机械通气治疗连枷胸合并呼吸衰竭16例

目的探讨连枷胸致呼吸衰竭的病理生理、机械通气治疗的指征、模式参数调节及撤离.方法总结16例采用机械通气治疗的连枷胸合并呼吸衰竭病例的临床治疗过程及转归.结果其中13例经机械通气4～14d后一次性成功脱机,转普通病房继续治疗5～1 3d后出院;3例死亡病例分别死于重度颅脑损伤及失血性休克.结论连枷胸如有机械通气指征,应尽早使用.机械通气模式可选用SIMV(同步间歇指令通气)+PSV(压力支持),宜选择偏高潮气量(10～12ml/kg),PEEP(呼气末正压)有利于病情恢复.浅快呼吸指数(f/VT)是目前撤机最有预测价值的指标.     

Traumatic respiratory insufficiency: comparison of conventional mechanical ventilation to high-frequency positive pressure with low-rate ventilation

Eleven patients suffering severe traumatic respiratory insufficiency were mechanically ventilated using a new system which combined high-frequency positive-pressure ventilation (HFPPV) with low-rate conventional mechanical ventilation (LRCMV). Ten similar patients were ventilated by conventional mechanical ventilation (CMV) with PEEP. HFPPV patients were fully conscious and cooperative during ventilation and did not need sedatives or muscle relaxants. Arterial oxygenation was significantly (p less than .005) better in HFPPV than CMV patients (89.91 +/- 10.24 vs. 78.43 +/- 11.13 torr, respectively), and pulmonary shunt was also better in the HFPPV group (13.1 +/- 4.7% vs. 20.4 +/- 6.4%, p less than .01). Moreover, inspired oxygen concentrations were lower (PaO2/FIO2 197.8 +/- 51.3 in the HFPPV group vs. 130 +/- 46.6 in the CMV group, p less than .005) and the time required for mechanical ventilation was shorter (4.2 +/- 0.91 vs. 6.1 +/- 0.8 days, p less than .1). All HFPPV patients immediately began breathing spontaneously when they were disconnected from the ventilator. We suggest this method as a better ventilatory mode for patients suffering traumatic respiratory insufficiency.     

High-frequency positive-pressure ventilation in neonates

Twenty-five newborn infants with severe respiratory failure responding poorly to conventional mechanical ventilation were switched to high-frequency positive-pressure ventilation (HFPPV) at 90 to 180 cycle/min (mean 158), an estimated tidal volume less than or equal to 3 ml/kg body weight, an inspiratory time of 0.1 sec, and a PEEP of 3 to 17 cm H2O. In all infants, HFPPV increased PaO2 (mean 66 torr) and decreased PaCO2 (mean 14 torr) within 1 h. Fourteen hours after onset of treatment, the FIO2 requirement had decreased from 1.0 to 0.6 in all infants. Mean airway pressure (Paw) with HFPPV was usually less than or equal to Paw during conventional ventilation. In spite of the often high level of PEEP used, pneumothorax occurred in only 2 infants and bronchopulmonary dysplasia in 1. Eighteen (72%) infants survived and none died of respiratory failure. The use of HFPPV might be beneficial in neonates with severe respiratory failure that responds poorly to conventional therapy.     

Pressure control ventilation and minitracheotomy in treating severe flail chest trauma

Objective To evaluate pressure control ventilation (PCV) delivered through a minit-racheotomy in treating severe flail chest trauma.Design Case report.Setting Intensive care unit of a trauma center.Patient A 34-year-old woman affected by flail chest trauma and acute respiratory failure, who was initially treated with tracheal intubation to obtain internal pneumatic stabilization. The patient failed extubation and noninvasive mask treatment (pressure support ventilation plus PEEP) due to poor chestwall mechanics.Interventions Minitracheotomy was performed and ventilation was achieved with high levels of inspiratory pressure (PCV or assisted PCV) to overcome the resistance of the cannula (Mini-Trach II, Portex, ID 4 mm). Esophageal and carinal pressures were monitored. Ventilatory treatment was always performed with the full cooperation of the patient; the patient's glottic function was always intact.Measurements and results The patient was successfully treated with pressure control ventilation delivered through the Mini-Trach. After 7 days of PCV, the patient was switched to assisted PCV. On the 20th day after admission, she was weaned from mechanical ventilation.Conclusions We conclude that a suitable gas exchange and pneumatic stabilization in a flail chest condition can be achieved using minitracheostomic ventilation. At the same time, this treatment could reduce some side effects of traditional tracheal intubation.     

