Intravenous Aminophylline Research Articles

Acute exacerbations in chronic obstructive pulmonary disease: current strategies with pharmacological therapy.

In acute exacerbation of chronic obstructive pulmonary disease (AECOPD), short-acting inhaled bronchodilators, such as salbutamol (albuterol) and ipratropium bromide, have proven useful. In patients who are refractory to these agents, intravenous aminophylline should be considered. Corticosteroids should also be used, either in the outpatient or inpatient setting. The duration of corticosteroids should probably not exceed 2 weeks and the optimum dosage is yet to be determined. Antibacterials, especially in patients with purulent or increased sputum, should be used, guided by the local antibiogram of the key microbes. Controlled oxygen therapy improves outcome in hypoxaemic patients and arterial blood gases should be performed to ensure hypercarbia is not becoming excessive. Should patients be in distress despite the above measures or if there is acidaemia or hypercarbia, noninvasive positive pressure ventilation could be used to improve outcomes without resorting to invasive mechanical ventilation. Mucous-clearing drugs and chest physiotherapy have no proven beneficial role in AECOPD.

Ventilación mecánica en el estado asmático

The indications for mechanical ventilation in status asthmaticus are cardiopulmonary arrest, significant alteration of consciousness, respiratory exhaustion, and progressive respiratory insufficiency despite aggressive bronchodilator treatment. In mechanical ventilation for status asthmaticus, a specific strategy directed at reducing dynamic hyperinflation must be used, with low tidal volumes and long expiratory times, achieved by diminishing respiratory frequency. This ventilatory pattern produces permissive hypercapnia, which is generally well tolerated with suitable sedation. The best methods for detecting and/or controlling dynamic hyperinflation in ventilated patients with status asthmaticus are the flow/time and flow/volume respiratory curves, pulmonary volume at the end of inspiration, and the pressure plateau. In addition to mechanical ventilation the child must receive sedation with or without a muscle relaxant to prevent barotrauma and accidental extubation. Bronchodilator treatment with beta-adrenergic agonists, methyl-prednisolone, and intravenous aminophylline are also required. A combination of inhaled salbutamol and nebulized ipratropium in the inspiratory branch of the ventilator should be used in patients in whom this treatment is effective. Currently there is insufficient evidence on the efficiency of other treatments in status asthmaticus and these should be used as rescue treatments.

Uso de terapias não convencionais no manejo da crise aguda de asma refratária

Uma paciente em crise aguda de asma, refratária ao uso de beta2-agonista inalatório e intravenoso, aminofilina intravenosa e corticóide, em ventilação mecânica, foi tratada com métodos terapêuticos não convencionais: broncoscopia, lavado broncoalveolar com N-acetilcisteína e ventilação com halotano. Houve melhora dos parâmetros ventilatórios após o lavado e a resolução do broncoespasmo ocorreu após a anestesia, propiciando a extubação e alta da UTI. É feita uma revisão da literatura sobre o uso desses métodos na crise aguda de asma.

Addition of intravenous aminophylline to β2 -agonist in adults with acute asthma

[Ann Emerg Med. 2002;40:350-352.]

Hospital Management of Children with Acute Asthma Exacerbations in Kuwait: Adherence to International Guidelines

Objectives: To evaluate the in-patient management of children with acute exacerbation of bronchial asthma and its adherence to international guidelines. Subjects and Methods: Medical records of 100 consecutive admissions for acute exacerbation of asthma to the paediatric wards at Mubarak Al-Kabeer Hospital, Kuwait, from October through December 1999 were retrieved. Data relevant to asthma symptoms, severity, treatment regimens and discharge plan were collected and evaluated. The mean age of patients was 4.3 years, ranging from 2 to 12 years. Admissions totalled 82 males and 18 females, with hospital stays ranging from 1 to 11 days (mean = 2.6 days). Results: There were no fatalities. Reported episodes were severe (17%), moderate (11%) and mild (9%); degree of severity was not documented in 63 cases. Pulse, respiratory rate, colour and use of accessory muscles were not documented in 48, 48, 47 and 63% of the patients, respectively. Arterial blood gas was checked in 16 patients and pulse oximetry in 71. Full blood count, serum urea and electrolytes were obtained in 86 patients and chest radiographs in 76. All patients received nebulized salbutamol. However, some received additional medications: ipratropium bromide (79%), steroids (95%), intravenous aminophylline (5%) and antibiotics (43%). Two children were shifted to an intensive care unit, 1 of whom needed intubation. On discharge, there was no documentation of follow-up arrangements, or prophylactic anti-inflammatory drugs or other medications in 52, 81 and 32 patients, respectively. Conclusion: Patient management showed deficits, and documentation was inadequate. Areas of particular concern were assessment of patients, unnecessary investigations and use of antibiotics, and lack of post-discharge planning and prophylaxis with steroids. Adherence to the international guidelines was partial.

