Noninvasive positive pressure ventilation in infants with upper airway obstruction: comparison of continuous and bilevel positive pressure

Objective This study evaluated the efficacy of noninvasive continuous positive pressure (CPAP) ventilation in infants with severe upper airway obstruction and compared CPAP to bilevel positive airway pressure (BIPAP) ventilation.Design and setting Prospective, randomized, controlled study in the pulmonary pediatric department of a university hospital.Patients Ten infants (median age 9.5 months, range 3—18) with laryngomalacia (n=5), tracheomalacia (n=3), tracheal hypoplasia (n=1), and Pierre Robin syndrome (n=1)Interventions Breathing pattern and respiratory effort were measured by esophageal and transdiaphragmatic pressure monitoring during spontaneous breathing, with or without CPAP and BIPAP ventilation.Measurements and results Median respiratory rate decreased from 45 breaths/min (range 24–84) during spontaneous breathing to 29 (range 18–60) during CPAP ventilation. All indices of respiratory effort decreased significantly during CPAP ventilation compared to unassisted spontaneous breathing (median, range): esophageal pressure swing from 28 to 10 cmH₂O (13–76 to 7–28), esophageal pressure time product from 695 to 143 cmH₂O/s per minute (264–1417 to 98–469), diaphragmatic pressure time product from 845 to 195 cmH₂O/s per minute (264–1417 to 159–1183) During BIPAP ventilation a similar decrease in respiratory effort was observed but with patient-ventilator asynchrony in all patients.Conclusions This short-term study shows that noninvasive CPAP and BIPAP ventilation are associated with a significant and comparable decrease in respiratory effort in infants with upper airway obstruction. However, BIPAP ventilation was associated with patient-ventilator asynchrony.     

A comparison of the I-gel supraglottic airway as a conduit for tracheal intubation with the intubating laryngeal mask airway: A manikin study

Background

Insertion of a supraglottic airway and tracheal intubation through it may be indicated in resuscitation scenarios where conventional laryngoscopy fails. Various supraglottic devices have been used as conduits for tracheal intubation, including the intubating laryngeal mask airway (ILMA), the Ctrach™ laryngeal mask and the I-gel supraglottic airway.

Methods

A prospective study with 25 participants evaluated the success rate of blind intubation (using a gum-elastic bougie, an Aintree intubating catheter (AIC) and designated tracheal tube) and fibrescope-guided tracheal intubation (through the intubating laryngeal mask airway and the I-gel supraglottic airway) on three different airway manikins.

Results

Twenty-five anaesthetists performed three intubations with each method on each of three manikins. The success rate of the fibrescope-guided technique was significantly higher than blind attempts (P < 0.0001) with both devices. For fibreoptic techniques, there was no difference found between the ILMA and I-gel (P > 0.05). All blind techniques were significantly more successful in the ILMA group compared to the I-gel (P < 0.0001 for bougie, Aintree catheter and tracheal tube, respectively).

Conclusions

The results of this study show that, in manikins, fibreoptic intubation through both ILMA and I-gel is a highly successful technique. Blind intubation through the I-gel showed a low success rate and should not be attempted.     

A new device for administration of continuous positive airway pressure in preterm infants: comparison with a standard nasal CPAP continuous positive airway pressure system

Objective We compared the effectiveness of a new continuous positive airway pressure (CPAP) device (neonatal helmet CPAP) with a conventional nasal CPAP system in preterm neonates needing continuous distending pressure.Design and setting Randomized, physiological, cross-over study in a tertiary referral, neonatal intensive care unit in a university teaching hospital.Patients Twenty very low birth weight infants with a postnatal age greater than 24 h who were receiving nasal CPAP for apnea and/or mild respiratory distress were enrolled.Interventions CPAP delivered by neonatal helmet CPAP and nasal CPAP in random order for two subsequent 90-min periods.Measurements and results Were continuously measured the Neonatal Infant Pain Scale (NIPS) score, oxygen requirements, respiratory rate, heart rate, oxygen saturation, transcutaneous PO₂ (tcPO₂) and PCO₂ (tcPCO₂), blood pressure, and desaturations. NIPS scores were significantly lower when the infants were on the neonatal helmet CPAP than when they were on nasal CPAP (0.26±0.07 vs. 0.63±0.12). The other studied parameters did not differ between the two CPAP modes. The number of deaturations was reduced during the neonatal helmet CPAP treatment (18 vs. 32), although this difference was not significant.Conclusions In this short-term physiological study the neonatal helmet CPAP appears to be as good as the golden standard for managing preterm infants needing continuous distending pressure, with enhanced tolerability. Further evaluation in a randomized clinical trial is needed to confirm these findings.     

