New developments in neonatal respiratory management

Respiratory distress syndrome (RDS) is the major cause of respiratory failure in preterm infants due to immature lung development and surfactant deficiency. Although the concepts and methods of managing respiratory problems in neonates have changed continuously, determining appropriate respiratory treatment with minimal ventilation-induced lung injury and complications is crucially important. This review summarizes neonatal respiratory therapy's advances and available strategies (i.e., exogenous surfactant therapy, noninvasive ventilation, and different ventilation modes), focusing on RDS management.     

经气道咳痰机对气管切开患者的应用价值

目的:探讨经气道咳痰机对气管切开后拔管困难患者改善痰液引流及控制医院感染等方面的作用。方法:收集重症监护病房97例气管切开后拔管困难患者的临床资料,采用回顾性队列研究方法,分析经气道咳痰机治疗组与空白对照组在呼吸力学参数、机械通气时间、医院感染发生率等方面的差异。结果:经气道咳痰机组呼吸力学参数明显改善、机械通气时间缩短、医院感染发生率下降(均P0.05)。结论:经气道咳痰机能够显著改善气管切开后拔管困难患者呼吸功能状况、缩短机械通气时间,有效预防和控制医院感染。     

生脉注射液辅助治疗儿童哮喘疗效观察

目的观察生脉注射液辅助治疗儿童哮喘的疗效。方法将95例哮喘息儿随机分为对照组和治疗组,两组缓解期均给予舒利迭治疗,哮喘发作期给予吸氧、氨茶碱、地塞米松治疗,治疗组在对照组的基础上加用生脉注射液,5d为一疗程,输液时加强巡视和护理,严防不良反应发生,并记录临床控制的患者数,哮喘发作持续时间、治疗天数。结果治疗组和对照组在治疗1年后观察,结果显示治疗组临床控制率及哮喘发作持续时间、治疗天数较对照组有显著性差异（P〈0．05）。结论生脉注射液辅助治疗哮喘患儿有利于缓解哮喘症状,改善机体缺氧,有利于病情恢复。     

Fast three-dimensional numerical hemolysis approximation

The in vivo implantation of a mechanical device contributes to hemodynamic disturbances, which are responsible for damage to the membranes of red blood cells that in turn can lead to their rupture (hemolysis). It is important to ascertain at the design stage of such mechanical devices that they are innocuous to blood. Because there is no in vivo hemolysis index, we concentrated our efforts on the in vitro hemolysis index of the American Society for Testing and Material (ASTM) standard. We present in this work a framework for minimizing medical device-induced hemolysis by the development of a numerical method for predicting hemolysis similar to that used in in vitro experiments. The method is based on a novel interpretation of the Giersiepen-Wurzinger blood damage correlation that replaces the computation of blood damage along the streamline by a volume integration of a damage function over the computational domain. We assess the behavior and accuracy of this methodology with 3D examples.     

Molecular adsorbents recirculating system dialysis for liver insufficiency and sepsis following right ventricular assist device after cardiac surgery

We report a case of right heart failure (RHF) and sepsis with liver insufficiency in a 70-year-old patient after coronary artery bypass graft surgery. Three hours after surgery the patient suddenly developed therapy refractory cardiac arrest caused by RHF. He had to have emergency surgery, under which the graft to the right coronary artery was revised and a right ventricular assist device was implanted. Heart function recovered and the assist device was explanted on day 1 after surgery. Thoracic closure was performed on day 5 after surgery. The patient went into septic shock on day 11. Liver dysfunction developed postoperatively and worsened the course of sepsis. Therefore, MARS (molecular adsorbents recirculating system) dialysis was performed once on day 20 after surgery. Liver function improved after MARS therapy and the patient recovered from sepsis. On day 46 the patient was transferred from the ICU of another hospital to one of the peripheral wards, to be finally discharged on day 67.     

Physiologic-insensitive left ventricular assist predisposes right-sided circulatory failure: a pilot simulation and validation study

Right-sided circulatory failure (RSCF) is a serious complication in 15-30% of patients receiving a left ventricular assist device (LVAD). It is hypothesized that left ventricular support which lacks physiologic properties predisposes to RSCF. An integral computer simulation and experimental validation protocol was performed. The results suggest that with conventional insensitive left ventricular support right-sided circulatory function is compromised, which may form a substrate for the onset or progress of RSCF. Feedback control of the LVAD could provide a means to counter this problem. A control concept for the LVAD which aims to preserve right-sided circulatory function, while supporting peripheral perfusion, is proposed     

