Aminophylline: exploring cardiovascular benefits versus medical malcontent

Although aminophylline/theophylline has been relegated to third- and fourth-line status in the cardiopulmonary armamentarium, its use in specific pathophysiologic states, especially those of cardiac etiology, can be of significant benefit. The consulting clinician should maintain an awareness of its potential as adjunctive therapy in cases of atrioventricular block, cardiac arrest, heart failure, and bradyarrhythmias in particular. It should not yet be shelved as an archaic agent.

Adenosine A1 antagonism attenuates beta-adrenergic-resistant sudden hypoxic cardiac insufficiency

OBJECTIVES

In states such as hypoxia, shock, and cardiac arrest, compromised systemic oxygenation or perfusion appears to induce cardiac insufficiency that can be resistant to beta-adrenergic drugs. Elevated levels of adenosine may mediate such beta-adrenergic-resistant cardiac insufficiency via the adenosine A(1) receptor (A(1)AdoR). The objective of this study was to test the hypothesis that selective A(1)AdoR antagonism attenuates hypoxic cardiac insufficiency more efficaciously than beta(1)-adrenergic agonism or nonselective adenosine antagonism.

METHODS

Rats were paralyzed and ventilated to a pCO(2) level of 35-40 mm Hg. Ten minutes before hypoxia (inspired o(2) concentration = 5%), rats were treated intravenously with one of the following: 0.1 mg/kg BG-9719 (n = 9), 10 mg/kg NPC-205 (n = 10; BG-9719 and NPC-205 are selective A(1)AdoR antagonists, with durations of action of 30-60 minutes and 60-90 minutes, respectively), 10 mg/kg aminophylline (n = 12), 5 microg/kg/min dobutamine (n = 11), or control solutions. These drug doses maximized survival duration in dose-response studies.

RESULTS

Before hypoxia, cardiac work was increased more by aminophylline and dobutamine than by BG-9719. Mean (+/-SEM) duration of survival (in minutes) after hypoxia increased from <13 (control solutions) to 13.8 (+/-1.4) (dobutamine), 20.0 (+/-1.6) (aminophylline), 31.7 (+/-4.6) (BG-9719), and 40.5 (+/-7.5) (NPC-205) (p < 0.0001). Heart rate and dP/dt decreased rapidly after hypoxia, but decreases were attenuated with BG-9719 and NPC-205 compared with dobutamine (p < 0.05) and tended toward attenuation with aminophylline.

CONCLUSIONS

BG-9719 and NPC-205 improved survival duration, heart rate, and left ventricular contractility during hypoxia more efficaciously than dobutamine and possibly aminophylline. Selective A(1)AdoR antagonists warrant further study as alternatives to beta-adrenergic agonists in hypoxia, shock, and cardiac arrest, in which compromised systemic perfusion or oxygenation impairs cardiac output.

Reversal of oliguric tacrolimus nephrotoxicity in children

BACKGROUND

Acute tacrolimus toxicity is manifest by oliguria and elevated serum creatinine. Various vasoregulatory molecules have been implicated in calcineurin inhibitor-mediated nephrotoxicity, including calcium, adenosine and endothelin. Theophylline (THEO), a non-specific adenosine-receptor antagonist prevents renal dysfunction from various nephrotoxins which mediate vasoconstriction. In the setting of acute tacrolimus toxicity, we demonstrated that administration of THEO along with a loop diuretic (LD) enhanced diuresis. This randomized, controlled trial was undertaken to confirm these earlier findings under more rigorous conditions.

METHODS

Children with non-renal visceral transplant(s) and evidence of tacrolimus nephrotoxicity oliguria with a 25% increase in serum creatinine concentration from baseline, a whole blood tacrolimus concentration >20 ng/dl and oliguria resistant to therapy with a LD were randomized to receive either THEO (n = 10) or normal saline placebo (n = 8). Using pre and post (6 h) timed urine collections and coincident plasma concentrations the following were measured or calculated: urine flow rate, net fluid balance, creatinine clearance, fractional excretion of chloride, free water clearance and distal delivery of chloride.

