Outcome of mechanical ventilation in children with acquired immunodeficiency syndrome

We retrospectively reviewed the records of 18 children with acquired immunodeficiency syndrome (AIDS) who required mechanical ventilation for respiratory failure. These patients represented 35% of the patients seen with pulmonary disease and AIDS. The most common causes of respiratory failure were Pnuemocystis carinii pneumonia (77%) and bacterial pneumonia (33%). Bronchial lavage by fiberoptic bronchoscopy or endotracheal tube suctioning in mechanically ventilated children with AIDS had a high yield for P. carinii. Eight of 18 (44%) children survived the episode of respiratory failure and were weaned from the ventilator. However, four of eight survivors died within 6 months. Arterial oxygen tension on admission and maximum peak inspiratory pressure on the ventilator did not differ between survivors and nonsurvivors. We conclude that children with AIDS who are mechanically ventilated can be weaned from the respirator but that the subsequent course remains poor.     

Safe intrahospital transport of critically ill ventilator-dependent patients

STUDY OBJECTIVE: To determine whether manual ventilation during intrahospital transport of mechanically ventilated critically ill patients results in blood gas and/or hemodynamic abnormalities. DESIGN: A single-blind prospective study evaluated arterial blood gas, blood pressure, heart rate, and arrhythmia changes during mechanical ventilation and manual transport ventilation. SETTING: University hospital ICUs and various diagnostic or treatment areas. PATIENTS: Twenty mechanically ventilated critically ill patients during intrahospital transport. INTERVENTION: Each patient received mechanical ventilation (MECH) with a volume ventilator while in the ICU and at the study/treatment area. They were manually ventilated (MAN) by a respiratory therapist during transport between areas. MEASUREMENTS AND MAIN RESULTS: The MECH settings were: VT = 0.75 +/- 0.17 L; f = 16 +/- 4; VE = 12.6 +/- 4.3 L/min; FIO2 = 0.46 +/- 0.2. Mean peak Paw = 31 +/- 12 cm H2O and mean effective Cst = 44 +/- 15 ml/cm H2O. No hemodynamic abnormalities were observed. Arterial blood gas values did not vary to any clinically significant degree, except in two patients: one patient had a reduced PaO2 and increased PaCO2 associated with an accidental O2 disconnection and clamped chest tube; another patient had an increased pH by 0.13 units with only a 9 mm Hg fall in PaCO2. CONCLUSIONS: Manual ventilation during intrahospital transport of critically ill mechanically ventilated patients is safe provided the person performing manual ventilation knows the inspired oxygen fraction and minute ventilation required before transport and is trained to approximate them during transport.     

Association between adrenal insufficiency and ventilator weaning

RATIONALE: Adrenal insufficiency is a common disorder in critically ill patients with mechanical ventilation and is usually associated with higher mortality and poor clinical outcome. OBJECTIVES: To determine whether stress dose corticosteroid supplementation can improve ventilator weaning and clinical outcome in patients with adrenal insufficiency. METHODS: A prospective, randomized, placebo controlled, double-blinded study was conducted in the intensive care unit of a tertiary teaching hospital. A total of 93 mechanically ventilated patients were enrolled in the ventilator weaning trial. Adrenal function was assessed in all patients. Patients with adrenal insufficiency were randomized to the treatment group (50 mg intravenous hydrocortisone every 6 h) and the placebo group. MEASUREMENTS AND MAIN RESULTS: The successful ventilator weaning percentage was significantly higher in the adequate adrenal reserve group (88.4%) and in the stress dose hydrocortisone treatment group (91.4%) than in the placebo group (68.6%). The weaning period was shorter in the hydrocortisone treatment group than in the placebo group. No significant adverse effects were observed in the corticosteroid treatment group. CONCLUSIONS: For patients with respiratory failure, early identification of adrenal insufficiency and appropriate supplementation with stress dose hydrocortisone increase the success of ventilator weaning and shortens the weaning period.     

