Effect of Inflow Cannula Tip Design on Potential Parameters of Blood Compatibility and Thrombosis

During ventricular assist device support, a cannula acts as a bridge between the native cardiovascular system and a foreign mechanical device. Cannula tip design strongly affects the function of the cannula and its potential for blood trauma. In this study, the flow fields of five different tip geometries within the ventricle were evaluated using stereo particle image velocimetry. Inflow cannulae with conventional tip geometries (blunt, blunt with four side ports, beveled with three side ports, and cage) and a custom‐designed crown tip were interposed between a mixed‐flow rotary blood pump and a compressible, translucent silicone left ventricle. The contractile function of the failing ventricle and hemodynamics were reproduced in a mock circulation loop. The rotary blood pump was interfaced with the ventricle and aorta and used to fully support the failing ventricle. Among these five tip geometries, high‐shear volume (, potential parameter of platelet activation) was found to be the greatest in the blunt tip. The cage tip was observed to have the highest low‐shear volume and recirculation volume ( and V_z > 0, respectively; potential parameters of thrombus formation). The crown tip, together with conventional tip geometries with side ports (blunt with four side ports and beveled with three side ports) showed no significant difference in either high‐shear volume or low‐shear volume. However, recirculation volume was reduced significantly in the crown tip. Despite limited generalizability to clinical situations, these transient‐state measurements supported the potential mitigation of complications by changing the design of conventional cannula tip geometries.     

Increased cerebrospinal fluid lactate reflects deterioration of neurological status in experimental portal-systemic encephalopathy

Increased brain and CSF lactate have been described in human and experimental portal-systemic encephalopathy (PSE). Using a recently described cisterna magna catheter technique, CSF lactate was measured in relation to deterioration of neurological status in portacaval shunted rats administered ammonium acetate to precipitate severe PSE. Loss of righting reflex (precoma stage of PSE) was accompanied by 2–3 fold increased CSF lactate and onset of coma by 4-fold increases of lactate (p< 0.001 compared to either sodium acetate treated portacaval shunted rats or sham-operated controls administered ammonium acetate). The most likely explanation for increased CSF lactate is ammonia-induced inhibition of malate-aspartate shuttle and/or inhibition of tricarboxylic acid cycle flux in brain. Similar mechanisms could be involved in the pathogenesis of PSE in patients with chronic liver disease.     

High-flow nasal cannula oxygen therapy in hypoxic patients with COVID-19 pneumonia: A retrospective cohort study confirming the utility of respiratory rate index

BackgroundAlthough high-flow nasal cannula (HFNC) oxygen treatment has been frequently used in coronavirus disease 2019 (COVID-19) patients with acute respiratory failure after the 3rd wave of the pandemic in Japan, the usefulness of the indicators of ventilator avoidance, including respiratory rate-oxygenation (ROX) index and other parameters, namely oxygen saturation/fraction of inspired oxygen ratio and respiratory rate (RR), remain unclear.MethodsBetween January and May 2021, our institution treated 189 COVID-19 patients with respiratory failure requiring oxygen, among which 39 patients requiring HFNC treatment were retrospectively analyzed. The group that switched from HFNC treatment to conventional oxygen therapy (COT) was defined as the HFNC success group, and the group that switched from HFNC treatment to a ventilator was defined as the HFNC failure group. We followed the patients’ oxygenation parameters for a maximum of 30 days.ResultsHFNC treatment success occurred in 24 of 39 patients (62%) treated with HFNC therapy. Compared with the HFNC failure group, the HFNC success group had a significantly higher degree of RR improvement in the univariate analysis. Logistic regression analysis of HFNC treatment success adjusting for age, respiratory improvement, and a ROX index ≥5.55 demonstrated that an improved RR was associated with HFNC treatment success. The total COT duration was significantly shorter in the HFNC success group than in the HFNC failure group.ConclusionsHFNC treatment can be useful for ventilator avoidance and allow the quick withdrawal of oxygen administration. RR improvement may be a convenient, useful, and simple indicator of HFNC treatment success.     

ICU机械通气患者气管内吸痰时插管深度的改进

目的探讨不同插管深度对ICU机械通气患者气管内吸痰效果的影响。方法便利选取2010年10月至2012年3月ICU机械通气患者64例,采用随机数字表法将其分为研究组(深吸痰)和对照组(浅吸痰),比较两组患者吸痰前后的血压、心率、呼吸、血氧饱和度等生命体征变化,以及吸痰效果和吸痰时不良事件的发生率。结果吸痰前后,研究组患者潮气量、呼吸道峰压及血氧饱和度的改善明显优于对照组,差异有统计学意义(P0.01);研究组患者的日吸痰次数、痰鸣音改善情况以及吸痰间隔时间等均优于对照组,差异有统计学意义(P0.05或P0.01);两组患者不良事件的发生率差异无统计学意义(P0.05)。结论 ICU机械通气患者进行人工气道内吸痰时,增加插管深度有助于清除呼吸道内分泌物、延长吸痰间隔时间、改善机体的缺氧状况,同时还不增加不良事件的发生率。     

