significant lower risk (0.40, n=63) of any arrhythmia compared to patients treated with trombolysis (0.60, n=30) or no revascularization (0.68, n=16) (p<0.001, unadjusted) (figure 1). Risk of MACE was significant higher in patients with any arrhythmia (0.25, n=76) compared to no arrhythmia (0.11, n=93) at two years follow-up (p=0.004, unadjusted).

Figure 1

Conclusion(s)

The long-term risk of new onset arrhythmias after AMI was significantly lower in patients treated with any PCI compared to patients not revascularized or treated with thrombolysis. Risk of MACE was significantly higher in patients with new onset arrhythmias compared to patients with no arrhythmias.

Long-term 2007-2013 monitoring of reproductive disturbance in the dun sentinel Assiminea grayana with regard to polymeric materials pollution at the coast of Lower Saxony, North Sea, Germany

During biological effect monitoring studies of endocrine active compounds with the snail Assiminea grayana in 2007-2013, reproductive disorders including atresia, transformation of capsule/albumen glands into prostates in females and ovotestis, transformation of prostates to capsule/albumen glands, disruption of spermatogenesis, and calcification of tubules in males, were encountered in several years. The search of sources of endocrine active substances was first directed to antifouling biocides from paint particles and extended to leaching compounds from polymeric materials. In contrast to the reference sites, most of the observed disorders occurred at a station near harbors and dockyards polluted with residues from antifouling paints and polymeric materials. Beside of investigations about the potential ingestion of polymer particles by the snails, further investigations of compounds of polymeric materials with endocrine potential should follow.

Exposure to treated sewage effluent disrupts reproduction and development in the seasonally breeding Ramshorn snail (subclass: Pulmonata, Planorbarius corneus)

Experiments were conducted to assess the impacts of exposure to sewage treatment works (STW) effluent upon the growth, reproductive function, and sexual development of the European mollusc, Planorbarius corneus under seasonally varying temperatures and photoperiodic conditions. In river water, a clear seasonal change in the number and weight of egg masses (during both 2003 and 2004), and in the number of eggs produced, was found, providing evidence for profound effects of both changing temperature and photoperiod on reproduction. Exposure to STW effluent caused disturbances in this seasonal reproductive cycle at all concentrations tested. The effects included significant dose-dependent increases in fecundity and in the overall length of the reproductive cycle in adult snails exposed to both 50% and 100% effluent relative to river water for a period of up to 14 weeks. Disturbances in the development of both the male and female gametes of the both the adult snails and their developmentally exposed offspring were also seen. These effects were more evident in the offspring than in the adults.

Low-dose indinavir in combination with low-dose ritonavir: steady-state pharmacokinetics and long-term clinical outcome follow-up

OBJECTIVES

To evaluate the long-term efficacy and pharmacokinetics of indinavir (IDV)/ritonavir (RTV) 400/100 mg twice a day in combination with two nucleoside reverse transcriptase inhibitors.

METHODS

The study was retrospective with a prospective pharmacokinetic study at a single centre. All HIV-1-infected patients who started the regimen in the period from January 1999 to February 2001 were included in the study. Plasma HIV RNA and CD4 cell counts were recorded from baseline to week 120. Results were evaluated as intention-to-treat and on-treatment analyses with separate analyses for protease inhibitor naive and experienced patients. Patients who were still on the regimen by August 2001 were asked to participate in a pharmacokinetic evaluation.

RESULTS

Twenty-one patients started treatment with the regimen (median follow-up: 116 weeks). The percentage of patients with below 20 HIV-1 RNA copies/mL was 70.0% at week 120 and the median CD4 cell count increased from 320 to 607 cells/microL (P=0.062). The median IDV morning and evening Cmin were 434 ng/mL and 220 ng/mL, respectively.

CONCLUSIONS

Treatment with the IDV/RTV 400/100 mg regimen appears to be efficacious for up to 2 years. However, rather low IDV Cmin suggests that the regimen should be evaluated further before its widespread use and that the regimen probably should be guided by pharmacokinetic evaluation.