RESULTS

These patients had markedly impaired creatinine clearance at the onset of tacrolimus toxicity. Urine flow increased in the LD + THEO group by 110% over baseline, but was unchanged in the LD + NS group. An increase in creatinine clearance did not reach statistical significance (P = 0.09). Fractional excretion of chloride and distal solute delivery increased after THEO treatment.

CONCLUSIONS

THEO induced a solute diuresis during furosemide-resistant oliguric tacrolimus toxicity in paediatric patients with a trend towards improved renal function.

Comparison of the effect of aminophylline and low PEEP vs. high PEEP on EGF concentration in critically ill patients with ALI/ARDS

BACKGROUND

Acute respiratory distress syndrome (ARDS) remains a serious, often fatal, condition, despite progress in modern critical care treatment. Cytokines play important roles in the pathogenesis of the syndrome, although their roles in the evaluation and outcome have not been clearly elucidated yet.

OBJECTIVES

We tested whether serum concentration of epidermal growth factor (EGF), as one of the important inflammatory mediators, changes with time and administration of mechanical ventilation and aminophylline.

PATIENTS AND METHODS

Thirty patients [mean (SD): age = 56.6 (17.4) years] with ARDS were enrolled. After diagnosis based on inclusion and exclusion criteria, the patients were intubated and mechanically ventilated. Two hours after ventilation with definite positive end-expiratory pressure (PEEP), aminophylline with a specific dose was started. Serum samples were obtained at five time points of 0, 2, 2.5, 4 and 8 h post-starting PEEP.

RESULTS

Serum EGF concentration decreased after mechanical ventilation with PEEP (P < 0.05). The serum EGF concentrations 8 h after intervention was statistically lower in the low PEEP group than in the high PEEP group. The Acute Physiology and Chronic Health Evaluation (APACHE) Pi score and PaO2/FiO2 improved significantly after 8 h (P < 0.05).

CONCLUSION

Beneficial effects of mechanical ventilation and aminophylline on APACHE Pi score and PaO2/FiO2 influence serum EGF levels. These findings may have relevance to the development of multisystem organ failure.

Implementing evidence-based guidelines: inpatient management of chronic obstructive pulmonary disease

BACKGROUND

Evidence-based guidelines exist to guide inpatient management of chronic obstructive pulmonary disease (COPD) exacerbations, but we do not know how well these recommendations are adhered to.

AIMS

The aims of this study were: (i) to examine concordance with evidence based guidelines for inpatient management of COPD and (ii)to address deficiencies in compliance with guidelines by feedback of audit results and distribution of an education package.

METHODS

Retrospective chart reviews were performed using a data collection tool based on current guidelines. Forty-nine consecutive COPD admissions were audited, and results presented to medical staff. An education package was distributed directly after the presentation. One month later,35 consecutive separations were reviewed. Concordance with recommendations supported by the highest level of evidence was calculated.

RESULTS

Data were complete for 84 cases. Concordance rates ranged from 0 to 100%. Apart from initiation of systemic steroids (80-83%)and avoidance of intravenous aminophylline (100%),concordance rates were less than 60%. The only significant improvement post-intervention was for steroid duration (10 vs 29%,95% confidence interval for difference (-36.2, -1.8)).

CONCLUSION

Recommendations for steroid initiation and avoidance of aminophylline are well adhered to. Concordance rates for other recommendations were generally less than 60%. Concordance with recommendations for steroid duration was significantly improved by our intervention. The findings suggest that to facilitate evidence-based practice, alternative interventions should be evaluated.

Aminophylline as an adjunct diuretic for neonates--a case series

Aminophylline is an adenosine receptor antagonist. Adult and paediatric studies have demonstrated a diuretic effect of aminophylline due to increased renal blood flow and the inhibition of solute reabsorption in various segments of the nephron. We report a case series of five infants with volume overload despite frusemide treatment. Aminophylline was successfully used as an adjunct diuretic with increased urine output and effective weight loss occurring in all five neonates following its introduction.

