‘Ammonia,lactate and blood gases – A user's guide’

Basic biochemical tests are frequently obtained in acutely unwell neonates and children, as well as in some elective situations. Correct interpretation can be invaluable in identifying rare inherited primary metabolic disorders, but secondary causes of hyperammonaemia, elevated blood lactate or blood gas derangement are more common and require appropriate treatment of the underlying cause. This Personal Practice guide provides an overview of these tests and their interpretation.     

Association of dietary acid-base load and psychological disorders among Iranian women: A cross-sectional study

Metabolic acidosis, which can be affected by dietary acid-base load, seems to be associated with psychological disorders through different pathways. Given limited evidence on dietary acid-base load, we aimed to examine the association of dietary acid-base load with psychological disorders in Iranian women. This cross-sectional study was performed on 447 female subjects (20–50 years old). Dietary intake was assessed using a valid food frequency questionnaire for Iran. Dietary acid-base load was calculated through different indices including potential renal acid load (PRAL), net endogenous acid production (NEAP), and dietary acid load (DAL). To assess psychological disorders, an Iranian validated version of depression, anxiety, and stress scale (DASS-21) was used. The mean value of PRAL, NEAP, and DAL were -8.87mEq/da, 37.94mEq/day, and 30.77mEq/day, respectively. Considering a wide range of confounding variables, compared with the first tertile, a significant positive association was observed between dietary acid-base load and depression (OR_PRAL: 3.63; 95 %CI:1.97, 6.71; P_trend = 0.0001) (OR_NEAP:3.42; 95 %CI: 1.87, 6.23; P_trend = 0.0001) (OR_DAL: 3.02; 95 %CI: 1.64, 5.58; P_trend = 0.0001). Women in the high dietary acid-base load category had higher anxiety (OR_PRAL: 3.31; 95 %CI: 1.81, 6.06; P_trend = 0.0001) (OR_NEAP:3.47; 95 %CI: 1.90, 6.33; P_trend = 0.0001) (OR_DAL: 3.25; 95 %CI: 1.76, 5.98; P_trend = 0.0001). Moreover, there was a strong positive relationship between dietary acid-base load and psychologicaldistress (OR_PRAL: 3.79; 95 %CI: 2.09, 6.90; P_trend = 0.0001) (OR_NEAP: 3.67; 95 %CI: 2.04, 6.58; P_trend = 0.0001) (OR_DAL: 3.00; 95 %CI: 1.66, 5.43; P_trend = 0.0001). Women with higher dietary acid-base load score had greater odds for depression, anxiety, and psychological distress compared to lower ones.     

Recruitment and PEEP level influences long‐time aeration in saline‐lavaged piglets: an experimental model

Objectives: To evaluate aeration/ventilation in saline‐lavaged piglets during a 3‐h follow‐up after a recruitment maneuver (RM)/PEEP titration compared with PEEP 10 cmH₂O without a RM. Background: Lung recruitment and PEEP titration are used to find a PEEP preventing repetitive opening/collapsing of lung. Methods: Twenty‐one lung‐lavaged piglets, mean age 7 weeks and mean weight 10 kg; a RM‐group and a PEEP10‐group, were ventilated at PEEP 5 cmH₂O (baseline) followed by zero PEEP ventilation. In the RM‐group, tidal elimination of CO₂ and dynamic compliance (Cdyn) guided recruitment and PEEP titration, respectively. A final 3‐h ventilation followed using PEEP 2 cmH₂O above the first decline of Cdyn and end‐inspiratory pressure (EIP) for a target tidal volume (V_T) of 10 ml·kg^?1. In the PEEP10‐group, PEEP 10 cmH₂O without a RM was used during the final 3‐h ventilation. CT scans and blood gases were repeated every 30 min. Airway pressures, Cdyn and hemodynamics were continuously recorded. Results: Aeration improved without differences between groups. The RM‐group PEEP level of 10 ± 0.6 cmH₂O did not differ from the PEEP10‐group. Compared to baseline EIP was lower in the RM‐group after 3‐h ventilation. In both groups, driving pressure (DP) was lower and Cdyn higher than baseline. In the RM‐group, final EIP and DP were lower and Cdyn higher than in the PEEP10‐group. Conclusions: Both RM/PEEP titration and PEEP elevation resulted in improved aeration without differences between groups at the end point. Lung aeration was achieved at lower EIP and DP and higher Cdyn in the RM‐group than in the PEEP10‐group.     

高渗羟乙基淀粉(200/0.5)氯化钠注射液用于择期颅脑手术麻醉效果探讨

目的 探讨高渗羟乙基淀粉(200/0.5)氯化钠注射液用于择期颅脑手术麻醉对患者血流动力学、电解质酸碱平衡及降低颅内压效果的影响.方法 选取行择期胶质瘤切除手术患者120例,以随机抽样方法分为对照组(60例)和高渗组(60例);分别给予常规羟乙基淀粉和高渗羟乙基淀粉(200/0.5)静脉输注,比较两组患者不同时间点心率(HR),平均动脉压(MAP),中心静脉压(CVP),Na+、K+、Ca2+、pH及颅内压(ICP)等指标水平.结果 两组患者T2、T3及T4时间点HR和CVP指标均较T0时间点明显提高,差异有统计学意义(P＜0.05);两组患者T3和T4时间点MAP指标均较T0时间点显著降低,差异有统计学意义(P＜0.05);而高渗组患者T4时间点HR和MAP指标水平均明显优于对照组,差异有统计学意义(P＜0.05);两组患者T1、T2、T3及T4时间点Na+和K+指标水平与T0时间点比较差异有统计学意义(P＜0.05);两组患者T2、T3及T4时间点ICP水平较T0时间点均显著降低,差异有统计学意义(P＜0.05);高渗组患者T4时间点ICP水平显著低于对照组,差异有统计学意义(P＜0.05).结论 高渗羟乙基淀粉(200/0.5)氯化钠注射液用于行颅脑外科手术治疗患者可有效稳定血流动力学,纠正电解质酸碱平衡平衡紊乱,并抑制颅内压升高.     