去除牙垫前后气管插管固定方法对患者舒适度的影响

目的:探讨去除牙垫前后气管插管固定方法对患者舒适程度的影响。方法:选取2011年1月~2012年3月我院收治的全麻手术后进重症监护室监护的患者共50例,运用疼痛视觉模拟量表评价去除牙垫前30 min与去除牙垫后30 min对患者口腔局部舒适度的影响程度。结果:去除牙垫后患者的口腔局部舒适度明显优于去除牙垫前,差异具有统计学意义(P0.05)。结论:采用去除牙垫后的气管插管固定方法,患者口腔分泌物相应地减少,同时运用寸带固定方法,增加了气管插管固定的有效性。     

先天性心脏病术后气管插管的护理

[目的]探讨先天性心脏病患儿术后常规给予机械通气,经口气管插管与经鼻气管插管的呼吸道的护理.[方法]心脏手术经口气管插管77例、经鼻气管插管15例,在机械通气阶段加强呼吸道护理.[结果]呼吸模式参数设定、保持呼吸道通畅、无菌操作、保护口腔、鼻腔黏膜完整性、病情动态观察与对比是术后机械通气的关键,经口与经鼻气管插管各有优缺点.[结论]留置气管插管与加强呼吸道管理是保证患儿渡过早期心肺功能不稳定阶段的主要措施,根据惠儿具体情况选择插管方式,使患儿最大受益.     

Single-port laparoscopic herniorrhaphy using a two-hooked cannula device with hydrodissection

Background

Laparoscopic percutaneous extraperitoneal closure (LPEC) with variable devices seems to be one of the most simple and reliable methods. We described our modifications of single-port laparoscopic herniorrhaphy using an inner two-hooked cannula device with preperitoneal hydrodissection.

昏迷患者气管切开术后气管套管的选择

目的探讨昏迷患者气管切开术后应用不同类型气管套管预防肺部感染的效果。方法将102例昏迷气管切开患者按入院时间分为对照组（50例）和观察组（52例），对照组采用不带气囊的金属气管套管；观察组采用一次性低压气囊气管套管，均予气管切开术后常规护理。两组分别在气管切开后第3天、第15天，从气管套管内留取痰标本进行细菌培养。结果两组气管切开术后第15天细菌阳性率比较，差异有显著性意义（P〈0．01）；观察组气管切开术后15d总菌株少于对照组（P〈0．01）；第3天与第15天总菌株比较，对照组差异有显著性意义（P〈0．01），观察组差异无显著性意义（P〉0．05）。观察组肺部感染率显著低于对照组（P〈0．05）。结论采用一次性低压气囊气管套管能有效降低昏迷气管切开术患者的肺部感染率。     

湿化高流量鼻导管通气在早产儿机械通气撤机中的应用研究

目的探讨湿化高流量鼻导管通气（HHFNC）的应用效果和安全性。方法选择2012年1-12月本院新生儿重症监护中心收治的胎龄〈34周且出生体重〈1500 g的Ⅲ-Ⅳ级呼吸窘迫综合征（RDS）患儿,患儿撤机后随机分为HHFNC组和经鼻持续气道正压通气（NCPAP）组,比较两组患儿的鼻部损伤发生率、重新气管插管率、气漏及支气管肺发育不良发生率、病死率以及撤机时间、住院时间、呼吸机治疗费用等。结果和NCPAP组相比,HHFNC组鼻损伤较少[1/28（3.6%）比8/31（25.8%）,P〈0.05],呼吸机治疗费用也较低[（5.8±1.9）千元比（8.6±1.8）千元,P〈0.01]。两组患儿的病死率、重新插管率、应用NCPAP/HHFNC后1 h的PaO2和PCO2值、撤机时间、机械通气时间、住院时间以及气漏、支气管肺发育不良、坏死性小肠结肠炎、严重脑室内出血、早产儿视网膜病发生率等差异均无统计学意义（P〉0.05）。结论 HHFNC是一种容易被接受且效果良好的早产儿呼吸支持方式,其潜在优势包括简便、容易耐受、较少鼻部损伤、成本更低,更便于推广。     

A review of non-invasive ventilation support in neonates

Non-invasive ventilation (NIV) is a mode of respiratory support commonly used on the neonatal unit. Since the advent of NIV, it has evolved from being used as a mode of respiratory support to wean infants from mechanical ventilation (MV) to a primary mode of respiratory support. Newer methods of NIV support such as nasal bilevel positive airway pressure (BiPAP) and humidified high flow nasal cannula oxygen therapy (HHFNC) have emerged in attempts to reduce intubation rates and subsequent MV in preterm infants. There is ongoing debate about the role of nasal continuous positive airway pressure (NCPAP) in reducing ventilator induced lung injury, its timing and use as a primary mode of ventilation in the very low birth weight and extreme preterm infants.This review gives an overview of the current understanding and practices of the different modes of NIV in the neonatal unit.