Interhospital transport of the adult mechanically ventilated patient

Interhospital transport of the adult mechanically ventilated patient may be necessary for those who require specialized care. An experienced medical team can safely transport even the most critically ill patients if the care is optimized before departure. Patients with severe respiratory failure may have to remain on an ICU ventilator throughout the transport period, depending on the specific transport ventilator. Near-terminal ARDS can be treated with ECLS, and these patients also may be safely transported to a regional center.     

Diaphragmatic paralysis in children: A review of 11 cases

We reviewed 11 pediatric cases of diaphragmatic paralysis related to nonspinal-cord injury which were managed in our Intensive Care Unit over the past 10 years. Three cases were secondary to birth trauma, 7 followed surgical procedures for congenital heart disease, and 1 occurred in association with injuries sustained in a motor vehicle accident. The paralysis was bilateral in 8 children. The diagnosis was initially suspected on clinical grounds because of respiratory distress, impossibility of weaning from the ventilator, and paradoxical abdominal respiratory movements. Confirmatory investigations included chest radiography, which revealed elevation of the affected hemidiaphragm, fluoroscopy and ultrasound, both of which demonstrated diminished diaphragmatic movement. Electromyography exhibited a failure of diaphragmatic response to phrenic nerve stimulation in 8 patients. All patients were mechanically ventilated: tracheostomy was required in 5 patients. Physiotherapy was considered a beneficial adjuvant measure. Diaphragmatic plication was attempted without success in 3 children. Seven children recovered without sequelae: Partial respiratory autonomy was achieved after an average of 2.6 months, complete autonomy after an average of 5.4 months. Two patients developed chronic lung disease; one of them remains unresponsive, and one child died following accidental extubation. We conclude that the diagnosis of diaphragmatic paralysis is predominantly clinical, and that the outcome of patients treated by adequate endotracheal mechanical ventilation is usually favorable. Pediatr Pulmonol. 1994;18:187–193. © 1994 Wiley-Liss, Inc.     

Air leaks from the respiratory tract in mechanically ventilated children with severe respiratory disease

Our objectives were to evaluate the frequency of air leaks (AL) from the respiratory tract (pneumothorax, pneumomediastinum, pneumoperitoneum, subcutaneous emphysema) in critically ill children on mechanical ventilation (MV) for severe respiratory diseases, and to examine whether AL could be correlated with specific clinical events or ventilator settings. The study constitutes a retrospective cohort of 80 consecutive critically ill children receiving MV for severe respiratory diseases between 1986 and 1993. Patients (mean age 2.9 +/- 0.6 years, 49 males and 31 females), were admitted to the Pediatric Intensive Care Unit (PICU) with acute respiratory syndrome (ARDS) (27%), asthma (15%), bronchiolitis (10%), pneumonia (21%), pulmonary congenital diseases (9%), or foreign body aspiration (18%). Patients were divided into two groups; those with AL (n=22) and those without air-leaks (non-AL) (n = 58). Air leaks developed in 22 of 80 patients or in 27.5%. Survival was significantly lower in the AL group, compared to the non-AL group (41% vs. 76%, P < 0.01). The odds ratio that a patient with multiple organ system failure (MOSF) or infection would develop AL was 2.96 and 2.19, respectively. Candida and Pseudomonas species were recovered with significantly higher frequency in the AL group compared with the non-AL group (P < 0.025). There was a strong positive correlation between the incidence of AL and high ventilatory pressures (PIP 36 vs. 29.7 cm H(2)O, P < 0.001), or large tidal volumes (V(T) 12 vs. 9 mL/kg, P < 0.05), suggesting that large volumes might elicit injury to the pulmonary epithelium. Multiple logistic regression analysis showed that only V(T) was independently associated with the development of AL in children with primary severe respiratory disease (r(2) = -0.38, P = 0.01). In conclusion, MV will produce AL, particularly when high peak airway pressures (barotrauma) or large tidal volumes (volotrauma) are delivered by the ventilator. Sepsis, MOSF, and lung superinfection with Pseudomonas or Candida species may be also important factors in the development of AL in critically ill children.     