Effect of passive smoking on theophylline clearance in children.

The author investigated the effects of passive tobacco smoking on the metabolism of theophylline in a pediatric population. In a retrospective analysis of 201 children admitted to a pediatric unit for asthma, 31 were identified with an acute exacerbation of asthma of noninfectious origin in which environmental exposure to tobacco smoke could be established. The parents were known smokers with a minimum 1-pack-per-day habit. An age-and gender-matched control population of children was then identified who had an acute exacerbation of asthma without any environmental exposure to tobacco smoke. In addition, the patients in both groups received the same dose of intravenous aminophylline for a minimum of 48 hours to ensure steady-state conditions. Total body clearance of theophylline was significantly elevated in the children exposed to environmental tobacco smoke (1.36 +/- 0.09 vs. 0.90 +/- 0.04 mL/min per kg, p < 0.0001). Steady-state serum levels were significantly lower in the passive smoking group (55.3 +/- 2.8 vs. 73.2 +/- 3.3 p < 0.00001) for those receiving nearly identical intravenous doses. The length of hospital stay was longer in the group exposed to passive smoke (4.4 +/- 2.6 vs. 2.9 +/- 1.3 days, p < 0.05). The clearance of theophylline is greater in asthmatic children exposed to passive tobacco smoke than in asthmatic children not exposed to passive tobacco smoke. These findings suggest that passive smoking may increase the clearance of other drugs metabolized in a manner similar to theophylline.

The safety of dipyridamole in patients undergoing myocardial perfusion scintigraphy prior to lung volume reduction surgery.

Patients with end-stage chronic obstructive pulmonary disease (COPD) undergoing lung volume reduction surgery (LVRS) are at high risk of peri-operative cardiac complications, and myocardial perfusion scintigraphy (MPS) is commonly used for risk stratification. This study prospectively assessed the safety of dipyridamole in these patients and compared the incidence of side-effects (particularly dyspnoea) with that in patients undergoing dipyridamole MPS prior to elective non-cardiothoracic surgery. Fifty patients were enrolled: 25 in the LVRS cohort (13 males, 12 females), with a mean age of 65 years and a mean FEV1 of 0.791, and 25 (with no history of asthma or COPD) in the control cohort (14 males, 11 females), with a mean age of 66 years. Fourteen patients (56%) in each group developed side-effects. Dyspnoea was reported by five patients (20%) in the LVRS and two patients (8%) in the control cohort (P=NS). One patient in each cohort developed severe hypotension and bradycardia. Eight (32%) other patients developed minor side-effects in the LVRS cohort compared with 11 (44%) in the control group. All side-effects responded promptly to intravenous aminophylline. In summary, there was a statistically non-significant increase in the incidence of dyspnoea in patients with end-stage COPD and all side-effects responded to aminophylline. Thus, dipyridamole can be used safely in these patients.

A pilot study to investigate the effects of an infusion of aminophylline on renal function following major abdominal surgery

Acute renal failure is a frequent complication of critical illness and optimal preventive therapy remains elusive. There is increasing evidence from animal models and some human studies that adenosine receptor antagonism by aminophylline may reduce the severity of renal impairment caused by a variety of aetiologies. We studied the renal effects of intravenous aminophylline in an unblinded, within-patient study of 20 patients admitted to a general intensive care unit following major surgery. We demonstrated that there were no adverse cardiovascular complications related to aminophylline therapy. Renal sodium and osmolar clearance increased with a non-significant trend towards increased diuresis during treatment. Creatinine clearance, however, was unchanged but the study was not designed and did not have the power to test whether aminophylline increased renal blood flow or glomerular filtration rate. We suggest the renal actions of aminophylline in critical illness merit further investigation.

