Mechanical modulation of atrial flutter cycle length

Although atrial flutter (AFL) is considered a highly regular rhythm, small fluctuations in cycle length have been described. The mechanisms responsible for these interval oscillations have been investigated by recent studies in humans which have shown that cyclic variations in atrial volume and pressure following ventricular contraction may account for the spontaneous variability of AFL. Other studies have shown that variations in the dimensions of the atria, caused by hemodynamical alterations due to imposed manoeuvres, directly modify the rate of AFL. All this evidence has led to the development of the mechano-electrical feedback (MEF) hypothesis, which assumes that changes in atrial volume directly affect AFL cycle length variability by modifying the conduction properties of the circulating impulse in the atrium.In the present study, we re-examined the variability pattern of typical AFL by spectral analysis aiming to support the MEF hypothesis for AFL cycle length variability. In a study population of 30 patients with typical AFL, we observed that AFL cycle length presented a spontaneous beat-to-beat variability, composed of two oscillations: a main oscillation at the frequency of ventricular contraction (1.70±0.48 Hz, spectral power: 15.4±17.6 ms²) and a second oscillation at the frequency of respiration (0.32±0.07 Hz, spectral power: 2.9±2.6 ms²). Both ventricular and respiratory oscillations persisted after pharmacologic autonomic blockade (ventricular spectral power: 17.7±14.7 ms² (before block) vs 20.2±18.3 ms² (after block), p=NS; respiratory spectral power: 6.0±3.8 ms² (before block) vs 5.0±3.4 ms² (after block), p=NS), suggesting a non-neurally mediated underlying mechanism. Contrary to respiratory modulation of heart rate during sinus rhythm, respiratory AFL cycle length oscillations displayed a reverse pattern, with longer cycle lengths during inspiration and shorter during expiration (AA_insp=223.2±28.6 ms vs AA_exp=221.1±28.2 ms, p<0.0005), which was consistent with a mechanical modulation of AFL reentry.The use of spectral analysis techniques applied to ventricular interval series and combined with computer simulations of atrioventricular conduction showed that the respiratory oscillation of atrial cycle length determined an oscillation in ventricular intervals with longer intervals during inspiration and shorter during expiration (VV_insp=639.9±186.0 ms vs VV_exp=634.8±182.9 ms, p<0.05). Ventricular interval oscillations resulted amplified by a factor 1.8 with respect to corresponding atrial cycle length oscillations. Thus, the mechanical fluctuations in AFL cycle length, although of small amplitude, might become clinically relevant through a magnified effect on ventricular variability.     

有创通气与大剂量沐舒坦治疗脑卒中后重症肺炎的疗效及对脑神经功能的影响

目的:探究有创通气与大剂量沐舒坦治疗脑卒中后重症肺炎的疗效及对脑神经功能的影响。方法:于2013年6月~2016年2月期间,选择广州医科大学附属第四医院呼吸重症医学科收治老年脑卒中合并重症肺炎患者76例为研究对象,采用随机数字法将所有研究对象分为观察组(40例)和对照组(36例);两组患者均给予常规治疗及有创通气,观察组患者给予大剂量沐舒坦治疗,对照组患者给予小剂量剂量沐舒坦治疗;观察并比较两组患者神经功能恢复情况、治疗情况、肺炎严重程度、记录氧分压(PaO_2)、二氧化碳分压(PaCO_2)、C反应蛋白(CRP)水平。结果:两组患者治疗前PaO_2、PaCO_2、肺炎严重程度评分(CURB-65)及CRP水平无差异(P0.05);治疗后两组患者PaCO_2、CURB-65及CRP水平均显著降低,PaO_2水平显著升高;且观察组患者PaCO_2、CURB-65及CRP水平低于对照组,PaO_2水平显著高于对照组(P0.05);治疗前两组患者脑卒中神经功能损伤程度评分(NFDS)及美国国立卫生院脑卒中评分(NIHSS)无差异(P0.05);治疗后两组患者NFDS及NIHSS评分均降低(P0.05),两组间NFDS及NIHSS评分无差异(P0.05);治疗后观察组患者机械通气时间、抗生素使用时间、症状缓解时间及ICU住院时间均低于对照组(P0.05)。结论:有创通气联合大剂量沐舒坦治疗脑卒中后重症肺炎疗效确切,能够提高患者脑神经功能,值得在临床应用推广。     