Recent advances in mechanical ventilation

Important advances have been made over the past decade towards understanding the optimal approach to ventilating patients with acute respiratory failure. Evidence now supports the use of noninvasive positive pressure ventilation in selected patients with hypercapnic respiratory failure and chronic obstructive pulmonary disease, cardiogenic pulmonary edema, and for facilitating the discontinuation of ventilatory support in patients with chronic pulmonary disease. The concept of a lung protective ventilatory strategy has revolutionized the management of the acute respiratory distress syndrome. The process of liberation from mechanical ventilation is becoming more standardized, with evidence supporting daily trials of spontaneous breathing in all suitable mechanically ventilated patients. This article critically reviews the most important recent advances in mechanical ventilation and suggests future directions for further research in the field.     

Doxofylline and respiratory mechanics. Short-term effects in mechanically ventilated patients with airflow obstruction and respiratory failure

To assess the short-term effects of a methylxanthine (doxofylline) on respiratory mechanics in mechanically ventilated patients with airway obstruction and respiratory failure, nine consecutive patients were examined within three days from the onset of mechanical ventilation. Flow, changes in pulmonary volume, and Paw were measured using a ventilator (Servo 900C). End-expiratory and end-inspiratory airway occlusion was performed to measure PEEPi, Cstrs, Rrsmax, and Rrsmin. Measurements were performed before and at 5, 15, and 30 minutes after an intravenous loading dose of doxofylline (5 to 6 mg/kg). We found that doxofylline determined, on the average, a marked decrease in respiratory resistance (Rrsmax and Rrsmin, -27.2 percent and -36.5 percent, respectively) without significant changes in Cstrs and Pmax. The PEEPi, reflecting pulmonary dynamic hyperinflation, was also significantly decreased by doxofylline (-41 percent, on the average). The Pmax was not reliable for evaluation of a single patient, since changes in the elastic pressure can offset changes in the resistive one. No patient experienced significant side effects due to doxofylline. We conclude that (1) the effects of therapy can be assessed noninvasively at bedside in critically ill patients; (2) doxofylline is a rapid and efficient bronchodilator in mechanically ventilated patients with ARF and airflow obstruction; and (3) the decrease in the respiratory resistance and PEEPi, associated with an improved mechanical efficiency of the respiratory muscles at a lower pulmonary volume, can provide better conditions for the patient-ventilator interaction and for weaning.     

Assessment of respiratory output in mechanically ventilated patients

Mechanically ventilated patients are subject to few pathophysiologic disturbances that have such intuitive importance as abnormal function of the respiratory output. Abnormal function of the respiratory output plays a fundamental role in all aspects of mechanical ventilation: in determining which patients require mechanical ventilation, in determining the interaction between a patient and the ventilator, and in determining when a patient can tolerate discontinuation of mechanical ventilation. Monitoring indexes such as the rate of rise in electrical activity of the diaphragm, Po.1, (dP/dt)max, and Pmus, has provided insight into the performance of the respiratory centers in critically ill patients, but these methods require considerable refinement. A large body of research on measurements of energy expenditure of the respiratory muscles, such as pressure-time product, and measurements of inspiratory effort, such as the tension-time index, is currently accumulating. Several challenges, however, lay ahead regarding these indices. First, there is the need to identify the correct level of pressure generation and respiratory muscle effort that should be attained in the day-to-day management of mechanically ventilated patients. The correct titration of ventilator setting should not cause iatrogenic muscle damage because the support is excessive or insufficient. One of the challenges in reaching this goal is that for the same patient, different underlying pathologic conditions (eg, sepsis or ventilator-associated muscle injury) may require different levels of support. Second, many of the measurements of pressure generation and effort have been confined to the research laboratory. Modifications of the technology to achieve accurate measurements in the intensive care unit-outside of the research laboratory--are needed. To facilitate individual titration of ventilator settings, the new technologies must provide easier access to quantification of drive, pressure output, and effort. Finally, more research is needed to define the effect of monitoring respiratory output on patient outcome and containment of costs.     