Review: Intravenous aminophylline does not have additional benefit when added to β2-agonists for acute asthma

Source Citation Parameswaran K, Belda J, Rowe BH. Addition of intravenous aminophylline to beta2-agonists in adults with acute asthma. Cochrane Database Syst Rev. 2000;(4):CD002742 (latest version 19 Jun 2000). 11034753 (All 2001 articles were reviewed for relevancy, and abstracts were last revised in 2007.)

Theophylline metabolism after cardiac surgery.

The effect and metabolism of theophylline administration after cardiac surgery has never been reported. Two series of 2-hour intravenous aminophylline administrations (3 mg/kg/h) were conducted in 10 adult patients on the operative day (acute phase) and on the 4th or 5th postoperative day (recovery phase). Both blood and urine samples were collected for 24 hours after dosing. Heart rate increased in both phases, but the cardiac index increased with the decrease of diastolic blood pressure only in the acute phase (p < 0.05). Plasma concentration levels of theophylline tended to be slightly higher in the acute phase, and renal clearance increased in the recovery phase (p < 0.05). The urinary ratio of 3-methylxanthine to theophylline was significantly higher in the acute phase (p < 0.05). This suggests that cytochrome P4501A2 is partially activated rather than depressed and that N-demethylation is promoted more than hydroxylation immediately after surgery.

Should aminophylline be abandoned in the treatment of acute asthma in adults?

Intravenous aminophylline is widely used for the treatment of acute asthma and anecdotes about its apparent effectiveness abound. Early studies demonstrated that aminophylline is an inefficient bronchodilator compared with adrenergic agonists given by injection or inhalation. This paper presents the results of a review of randomized controlled trials examining the effect of adding aminophylline to standard modern therapy with a nebulized beta(2) agonist and systemic corticosteroids in acute asthma in adults. Six of the seven trials, comprising 343 patients, failed to demonstrate any beneficial effect of aminophylline. Furthermore, minor toxicity was common. There is presently no evidence to support the use of aminophylline in addition to standard therapy for acute asthma in adults.

Addition of intravenous aminophylline to beta2-agonists in adults with acute asthma.

Aminophylline has been used extensively in acute asthma, but its role is unclear especially with respect to any additional benefit when added to beta2-agonists. To determine the magnitude of effect of the addition of intravenous aminophylline to beta2-agonists in adult patients with acute asthma treated in the emergency setting. Studies were identified from the following sources: The Cochrane Airways Group register (derived from MEDLINE, EMBASE, CINAHL standardised searches), hand searched respiratory journals and meeting abstracts. Potentially relevant articles were obtained, and their bibliographic lists were hand searched for additional articles. The search included searches of the database up to 1999. Randomised controlled trials comparing intravenous aminophylline versus placebo in adults with acute asthma and treated with beta-adrenergic agonists. Patients could be treated with or without corticosteroids or other bronchodilators. A total of 210 abstracts were identified. Two independent reviewers selected a total of 27 eligible studies for possible inclusion, in which quality assessment was performed and a third reviewer was used to adjudicate disagreements. Peak expiratory flow (PEFR) and forced expiratory volume in the first second (FEV1) data were extracted and entered in Review Manager from these studies. Information not obtained from the authors was estimated from graphs. All data were entered and double checked by two reviewers. Results are reported as weighted mean differences (WMD) or odds ratio (OR), both with 95% confidential intervals (CI). Fifteen trials were included. Overall, the quality of the studies was only moderate; concealment of allocation was assessed as clearly adequate in only seven (45%) of the trials. The doses of aminophylline and other medications and the severity of asthma varied between studies. There was no statistically significant effect of aminophylline on airflow outcomes at any time period. The aminophylline treated group had higher values of PEFR at 12 (PEFR 8 L/min or 2.3%) and 24 hours (PEFR 22 L/min or 6.4%), but these were not significant (p>0.05). Two subgroup analyses were performed by grouping studies according to mean baseline airflow limitation (n = 11 studies) and the use of any steroids (n = 9 studies). There was no relationship between baseline airflow limitation nor the use of steroids on the effect of aminophylline. Aminophylline treated patients reported more palpitations/arrhythmias (OR: 2.9; 95% CI: 1.5 to 5.7) and vomiting (OR: 4.2; 95% CI 2.4 to 7.4), but no difference was found in tremor or hospital admissions. In acute asthma, the use of intravenous aminophylline did not result in any additional bronchodilation compared to standard care with beta-agonists. The frequency of adverse effects was higher with aminophylline. No subgroups in which aminophylline might be more effective could be identified. These results should be added to consensus statements and guidelines.