Cytokine production by mononuclear cells following stimulation with a peptide-containing, endotoxin-free Escherichia coli extract

The beneficial effects of the E. coli extract Colibiogen inj. N (Cb) observed in therapy of inflammatory bowel diseases, allergies, or gastrointestinal tumors are possibly mediated by the induction of cytokines in human leukocytes or vascular cells. Thus, the induction of the cytokines interleukin 1 (IL1), IL6 and tumor necrosis factor (TNF) in human mononuclear cells (MNC) and vascular cells was investigated in vitro. Various administration forms of the extract (including Cb-inj. N, Cb-oral, and Cb-infantibus N) induced the release of IL1 and IL6 from MNC. The compounds stimulated TNF production less potently, possibly due to a lower sensitivity of the TNF assay system, as compared to the IL1 and IL6 detection system. The MNC produced the cytokines with a kinetics similar to that observed with other stimuli. Monospecific antibodies abolished the respective cytokine activity in the biological assays. Addition of submaximal amounts of endotoxin potently enhanced the IL1- and IL6-inducing activity of the bacterial extract, indicating synergism of the extract and endotoxin. These results provide evidence that cytokines produced by MNC following administration of the tested bacterial extract may contribute to the regulation of the immune response during therapy of gastrointestinal tumors. At present the in vivo production of cytokines following treatment with the bacterial extract tested is under investigation in a phase III study.

Pulse-width modulation drive technique for high-resolution liquid-crystal gratings

We report the use of a pulse-width modulation drive technique for high-resolution liquid-crystal gratings and show how the grating diffraction efficiency depends on the duty cycle of the drive signal. We identify a regime in which the diffraction efficiency is linearly proportional to the duty cycle, thereby providing a linear drive characteristic.

[Screening for neuroblastoma in infants aged 6 months. A method of testing]

In a number of cases, neuroblastoma (NB) may be diagnosed by routine screening of the urine for vanillinic-mandelic acid (VMA) and homovanillinic acid (HVA) in symptomfree infants at the age of six months. Early diagnosis of this disease may possibly improve the prognosis. The object of this project was to establish a method of measuring VMA and HVA concentrations in urine collected on filter paper and to assess participation by the parents as regards three different methods of collecting urine with the object of establishing a population screening programme for NB in Denmark. A total of 1,111 infants aged 6-8 months participated in the investigation. The equipment for testing the urine was given in three different was: 1) By the health nurses (County of Arhus), 2) By the general practitioner at the 6-month vaccination (County of Ringkøbing) and 3) By post (County of Viborg). In Arhus, the health nurses delivered the equipment to 96.7% of the age group concerned. Altogether, urine samples were obtained from 673 infants (61%). Participation was greatest in the County of Arhus (66%) and the County of Ringkøbing (62%) and lowest in the County of Viborg (54%). Two infants were found with marginally raised VMA or HVA but these values were found to be normal on repeated examinations. No cases of neuroblastoma were found in the material nor in the screened group in the course of 1 1/2 years after the conclusion of the investigation. In just over 3% of the cases, renewed urine samples had to be sent on account of too little urine on the filter paper. If current population investigations reveal that screening for neuroblastoma can alter the course of the disease in children, the method described here may form the basis for introduction of population investigations in Denmark.

Multipoint linkage analysis in X-linked Alport syndrome

In order to localize the gene for the X-linked form of Alport syndrome (ATS) more precisely, we performed restriction fragment length polymorphism analysis with nine different X-chromosomal DNA markers in 107 members of twelve Danish families segregating for classic ATS or progressive hereditary nephritis without deafness. Two-point linkage analysis confirmed close linkage to the markers DXS17(S21) (zeta max = 4.44 at theta = 0.04), DXS94(pXG-12) (zeta max = 8.07 at theta = 0.04), and DXS101(cX52.5) (zeta max = 6.04 at theta = 0.00), and revealed close linkage to two other markers: DXS88(pG3-1) (zeta max = 6.36 at theta = 0.00) and DXS11(p22-33) (zeta max = 3.45 at theta = 0.00). Multipoint linkage analysis has mapped the gene to the region between the markers DXS17 and DXS94, closely linked to DXS101. By taking into account the consensus map and results from other studies, the most probable order of the loci is: DXYS1(pDP34)-DXS3 (p19-2)-DXS17-(ATS,DXS101)-DXS94-DXS11 -DXS42(p43-15)-DXS51(52A). DXS88 was found to be located between DXS17 and DXS42, but the order in relation to the ATS locus and the other markers used in this study could not be determined.