The clinical course of critically ill COVID-19 patients receiving invasive mechanical ventilation with subsequent terminal weaning: Primary data from 11 cases

The coronavirus disease (COVID-19) outbreak was first reported in December 2019 in Wuhan, China. Specific information about critically ill COVID-19 patients receiving invasive mechanical ventilation (IMV) is rare.To describe the clinical course and complications of critically ill patients with COVID-19 who received IMV and were successfully weaned from it.This retrospective study included patients admitted to 3 intensive care units (ICUs) and 1 sub-ICU of Renmin Hospital of Wuhan University and Wuhan Jin Yin-tan Hospital between December 24, 2019, and March 12, 2020. Eleven patients who had been diagnosed with critically ill COVID-19 according to the World Health Organization interim guidance, received invasive ventilation, and were finally successfully weaned from it, were enrolled in our study. Their presenting symptoms, comorbidity conditions, laboratory values, ICU course, ventilator parameters, treatments, and relative complications were recorded.Of 108 critically ill COVID-19 patients who received invasive ventilation, 11 patients who underwent tracheal extubation or terminal weaning were included. The mean age of the 11 patients was 52.8 years (range, 38–70 years), 8 (72.7%) were male, and 2 were health care workers. The median time from onset of symptoms to dyspnea was 6.6 days (range, 3–13 days), and the median duration of IMV was 15.7 days (range, 6–29 days). All 11 patients presented with acute severe hypoxemic respiratory failure and received IMV, and 1 patient switched to extracorporeal membrane oxygenation assistance. A lung-protective strategy with lower tidal volume ventilation and proper driving pressure is the main strategy of IMV. All patients had extrapulmonary manifestations, including acute kidney injury, hepatic dysfunction, myocardial damage, and/or lymphopenia. Hospital-acquired infections occurred in 7 (63.6%) patients.Critical COVID-19 illness is characterized by acute hypoxemic respiratory failure and subsequent dysfunction of other organs with a high mortality rate. Correct ventilation strategies and other clinical strategies to improve oxygenation based on the skilled trained group and the availability of equipment are the key methods to rescue lives.     

Transesophageal echocardiography in critically ill patients

The feasibility, safety and clinical impact of transesophageal echocardiography were evaluated in 51 critically ill intensive care unit patients (28 men and 23 women; mean age 63 years) in whom transthoracic echocardiography was inadequate. At the time of transesophageal echocardiography, 30 patients (59%) were being mechanically ventilated. Transesophageal echocardiography was performed without significant complications in 49 patients (96%), and 2 patients with heart failure had worsening of hemodynamic and respiratory difficulties after insertion of the transesophageal probe. The most frequent indication, in 25 patients (49%), was unexplained hemodynamic instability. Other indications included evaluation of mitral regurgitation severity, prosthetic valvular dysfunction, endocarditis, aortic dissection and potential donor heart. In 30 patients (59%), transesophageal echocardiography identified cardiovascular problems that could not be clearly diagnosed by transthoracic echocardiography. In the remaining patients, transesophageal echocardiography permitted confident exclusion of suspected abnormalities because of its superior imaging qualities. Cardiac surgery was prompted by transesophageal echocardiographic findings in 12 patients (24%) and these findings were confirmed at operation in all. Therefore, transesophageal echocardiography can be safely performed and has a definite role in the diagnosis and expeditious management of critically ill cardiovascular patients.     

Conjunctival and corneal colonization by Pseudomonas aeruginosa in mechanically ventilated patients. A prospective study.