Evaluation of coronary flow reserve in hypertensive patients by dipyridamole transesophageal Doppler echocardiography

This study evaluates the coronary flow reserve (CFR) in hypertensive patients with and without left ventricular (LV) hypertrophy. CFR was assessed by transesophageal Doppler echocardiography in 15 normal subjects (group I), 21 hypertensive patients without LV hypertrophy (group II), and 27 hypertensive patients with LV hypertrophy (group III). All hypertensive patients were complaining of typical anginal pain and had normal coronary angiograms. The sample volume was placed at the bifurcation of the left main and left anterior descending coronary arteries. Coronary blood flow velocities were evaluated at rest, 2 minutes after dipyridamole infusion, and 2 minutes after intravenous aminophylline. The ratios of dipyridamole to rest peak diastolic and systolic velocities were considered as indexes of CFR. Peak diastolic velocity ratio was significantly lower in group III than in groups I and II (1.6 ± 0.2, 2.7 ± 0.4, and 2.1 ± 0.2, respectively; p <0.05), and it was significantly lower in group II than I (p <0.05). The peak systolic velocity ratio was significantly lower in group III than in groups I and II (1.7 ± 0.3, 2.8 ± 0.3, and 2.1 ± 0.2, respectively; p <0.05), and it was significantly lower in group II than I (p <0.05). The peak diastolic velocity ratio was inversely related to systolic blood pressure, diastolic blood pressure, and LV mass index (r = −0.48, −0.51, and −0.37 respectively) in hypertensive patients. It is concluded that CFR is significantly impaired in hypertensive patients, especially those with LV hypertrophy, compared with healthy subjects. The degree of impairment of CFR is related to LV mass index.

Intravenous aminophylline for acute severe asthma in children over 2 years using inhaled bronchodilators.

Intravenous aminophylline was the bronchodilator of choice for many years until supplanted by more effective bronchodilators in the treatment of acute paediatric asthma. Recently there has been renewed interest in this therapy for children with acute severe asthma. To determine whether addition of intravenous aminophylline produces a beneficial effect in children with acute severe asthma receiving oxygen, maximised inhaled bronchodilators and oral/intravenous glucocorticoids. The Cochrane Airways Group register of trials (based on MEDLINE, EMBASE, CINAHL and hand searched respiratory journals) and reference lists of relevant articles were used to identify relevant studies. The latest search was carried out in October 2000. Only randomised-controlled trials comparing intravenous aminophylline with placebo in children treated with inhaled bronchodilators and systemic glucocorticoids for acute asthma were considered for this review. Full text of 35 trials were anonymized for author, date and publication and two blinded independent reviewers selected eligible studies for inclusion. Disagreement was resolved through consensus. Seven trials met the inclusion criteria. Attempts were made to contact authors to verify accuracy. Results were reported as weighted mean differences (WMD) or relative risk (RR) with 95% confidential intervals (CI). Patients in these trials were predominantly school-aged children hospitalised for acute severe asthma with a baseline FEV1 at 35-40% of predicted and/or a baseline Pulmonary Index of 6-7. Aminophylline significantly improved percentage predicted FEV1 by 6 - 8 hours (WMD 8.4%; 95% CI: 0.82, 15.92%). The effect was maintained for 24 hours. Improvements were also seen in symptom scores at 6-8 hours (WMD= -0.71; 95% CI: -0.82,-0.60). There was no reduction in hospital stay or in number of nebulisers required. Vomiting was more likely with aminophylline therapy (Relative Risk = 3.69; 95% CI: 2.15, 6.33). Addition of intravenous aminophylline should be considered early in the treatment of children hospitalised with acute severe asthma with sub optimal response to the initial inhaled bronchodilator therapy. Although the improvement is sustained for 24 hours, there is no apparent reduction in length of hospital stay or number of inhaled beta2-agonists nebulisations. Treatment with aminophylline is associated with an increased risk of vomiting.

