Effective treatment of acute hyperkalaemia in childhood by short-term infusion of salbutamol

Hyperkalaemia is a lifethreatening emergency and infusion of glucose with insulin has so far been regarded as the standard treatment of choice. Recently the -2 stimulatory drug salbutamol has been shown to be an effective agent to treat hyperkalaemia by inducing a shift of potassium into the intracellular compartment. We treated 15 children aged 0.1–14 (mean 5.2) years suffering from acute hyperkalaemia (mean level 6.6±0.54, range 5.9–7.7 mmol/l) with a single infusion of salbutamol (5 g/kg over 15 min). Serum potassium concentrations decreased significantly within 30 min to levels of 5.74±0.53 and 4.92±0.53 mmol/l after 120 min (P<0.001, respectively). No side-effects occurred other than a slight increase in heart rate in 3 patients.Conclusion A single intravenous infusion of salbutamol at a dose of 5 g/kg is a highly effective treatment for hyperkalaemia with minimal clinical side-effects. The effect lasts for at least 120 min and may reverse hyperkalaemia in some patients without further interventions so that salbutamol seems justified as the first choice treatment for this condition in childhood.     

Preliminary study of electrocautery smoke particles produced in vitro and during laparoscopic procedures

Background: The objective of this preliminary study was to describe the particles contained in cautery smoke produced during five laparoscopic procedures and verify the collection method during three laboratory experiments on ex vivo animal tissue. Methods: A cascade impactor collected the smoke according to particle size, and particle weights were calculated on an electronic microbalance. Electron microscopic analysis and energy dispersive X-ray evaluation were used to determine particle morphology and elemental composition. Results: The particles, distributed according to size on the seven rotating trays of the impactor, had diameters ranging from 0.05 to >25 m, with most being 0.1–1 m. In vitro experiments yielded more particles, especially larger (>5 m) ones, than the surgical procedures, because the cauterized specimens could be placed much closer to the cascade impactor in the laboratory environment, eliminating most obstacles to particle recovery. In the laparoscopic surgery patients, larger particles, because of their physical properties, were more likely to remain trapped in the abdomen or to drop off in the collection apparatus. Uniformly, two populations of particles were demonstrated—either large, irregular fragments (2–25 m) rich in carbon and oxygen, suggesting structural cellular components, or small homogeneous spheres (0.1–0.5 m) composed of sodium, magnesium, calcium, and potassium salts. Conclusions: This study demonstrates the presence of breathable areosols and cell-size fragments in the cautery smoke produced during laparoscopic procedures. Their exact chemical composition and potential adverse effects for patients and personnel are not known.     

Metabolic acidosis due to inhaled salbutamol toxicity: A hazardous side effect complicating management of suspected cases of acute severe asthma

Metabolic acidosis has seldom been reported during treatment of asthma with use of beta agonist but not with much clinical consequence. We report two cases of metabolic acidosis with hyperventilation as a direct effect of salbutamol that caused difficulty in assessment and management of their respiratory symptoms which resolved with appropriate tapering of beta agonist.     

Bronchodilation and safety of supratherapeutic doses of salbutamol or ipratropium bromide added to single dose GSK961081 in patients with moderate to severe COPD

BackgroundThere are few data on the bronchodilatory effects of adding short-acting bronchodilators (SABA) to maintenance, long-acting bronchodilator therapy. This study assessed the additional bronchodilation and safety of adding supratherapeutic doses of salbutamol (SALB) or ipratropium bromide (IPR) to the novel bi-functional molecule (or dual pharmacophore) GSK961081 400 μg (MABA 400) or 1200 μg (MABA 1200).MethodsThis randomised, double-blind, complete, crossover study in 44 patients with moderate to severe COPD, evaluated 6 treatments with a washout of at least 7 days between treatments: single doses of MABA 400 or MABA 1200 followed by cumulative doses of either SALB (3× 200 μg at 20 min intervals), IPR (20 μg, 20 μg and 40 μg at 20 min intervals) or placebo (PLA) (three doses at 20 min intervals) at 1 h, 12 h and 24 h post-MABA dose. The primary endpoint was maximal increase in FEV₁, from pre-dose bronchodilator (SABA/PLA), measured 15 min after each cumulative dose of SALB, IPR or PLA. Systemic pharmacodynamics (potassium, heart rate, glucose and QTc), adverse events and systemic pharmacokinetics were also assessed.ResultsThe additional bronchodilatory effects at 12 h and 24 h for both SALB and IPR were of a similar magnitude and statistically significant relative to PLA; mean differences (SE) (L) following MABA 400 dosing: 0.139 (0.023) after SALB at 12 h; 0.123 (0.022) after SALB at 24 h; 0.124 (0.023) after IPR at 12 h; 0.141 (0.021) after IPR at 24 h; and after MABA 1200 dosing: 0.091 (0.023) after SALB at 12 h; 0.126 (0.022) after SALB at 24 h; 0.055 (0.023) after IPR at 12 h; 0.122 (0.022) after IPR at 24 h. Any additional bronchodilator effects at 1 h were small and not clinically significantly different from PLA. There were small, non-clinically significant increases in mean heart rate after both MABA doses plus SALB, and decreased potassium levels in four patients after MABA 1200 plus SALB (×3) or PLA (×1) were observed but overall all treatments were well tolerated and raised no significant safety signals.ConclusionThe additional bronchodilation achieved following supratherapeutic doses of SALB and IPR on top of single doses of MABA 400 or 1200 was comparable for the two agents and neither were associated with any clinically relevant systemic pharmacodynamic effects other than the small transient hypokalemic effect in a 3 out of 41 patients receiving additional high dose salbutamol and MABA 1200. Either short-acting bronchodilator could potentially be used as rescue medication on top of MABA therapy.     