重症肺炎患儿俯卧位与仰卧位机械通气的临床效果比较及其脱机结局的影响因素分析

摘要 目的：比较重症肺炎患儿俯卧位与仰卧位机械通气的临床效果,并分析其脱机结局的影响因素。方法：选择2020年5月~2021年12月期间在我院重症监护室（ICU）住院的重症肺炎患儿120例作为研究对象。根据机械通气体位方式的不同将患儿分为仰卧组（n=52）和俯卧组（n=68）,对比仰卧组、俯卧组的临床症状改善时间和血气分析指标[动脉血氧分压（PaO₂）、动脉血二氧化碳分压（PaCO₂）、平均动脉压（MAP）]。记录仰卧组、俯卧组的死亡例数、脱机成功和脱机失败例数,计算死亡率、脱机失败发生率。采用单因素及多因素Logistic回归分析脱机失败的影响因素。结果：俯卧组的发热消失时间、肺部啰音消失时间、呼吸改善时间短于仰卧组（P<0.05）。两组治疗5 d后 PaO₂、MAP较治疗前升高,PaCO₂较治疗前下降（P<0.05）;俯卧组的PaO₂、MAP高于仰卧组,PaCO2低于仰卧组（P<0.05）。两组患儿死亡率组间对比未见统计学差异（P>0.05）。俯卧组的脱机失败率低于仰卧组（P<0.05）。在120例患儿中,死亡7例,根据重症肺炎患儿脱机结局将剩余113例分为脱机成功组（n=72）和脱机失败组（n=41）,脱机失败组、脱机成功组在年龄、急性生理与慢性健康评分系统II（APACHE II）评分、病程、先天性病史、D-二聚体（D-D）、白蛋白（ALB）、血乳酸、脑尿钠肽（BNP）方面对比有统计学差异（P<0.05）。多因素Logistic回归分析结果显示：年龄偏小、APACHE II评分偏高、D-D偏高、ALB偏低、先天性病史均是重症肺炎患儿脱机结局的影响因素（P<0.05）。结论：与仰卧位相比,俯卧位机械通气用于重症肺炎患儿可获得更好的临床效果和脱机成功率,且患儿的脱机结局受到年龄、APACHE II评分、D-D、ALB、先天性病史的影响。     

Sustained inflation and incremental mean airway pressure trial during conventional and high-frequency oscillatory ventilation in a large porcine model of acute respiratory distress syndrome

Background

To compare the effect of a sustained inflation followed by an incremental mean airway pressure trial during conventional and high-frequency oscillatory ventilation on oxygenation and hemodynamics in a large porcine model of early acute respiratory distress syndrome.

Methods

Severe lung injury (Ali) was induced in 18 healthy pigs (55.3 ± 3.9 kg, mean ± SD) by repeated saline lung lavage until PaO₂ decreased to less than 60 mmHg. After a stabilisation period of 60 minutes, the animals were randomly assigned to two groups: Group 1 (Pressure controlled ventilation; PCV): FIO₂ = 1.0, PEEP = 5 cmH₂O, V_T = 6 ml/kg, respiratory rate = 30/min, I:E = 1:1; group 2 (High-frequency oscillatory ventilation; HFOV): FIO₂ = 1.0, Bias flow = 30 l/min, Amplitude = 60 cmH₂O, Frequency = 6 Hz, I:E = 1:1. A sustained inflation (SI; 50 cmH₂O for 60s) followed by an incremental mean airway pressure (mPaw) trial (steps of 3 cmH₂O every 15 minutes) were performed in both groups until PaO₂ no longer increased. This was regarded as full lung inflation. The mPaw was decreased by 3 cmH₂O and the animals reached the end of the study protocol. Gas exchange and hemodynamic data were collected at each step.

Results

The SI led to a significant improvement of the PaO₂/FiO₂-Index (HFOV: 200 ± 100 vs. PCV: 58 ± 15 and T_Ali: 57 ± 12; p < 0.001) and PaCO₂-reduction (HFOV: 42 ± 5 vs. PCV: 62 ± 13 and T_Ali: 55 ± 9; p < 0.001) during HFOV compared to lung injury and PCV. Augmentation of mPaw improved gas exchange and pulmonary shunt fraction in both groups, but at a significant lower mPaw in the HFOV treated animals. Cardiac output was continuously deteriorating during the recruitment manoeuvre in both study groups (HFOV: T_Ali: 6.1 ± 1 vs. T₇₅: 3.4 ± 0.4; PCV: T_Ali: 6.7 ± 2.4 vs. T₇₅: 4 ± 0.5; p < 0.001).

Conclusion

A sustained inflation followed by an incremental mean airway pressure trial in HFOV improved oxygenation at a lower mPaw than during conventional lung protective ventilation. HFOV but not PCV resulted in normocapnia, suggesting that during HFOV there are alternatives to tidal ventilation to achieve CO₂-elimination in an "open lung" approach.     