Comparison of intravenous and topical lidocaine as a suppressant of coughing after bronchoscopy during general anesthesia

Twenty-four consecutive patients scheduled for fiberbronchoscopy were randomized to receive double-blind either intravenous (1.5 mg/kg) or laryngotracheal (3 mg/kg) lidocaine to evaluate the influence on post-bronchoscopic laryngospasm, pain in the throat and coughing. Plasma lidocaine concentrations were analyzed 5, 15, 30 and 60 min after administration. None of the patients demonstrated laryngospasm or pain in the throat during the first hour after bronchoscopy. Patients receiving topical lidocaine coughed significantly more than patients receiving intravenous lidocaine, with a median number of coughs of 20 compared to 4, during the first hour (P less than 0.01). The plasma lidocaine concentrations were significantly higher after intravenous than after topical administration (P less than 0.001). After intravenous administration the plasma lidocaine concentrations exceeded the accepted level for potential toxicity in five out of 11 patients, but none of the patients developed toxic symptoms and no side-effects were observed.

Evaluation of simple tests for detection of HIV antibodies: analysis of interobserver variation in Tanzania

200 sera were tested for HIV antibodies with different tests in Tanzania. The results were interpreted by 5 different observers with different laboratory experience. There was considerable variation between observers and between testing methods. HIV-Chek was easiest to perform with little interobserver variation, but a few probably false negative readings were seen. Serodia gave many false positives. Western Blots gave more diverging results due to indeterminate sera and lack of training. HIV-Chek seems best when time, facilities, and training are limited and if combined with Serodia false negative results can be excluded.

Long-term prognosis of pregnancies in women with intrauterine hematomas

To evaluate the long-term significance of intrauterine hematomas in patients with threatened abortion, 380 women with a living fetus of more than 8 weeks were studied. On ultrasound, intrauterine hematomas, defined as an echo-poor subchorionic collection, were found in 86 women. Two hundred ninety-four patients without hematomas served as controls. The rate of miscarriage was significantly increased in the study group (22.1 versus 8.2%; P less than .05). Patients discharged from the initial hospitalization without aborting still had a higher abortion risk than controls (16.3 versus 5.6%; P less than .05). Second-trimester debut of symptoms was followed more often by preterm delivery. Thus, patients with intrauterine hematomas continue to be a high-risk group for the remainder of their pregnancies.

Bronchoscopy and nitrous oxide pollution

The purpose of the investigation was to assess the extent of nitrous oxide pollution during bronchoscopy (rigid ventilation bronchoscope) and further to elucidate the possible reduction in air pollution during local scavenging of leaking gas by a suction catheter placed in the pharynx. The study included 14 adult patients. The leakage of anaesthetic gas was 11.4 +/- 3.2 l min-1 and the median value of the nitrous oxide concentration in the breathing zone of the endoscopist was greater than 300 ppm. Air pollution could not be reduced significantly by scavenging with a suction catheter. The use of inhalation anaesthetics is therefore inadvisable during bronchoscopy in adults unless sufficient anaesthetic scavenging can be established. Other ways of reducing air pollution are discussed and the use of total intravenous anaesthesia or local anaesthesia is advocated.

Ribosome specificity of archaebacterial elongation factor 2. Studies with hybrid polyphenylalanine synthesis systems

Polyphenylalanine synthesis with ribosomes and two separated, partially purified elongation factors (EF) was measured in cell-free systems from the archaebacteria Thermoplasma acidophilum and Methanococcus vannielii, in an eukaryotic system from rat liver and an eubacterial one with Escherichia coli ribosomes and factors from Thermus thermophilus. By substitution of heterologous EF-2 or EF-G, respectively, for the homologous factors, ribosome specificity was shown to be restricted to factors from the same kingdom. In contrast, EF-1 from T. thermophilus significantly cooperated with ribosomes from T. acidophilum.