Relation between extracellular [K+], membrane potential and contraction in rat soleus muscle: modulation by the Na+-K+ pump

An increased extracellular K⁺ concentration ([K⁺]₀) is thought to cause muscle fatigue. We studied the effects of increasing [K⁺]₀ from 4 mM to 8–14 mM on tetanic contractions in isolated bundles of fibres and whole soleus muscles from the rat. Whereas there was little depression of force at a [K⁺]₀ of 8–9 mM, a further small increase in [K⁺]₀ to 11–14 mM resulted in a large reduction of force. Tetanus depression at 11 mM [K⁺]_o was increased when using weaker stimulation pulses and decreased with stronger pulses. Whereas the tetanic force/resting membrane potential (E _M) relation showed only moderate force depression with depolarization from –74 to –62 mV, a large reduction of force occurred whenE _M fell to –53 mV. The implications of these relations to fatigue are discussed. Partial inhibition of the Na⁺-K⁺ pump with ouabain (10^–6 M) caused additional force loss at 11 mM [K⁺]₀. Salbutamol, insulin, or calcitonin gene-related peptide all stimulated the Na⁺-K⁺ pump in muscles exposed to 11 mM [K⁺ ₀] and induced an average 26–33% recovery of tetanic force. When using stimulation pulses of 0.1 ms, instead of the standard 1.0-ms pulses, force recovery with these agents was 41–44% which was significantly greater (P < 0.025). Only salbutamol caused any recovery ofE _M (1.3 mV). The observations suggest that the increased Na⁺ concentration difference across the sarcolemma, following Na⁺-K⁺ pump stimulation, has an important role in restoring excitability and force.     

布地奈德联合沙丁胺醇氧驱动治疗喘憋性肺炎痰堵的临床护理观察

目的通过布地奈德混悬液联合硫酸沙丁胺醇溶液经氧驱动雾化吸入辅助治疗喘憋性肺炎,观察喘憋性肺炎痰堵患儿的临床护理疗效。方法80例喘憋肺炎患儿随机分为两组,观察组和对照组各40例,两组患儿均常规给予抗病毒、止咳化痰、吸氧、镇静等常规治疗与护理;观察组在此基础上给予布地奈德混悬液联合沙丁胺醇溶液氧驱动雾化吸入治疗,并进行仔细的临床观察,予以综合护理措施,观察临床护理效果。结果通过仔细观察和有针对性的护理,两组患儿有效率差异有显著意义（P〈0．05）,未见不良反应和并发症。结论布地奈德混悬液联合沙丁胺醇溶液经氧驱动雾化吸入辅助治疗,结合临床观察和综合护理,可有效解除喘憋性肺炎患儿的痰堵,缓解临床症状,缩短病程,提高治愈率。     

硫酸沙丁胺醇丙卡特罗治疗小儿支气管哮喘的临床对照研究

目的评价高选择行β2受体激动剂硫酸沙丁胺醇治疗小儿急性轻中度支气管哮喘是否差于丙卡特罗。方法93例诊断为小儿轻中度急性支气管哮喘患儿,随机分为硫酸沙丁胺醇组(实验组)42例,丙卡特罗组(对照组)51例。分别记录患儿用药前和用药后第3,7,10,14 d的肺功能。结果用药后实验组和对照肺功能指标(FEV1%,PEF%)与治疗前相比均有显著改善(P<0.05);实验组与对照组相比,患儿用药后第3,7,10,14 d肺功能指标FEV1%(P=0.36,0.72,0.52,0.63)和PEP%(P=0.50,0.59,0.62,0.83)差别无统计学意义。结论硫酸沙丁胺醇治疗小儿急性轻中度支气管哮喘在改善肺功能方面并不差于丙卡特罗。     

El salbutamol mejora la contractilidad diafragmática en la obstrucción crónica de la vía aérea

Introduction

Chronic airflow obstruction in conditions such as chronic obstructive pulmonary disease is associated with respiratory muscle dysfunction. Our aim was to study the effects of salbutamol—a β-adrenergic agonist known to improve muscle strength in physiologic and pathologic conditions—on diaphragm contractility in an animal model of chronic airway obstruction achieved by tracheal banding.

Materials and Methods

Twenty-four Sprague-Dawley rats were randomized into a control group and 3 tracheal banding groups, 1 that received acute salbutamol treatment, 1 that received chronic salbutamol treatment, and 1 that received nothing. Arterial blood gases, acid-base balance, and in vitro diaphragmatic contractility were evaluated by measuring peak twitch tension, contraction time, contraction velocity, half-relaxation time, relaxation velocity, and force-frequency curves.

Results

The 3 study groups had significantly reduced arterial pH and increased PaCO₂ and bicarbonate levels compared to the control group (P<.05). The untreated tracheal banding group had significantly reduced peak twitch tension and contraction velocity, and a significantly lower force-frequency curve in comparison with the other groups (P<.05). The chronic treatment group had a higher relaxation velocity than the untreated study group (P<.05). The mean (SE) peak twitch tension values were 6.46 (0.90) N/cm² for the control group, 3.28 (0.55) N/cm² for the untreated tracheal banding group, 6.18 (0.71) N/cm² for the acute treatment group, and 7.09 (0.59) N/cm² for the chronic treatment group.

Conclusions

Diaphragmatic dysfunction associated with chronic airflow obstruction improves with both the acute and chronic administration of salbutamol. The mechanisms involved in respiratory muscle dysfunction warrant further study.