Protective Effect of Aminophylline on Renal Perfusion Changes Induced by High-Energy Shockwaves Identified by Gd-DTPA-Enhanced First-Pass Perfusion MRI

The purpose of this study was to evaluate regional renal hemodynamics in a noninvasive manner using gadolinium-DPTA magnetic resonance imaging (MRI) before and after extracorporeal shockwave lithotripsy (SWL). In addition, the renoprotective effect of intravenous aminophylline was evaluated on the perfusion on kidneys undergoing SWL. Ten randomly selected patients were evaluated for regional renal blood flow in the cortex and medulla with Gd-DTPA MRI studies within 2 weeks before and 4 hours after SWL. Five of these patients were treated with 500 mg of intravenous aminophylline 45 minutes prior to SWL. Renal hemodynamics were assessed utilizing relative perfusion indices (PI) calculated from signal intensity-v-time curves obtained from regions of interest (ROI). The ROI choice was based on the contrast-enhanced MRI images. Relative PIs of pre-SWL and post-SWL studies were compared in the first group of patients. Relative PIs of the treated kidney were compared with those of the contralateral kidney in the second group of patients, who received aminophylline. In the group not treated with aminophylline, there was no significant difference in cortical perfusion before SWL (average PI -7+/-3%). However, after lithotripsy, there was a reduction of cortical flow (average PI 31+/-12%) in the treated kidney. In the group treated with aminophylline, renal hemodynamics study after SWL revealed no significant difference in relative perfusion (average PI -8+/-6%). Relative PIs of the medulla were small for all patients, but standard errors were large, indicating a wide range of values. This study helps to establish reduced cortical flow after SWL and demonstrates that aminophylline attenuated this response in the kidneys subjected to lithotripsy. It appears that aminophylline administration causes no alteration in medullary blood flow.

The effect of aminophylline administration on 99mTc-MIBI lung and liver uptake in patients with or without myocardial ischemia

This work aims to analyze the influence of aminophylline in the pulmonary and hepatic uptake of 99mTc-methoxyisobutil isonitrile (99mTc-MIBI). 72 patients were studied and a myocardial perfusion (MPS) single photon emission computed tomography (SPECT) with 99mTc-MIBI was carried out after the administration of dipyridamole. According to the MPS, the patients were classified into 2 groups: Group A: 45 patients without myocardial ischemia and Group B: 27 with ischemia. Each group was divided into 2 subgroups according to whether they had (I) or had not (II) received intravenous aminophylline. The dipyridamole was administered for 4 minutes at a dose of 0.56 mg/kg. If the patients presented any complication, intravenous aminophylline was administered. At 30 minutes p.i., planar images were obtained during a scintigraphy in the interior projection after the injection of 99mTc-MIBI. The regions of interest in the heart, hepatic cupula, and most active area of the left lung were outlines and the activity rates were calculated: lung/heart (LHR) and liver/heart (LivHR). No statistically significant differences were observed in the uptake of 99mTc-MIBI between subgroups I and II. However, the LHR rates in both subgroups were significantly lower in the patients with normal myocardial perfusion than in the patients with ischemia: LHR group A1 vs B1: 0. 32 +/- 0.08 vs 0.36 +/- 0.06, p = 0.03; group AII vs BII 0.31 +/- 0. 07 vs 0.35 +/- 0.07, p = 0.01 respectively. In conclusion, the administration of aminophylline, after the infusion of dipyridamole for MPS, does not modify the pulmonary or hepatic uptake of 99mTc-MIBI.

Effects of intravenous theophylline, aminophylline and ethylenediamine on antigen-induced bronchoconstriction in guinea pigs.

The antiasthmatic effect of i.v. injection of theophylline was compared with that of aminophylline by using an antigen-induced bronchoconstriction model in sensitized guinea pigs. Both theophylline and aminophylline showed dose-dependent inhibition of antigen-induced bronchoconstriction. Statistically significant differences were observed at theophylline doses of 20 and 40 mg/kg and at aminophylline doses of 25 and 50 mg/kg. Thus, antiasthmatic effects of both drugs appeared to be similar. In addition, intravenous ethylenediamine did not influence either airflow in normal guinea pigs or bronchoconstriction induced by antigen at doses up to 30 mg/kg. In conclusion, the ethylenediamine in aminophylline may not influence the antiasthmatic action of theophylline, and the therapeutic effects of theophylline and aminophylline are suggested to be similar.