Left Ventricular Assist Device Support as a Bridge to Recovery in Young Children

Objective. Left ventricular assist device (LVAD) experience and follow‐up data in children are limited. We report the deployment and successful weaning from LVAD in young children with severe heart failure (HF). Design. From 2004–2009, 13 children suffering from HF were placed on LVAD. All presented with a dilated left ventricle (LV) with severely reduced contractility, secondary to myocarditis, atrial arrhythmia or idiopathic HF. This study reports their outcomes and longitudinal follow‐up. Results. Of 13 young children with HF (ages 1 month–6 years; mean 19.2 months) placed on LVAD: eight weaned to recovery and successful hospital discharge, one was transplanted and four died. Echo follow‐up in the weaned patients (mean age 22.1 months) revealed significant improvements from pre‐LVAD measurements: LV end‐diastolic dimension (LVED) mean z‐score decreased from +4.8 to +0.95 (P < .001); fractional shortening (FS %) improved from a mean of 9.3% to 33% (P < .001); and the degree of mitral regurgitation (MR) significantly improved (P < .05). Time to LVAD deployment from HF diagnosis was more likely to be less than 30 days in the successfully weaned patients (100%) than patients who died or were transplanted (20%); P= .007. Conclusions. LVAD support can be utilized as a bridge to recovery in young children with HF. Following LVAD weaning, children sustain improvements in LV size, function and degree of MR. LVAD deployment less than 30 days from HF diagnosis improves the likelihood of successful weaning and illustrates that children with acute etiologies of HF are more likely to achieve recovery.     

Allosensitization in bridge to transplant Novacor left ventricular assist device patients: analysis of long-term outcomes with regard to acute rejection and chronic allograft vasculopathy

BACKGROUND: The true relevance of allosensitization in patients benefiting from left ventricular assist device (LVAD) as bridge to transplant (BTT) is still debated. Available registry data referred to numerous devices precluding LVAD-specific analysis. Therefore, we studied all patients with Novacor LVAD prior to transplantation. METHODS: From 1985 to 2006, 37 Novacor LVADs were implanted as BTT, with 30 patients surviving to transplantation (81%). Post-LVAD sensitization was determined for anti-HLA-class I and class II IgGs. Study endpoints were overall survival and/or graft loss, > or =3A cellular rejection and chronic allograft vasculopathy (CAV). The results from LVAD patients were compared to non-LVAD primary heart transplant recipients (n=318). RESULTS: After LVAD insertion, 5 out of 27 patients available for analysis developed anti-HLA antibodies (18.5%). The mean anti-HLA titer after Novacor LVAD implantation was 14% [SD 31]. Actuarial 5- and 10-year patient/graft survival for LVAD and non-LVAD transplant recipients were 73% and 55%, and 70% and 55%, respectively (p=NS). Overall prevalence of rejection > or =3A was 23.3 % (LVAD group) and 18.9% (non-LVAD group) (p=NS). At follow-up, the respective incidence of CAV was 8% (LVAD group) and 32.4% (non-LVAD group) (p<0.01). However, mean follow-up was significantly different for LVAD and non-LVAD patients, 46 vs 90 months (p<0.001). CONCLUSION: In this study, allosensitization occurred infrequently after Novacor LVAD implantation. Secondly, analysis of outcome variables shows that Novacor-LVAD BTT patients can anticipate similar survival to non-LVAD patients, thus minimizing the impact of allosensitization after LVAD implantation.     

Pediatric heart support with a newly developed catheter based pulsatile 12F rotary blood pump: an animal study

Background: To evaluate mechanical and hematological compatibility of a pediatric, temporary left heart support system in a lamb model as a less traumatic alternative to the widely used ECMO. Methods: A small, pulsatile rotary blood pump (target flow 0.5 l/m at 80 mmHg pressure head at 120 pulses per min) was inserted in six lambs (15.1 ± 1 kg) via a left thoracotomy, through a purse string in the arcus aortae. With fluoroscopy the tip (=inflow) of the catheter was positioned in the outflow tract of the left ventricle. The outflow part was positioned immediately above the aortic valve. Animals were extubated at the end of the procedure. Mechanical and hematological parameters were followed for 14 days. Results: Five animals survived a 2-week follow-up. One animal died because of empyema on day 6. Flow maintained stable (0.8 ± 0.2 l/m) in all animals during the evaluation period. Free hemoglobin as a parameter of hemolysis and hematocrit remained also stable. Necropsy revealed minimal fibrous reaction on one aortic valve leaflet in one animal and small hematoma formation in three. All animals showed mild signs of endothelial damage on the aortic arch at the level of the motor housing. One animal showed signs of old kidney infarction suggesting possible embolization during placement. Conclusion: This newly developed, catheter based, pediatric heart support system generates a stable flow for 14 days without compromising hematological stability and with acceptable tissue damage due to positioning of the catheter.     

Acute heart failure: is there a role for surgery?

Many of the disorders and lesions leading to acute heart failure can be treated surgically. Modern surgical techniques like the off pump coronary surgery, newer techniques for the surgical treatment of the mechanical complications of acute MI and valvular reparative techniques have been added to the surgical armamentarium in recent years. Modern ventricular assist devices have started their career in the clinical arena promising to be less invasive. At the same time the spectrum of indications for mechanical circulatory support continues to witness a rapid expansion. Technical advances have led to an evolution of surgical strategies. Heart failure surgery is now in a position to offer improved outcomes, avoidance of recurrence of acute heart failure or the development of advanced chronic heart failure.