Aminophylline therapy during endotoxemia in anesthetized spontaneously breathing rats

Phosphodiesterase inhibitors, such as pentoxifylline and aminophylline, may reduce inflammatory cytokine-induced endothelial permeability. We tested the hypothesis that aminophylline treatment may ameliorate the pulmonary and extrapulmonary effects of endotoxemia in a rat model. In anesthetized rats, a tracheotomy was performed along with catheterization of a femoral vein and artery. Anesthesia, fluid balance, and normothermia were maintained throughout the 6-h experiment. A stable hemodynamic and gas-exchange baseline was established at which time the rats were randomly divided into three groups. Group I received aminophylline (1mg/kg) over 30 min followed by 0.5mg/kg/h. Group II received a single dose of endotoxin (4 mg/kg) while Group III received both aminophylline and endotoxin as described for Groups I and II, respectively. Gas-exchange profiles, mean arterial blood pressure, and heart rate were determined every 2h. At hour 6, the rats were euthanized and lung, kidney, and heart tissue were removed for determination of water content. As our control group, we utilized data from our previously published study involving an identical surgical procedure with normal saline. Endotoxemia produced characteristic respiratory and hemodynamic signs of sepsis including hypotension, hyperventilation, tachycardia, and renal and pulmonary edema. Aminophylline treatment failed to prevent these endotoxemia-induced respiratory and hemodynamic manifestations of sepsis, but significantly improved the acid-base imbalance that developed during surgical procedures in saline-treated control rats. Further studies are warranted to determine potentially beneficial doses of aminophylline and resulting theophylline serum concentrations under such septic conditions.

Predictors of successful extubation of preterm low-birth-weight infants with respiratory distress syndrome

OBJECTIVE

The aim of the study was to measure pulmonary mechanics in infants with respiratory distress syndrome before extubation and to correlate pulmonary function values with successful extubation.

DESIGN

Clinical study.

SETTING

Neonatal intensive care unit.

PATIENTS

Fifty-one infants (birth weight, 1158.6 +/- 150.6 g; gestational age, 29.1 +/- 2.0 wks).

INTERVENTIONS

Ventilation and daily ventilatory management.

MEASUREMENTS AND MAIN RESULTS

Of the 51 infants studied, 35 (60.8%) were successfully extubated, whereas 16 (39.2%) required reintubation and mechanical ventilation within 72 hrs after extubation. All patients met the clinical and biochemical criteria for extubation. Variables of artificial ventilation before extubation were minimal in all the studied cases (Fio(2) </=0.4, inspiratory pressure </=20 cm H(2)O, ventilatory rate, </=10/min). Pulmonary mechanics were measured before extubation using a noninvasive, mobile VenTrak measuring station.

RESULTS

Significant differences in pulmonary function values between the groups were found. Lower resistance of airways and work of breathing and higher dynamic compliance, tidal volume, and minute ventilation before extubation were associated with successful extubation.

CONCLUSION

On the average, tidal volume values of >6 mL/kg, minute ventilation of >309 mL/kg/min, work of breathing of <0.172 J/L, dynamic compliance of >/=1 mL/cm H(2)O/kg, and resistance of airways of </=176 cm H(2)O/L/sec predicted successful extubation. We recommend measurement of pulmonary function as an assessment tool in determining readiness for extubation.

Artificial fetal lung maturation--prevention of antenatal complications in premature deliveries

Keeping in mind the frequency of preterm deliveries as well as the morbidity and mortality of the newborn population, many ways of bringing about faster maturation of the fetus have been. Today, we can say that after the 24th week of gestation, when the pneumocites time 2 are anatomically formatted, medical treatment of the fetus for maturation not only of the lungs but all the vulnerable organs is available. By stimulating the pneumocites to make surfactant and sphingomyeline and phosphatidilinositol and phosphatidilglycerol, we can reduce respiratory distress syndrome. Moreover, the frequency of intracranial haemorage is lowered. We have performed many studies with all of their positive and negative effects, including: use of corticosteroids, thyroxine, aminophilline, surfactant, inositole and beta adrenergic agonist.