3,5,3'-Triiodothyronine-induced synthesis of rat liver phosphoenolpyruvate carboxykinase

Recent studies have indicated that the starvation induced increase in hepatic phosphoenolpyruvate carboxykinase (PEPck; EC 4.1.1.32) is accelerated in hyperthyroid animals, whereas enzyme degradation is unaffected by the thyroid state. Therefore, the present study was undertaken to investigate the possible direct effect of T3 on the synthesis of this important gluconeogenic regulatory enzyme in vivo and in the isolated perfused liver. T3 injection in hypothyroid animals stimulated PEPck synthesis within 6-12 h. The effect, being dose dependent and significant for 0.1 microgram T3/100 g BW, could be demonstrated in animals fasted or fed a carbohydrate-rich diet. Although varying in the basal rate of synthesis, the T3-induced increase in PEPck synthesis was similar in intact, thyroidectomized, adrenalectomized, and hypophysectomized animals. No additive effect with glucocorticoids was observed, suggesting that endogenous glucocorticoids are not necessary for the hormone action. The T3-induced effect on PEPck synthesis was not mediated by alterations in the endogenous cAMP level, as was indicated (1) by the different time course of PEPck induction via (Bu)2cAMP or T3, and 2) by the finding that T3 was effective also in diabetic animals, despite maximally enhanced tissue cAMP levels. In these animals insulin antagonized the T3 action on the enzyme. T3-mediated PEPck synthesis was not prevented by propranolol. Conversely, an additive effect with isoproterenol on enzyme activity was observed. T3 (1 nM) added to the isolated liver of hypothyroid rats perfused with the synthetic fluorocarbon medium supplemented with 10% iodothyronine free serum, stimulated incorporation of labeled leucine into PEPck protein within a 6-h perfusion time. Taken together, our data demonstrate that T3 at a physiological dose stimulates hepatic PEPck synthesis.

Renal phosphoenolpyruvate carboxykinase turnover in hypo- and hyperthyroid rat in vivo

The effect of hypo- and hyperthyroidism on activity, synthesis and degradation of renal cytosolic phosphoenolpyruvate carboxykinase (GTP) (EC 4.1.1.32) was studied in the rat by radioimmunological techniques. In hypo- and euthyroid rats, starvation induced similar alterations in enzyme activities and relative rates of synthesis, whereas in hyperthyroid rats the increase in both was significantly reduced. Substitution of L-thyroxine in hypothyroid rats resulted in a decrease in activity and synthesis within 18 h as observed in hyperthyroid animals. The apparent half-life of the enzyme measured by double-pulse labeling experiments was approx. 13 h in euthyroid animals. The rate of degradation was unaffected by the different thyroid states.

Preanaesthetic medication with rectal diazepam in children

With the purpose of avoiding injections to children, the quality of rectal premedication with a solution of diazepam (Apozepam) was investigated in a double-blind study. Compared with a lytic cocktail (containing pethidine, promethazine and chlorpromazine), adequate preanaesthetic sedation was obtained with rectally administered diazepam in a dose of 0.75 mg kg-1. However, following rectal diazepam, the majority of the children were very restless during recovery, but the combination of diazepam premedications and a small dose of lytic cocktail given i.m. during anaesthesia secured a smooth recovery in practically all children. The proportion of cases classified as "unsatisfactory' was higher in children below the age of 5 years than in the older children.

Factors influencing seizure duration and number of seizures applied in unilateral electroconvulsive therapy. Anaesthetics and benzodiazepines

A certain minimum in the duration of seizures appears to be a condition for a satisfactory therapeutic effect in ECT. The aim of the present investigation is to elucidate the importance of some factors which may influence the seizure duration. In a controlled double-blind investigation with crossover, carried out on 19 patients, thiopentone and methohexitone were compared as anaesthetics for unilateral ECT. No differences were found between the anaesthetics regarding duration of seizures, number of treatments with insufficient seizures duration or amount of energy applied. Blood pressure measured after the seizure was slightly higher with thiopentone than with methohexitone and methohexitone as anaesthetic for ECT. In a retrospective investigation concerning seizure duration in unilateral ECT, patients given benzodiazepines during the treatment period were compared with patients who received no such medication. The benzodiazepine group showed shorter seizure duration, more cases with insufficient seizure duration and a need for a greater number of treatments. Benzodiazepines should be administered with caution during ECT, as they can impair the efficacy of treatments and consequently prolong the treatment period.