Clinical Effects of Theophylline on Inspiratory Muscle Drive in Tetraplegia

Theophylline has been shown to restore diaphragmatic function in animals following cervical spinal cord hemisection, which induces hemidiaphragm paralysis. Although theophylline had been used clinically in the treatment of various pulmonary diseases, its effects on respiratory muscle function in cervical spinal cord injured tetraplegics has not been studied. In the present case study, we evaluated a patient injured in 1979 with a chronic asymmetric C5-7 tetraplegia (left C5-6, right C6-7) before and after receiving theophylline chronically by mouth for three weeks and again before and after receiving acute intravenous (IV) aminophylline after the effects of the chronic drug administration wore off. Neural activation to inspiratory muscles was assessed by right and left parasternal intercostal and diaphragm EMGs during quiet breathing and max imal inspiratory efforts. Global respiratory drive was assessed by P100, and inspiratory muscle force was assessed by maximal inspiratory pressures and vital capacity. Both long-term orally administered and acute IV theophylline increased neural activation to the diaphragm, especially on the more affected left side. Theophylline treatment was also associated with an increase in global central respiratory drive and inspiratory muscle force, without changing expiratory airflows. Left diaphragm EMG activity was markedly increased following the administration of theophylline. Of interest, upper parasternal intercostal EMG activity was also recruited on the left in spite of being below the level of cervical injury. We speculate that the administration of theophylline in selected patients with an asymmetric cervical spinal cord injury may activate la tent bulbospinal respiratory pathways and improve inspiratory muscle function, re ducing the likelihood of associated respiratory failure.

Reversal of propranolol blockade of adrenergic receptors and related toxicity with drugs that increase cyclic AMP.

An overdose of propranolol, a widely used nonselective beta-adrenergic receptor blocking agent, can result in hypotension and bradycardia leading to irreversible shock and death. In addition, the blockade of adrenergic receptors can lead to alterations in neurotransmitter receptors resulting in the interruption of the activity of other second messengers and the ultimate cellular responses. In the present experiment, three agents, aminophylline, amrinone, and forskolin were tested in an attempt to reverse the potential lethal effects of a propranolol overdose in dogs. Twenty-two anesthetized beagle dogs were given a 10-min infusion of propranolol at a dose of 1 mg/kg/min. Six of the dogs, treated only with intravenous saline, served as controls. Within 15-30 min all six control dogs exhibited profound hypotension and severe bradycardia that led to cardiogenic shock and death. Seven dogs were treated with intravenous aminophylline 20 mg/kg 5 min after the end of the propranolol infusion. Within 10-15 min heart rate and systemic arterial blood pressure returned to near control levels, and all seven dogs survived. Intravenous amrinone (2-3 mg/kg) given to five dogs, and forskolin (1-2 mg/kg) given to four dogs, also increased heart rate and systemic arterial blood pressure but the recovery of these parameters was appreciably slower than that seen with aminophylline. All of these animals also survived with no apparent adverse effects. Histopathologic evaluation of the hearts of the dogs treated with aminophylline showed less damage (vacuolization, inflammation, hemorrhage) than the hearts from animals given propranolol alone. Results of this study showed that these three drugs, all of which increase cyclic AMP, are capable of reversing the otherwise lethal effects of a propranolol overdose in dogs.

Aminophylline in undifferentiated out-of-hospital asystolic cardiac arrest

Primary objective: To determine if the introduction of intravenous aminophylline, a nonspecific adenosine receptor antagonist, into the resuscitation algorithm of asystole will increase return of spontaneous circulation when used in undifferentiated prehospital cardiac arrest. Methods: An urban, prehospital, prospective, randomized, double-blind, placebo-controlled trial of nonpregnant normothermic adults suffering nontraumatic out-of-hospital asystolic cardiac arrest. Subjects were treated in accordance with published advanced cardiac life support guidelines and standard pharmacotherapy. They were randomly assigned to receive either placebo or aminophylline along with the initial boluses of atropine and epinephrine. Cardiac rhythms and carotid pulses were monitored throughout the resuscitation. Results: Eighty-two patients were entered into the trial. Forty-five patients were assigned to the placebo group and 37 received aminophylline. Nine of 45 controls (20%; 95% CI 10–35%) achieved return of spontaneous circulation compared to ten of 37 (27%; 95% CI 14–44%) in the aminophylline group. Conclusions: We were not able to show a statistically significant improvement in return of spontaneous circulation when aminophylline was given during the early resuscitation phase of undifferentiated asystolic cardiac arrest in the prehospital setting with this sample size.