In patients on mechanical ventilation the eyes may be colonized with P. aeruginosa. This study was designed to establish an association between endotracheal suctioning and this colonization. During the study period from January to August 1996, ten out of twenty-eight (36%) patients who were mechanically ventilated for than 3 days developed colonization of the respiratory tract with P. aeruginosa. In seven out of these ten patients (70%) conjunctival colonization with P. aeruginosa could be established. Subsequently three patients (11%) developed a clinical eye infection. In all patients the eye on the side corresponding to the position of the ventilator, the suction device and the location of the nurse during suctioning procedures, was colonized first. Contamination of the conjunctiva probably occurs by aerosol exposure during disconnection of the intubation tube from the ventilator for tracheal suctioning. Patients on mechanical ventilation may have an increased risk for eye infections.     

Recombinant human deoxyribonuclease shortens ventilation time in young, mechanically ventilated children

Recombinant human deoxyribonuclease I (dornase alfa) is currently used as an inhaled mucoactive agent in the treatment of cystic fibrosis. In a randomized, placebo-controlled, double-blind clinical study in 100 infants, we investigated whether the therapeutic use of dornase alfa can be extended to ventilated, fluid-restricted children to reduce reintubation rate, ventilation duration, pediatric intensive care unit (PICU) stay, and ventilation complications. While reintubation rates were similar for dornase alfa 7% vs. placebo 9% (odds ratio, 0.77; confidence interval, 0.11-4.9), the incidence of atelectasis (6 vs. 17, respectively; P-value 0.051), median ventilation time (2.2 vs. 3.4 days, respectively; P-value 0.043), median length of PICU stay (7 vs. 8 days, respectively; P-value 0.051), and mean costs (4,830 vs. 6,320, respectively) were lower in the dornase alfa group. No adverse effects were observed, even in critically ill patients. We found that dornase alfa was beneficial and safe. Our findings also indicate that dornase alfa is possibly of value from the first day of mechanical ventilation onward, particularly when longer ventilation (>3 days) is expected in fluid-restricted children after cardiac surgery.     

Effect of mechanical ventilator mode on tendency towards respiratory alkalosis

The question whether assist-control ventilation (A/C) results in more frequent or more severe respiratory alkalosis than intermittent mandatory ventilation (IMV) is often raised. We prospectively compared the respiratory rates and arterial blood tensions of 18 critically ill patients with respiratory failure of diverse causes who were mechanically ventilated for 1 h with each of these ventilatory modes. Each patient served as his own control. We found that after 1 h of IMV the average pH was 7.42 +/- 0.2 (mean +/- SEM), after 1 h of A/C the pH was 7.45 +/- 0.01 (p less than 0.005), the average PaCO2 during IMV was 40.7 +/- 1.8, the average PaCO2 during A/C was 37.9 +/- 1.6 (p less than 0.001), the average respiratory rate during IMV was 21 +/- 2.0, and the average respiratory rate during A/C was 15 +/- 2.0 (p less than 0.001). One patient became alkalemic (pH 7.55) during A/C. These pH and PaCO2 changes were not associated with any adverse clinical sequelae. We conclude that the responsible physician should be guided by factors other than control of pH in choosing the mode of mechanical ventilation for most patients.     

Incidence and short-term outcome of acute lung injury in mechanically ventilated children.

The aim of this study was to determine the incidence and short-term outcome of mechanically ventilated children suffering from acute lung injury (ALI) on a paediatric intensive care unit (PICU). Between January 1 1998 and January 1 2000, all mechanically ventilated children were evaluated using the criteria of an American-European Consensus Conference. Of the 443 children eligible for analysis, 44 (9.9%) were diagnosed as suffering from ALI. Of these, 79.5% developed the acute respiratory distress syndrome (ARDS); 54.5% (24 of 44) fulfilled the ARDS criteria at inclusion and 25% (11 of 44) later. PICU mortality for ALI was 27.3% (12 of 44) and within the ARDS subgroup 31.4% (11 of 35). Of the 12 children who died, 11 had ARDS; the main cause of death was cerebral damage (seven of 12). Acute lung injury and acute respiratory distress syndrome are rare diseases on a paediatric intensive care unit with a high mortality. Most of the children with acute lung injury develop acute respiratory distress syndrome. In the acute respiratory distress syndrome subgroup, mortality is higher than in the acute lung injury nonacute respiratory distress syndrome subgroup. Further investigations should confirm prognostic factors (e.g. respiratory parameters) for prediction of outcome.     