Definitive airway management after pre-hospital supraglottic airway insertion: Outcomes and a management algorithm for trauma patients

Background

Prehospital airway management increasingly involves supraglottic airway insertion and a paucity of data evaluates outcomes in trauma populations. We aim to describe definitive airway management in traumatically injured patients who necessitated prehospital supraglottic airway insertion.

Budesonide/formoterol decreases expression of vascular endothelial growth factor (VEGF) and VEGF receptor 1 within airway remodelling in asthma

INTRODUCTION: Angiogenesis and microvascular remodelling may play a vital role in the chronic inflammatory process within asthma. One of the most important factors involved in angiogenesis is vascular endothelial growth factor (VEGF). In this study we hypothesised that an increased expression of VEGF may be involved in airway remodelling in asthma patients. To this end, we compared the histology and expression levels of VEGF and one of its receptors (VEGFR1) in bronchial tissues of patients with asthma compared with control patients. We also investigated the effect of treatment with budesonide/formoterol (Symbicort(R); AstraZeneca, Lund, Sweden) in the relationship between VEGF and airway remodelling. METHODS: Bronchial tissues were obtained from patients attending the West China Hospital from April to November 2006. Thirteen patients were diagnosed with moderate asthma and 10 others were treated as control. Histological and immunohistochemical comparisons between asthmatic and control patients were made at baseline, and (for asthmatic subjects) following 6 months of treatment with budesonide/formoterol. RESULTS: Compared with control patients, asthmatic patients had significantly decreased respiratory parameters, including forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV(1)) (% predictive). Furthermore, patients with asthma had submucosal gland hyperplasia, increased smooth muscle mass, increased subepithelial fibrosis and neovascularisation. Asthmatic patients also exhibited increased expression of VEGF and VEGFR1 within epithelial cells. The increased expression of VEGF and its receptor correlated well with airway remodelling, airflow obstruction and airway hyper-responsiveness. After treatment with budesonide/formoterol for 6 months, the expression of VEGF and VEGFR1 was decreased, with correlatory decreased airway remodelling in patients with asthma. CONCLUSION: The increased expression of VEGF and VEGFR(1) in asthmatic patients is accompanied by an increased number and size of blood vessels in asthmatic airways, as well as airway remodelling. Budesonide/formoterol therapy for 6 months can decrease the expression of VEGF and VEGFR(1) alongside airway remodelling in asthma. The inhibition of VEGF and its receptor may be a good therapeutic strategy for asthma.     

Managing the difficult airway: a survey of residency directors and a call for change

This study examines airway management issues in Emergency Medicine residency programs (EMRP) including; airway adjunct availability and frequency of use, number of pediatric intubations, approach to trauma airways, and teaching methods. Surveys were distributed to all accredited EM program directors, who were asked about these issues. Availability of airway adjuncts among respondents included: cricothyrotomy kits (94.9%), fiberoptic scopes (76.3%), Bougies (69.5%), LMAs (66.1%), intubating LMAs (61.0%), lighted stylets (54.2%), retrograde intubation kits (49.2%), Combitube (45.8%), and esophageal obturator airways (15.3%). Responses indicated that 93.6% of airways were orotracheal intubations. A small percentage of intubations used airway adjuncts. Programs use didactics, mannequins, cadavers, direct care and operating rooms for airway training. Emergency Physicians (EPs) are responsible for trauma airways in 89.9% of programs. Most programs have multiple airway adjuncts available, but they are rarely utilized. EPs must become proficient with airway adjuncts. EMRPs must increase resident exposure by using airway adjuncts during routine intubations.     

持续气道湿化在经鼻气管插管患者中的应用及效果

目的:探讨持续气道湿化在经鼻气管插管患者中的应用及临床效果。方法:将60例经鼻气管插管患者随机分实验组和对照组各30例,实验组给予持续气道湿化,对照组给予间断气道湿化。随访1～3个月,比较两组抗生素应用时间、住院时间、住院费用、病死率及血气分析结果。结果:实验组血气分析结果优于对照组(P<0.05),抗生素应用时间、住院时间、住院费用少于对照组(P<0.05),病死率低于对照组(P<0.05)。结论:经鼻气管插管患者行持续气道湿化,可改善其血气指标,减少抗生素应用时间、住院时间、住院费用,降低病死率,值得临床推广应用。     

A comparison of high frequency chest wall oscillation and intrapulmonary percussive ventilation for airway clearance in pediatric patients with tracheostomy

Objectives: The aim of this study was to compare two modes of airway clearance, the intrapulmonary percussive ventilation system (IPV) to high frequency chest wall oscillation system (HFCWO) in medically complex pediatric patients with tracheostomy requiring long term care.