Calculation of the fresh gas flow requirements of the Hafnia A and D anaesthetic circuits

Semi-closed anaesthetic circuits are converted into the corresponding Hafnia circuits by replacing the expiratory valve by a side tube connected to an ejector flowmeter. Theoretical analysis of the Hafnia A and D circuits revealed by the fresh gas flow requirements are dependent on the inspiration/expiration time ratio. Using a ratio of 1/1.2 and a sine-wave respiratory waveform, the minimal fresh gas requirements were calculated as 2.1 (Hafnia A) and 2.5 (Hafnia D) times the respiratory minute volume. The fresh gas requirements are identical with spontaneous or controlled ventilation.

Measurements of cardiac stroke volume in various body positions in pregnancy and during Caesarean section: a comparison between thermodilution and impedance cardiography

A total of 220 simultaneous pairs of measurements of cardiac stroke volume were made in twelve women before and during Caesarean section in order to compare impedance cardiography with the thermodilution method. A significantly higher coefficient of correlation was found before (r = 0.77) than during anaesthesia (r = 0.55). Further, there was a significant difference in the slope of the regression lines: before anaesthesia the slope was 1.07 and during anaesthesia with thiopentone, nitrous oxide, oxygen and suxamethonium it was 0.45. Significant changes in the intercept on the Y-axis were found before (-13.9 ml) and during anaesthesia (33.4 ml). When the uterus was displaced upwards and to the left from the 15 degrees tilt position the stroke volume and the cardiac output were increased when measured by both methods to nearly the same values as in the left lateral position. It is concluded that the impedance method is reliable for measuring cardiac stroke volume in late pregnancy under physiological conditions in the conscious patient, but that it cannot replace the thermodilution method in pharmacological studies.

The ejector flowmeter: an evaluation of its accuracy

The accuracy of five ejector flowmeters was assessed using three different gases and four flow-rates. A soap-bubble flowmeter was used for the calibaration. Significant variations were found between individual flowmeters and between different gas mixtures. No variation was found between the four different flowrates, indicating that the calibration is linear. The mean calibration factor was 84.8% +/- 4.1 (100% O2:87.4 +/- 3.4, 50% N2O/O2: 84.2 +/- 2.8, and 100% N2O: 83.0 +/- 4.6).

Effect of a single graded dose of terbutaline tablets in patients with chronic bronchitis and bronchoconstriction. A double-blind, placebo, cross-over study

Terbutaline, a selective beta2-adrenergic receptor stimulator was given to 10 patients with chronic bronchitis. The effects of the drug were tested by measurements of forced expiratory volume in 1 sec (FEV1), peak expiratory flow rate (PEFR), heart rate, blood pressure and blood gas analysis. The measurements were performed before and 1, 2, 4, 5, and 6 h after oral administration of placebo, 2.5 mg, or 5.0 mg terbutaline. Terbutaline caused a significant dose-related increase in FEV1 and PEFR as compared with placebo. The maximal effects were found at the 4-h measurement and were still present at the measurements performed at 6 h. Heart rate, blood pressure and arterial oxygen tension (PaO2) were not significantly affected. Four patients experienced side effects as tremor and/or heart palpitations. It is concluded that orally administered terbutaline may be an important therapeutical agent in the treatment of chronic bronchitis.

Calculation of oxygen saturation of mixed venous blood in infants

A retrospective survey of the heart catheterizations of twenty-two children below the age of three years was carried out in order to evaluate different formulae for calculation of the oxygen saturation in mixed venous blood (MVB) from the oxygen saturation in blood from the superior caval vein (SVC) and inferior caval vein (IVC). The formula MVB = (3SVC + IVC)/4 was found satisfactory, also during halothane anesthesia.

[Aerobic blood sampling technique using the B 109-syringe (author's transl)]

A syringe (B 109 Radiometer) for arterial blood sampling with modified aerobic technique is described. The blood sampling and subsequent storage during 2 h in ice water induces no clinically significant changes in the pH, pCO2 and pO2 of the blood.