High systemic HCO 3 − and topical 16,16-dimethyl-PGE2 protect gastric mucosa against luminal acid by enhancing its preepithelial buffer capacity

Systemic metabolic alkalosis and topical prostaglandins protect the gastric mucosa against luminal acid. This study investigates whether this protection is mediated by increased epithelial HCO ₃ ^– secretion with resultant alkalization of the preepithelial mucus-HCO ₃ ^– buffer layer. Surface pH of chamberedex vivo rat gastric epithelium was measured with liquid sensor pH microelectrodes during luminal perfusion of increasing acidities (0, 10, 30, 50, 100 mM HCl). The experimental groups were: (1) control, (2) topical 16,16-dimethyl-PGE₂ treatment, (3) high-HCO ₃ ^– metabolic alkalosis, and (4) low-HCO ₃ ^– respiratory alkalosis. The gastric mucosa of PGE₂-treated and high-HCO ₃ ^– alkalotic rats tolerated significantly better luminal acid than that of controls, but the tolerance of low-HCO ₃ ^– alkalotic rats was significantly impaired. There was a significant correlation between arterial HCO ₃ ^– concentration (but not arterial pH) and surface pH (r=0.81,P<0.01). This suggests that the protective actions of systemic high-HCO ₃ ^– alkalosis and topical-PGE₂ treatment in the gastric mucosa against luminal acid are, at least in part, mediated by enhanced buffer capacity of the preepithelial mucus-HCO ₃ ^– layer.This study is supported by grants from the Medical Research Council of the Academy of Finland and Sigrid Juselius Foundation, Helsinki, Finland and Orion Research Council, Espoo, Finland.     

电导滴定法测定氨基化磁性微球表面氨基含量

目的建立电导滴定法测定磁性微球表面微量氨基的化学计量点选择新方法,定量分析其氨基含量,为其表面修饰及偶联奠定基础。方法观察不同因素对滴定结果准确度的影响,在此基础上采用电导滴定法对磁性微球表面氨基进行定量测定,比较曲线拟合及电导率的变化率(ΔK)确定化学计量点2种不同方法对滴定结果的影响。结果建立了更为直接、客观的电导滴定法测定磁性微球表面微量氨基的新方法。利用滴定曲线拟合计算氨基化磁性微球表面氨基含量为(35.05±14.18)μmol/g(RSD=40.47%,n=5);而用ΔK确定化学计量点计算氨基化磁性微球表面氨基含量为(51.38±2.91)μmol/g(RSD=5.66%,n=5),后者的测定精度明显高于前者。结论利用电导率的变化率(ΔK)确定滴定拐点更为直接客观,降低了主观误差,测定精度较高。     

不同治疗方案对急性脑出血合并高血糖患者神经功能预后的影响

目的探讨不同治疗方案对急性脑出血合并高血糖患者神经功能预后的影响。方法共纳入78例我院急性脑出血合并高血糖患者,采用随机数字法平均分为观察组与对照组,观察组给予胰岛素滴定,控制血糖4.4~8.3mmol/L,对照组给予常规治疗,控制血糖4.4~10.0mmol/L。于治疗前、治疗后1d、3d、7d、14d空腹抽取静脉血,检测血清髓鞘碱性蛋白(MBP)、血清胶质纤维酸性蛋白(GFAP)及肿瘤坏死因子(TNF?α)水平,并对其神经功能进行评价。结果观察组血糖水平明显低于对照组,差异有统计学意义(P0.05);但低血糖发生率比较差异无统计学意义(P0.05)。与治疗前相比,治疗后1d、3d2组患者血浆MBP、GFAP、TNF?α水平均明显增高,差异有统计学意义(P0.05);治疗后7d、14d患者血浆MBP、GFAP、TNF?α水平较治疗前明显降低,差异有统计学意义(P0.05),治疗后1d、3d、7d、14d,观察组的血浆MBP、GFAP、TNF?α水平均明显低于对照组,差异有统计学意义(P0.05)。观察组有效率92.3%明显高于对照74.4%,且NIHSS评分亦低于对照组,差异有统计学意义(P0.05)。结论胰岛素滴定治疗可更好控制患者血糖水平,降低MBP、GFAP、TNF?α水平,进而改善患者的神经功能及预后,值得临床推广应用。     

Overcoming the Challenges of Low Drug Solubility in the Intravenous Formulation of Solithromycin

Solithromycin is a fluoro-ketolide (a fourth-generation macrolide) antibiotic that has been undergoing clinical trials for the treatment of community-acquired bacterial pneumonia. In this study, development of the tri-amino acid–buffered solithromycin intravenous (IV) formulation was performed to minimize the occurrence of infusion-associated local adverse events (infusion-site pain or phlebitis) observed in patients who received the tartaric acid–buffered IV formulation with a lower buffered capacity during phase I clinical trials. Development of the tri-amino acids–buffered solithromycin IV formulation was achieved using a dynamic in vitro precipitation model. Computational modeling also supports the superiority of the amino acid-buffered formulation over the tartaric aid–buffered formulation.