老年支气管哮喘患者血清MC-CP、Th17的表达及其与呼吸功能、肺功能的相关性分析

摘要 目的：探究老年支气管哮喘患者血清肥大细胞羧肽酶（MC-CP）、Th17表达及其与患者呼吸功能、肺功能的相关性。方法：选择2018年4月至2021年8月于中国人民解放军东部战区总医院接受治疗的120例老年支气管哮喘患者为研究组（SG）,另选同期于我院接受治疗的100例支气管炎患者为对照组（CG）,对比两组患者血清MC-CP、Th-17、呼气峰值流速（PEF）、第1秒用力呼气量（FEV₁）、血氧分压（PaO₂）、FEV₁占预计值的百分数（FEV₁/FVC）差异,就研究组患者MC-CP、Th-17水平与其呼吸功能、肺功能的相关性开展Spearman分析。结果：（1）研究组患者的MC-CP水平明显高于对照组,Th17百分比同样明显高于对照组（P<0.05）;（2）研究组患者的呼吸功能指标PEF、PaO₂,以及肺功能指标FEV₁、FEV₁/FVC均明显低于对照组（P<0.05）;（3）研究组患者MC-CP与PEF、PaO₂呈现明显负相关联系（r=-0.558、-0.700,P<0.001）,研究组患者Th17与PEF、PaO₂呈现明显负相关联系（r=-0.695、-0.774,P<0.001）;（4）研究组患者MC-CP与FEV₁、FEV₁/FVC呈现明显负相关联系（r=-0.609、-0.481,P<0.001）,研究组患者Th17与FEV₁、FEV₁/FVC呈现明显负相关联系（r=-0.622、-0.561,P<0.001）。结论：老年支气管哮喘患者血清MC-CP及Th17水平会出现异常升高状态,而呼吸功能与肺功能会出现降低,相关性分析显示此类患者血清MC-CP及Th17水平与其呼吸功能、肺功能均呈现负相关联系。     

Single Sustained Inflation followed by Ventilation Leads to Rapid Cardiorespiratory Recovery but Causes Cerebral Vascular Leakage in Asphyxiated Near-Term Lambs

BackgroundA sustained inflation (SI) rapidly restores cardiac function in asphyxic, bradycardic newborns but its effects on cerebral haemodynamics and brain injury are unknown. We determined the effect of different SI strategies on carotid blood flow (CaBF) and cerebral vascular integrity in asphyxiated near-term lambs.MethodsLambs were instrumented and delivered at 139 ± 2 d gestation and asphyxia was induced by delaying ventilation onset. Lambs were randomised to receive 5 consecutive 3 s SI (multiple SI; n = 6), a single 30 s SI (single SI; n = 6) or conventional ventilation (no SI; n = 6). Ventilation continued for 30 min in all lambs while CaBF and respiratory function parameters were recorded. Brains were assessed for gross histopathology and vascular leakage.ResultsCaBF increased more rapidly and to a greater extent during a single SI (p = 0.01), which then decreased below both other groups by 10 min, due to a higher cerebral oxygen delivery (p = 0.01). Blood brain barrier disruption was increased in single SI lambs as indicated by increased numbers of blood vessel profiles with plasma protein extravasation (p = 0.001) in the cerebral cortex. There were no differences in CaBF or cerebral oxygen delivery between the multiple SI and no SI lambs.ConclusionsVentilation with an initial single 30 s SI improves circulatory recovery, but is associated with greater disruption of blood brain barrier function, which may exacerbate brain injury suffered by asphyxiated newborns. This injury may occur as a direct result of the initial SI or to the higher tidal volumes delivered during subsequent ventilation.     

经鼻间歇正压通气联合猪肺磷脂注射液治疗新生儿呼吸窘迫综合征的临床疗效

目的:探讨经鼻间歇正压通气联合猪肺磷脂注射液治疗新生儿呼吸窘迫综合征临床疗效及安全性的影响。方法:前瞻性研究于我院进行治疗的呼吸窘迫综合症患儿60例,根据电脑生成的随机数字表将所有患儿随机分为实验组与对照组,每组各30例,对照组患儿使用经鼻间歇正压通气进行治疗,实验组患儿在对照组的基础上联合猪肺磷脂注射液进行治疗。治疗结束后比较两组患儿动脉血氧分压(Pa O_2)、动脉血二氧化碳分压(Pa CO_2)、氧合指数及血样饱和度(Sa O_2)水平的变化,统计并记录两组患儿并发症的发病情况,并对两组患儿的临床疗效进行评价。结果:与治疗前相比,两组患儿Pa CO_2水平均降低,Pa O_2、Sa O_2水平及氧合指数均升高(P0.05);与对照组相比,实验组患儿Pa CO_2水平较低,Pa O_2、Sa O_2水平及氧合指数较高(P0.05);且与对照组相比,实验组的并发症发病率较低,临床总有效率较高(P0.05)。结论:经鼻间歇正压通气联合猪肺磷脂注射液治疗新生儿呼吸窘迫综合征安全有效,值得在临床上推广应用。     

Repolarization Parameters Are Associated With Mortality In Chagas Disease Patients In The United States

Objective

The goal of this study was to examine the association between ECG repolarization parameters and mortality in Chagas disease (CD) patients living in the United States.