Methods: This was a single center, retrospective study comparing the number of respiratory illnesses, lower respiratory tract infections (LRTI), utilization of bronchodilator and systemic steroids, and respiratory illnesses requiring acute care hospitalizations. A total of 8 tracheostomy dependent patients between the ages of 1–22 years were included for a 2-year study period. Each patient was used as their own control. During the period studied, the only variable in the medical regimen was the modality used for airway clearance. A Poisson regression model and generalized estimating equations were used to compare pre and post rates and to account for the correlation of count data from the same individual. Additionally, the paired differences (post—pre) for each event count were computed to provide the median and range of reductions in event rates while using intrapulmonary percussive ventilation system device. The non-parametric wilcoxon signed-rank test employed to determine whether the results from the Poisson model were consistently observed regardless of method of analysis.

Results: The total number of respiratory illnesses were reduced from 32 per year on HFCWO therapy to 15 per year on IPV system therapy (p < 0.001). The total number of LRTI requiring antibiotic use were decreased from 15 per year to 6 per year (p = 0.01), use of bronchodilator treatments were reduced from 53 to 21 (p < 0.001) and utilization of systemic steroids were reduced from 12 to 4 on IPV (p = 0.003). Numbers of hospitalizations to acute care facilities were reduced from 8 to 3 hospitalizations during the period of IPV use for airway clearance (p = 0.003).

Conclusion: This study suggests that airway clearance by IPV therapy could be more effective and beneficial in providing airway clearance in specific subsets of the medically complex pediatric population.     

Thoracoscopic segmentectomy for congenital pulmonary airway malformation arising in a lung with an accessory fissure: A case report

Congenital pulmonary airway malformation is a rare congenital lung lesion. This report documents the successful application of thoracoscopic segmentectomy in a 1-year-old boy prenatally diagnosed with congenital pulmonary airway malformation. Preoperative imaging studies revealed a microcystic lesion with a region of consolidation in the middle area of the right lung. Elective thoracoscopic resection was performed when the patient was aged 1 year and 4 months. Intraoperatively, the superior segment of the right lower lobe was partially separated from the normal lower lobe by a superior accessory fissure. A solid mass, fused with this segment, shared the visceral pleura. Thoracoscopic segmentectomy was successfully performed, and the patient had an uneventful postoperative course. Histological examination revealed congenital pulmonary airway malformation stocker type 2. Thoracoscopic segmentectomy is a viable surgical option that preserves the normal lung parenchyma in pediatric patients with congenital pulmonary airway malformation.     

Anesthesia and airway management in a patient with acromegaly and tracheal compression caused by a giant retrosternal goiter: a case report

A giant retrosternal goiter can lead to compression of vital organs in the mediastinum with high risk of acute cardiorespiratory decompensation. Additionally, patients with acromegaly are prone to developing severe airway obstruction and ventilation difficulties during anesthetic induction, leading to hypoxia and an increased partial pressure of carbon dioxide. Therefore, more comprehensive airway management strategies are needed. We herein describe a 57-year-old man with acromegaly and severe tracheal obstruction caused by a giant retrosternal goiter. He presented with a 1-week history of progressive dyspnea and was scheduled to undergo right lobe thyroidectomy and retrosternal goiter thyroidectomy. We created a comprehensive emergency plan for a difficult airway, including regional and topical anesthesia for awake endotracheal intubation, sevoflurane inhalation, small doses of midazolam and sufentanil to increase tolerance, self-made extended-length tracheostomy, video laryngoscope-assisted fiber-optic bronchoscopy, extracorporeal membrane oxygenation, and surgical tracheostomy. Importantly, tetracaine was inhaled through an atomizer, and a laryngotracheal topical anesthesia applicator was used to spray the larynx with 1% tetracaine to reduce stimulation during intubation. The giant goiter was successfully removed through the cervical approach. A carefully designed airway management strategy and close communication among a multidisciplinary operation team are the basis of perioperative anesthetic management for these patients.     

Levosimendan restores both systolic and diastolic cardiac performance in lipopolysaccharide-treated rabbits: comparison with dobutamine and milrinone