Noninvasive ventilation in childhood acute neuromuscular respiratory failure: a pilot study

BACKGROUND: Over a 36-month study period, 10 nonconsecutive neuromuscular pediatric patients (6 infants, mean age 10.16 months, and 4 children, mean age 9.3 years) presenting with acute respiratory failure (ARF) were treated by noninvasive positive pressure ventilation (NPPV). All patients required immediate respiratory support and fulfilled our intubation criteria. OBJECTIVE: The aim of the study was to verify if early NPPV was able to avoid endotracheal intubation and to improve both oxygenation and ventilation within 24 h from admission in this clinical setting. PATIENTS AND METHODS: A prospective pilot study was carried out on neuromuscular patients admitted to the pediatric intensive care unit (PICU) of the Catholic University of Rome because of ARF and managed exclusively with NPPV for at least 24 h following admission. All patients were treated using a flow-triggered mechanical ventilator through a face mask or using the new helmet interface. RESULTS: Eight patients were successfully ventilated during the observation period and 2 early failures occurred. Among children undergoing face mask NPPV, the PaO(2)/FiO(2) ratio increased from a median value of 75 (range 48-149) to 240 (range 133-385; p < 0.001) and 328 (range 180-371; p < 0.001) at selected time points (3 and 12 h after NPPV introduction, respectively); the alveolar-to-arterial oxygenation difference showed a similar trend, i.e. decreasing from a median value of 589 (range 213-659) to 128 (range 62-527; p < 0.01) and 69 (range 45-207; p < 0.001), respectively. Hypercarbic ARF resolved within 6 h from admission even in the most severe cases. CONCLUSIONS: NPPV was a safe and effective first-line therapeutic approach in hypoxemic ARF children/infants with neuromuscular disease. It seems of importance to identify children with neuromuscular disorders who may be able to achieve residual ventilator-free breathing and to perform an NPPV trial avoiding tracheal intubation. Life-threatening respiratory distress and very young age should not preclude NPPV application in the PICU setting. The new helmet interface represents a promising tool for noninvasive ventilation in older children.     

Severity of illness and outcome in adult patients with primary varicella pneumonia

BACKGROUND: Varicella pneumonia is a serious complication of primary varicella infection in adults that often results in respiratory failure and death. OBJECTIVE: To analyze the clinical and laboratory manifestations of primary varicella pneumonia in patients admitted to our intensive care unit (ICU). METHODS: Retrospective study on patients treated in our ICU with a diagnosis of primary varicella pneumonia during a period of 15 years. We recorded age, gender, smoking habits, clinical and laboratory findings, arterial blood gases, chest radiograph, illness severity (SAPS II), length of stay, necessity for mechanical ventilation, complications, therapy and survival. We examined the influence of the duration of respiratory symptoms and rash prior to admission, and the influence of illness severity on outcome. RESULTS: There was a statistically significant difference in duration of respiratory symptoms, duration of rash and SAPS II on admission between: (a) mechanically ventilated patients vs. spontaneously breathing patients (p < 0.007, p < 0.00, p < 0.00), (b) patients who survived vs. patients with poor outcome (p < 0.001, p < 0.000, p < 0.000), and (c) mechanically ventilated patients with poor outcome vs. mechanically ventilated patients who survived (p < 0.001, p < 0.00, p < 0.000). Overall mortality was 13.6%; death occurred only in mechanically ventilated patients (mortality 33.3%). CONCLUSIONS: Primary varicella pneumonia remains a critical problem with significant mortality. When recognized before respiratory failure ensues and mechanical ventilation becomes mandatory, patients could have an excellent outcome. Adult patients who delay asking for medical support, the disease may lead to the need for mechanical ventilation and severe complications with a fatal outcome.     