Methods

CD patients with cardiomyopathy (CM) and bundle branch block (BBB) or BBB alone were compared to age- and sex-matched controls. QT interval, QT dispersion (QTd), T wave peak to T wave end duration (Tp-Te) and T wave peak to T wave end dispersion ((Tp-Te)d) were measured. Presence of fractionated QRS (fQRS) was also assessed. The main outcome measure was the association between ECG parameters and mortality or need for cardiac transplant.

Results

A total of 18 CM and 13 BBB CD patients were studied with 97% originating from Mexico or Central America. QTd (60.0±15.0 ms vs 43.5±9.8 ms, P=0.0002), Tp-Te (102.6±29.3 ms vs 77.1±11.0 ms, P=0.0002) and (Tp-Te)d (39.5±9.4 ms vs 22.7±7.6 ms, P<0.0001) were prolonged in CD CM patients compared to CM controls. Chagas CM patients had more fQRS then controls (84.2±0.10% vs 33.3±0.11%, p=0.0005). QTd (59.9±15.0 ms vs 29.5±6.9 ms, P=0.0001) and (Tp-Te)d (40.0±15.9 ms vs 18.5±5.4 ms, p<0.0001) were longer in the CD BBB group compared to BBB controls. Univariate analysis showed QTd (56.9±15.0 ms vs 46.5±17.3 ms, p=0.0412) and (Tp-Te)d (36.8±13.5 ms vs 28.5±13.3 ms, p=0.0395) were associated with death and/or need for cardiac transplant.

Conclusion

Our results indicate that P-max and PD are useful electrocardiographic markers for identifying the β-TM-high-risk patients for AF onset, even when the cardiac function is conserved.     

Gender and respiratory factors associated with dyspnea in chronic obstructive pulmonary disease

Rationale

We had shown that COPD women expressed more dyspnea than men for the same degree of airway obstruction.

Objectives

Evaluate gender differences in respiratory factors associated with dyspnea in COPD patients.

Methods

In a FEV₁ % matched population of 100 men and women with COPD we measured: age, MMRC, FEV₁, FVC, TLC, IC/TLC, PaO₂, PaCO₂, D_LCO, P_imax, P_0.1, Ti/Ttot, BMI, ffmi, 6MWD and VAS scale before and after the test, the Charlson score and the SGRQ. We estimated the association between these parameters and MMRC scores. Multivariate analysis determined the independent strength of those associations.

Results

MMRC correlated with: BMI (men:-0.29, p = 0.04; women:-0.28, p = 0.05), ffmi (men:-0.39, p = 0.01), FEV₁ % (men:-0.64, p < 0.001; women:-0.29, p = 0.04), FVC % (men:-0.45, p = 0.001; women:-0.33, p = 0.02), IC/TLC (men:-0.52, p < 0.001; women: -0.27, p = 0.05), PaO₂ (men:-0.59, p < 0.001), PaCO₂ (men:0.27, p = 0.05), D_LCO (men:-0.54, p < 0.001), P_0.1/P_imax (men:0.46, p = 0.002; women:0.47, p = 0.005), dyspnea measured with the Visual Analog Scale before (men:0.37, p = 0.04; women:0.52, p = 0.004) and after 6MWD (men:0.52, p = 0.002; women:0.48, p = 0.004) and SGRQ total (men:0.50, p < 0.001; women:0.59, p < 0.001). Regression analysis showed that P_0.1/P_imax in women (r² = 0.30) and BMI, DL_CO, PaO₂ and P_0.1/P_imax in men (r² = 0.81) were the strongest predictors of MMRC scores.

Conclusion

In mild to severe COPD patients attending a pulmonary clinic, P_0.1/P_imax was the unique predictor of MMRC scores only in women. Respiratory factors explain most of the variations of MMRC scores in men but not in women. Factors other than the respiratory ones should be included in the evaluation of dyspnea in women with COPD.     