Mitral Valve Replacement in a Patient With a Collapsed Lung and a Giant Abscess

Mitral valve replacement was performed on a 75-year-old man with a history of pulmonary tuberculosis. Computed tomography showed a collapsed left lung and counterclockwise rotation of the heart due to a hard abscess. Surgery was performed through a median sternotomy, and extensive pericardial suspension was useful for obtaining an adequate view. Despite poor pulmonary function, the patient was extubated on the day of surgery and had an uneventful postoperative course. Cardiac surgery can be performed in patients with a single functional lung if their preoperative respiratory function is good enough to have daily life without dyspnea.

Doxapram treatment for apnea in preterm infants

BACKGROUND

Recurrent apnea is common in preterm infants, particularly at very early gestational ages. These episodes of loss of effective breathing can lead to hypoxemia and bradycardia which may be severe enough to require resuscitation including use of positive pressure ventilation. Doxapram has been used to stimulate breathing and so prevent apnea and its consequences.

OBJECTIVES

In preterm infants with recurrent apnea, does treatment with Doxapram lead to a clinically important reduction in apnea and use of intermittent positive airways pressure (IPPV), without clinically important side effects?

SEARCH STRATEGY

Searches were made of the Oxford Database of Perinatal trials, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2004), MEDLINE from 1966 - June 2004, EMBASE from 1980 - June 2001, CINAHL from 1982- June 2004. Text words 'doxapram', 'apnea or apnoea' and the MeSH term 'infant, premature' were used. Previous reviews including cross references, abstracts from conferences and symposia proceedings were also examined. Abstracts of the Society for Pediatric Research were searched from 1996 - 2004 inclusive.

SELECTION CRITERIA

All trials utilising random or quasi-random patient allocation, in which doxapram was used for the treatment of apnea in preterm infants were included.

DATA COLLECTION AND ANALYSIS

Each author evaluated the papers for quality and inclusion criteria. Independent data extraction was carried out.

MAIN RESULTS

Only one trial, which randomized 11 infants to intravenous doxapram and 10 infants to placebo, was found. There were fewer treatment failures after 48 hours in the group of preterm infants treated with doxapram (4/11) compared with the group treated with placebo (8/10). The wide confidence intervals made this result non-significant [RR 0.45 (0.20, 1.05)]. Only one infant, who was from the placebo group, was given IPPV. Of the seven responders by 48 hours in the group of 11 who received doxapram, five failed to respond between 48 hours and seven days after commencement of therapy. This gives a late failure rate of 9/11, similar to the short term failure rate in the placebo group of 8/10. It is not possible to evaluate the late responses of all those in the placebo group since they crossed over to a treatment arm.

REVIEWERS' CONCLUSIONS

Although intravenous Doxapram might reduce apnea within the first 48 hours of treatment, there are insufficient data to evaluate the precision of this result or to assess potential adverse effects. No long term outcomes have been measured. Further studies are needed to determine the role of this treatment in clinical practice.

Theophylline for the prevention of radiocontrast nephropathy: a meta-analysis

BACKGROUND

Radiocontrast nephropathy is a common cause of acute renal failure in hospitalized patients. Several studies have examined the capacity of theophylline or aminophylline to prevent radiocontrast nephropathy, with conflicting results. We conducted a meta-analysis of published randomized controlled trials to determine if the pre-procedural administration of theophylline or aminophylline prevents radiocontrast-induced declines in kidney function.