OBJECTIVE: Current treatment strategies for severe septic conditions (i.e., intravenous fluids, vasopressors, and cardiac inotropes) reestablish fluid balance and improve cardiac systole but do not address diastolic dysfunction. Our study aimed to fully characterize both systolic and diastolic abnormalities of sepsis-associated heart failure and to identify treatment that would support full-cycle cardiac improvement. DESIGN: Endotoxin-injected rabbits, an animal model of abnormal cardiac function in human sepsis, were used to delineate cardiac abnormalities and to examine effects of drug treatments on heart systolic and diastolic function (n = 30); saline-injected animals served as comparators (n = 17). As treatment, three inotropes commonly used for treatment of cardiac failure were infused for 45 mins in separate animal groups-milrinone, dobutamine, and levosimendan. MEASUREMENTS: Variables of left ventricular systolic and diastolic function were assessed with a pressure conductance catheter. Measurements were made before and after endotoxin/saline injection and before and after inotrope treatment. RESULTS: Pressure-volume analyses of the left ventricle showed marked impairment in systolic function and in all indices of diastolic function (isovolumic relaxation time constant, left ventricular end-diastolic pressure, and end-diastolic pressure-volume relationship) in endotoxin-treated rabbits. The inotropes, milrinone, dobutamine, and levosimendan, could each partially or completely restore systolic function in the lipopolysaccharide-treated rabbits. However, only levosimendan therapy led to additional beneficial effects on left ventricular relaxation and diastolic function. CONCLUSIONS: Cardiac failure in severe sepsis results from impairments in both systolic and diastolic functions. Treatment with the calcium sensitizer levosimendan improved both systolic and diastolic cardiac functions in septic animals, but cyclic adenosine monophosphate-dependent inotropes milrinone and dobutamine only improved systolic function.     

过敏原所致小鼠气道高反应性的动态演变和布地奈德干预对其的影响

目的观察哮喘模型小鼠气道高反应性动态演变过程。探讨雾化吸入布地奈德后的疗效。方法36只雌性BALB／c小鼠随机分组，阴性对照组（C组）腹腔注射氢氧化铝凝胶[Al（OH）3]；其余用卵白蛋白（OVA）诱导制备哮喘模型。①分别于实验第15、18、21和25d（分别为A1、A2、A3和A4组）测定小鼠在不同氯化乙酰甲胆碱（MCH）剂量下的潮气量（VT）、呼气相气道阻力（RA）和胸肺动态顺应性（CT-L），并观察肺组织病理变化。C组第15d测定上述肺功能指标后处死。②于第15～17d给予1mg布地奈德混悬液雾化吸入（B组），每日1次，第18d同A2组一起检测呼吸生理及病理变化。结果①MCH200ng／g时，A1、A2、A3组小鼠RA增长率明显大于C组。②MCH100ng／g和200ng／g时，A1、A2组小鼠C“下降率均较C组明显。⑧MCH100ng／g时，A2组V1下降率大于C组；MCH200ng／g时，A1、A2、A3、A4组小鼠VT下降率均大于C组。④模型小鼠气道周围和血管旁可见以嗜酸粒细胞为主的大量炎性细胞浸润，以A1组最明显，随时间延长而逐渐减轻。⑤MCH200ng／g时，B组RA增长率明显小于A2组，与C组间差异无显著性；MCH100和200ng／g时，B组CT-L下降率均低于A2组，但与C组间差异无显著性；B组VT下降率明显小于A2组，但与C组间差异无显著性；B组经布地奈德治疗后肺部炎性浸润明显减轻。结论MCH可增加模型小鼠的RA和降低CT-L，并持续7d左右；布地奈德混悬液雾化吸入可明显减轻模型小鼠的气道炎症和气道高反应性。     

Comparison of inhaled and intravenous milrinone in patients with pulmonary hypertension undergoing mitral valve surgery

Introduction  Increased pulmonary vascular resistance (PVR) is detrimental to cardiac output in postoperative cardiac-surgery patients. The aim of this study was to investigate the postoperative hemodynamic effects of milrinone inhalation, and determine whether it has a selective effect of pulmonary vasodilation in patients with pulmonary hypertension undergoing mitral valve replacement surgery. Methods  In this study, 48 patients with pulmonary hypertension who underwent mitral valve replacement surgery were included. Patients were randomly divided into two groups with 24 patients in each: the inhaled group and the control group (intravenous [i.v.] milrinone). In the inhaled group, milrinone was administered with a jet nebulizer, and nebulized for 4 hours. In the control group, patients received a bolus of 50 μg/kg i.v. milrinone, then received a continuous milrinone infusion, 0.5 μg/kg/min, for 4 hours. A number of hemodynamic changes in all patients were evaluated. Results  With milrinone administration, mean pulmonary artery pressure (MPAP) and PVR showed a comparable decrease in both groups. However, after initiation of milrinone, both mean arterial pressure and systemic vascular resistance in the inhaled group were significantly higher than in the control group. MPAP and PVR returned to baseline values 60 minutes after termination of milrinone inhalation. In addition, in the inhaled group, there was a reduction in intrapulmonary shunt fraction (Qs/Qt), with an improvement in PaO₂/FiO₂ (arterial oxygen tension/fraction of inspired oxygen). Conclusion  The major advantage of inhaled milrinone is its pulmonary selectivity, thereby avoiding systemic side effects and ventilationperfusion mismatch. Inhaled milrinone is an effective pulmonary vasodilator and appears to be an alternative promising approach in addressing the problem of right-ventricular decompensation following cardiopulmonary bypass.