限制性补液复合去甲肾上腺素对脓毒性休克患者血流动力学及氧代谢的影响

目的:探讨限制性补液复合去甲肾上腺素对脓毒性休克患者血流动力学及氧代谢的影响。方法:将62例脓毒性休克患者按照液体复苏策略随机分为限制性液体复苏(治疗组)和常规液体复苏(对照组),每组各31例。观察和比较复苏前后血流动力学指标、氧代谢指标的变化,记录两组低血压、弥散性血管内凝血(DIC)、多器官功能障碍综合征(MODS)、急性呼吸窘迫综合症(ARDS)的发生率及2周病死率。结果:治疗后1 h、3 h、6 h,两组患者CVP、MAP明显升高,HR明显下降(P0.05);治疗后3 h、6 h,治疗组MAP明显低于对照组(P0.05),而两组HR、CVP比较差异均无统计学意义(P0.05)。治疗后1 h、3 h、6 h,两组患者PaCO_2、PaO_2、SaO_2、PaO_2/Fi O_2均不同程度改善,治疗组治疗后3 h、6 h PaO_2、PaO_2/Fi O_2明显高于对照组(P0.05)。治疗后3 d,治疗组MODS的发生率较对照组显著降低(P0.05),而两组低血压、ARDS、DIC及2周病死率均无显著性差异(P0.05)。结论:限制性液体复合小剂量去甲肾上腺素对脓毒性休克患者有助于维持血流动力学稳定,改善全身氧代谢,减少并发症的发生,改善预后。     

乌司他丁联合无创机械通气对SAP并发ARDS患者血气指标、肝肾功能和肠黏膜功能的影响

摘要 目的：探讨乌司他丁联合无创机械通气对重症急性胰腺炎（severe acute pancreatitis,SAP）并急性呼吸窘迫综合征（acute respiratory distress syndrome,ARDS）患者血气指标、肝肾功能和肠黏膜功能的影响。方法：选取2015年1月~2020年1月期间青海省中医院收治的73例SAP并发ARDS患者。根据随机数字表法分为对照组（n=36）和研究组（n=37）,对照组患者予以无创机械通气治疗,研究组在对照组的基础上联合乌司他丁治疗,比较两组患者疗效、血气指标、肝肾功能指标以及肠黏膜功能指标,记录两组治疗期间不良反应情况。结果：研究组治疗7 d后的临床总有效率为89.19 %（33/37）,高于对照组的66.67 %（24/36）（P<0.05）。两组治疗7 d后动脉血氧分压（PaO₂）、氧合指数均较治疗前升高,天冬氨酸氨基转移酶（aspartate aminotransferase,AST）、丙氨酸氨基转移酶（alanine aminotransferase,ALT）、血尿素氮（blood urea nitrogen,BUN）以及血清肌酐（creatinine,Cr）、二胺氧化酶（diamine oxidase,DAO）、D-乳酸、动脉血二氧化碳分压（arterial partial pressure of carbon dioxide,PaCO₂）较治疗前降低,且研究组优于对照组（P<0.05）。两组不良反应发生率对比无差异（P>0.05）。结论：乌司他丁联合无创机械通气治疗SAP并发ARDS患者,疗效显著,可有效改善患者血气指标、肝肾功能和肠黏膜功能,且不增加不良反应发生率,安全可靠。     

The effect of insulin treatment on HbA1c, body weight and lipids in type 2 diabetic patients with secondary-failure to sulfonylureas. A five year follow-up study.

No conclusive data are available about the long-term effect of insulin treatment in type 2 diabetic patients failing to maximal doses of sulfonylureas and caloric restriction. In total 160 non-obese type 2 diabetic patients with secondary failure were substituted with insulin using a diabetic teaching and care program. From these 160 patients 40 died within the observation period of five years; 102 patients had a complete five year follow-up, whereas the remaining 18 patients did not come to regular follow-up visits. Metabolic control parameters improved significantly in the 102 patients with the complete five year follow-up. Postprandial plasma glucose (16.0 mM vs 10.9 mM; p < 0.0001) and HbA1c values (8.7% vs 7.1%, p < 0.0001) decreased significantly from the state before to five years after insulin substitution. In addition, plasma lipid levels could be significantly lowered under insulin therapy (cholesterol 6.2 +/- 1.5 mM vs 5.4 +/- 3.6 mM, p < 0.0002; triglycerides 2.8 +/- 1.6 mM vs 2.4 +/- 2.1 mM, p < 0.01). However, we observed a significant weight gain (mean: 10.6 kg) associated with insulin application during the five year follow-up. Thus, the body-mass-index decreased from 28.9 at onset of type 2 diabetes to 24.5 (p < 0.0001) at time of secondary failure and increased again to 28.5 (p < 0.0001) at five years after onset of insulin treatment. Furthermore, small increases of plasma creatinine from 88.4 microM to 115 microM, as well as systolic (19.3 kPa to 20.7 kPa) and diastolic (10.7 kPa to 11.3 kPa) blood pressures were observed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Improvement in symptoms and pulmonary function of asthmatic patients due to their treatment according to the Global Strategy for Asthma Management (GINA)

Background

Endothelin-1 (ET-1) and Nitric Oxide (NO) are crucial mediators for establishing pulmonary artery hypertension (PAH). We tested the hypothesis that their imbalance might also occur in COPD patients with PAH.