METHODS

We searched MEDLINE, EMBASE, the Cochrane Collaboration Database, bibliographies of retrieved articles, and consulted with experts to identify relevant studies. Randomized controlled trials of theophylline or aminophylline in hospitalized patients receiving radiocontrast were included. Studies were excluded if they did not report changes in serum creatinine or creatinine clearance within 48 h after radiocontrast exposure.

RESULTS

Seven randomized controlled trials satisfied all inclusion criteria and were included in the analysis (pooled sample size n = 480). The difference in mean change in serum creatinine was 11.5 micromol/l (95% confidence intervals 5.3-19.4 micromol/l, P = 0.004) lower in the theophylline- or aminophylline-treated groups than controls. One participant (0.6%) required dialysis.

CONCLUSIONS

Prophylactic administration of theophylline or aminophylline appears to protect against radiocontrast-induced declines in kidney function. Whether these agents reduce the proportion of patients who experience large decrements in serum creatinine concentration, or require dialysis, is unknown.

Pharmacokinetics of theophylline in preterm neonates during the first month of life

OBJECTIVE

The present work aimed to estimate the theophylline pharmacokinetic parameters (TH-PKP) in preterm neonates with apnea during the first month of life in order to optimize its dosage regimen.

METHODS

Fifty preterm neonates enrolled in the study with recurrent apnea were admitted during 1998-2000 to the Neonatal Intensive Care Unit of Maternity and Children's Hospital, Al-Mosaida, Jeddah, Kingdom of Saudi Arabia. Criteria for this study were preterm with gestational age (GA) of 26-33 weeks (mean +/- SD 30 +/- 3.9). They received TH of 3-6 mg/kg loading dose (LD) followed by maintenance dose (MD) of 0.5 - 3.0 mg/kg/12 hours. Eight of these patients received phenobarbital and 19 received cimetidine concomitantly for at least 7 days. Blood samples were taken one hour post LD and at steady state (Css). Theophylline levels were determined by fluorescence polarization immunoassay.

RESULTS

Phenobarbital significantly enhanced TH clearance (CL) and reduced its half-life (t0.5) but cimetidine had no significant effect. Excluding patients receiving phenobarbital. The mean +/- SD TH-PKP were volume of distribution (Vd) = 0.77 +/- 0.25 L/kg; elimination rate constant (Ke) = 0.027 +/- 0.011 h(-1); CL = 0.019 +/- 0.006 L/h/kg, t0.5 = 30.7 +/- 12.1. There was marked intra patient variability in all TH-PKP.

CONCLUSION

In view of the results and practical considerations, initial dosage regimen to attain a TH Css level within the therapeutic range (6-12 ug/ml) was suggested: LD 6-7 mg/kg, MD 1.5 - 2.0 mg/kg/12 hours. To compensate for maturation changes or drug interaction, a method, based on estimation of individual TH CL, was described for adjusting MD.

Use of Aminophylline in the Treatment of Severe Symptomatic Bradycardia Resistant to Atropine

Bradycardia and cardiac arrest are known complications of acute spinal cord injuries and are usually temporary. If the general measures of correcting hypoxia and using atropine fail, placement of a temporary followed by a permanent pacemaker is typically considered. We describe 2 very interesting cases of severe symptomatic bradycardia resistant to atropine, where we were able to obviate the use of pacemaker placement by the simple use of intravenous aminophylline. Aminophylline had been used in the past for treating resistant bradycardia in settings such as acute inferior wall myocardial infarction, cardiac transplantation, and so on, but has never been used in the setting of acute spinal cord injuries. Aminophylline probably works in this setting by increasing cyclic adenosine monophosphate (cAMP) and activating the sympathoadrenal system.

[Hemodynamic effects of aminophylline and nifedipine in patients with high altitude pulmonary edema]

AIM

To evaluate the hemodynamic effects of aminophylline and nifedipine in patients with HAPE.

METHODS

10 patients with HAPE undergone Swan-Ganz catheter. The parameters of hemodynamics and arterial blood gases in HAPE were measured before and after administration of nifedipine 20 mg sublingually and aminophylline 0.25 g intravenously respectively.