Flow requirements in the Hafnia modifications of the Mapleson circuits during spontaneous respiration

The Mapleson A, B, C and D circuits can be changed into non-polluting circuits by employing continuous gas evacuation directly from the circuit, via an ejector flowmeter (Jørgensen 1974); Mapleson A and C circuits with this modification have been described previously as the Hafnia A and C circuits (Christensen 1976, Thomsen & Jørgensen 1976). If evacuation from a closed reservoir is employed, total removal of the expired and surplus gases from the operating theatre is obtained (Jørgensen & Thomsen 1976). There will be resistance to expiration in all the circuits with a relief valve for the discharge of surplus gas. If surplus gas is continuously removed directly from the anaesthetic circuit, the patient breathes in an air compartment at ambient pressure, as long as the removal rate equals the inflow of fresh gas. The relief valve is only included in the circuit to ensure that high pressures do not develop. As in any other circuit, the relief valve remains open except during controlled ventilation. A dumping valve may also be included as a safeguard against low pressures (Jørgensen & Thomsen 1976). The flow requirements of the Hafnia B and D circuits and the corresponding Mapleson circuits have been studied in conscious, spontaneously breathing subjects, and the results are discussed in relation to the flow requirements of other semi-closed system.

Measurement of rapid changes in cardiac stroke volume. An evaluation of the impedance cardiography method

One hundred and twenty-nine simultaneous measurements were carried out on seven patients, 67 at rest and 62 during the Valsalva manoeuvre, in order to compare impedance cardiography with the thermodilution method, during rapid changes in cardiac stroke volume and pulmonary blood volume. A coefficient of correlation of 0.86 was found following linear regression analysis of the whole material. Analysis of the individual patient showed that the mean coefficient of correlation was 0.94 (range 0.91-0.97), and that the slope of the regression lines was 0.41 to 1.82, and further that the mean intercept was 0.2 ml. It is concluded that impedance cardiography can be employed for measuring the relative intraindividual changes in cardiac stroke volume during the Valsalva manoeuvre, and it is suggested that it may be of use in other situations, such as during haemorrhage or continuous positive pressure ventilation.

The effects of moderate heat stress on patients with ischemic heart disease

With the use of a climate chamber, the effects of a 3-h exposure to moderate heat stress (23 to 29 degrees C) on the physiology, comfort, and performance of 20 subjects, 10 with slight (group I) and 10 with moderate (group II) ischemic heart disease (IHD), were studied. Twenty matched control subjects were similarly exposed. All of the subjects performed sedentary, mental work throughout the exposure. Humidity was 9 mm Hg; air velocity, 10+/-3 cm per second; and thermal resistance of the clothing, 0.7 clo. Under identical conditions no significant differences in rectal, skin, and finger temperatures or weight loss existed between the three groups, but during heat stress the temperatures and weight loss were always significantly higher than under the control conditions, except for rectal temperatures during the first 2 h. There was no difference between the groups or the two sets of conditions in respiration rate and diastolic blood pressure, but the patients had a significantly lower systolic blood pressure in the third hour of heat stress than under the control conditions. Heart rate and the rate-pressure-product during heat stress were significantly higher in the controls than in the patients. A few patients experienced a slight retrosternal oppression during heat stress, but only one had ECG changes, and none of these symptoms or signs were present under control conditions. Under both sets of temperature conditions the patients were uncomfortable during a longer period of time than the controls, and they were more sensitive to temperature changes, group II being more sensitive than group I. The comfort distribution curve was very narrow for group II. The performance tests were numerical addition, card punching, cue-utilization and creative association. In numerical addition no temperature effect could be shown on the speed of working, but for the patients in group II during heat stress the level of accuracy in the second hour was lower than under control conditions; the trend was the opposite for control subjects. No differences occurred in the first or third hour. In card punching the patients in group II worked significantly more slowly during heat stress than did the control subjects, who improved their performance in heat, as did the paracy with which this task was performed, the patients in group II making significantly more errors in the heat than patients in group I. Cue-utilization did not differ between groups or conditions. Patients performing the creative association test under heat stress supplied significantly fewer unique answers than did patients working under control conditions; no such effect of heat was observed for control subjects. We conclude that patients with IHD are more sensitive to moderate heat stress than healthy control subjects in terms of mental performance and comfort. There are some differences in cardiopulmonary function but no differences in thermoregulation.

Evaluation of the sampling technique and storage of blood using the B 109 Arterial Blood Sampler syringe

To evaluate the B 109 Arterial Blood Sampler (Radiometer), 10 different samples were analyzed for Pco2, Po2, and pH. The aerobic sampling technique, followed by storage for 2 h in water at 1 degrees C, induced small, but clinically insignificant, changes in the measured values.