Methods

The aims of the study were to measure exhaled breath condensate (EBC) and circulating levels of ET-1, as well as exhaled NO (FENO) levels by, respectively, a specific enzyme immunoassay kit, and by chemiluminescence analysis in 3 groups of subjects: COPD with PAH (12), COPD only (36), and healthy individuals (15). In order to evaluate pulmonary-artery systolic pressure (PaPs), all COPD patients underwent Echo-Doppler assessment.

Results

Significantly increased exhaled and circulating levels of ET-1 were found in COPD with PAH compared to both COPD (p < 0.0001) only, and healthy controls (p < 0.0001). In COPD with PAH, linear regression analysis showed good correlation between ET-1 in EBC and PaPs (r = 0.621; p = 0.031), and between arterial levels of ET-1 and PaPs (r = 0.648; p = 0.022), while arterial levels of ET-1 inversely correlated with FEV₁%, (r = -0.59, p = 0.043), and PaPs negatively correlated to PaO₂ (r = -0.618; p = 0.032). Significantly reduced levels of FENO were found in COPD associated with PAH, compared to COPD only (22.92 ± 11.38 vs.35.07 ± 17.53 ppb; p = 0.03). Thus, we observed an imbalanced output in the breath between ET-1 and NO, as expression of pulmonary endothelium and epithelium impairment, in COPD with PAH compared to COPD only. Whether this imbalance is an early cause or result of PAH due to COPD is still unknown and deserves further investigations.     

The assessment of pulmonary vein potentials using the new achieve advance during cryoballoon ablation of atrial fibrillation

BackgroundThe new version of inner lumen mapping catheter (Achieve Advance?; Medtronic, Minnesota, USA) includes a new solid core which provides improved rotational response, as compared to the current Achieve Mapping Catheter. In the present study, we sought to analyze the rate of visualisation of real-time recordings using this new device comparing it with a large cohort of patients having undergone second generation cryoballoon (CB) ablation using the previous Achieve mapping catheter.MethodsAll patients having undergone CB ablation using the Achieve Advance and the last 150 consecutive patients having undergone CB ablation using the previous Achieve were analysed. Exclusion criteria were presence of an intracavitary thrombus, uncontrolled heart failure, moderate or severe valvular disease and contraindications to general anesthesia.ResultsA total of 200 consecutive patients (60.1 ± 9.5 years, 75% males) were evaluated (50 Achieve Advance and 150 old Achieve). Real-time recordings were significantly more prevalent in the “new Achieve Advance” population compared with the “old Achieve” group (73.5% vs 56.8%; p = 0.0001). Real-time recordings could be more frequently visualized in the “Achieve Advance” group in all veins except RIPV (LSPV: 86% vs 71.3%, p = 0.04; LIPV: 84% vs 62.7%, p = 0.005; RSPV: 78% vs 52%, p < 0.0001; RIPV: 46% vs 41.3%, p = 0.3).ConclusionsThe rate of visualisation of real-time recordings is significantly higher using the new Achieve Advance if compared to the previous Achieve mapping catheter in the setting of CB ablation. Real-time recordings can be visualized in approximately 73.5% of veins with this new device.     

双水平气道内正压通气治疗尿毒症合并左心衰竭患者的疗效观察

目的:观察双水平气道内正压通气(BiPAP)治疗尿毒症合并左心衰竭患者的临床疗效。方法:选取82例确诊为尿毒症合并左心衰竭的患者,在患者进行常规的强心、利尿、扩血管、持续性肾替代治疗(CRRT)30 min后无缓解后,立即对患者进行BiPAP治疗。比较患者在常规治疗30 min末、BiPAP治疗后1 h、2 h后收缩压、舒张压、心率、呼吸频率、二氧化碳分压(PaCO_2)、动脉血氧分压(PaO_2)等指标的变化,以及常规治疗30 min末、BiPAP治疗2h后的血浆脑钠肽(BNP)、血乳酸(Lac)水平和临床表现的变化。结果:经Bi PAP治疗后患者症状和体征缓解的有效率为93.90%。BiPAP治疗1 h、2 h后与常规治疗30 min末比较,患者的收缩压、舒张压、心率、呼吸频率具有显著下降(P0.05),PaO_2则显著升高(P0.05),PaCO_2的变化经比较则无显著的统计学意义(P0.05)。BiPAP治疗2 h后患者的血浆BNP、Lac水平与常规治疗30 min末比较均显著下降(P0.05)。结论:BiPAP治疗尿毒症并发急性左心衰竭患者可有效改善患者的症状和体征,改善心功能,适合在临床上推广应用。     