探讨232例院际转运先天性心脏病危重患儿的安全性及其转归

目的探讨先天性心脏病危重症患儿院际转运的安全性。方法回顾性分析2009年8月至2011年7月院际转运的232例先天性心脏病危重症患儿的转运前、中和NJL科监护病房（pediatric intensive careunit,PICU）后的临床资料、转运距离、时间和患儿的转归。结果232例患儿,男152例,女80例;年龄1个月～12岁,中位年龄5个月;体质量2．5—25蝇,中位体质量5．5k;转运花费时间20—990min,中位时间156min;转运距离是74。620km,中位距离204km,其中47．2％的患儿转运距离100～200km,中位距离148km。转运过程中需要呼吸机正压通气的患儿56例（24．1％）,无1例死亡。转运的患儿均人住广东省人民医院PICU,其中治愈及好转220例（94．8％）,放弃治疗9例,死亡3例。结论配备专业的转运队伍,做好转运前的充分准备,转运中的密切监护和及时的处理,能提先天性心脏病高危重症患儿的院际转运安全性和预后。     

Lung function tests in neonates and infants with chronic lung disease: global and regional ventilation inhomogeneity

This review considers measurement of global and regional ventilation inhomogeneity (VI) in infants and young children with acute neonatal respiratory disorders and chronic lung disease of infancy (CLDI). We focus primarily on multiple-breath inert gas washout (MBW) and electrical impedance tomography (EIT). The literature is critically reviewed and the relevant methods, equipment, and studies are summarized, including the limitations and strengths of individual techniques, together with the availability and appropriateness of any reference data. There has been a recent resurgence of interest in using MBW to monitor lung function within individuals and between different groups. In the mechanically ventilated, sedated, and paralyzed patient, VI indices can identify serial changes occurring following exogenous surfactant. Similarly, global VI indices appear to be increased in infants with CLDI and to differentiate between infants without lung disease and those with mild, moderate, and severe lung disease following preterm birth. While EIT is a relatively new technique, recent studies suggest that it is feasible in newborn infants, and can quantitatively identify changes in regional lung ventilation following alterations to ventilator settings, positive end expiratory pressure (PEEP), and administration of treatments such as surfactant. As such, EIT represents one of the more exciting prospects for continuous bedside pulmonary monitoring. For both techniques, there is an urgent need to establish guidelines regarding data collection, analysis, and interpretation in infants both with and without CLDI.     

自主呼吸试验在撤离呼吸机中的作用

目的 探讨自主呼吸试验(SBT)在机械通气的撤离、拔除气管插管过程中的作用.方法 采用前瞻性随机对照方法,选择67例机械通气超过48 h的患者,当所有患者达到撤离呼吸机状态时将其随机(采用从密封信封中抽取随机号的方法)分为自主呼吸试验组(SBT组,35例)和无自主呼吸试验组(NO-SBT组,32例)两组.SBT组患者顺利通过SBT后随即拔除气管插管,NO-SBT组患者在达到撤离呼吸机条件后,不进行SBT,即拔除气管插管.以拔除气管插管的成功率作为评判的主要指标,成功的标志为拔除气管插管后能维持自主呼吸48 h以上.两组均数的比较采用两个独立样本的t检验,频数的比较采用X~2检验.结果 两组患者在拔除气管插管前的一般状况、呼吸生理和血流动力学等指标比较差异无统计学意义;年龄、性别、气管插管的口径、疾病的严重程度和疾病种类相似,机械通气的时间比较差异尢统计学意义.两组各有3例患者再次气管插管(X~2=0.013,P=0.908).两组患者拔除气管插管后,需无创辅助通气的患者NO-SBT组为5例,SBT组为4例(X~2=0.253,P=0.727).两组患者医院内病死率[N0-SBT组为12.5%(4/32),SBT组为9.7%(3/35),X~2=0.311,P=0.600]差异无统计学意义.结论 SBT可能不是拔除气管插管前的必需过程.