RESULTS

After administering 0.25 g aminophylline the mPAP and PVR significantly decreased, the cardiac output and the level of PaO2, SaO2 increased obviously, the mSAP, HR did not change so much. After using 20 mg nifedipine, the mPAP, PVR and mSAP also decreased, while the cardiac output, HR and the level of PaO2, SaO2 did not show any changes.

CONCLUSION

Both of aminophylline and nifedipine can attenuate pulmonary hypertension in patients with HAPE, but the effect of aminophylline was better than the effect of nifedipine.

Theophylline, aminophylline, caffeine and analogues for acute ischaemic stroke

BACKGROUND

Theophylline causes potent cerebral vasoconstriction which decreases blood flow in the non-ischaemic areas of the brain and increases collateral blood flow surrounding the ischaemic region. NOTE: This review covers an area where no active research is taking place. It will be updated if relevant information becomes available, e.g. on completion of an appropriate study.

OBJECTIVES

The objective of this review was to assess the effect of theophylline and its analogues, aminophylline and caffeine, in people with confirmed or presumed acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched November 2003). For the first version, we also searched EMBASE (1980 to 1999), MEDLINE (1966 to 1999) and Science Citation Index (1981 to 1999). We also contacted the principal investigators of the identified trials.

SELECTION CRITERIA

Randomised trials of theophylline or an analogue compound compared with placebo or control in people with confirmed or presumed acute ischaemic stroke. Trials were included if treatment was started within one week of stroke onset.

DATA COLLECTION AND ANALYSIS

Three reviewers applied the inclusion criteria, assessed trial quality and extracted data for the first version. The review was updated by one reviewer.

MAIN RESULTS

Two trials involving just 119 patients were included; 6 studies were excluded. Trial quality was good. Both of the trials tested aminophylline. Analysis was by intention-to-treat where possible. No significant difference was shown in early case fatality (within four weeks) between aminophylline and placebo although the confidence intervals were wide (odds ratio [OR] 1.12, 95% confidence interval [CI] 0.49 to 2.56). There was no significant difference for early death and deterioration (OR 0.87, 95% CI 0.41 to 1.88). Death or disability was not significantly reduced by treatment based on 73 patients in one trial (OR 0.64, 95% CI 0.24 to 1.68). Data for late death and disability were not in a form suitable for analysis. No data on quality of life were available.

REVIEWERS' CONCLUSIONS

There is not enough evidence to assess whether theophylline or its analogues, e.g. aminophylline, are safe and improve outcome in people with acute ischaemic stroke.

Best evidence topic reports. Is intravenous aminophylline better than intravenous salbutamol in the treatment of moderate to severe asthma?

A short cut review was carried out to establish whether intravenous salbutamol or intravenous aminophylline offers the quickest and least complicated treatment for patients with moderate to severe asthma not responding to inhaled therapy. Altogether 71 papers were found using the reported search, of which nine presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are tabulated. A clinical bottom line is stated.

[Effect of Shen-Mai injection and aminophylline on diaphragmatic muscle cell apoptosis and related gene expression in rats with chronic hypoxia]

OBJECTIVE

To investigate the effect of Shen-Mai injection (SMI) and aminophylline on diaphragmatic muscle cell apoptosis and the Fas/FasL expression in chronic hypoxic rats.

METHODS

Seventy-five male Wistar rats were randomly divided into three equal groups, control group (A group), SMI group (B group) and aminophylline group (C group). Then each group was further divided into five subgroups of pre-hypoxia, hypoxia 1 w, 2 w, 3 w and 4 w groups (5 rats each). The concentration of oxygen was (10 +/- 3)%, 7 d/w, 8 h/d for all groups, but only B group and C group received SMI (2 ml/d) and aminophylline (10 mg/kg) respectively. Apoptosis and Fas/FasL expression of diaphragmatic muscle cells were examined by the streptavidin biotin-peroxidase complex (SABC) immunohistochemistry techniques and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay, and Dunnett-t test was employed to compare the effects of SMI and aminophylline.