血乳酸和心肌酶变化在胎儿宫内窘迫新生儿中的临床意义

目的:探讨血乳酸和心肌酶变化在胎儿宫内窘迫新生儿中的临床意义。方法:选取2017年3月到2018年8月期间在我院出生的胎儿宫内窘迫新生儿120例,其中有55例出生后未出现窒息,将其纳入观察1组,另外65例新生儿出生后出现窒息则纳入观察2组,同时选取同期在我院出生的健康、足月新生儿60例作为对照组。比较三组新生儿的血乳酸、乳酸脱氢酶(LDH)、肌酸激酶(CK)、肌酸激酶同工酶MB(CKMB)、血氧分压(PaO_2)、二氧化碳分压(PaCO_2)的水平,并分析血乳酸与心肌酶、PaO_2、PaCO_2的相关性。结果:出生时、出生后5d,观察2组的血乳酸、LDH、CK、CKMB水平均高于观察1组和对照组,且观察1组的血乳酸、LDH、CK、CKMB水平均高于对照组,差异均有统计学意义(P0.05)。出生时,观察2组的PaO_2水平低于观察1组和对照组,PaCO_2水平高于观察1组和对照组,差异均有统计学意义(P0.05),观察1组的PaO_2水平低于对照组,PaCO_2水平高于对照组,差异均有统计学意义(P0.05)。Pearson相关性分析结果显示,胎儿宫内窘迫新生儿血乳酸水平与CK、CKMB、PaCO_2呈正相关,与PaO_2呈负相关(P0.05),与LDH无明显的相关性(P0.05);LDH、CK、CKMB与PaCO_2呈正相关,与PaO_2呈负相关(P0.05)。结论:胎儿宫内窘迫新生儿血乳酸和心肌酶水平明显升高,且出生后存在窒息的新生儿中更为明显,胎儿宫内窘迫新生儿血乳酸、心肌酶水平与缺氧程度密切相关。     

腹式呼吸训练法对COPD伴Ⅱ型呼吸衰竭患者肺通气状态、血气指标及运动耐力的影响

摘要 目的：探讨腹式呼吸训练法对慢性阻塞性肺疾病（COPD）伴Ⅱ型呼吸衰竭患者肺通气状态、血气指标及运动耐力的影响。方法：选择我院2020年07月2022年12月期间收治的100例COPD伴Ⅱ型呼吸衰竭患者,根据随机数字表法将患者分为对照组[常规治疗基础上接受双水平气道正压（BIPAP）辅助通气,n=50]和研究组（对照组的基础上接受腹式呼吸训练法干预,n=50）。对比两组临床相关指标、肺通气状态、血气指标及运动耐力指标。结果：研究组的喘憋消失时间、体温恢复正常时间、住院时间、肺部啰音消失时间短于对照组（P<0.05）。两组干预1周后第1秒呼气的最大容积（FEV₁）、最大自主分钟通气量（MVV）、用力肺活量（FVC）均升高,且研究组高于对照组（P<0.05）。两组干预1周后氧分压（PaO2₂）、血氧饱和度（SpO₂）均升高,且研究组高于对照组;二氧化碳分压（PaCO₂）下降,且研究组低于对照组（P<0.05）。两组干预1周后6 min步行距离（6MWT）升高,且研究组高于对照组（P<0.05）。结论：腹式呼吸训练法有助于改善COPD伴Ⅱ型呼吸衰竭患者的临床症状,调节肺通气状态、血气指标,提高运动耐力。     

Effect of Intravenous Infusion of Dexmedetomidine Combined with Inhalation of Isoflurane on Arterial Oxygenation and Intrapulmonary Shunt During Single-Lung Ventilation

To investigate the changes in arterial oxygenation and intrapulmonary shunt during one-lung ventilation (OLV) with intravenous infusion of dexmedetomidine combined with isoflurane inhalation. ASA I–II 60 patients aged 18–70 year, undergoing OLV during elective thoracic surgery were randomly allocated to two groups: (1) isoflurane + saline (group NISO, n = 30) and (2) isoflurane + dexmedetomidine (group DISO, n = 30). After induction, anesthesia was maintained with intravenous infusion of remifentanil 0.1–0.2 μg kg^?1 min^?1 and inhalation isoflurane (1.0–2.0 %). In addition, anesthesia was maintained with intravenous infusion of dexmedetomidine 0.7 μg kg^?1 h^?1 in DISO group and saline 0.25 ml kg^?1 h^?1 in NISO group. Bispectral Index values were maintained within 40–60 by changing the concentration of isoflurane in all groups. Arterial blood gas samples and central venous blood gas samples were taken as follows: during two-lung ventilation before OLV and during the first 40 min of OLV. 45 Patients completed the study, with 23 patients in DISO group and 22 patients in NISO group. The two groups were comparable in terms of demographic variables, hemodynamic, PaO₂, Qs/Q_T, end expiration isoflurane and BIS levels during the operation. Compared with patients in the group NISO, there were significant increases with PaO₂, significant decrease with Qs/Q_T, significant decrease with end expiration isoflurane, and significant decrease with HR in the group DISO during the first 40 min of OLV (P < 0.05). Dexmedetomidine infusions decrease the requirement for isoflurane, decrease intrapulmonary shunt, and moderate the change in PaO₂ and may be useful in managing OLV.     