RESULTS

(1) Fas, FasL expression in normal diaphragmatic muscle cells was very low with a positive rate of (2.77 +/- 0.45)% and (2.32 +/- 0.61)%. After hypoxia, the positive rates increased with the time of hypoxia time. SMI showed an inhibition on diaphragmatic muscle cell Fas and FasL expression;after hypoxia 1 w, 2 w, 3 w and 4 w, Fas expression [(6.36 +/- 4.17)%, (9.77 +/- 4.12)%, (18.02 +/- 6.91)% and (21.09 +/- 8.09)%] and FasL expression [(5.32 +/- 6.16)%, (9.58 +/- 3.79)%, (12.01 +/- 8.71)%, (19.43 +/- 10.31)%] in B group were different from those in A group respectively (all P < 0.05). But aminophylline did not show such an effect, the expression of Fas [(10.87 +/- 3.62)%, (24.13 +/- 3.79)%, (35.39 +/- 9.02)%, (39.56 +/- 10.12)%] and FasL [(9.37 +/- 4.07)%, (20.16 +/- 4.88)%, (31.81 +/- 7.07)%, (35.51 +/- 9.13)%] were not significantly different from those in A group respectively (all P > 0.05). (2) Diaphragmatic muscle cell apoptosis was very low in normal rats with a rate of (0.93 +/- 0.29)%, which also increased after hypoxia and the increase was associated with the time of hypoxia. Apoptosis rate was decreased by the administration of SMI, the rates of B group were (5.01 +/- 3.71)%, (9.37 +/- 3.12)%, (14.66 +/- 8.76)%, (18.16 +/- 7.02)%, respectively. Except for the first week, the differences of other weeks were all statistically significant when compared with A groups (all P < 0.05). But the effect of aminophylline was different, as compared to A group, only the apoptosis rate in hypoxia 4 w [(30.92 +/- 11.13)%] of C group being statistically significant different (P < 0.05).

CONCLUSIONS

Fas and FasL participated in diaphragmatic muscle cell apoptosis in rats with chronic hypoxia. SMI showed a definite effect on the Fas and FasL protein expression and decreased diaphragmatic muscle cell apoptosis, which contributed to the therapeutic effect on diaphragmatic fatigue caused by hypoxia.

Methylxanthines for exacerbations of chronic obstructive pulmonary disease: meta-analysis of randomised trials

OBJECTIVE

To evaluate the addition of methylxanthines to standard treatments in patients presenting with acute exacerbations of chronic obstructive pulmonary disease (COPD).

DESIGN

Meta-analysis of randomised controlled trials.

DATA SOURCE

The Cochrane airways review group's COPD register. Two reviewers independently selected articles for inclusion, assessed methodological quality, and extracted data.

SELECTION OF STUDIES

Four trials met the inclusion criteria, with 169 patients.

MAIN OUTCOME MEASURES

Mean change in spirometry, clinical end points, symptom scores, and adverse events.

RESULTS

Mean change in forced expiratory volume at one second at two hours was similar in methylxanthine and placebo groups but transiently increased with methylxanthines at three days. Non-significant reductions in admissions to hospital and length of stay were offset by a non-significant increase in relapses at one week. Changes in symptom scores did not reach significance. Methylxanthines caused more nausea and vomiting than placebo (odds ratio 4.6, 95% confidence interval 1.7 to 12.6), and non-significant increases in tremor, palpitations, and arrhythmias were also observed.

CONCLUSIONS

The available data do not support the use of methylxanthines for the treatment of exacerbations of chronic obstructive pulmonary disease. Potential benefits of methylxanthines for lung function and symptoms were generally not confirmed at standard levels of significance, whereas the potentially important adverse events of nausea and vomiting were significantly increased in patients receiving methylxanthines.