Heliox Allows for Lower Minute Volume Ventilation in an Animal Model of Ventilator-Induced Lung Injury

Background

Helium is a noble gas with a low density, allowing for lower driving pressures and increased carbon dioxide (CO₂) diffusion. Since application of protective ventilation can be limited by the development of hypoxemia or acidosis, we hypothesized that therefore heliox facilitates ventilation in an animal model of ventilator–induced lung injury.

Methods

Sprague-Dawley rats (N=8 per group) were mechanically ventilated with heliox (50% oxygen; 50% helium). Controls received a standard gas mixture (50% oxygen; 50% air). VILI was induced by application of tidal volumes of 15 mL kg^-1; lung protective ventilated animals were ventilated with 6 mL kg^-1. Respiratory parameters were monitored with a pneumotach system. Respiratory rate was adjusted to maintain arterial pCO₂ within 4.5-5.5 kPa, according to hourly drawn arterial blood gases. After 4 hours, bronchoalveolar lavage fluid (BALF) was obtained. Data are mean (SD).

Results

VILI resulted in an increase in BALF protein compared to low tidal ventilation (629 (324) vs. 290 (181) μg mL^-1; p<0.05) and IL-6 levels (640 (8.7) vs. 206 (8.7) pg mL^-1; p<0.05), whereas cell counts did not differ between groups after this short course of mechanical ventilation. Ventilation with heliox resulted in a decrease in mean respiratory minute volume ventilation compared to control (123±0.6 vs. 146±8.9 mL min^-1, P<0.001), due to a decrease in respiratory rate (22 (0.4) vs. 25 (2.1) breaths per minute; p<0.05), while pCO₂ levels and tidal volumes remained unchanged, according to protocol. There was no effect of heliox on inspiratory pressure, while compliance was reduced. In this mild lung injury model, heliox did not exert anti-inflammatory effects.

Conclusions

Heliox allowed for a reduction in respiratory rate and respiratory minute volume during VILI, while maintaining normal acid-base balance. Use of heliox may be a useful approach when protective tidal volume ventilation is limited by the development of severe acidosis.     

HFNC与NIV治疗合并Ⅱ型呼衰的COPD患者的临床疗效对比

摘要 目的：探讨高流量湿化治疗仪（HFNC）治疗合并Ⅱ型呼吸衰竭的慢性阻塞性肺疾病患者的临床效果及安全性。方法：选择2020 年 4 月至 2022 年 3 月就诊于我院的合并Ⅱ型呼吸衰竭的慢性阻塞性肺疾病的患者共151名。随机分为接受 HFNC治疗组和NIV治疗组（HFNC组77名，NIV组74名）。分别评估患者治疗前和治疗后1小时、24小时以及治疗结束前心率（heart rate，HR）、呼吸频率（respiratory rate，RR）、氧合指数（Oxygenation index，PaO₂/FiO₂）、CO₂分压（arterial partial pressure of CO₂，PaCO₂）的变化、治疗不耐受和失败、有气管插管需求的情况、住院时间以及住院死亡率。结果：治疗后，两组各有6名患者死亡，死亡率分别为HFNC组7.8%，NIV组8.2%，组间比较差异无统计学意义（P=0.94）。两组患者治疗前后HR、RR、平均动脉压、白细胞计数、中性粒细胞百分比、C-反应蛋白、降钙素原及PaO₂/FiO₂、PaCO₂、动脉血酸碱度均无明显统计学差异。与NIV组相比，HFNC组气道护理干预次数明显减少（4±1 vs 8±2，P<0.05），皮肤破损发生率明显降低（5.2% vs 20.3%，P<0.05），住院天数明显缩短（6±2 vs 8±2，P<0.05）。结论：HFNC治疗合并Ⅱ型呼吸衰竭的COPD 患者效果并不亚于NIV，且HFNC的安全性更高，可作为该类患者的首选通气支持治疗方式。