创伤性连枷胸48例临床治疗分析

目的探讨创伤性连枷胸的治疗方法。方法分析48例创伤性连枷胸患者机械通气后血气分析等各种参数的变化及手术治疗的疗效。结果 22例患者行机械通气24小时后动脉血氧分压(PaO2)、氧合指数(PaO2/FiO2)和脉搏血氧饱和度(SpO2)均较治疗前明显改善(P0.001);手术治疗23例,ICU住院时间(3.39±2.29)天,肺部感染2例(8.70%),血管活性药物使用率17.39%(4/23);全组死亡2例,明显低于预测死亡风险。结论有创机械通气不仅能固定连枷胸,而且可有效改善氧合,与手术治疗有效结合,可显著改善连枷胸患者预后。     

BIPAP模式治疗连枷胸合并肺挫伤

目的探讨双相气道正压通气（BIPAP）模式治疗连枷胸合并肺挫伤的临床效果。方法回顾性分析11例连枷胸合并肺挫伤的患者，出现呼吸功能不全需要机械通气时，均采用BIPAP模式，设计高呼气末正压通气（PEEP）、低PEEP、高PEEP持续时间、压力支持（PSV）、呼吸频率（f）、吸氧浓度（FiO2），当低PEEP≤6cmH2O、高PEEP≤10cmH2O、PSV≤5cmH2O、f≤4次／min、FiO2≤0，4时即可脱机。结果采用BIPAP模式治疗后患者症状、氧合指数、Pa02明显改善，经机械通气3—14d后一次性成功脱机，无一例发生急性呼吸窘迫综合征（ARDS）和死亡。结论对连枷胸合并肺挫伤采用BIPAP模式治疗能起到胸廓内固定，同时治疗急性肺损伤的共同作用，阻止ARDS的发生，是一种很好的机械通气方法。     

Flail chest in a neonate resulting from nonaccidental trauma

The authors present a 21-day-old infant who sustained a flail chest as a result of nonaccidental trauma. Initial treatment included endotracheal intubation and mechanical ventilation for hypoxemic respiratory failure followed by the administration of continuous positive airway pressure by nasal cannula. Further evaluation resulted in the identification of nonaccidental as the mechanism of injury. The pathophysiology of flail chest, its etiology, and treatment options are reviewed. In the absence of a documented history of significant thoracic injury or the presence of metabolic bone disease, nonaccidental trauma is the most likely diagnosis in infants and children with a flail chest.     

Treatment of postoperative respiratory distress syndrome

We have studied 45 patients with postoperative adult respiratory distress syndrome (ARDS) who were treated by mechanical ventilation during the last four years. This period was divided into two periods, and the mortality and progress after treatment were analysed. The overall mortality was 56%. In the first period this rate was as high as 76%, while in the second period this rate improved to 43%. This improvement in the second period was thought to have resulted from aggressive cardiorespiratory treatment and the diminution of infection.According to the course of ARDS after treatment, four types could be classified. Type 1 showed rapid improvement in respiratory function. Type 2 showed gradual improvement. Type 3 showed relapse of respiratory failure. Type 4 resisted mechanical ventilation. Patients of types 3 and 4 had extremely poor prognoses. Stricter management to avoid infection, specific treatment of multiple organ failure (which was seen frequently) seemed advantageous. High frequency positive pressure ventilation (HFPPV) may have some role in improving the respiratory function of the patients with ARDS.     

A comparative study of continuous positive airway pressure (CPAP) and intermittent positive pressure ventilation (IPPV) in patients with flail chest

Introduction: The role of non-invasive positive pressure ventilation delivered through a face mask in patients with flail chest is uncertain. We conducted a prospective, randomised study of continuous positive airway pressure (CPAP) given via a face mask to spontaneously breathing patients compared with intermittent positive pressure ventilation (IPPV) with endotracheal intubation (ETI) in 52 patients with flail chest who required mechanical ventilation.

Method: The 52 mechanically ventilated patients were randomly divided into two treatment groups: the ET group (n = 27) received mechanical ventilation with ETI, whereas patients in the CPAP group (n = 25) received CPAP via a face mask with patient controlled analgesia (PCA). Major complications, arterial blood gas levels, length of intensive care unit (ICU) stay and ICU survival rate were recorded.

Results: Nosocomial infection was diagnosed in 10 of 21 patients in the ET group, but only in 4 of 22 in the CPAP group (p = 0.001). Mean PO₂ was significantly higher in the ET group in the first 2 days (p<0.05). There were no significant differences in length of ICU stay between groups. Twenty CPAP patients survived, but only 14 of 21 intubated patients who received IPPV (p<0.01).

Conclusion: Non-invasive CPAP with PCA led to lower mortality and a lower nosocomial infection rate, but similar oxygenation and length of ICU stay. The study supports the application of CPAP at least as a first line of treatment for flail chest caused by blunt thoracic trauma.

     

早期机械通气治疗连枷胸并发急性肺挫伤的疗效评价

目的:观察不同时期机械通气对连枷胸并发急性肺挫伤的治疗效果。方法:回顾性分析2001年3月—2010年2月我院收治的51例连枷胸并发肺挫伤患者的临床资料。根据受伤后至实施机械通气的间隔时间分为早期机械通气组(32例)和后期机械通气组(19例),观察治疗前后的血气参数变化,比较两组间的机械通气治疗时间、ICU时间和并发症发生率、病死率等。结果:早期机械通气者入院时呼吸衰竭程度比后期机械通气者严重,而机械通气后24h前者呼吸衰竭程度比后者轻(P<0.01)。前者机械通气治疗时间、ICU时间及急性呼吸窘迫综合征(ARDS)的发生率明显低于后者(P<0.01),且肺部感染、多脏器功能障碍综合征(MODS)的发病率及病死率亦低于后者(P<0.05)。结论:尽早对连枷胸并发急性肺挫伤患者实施机械通气不仅能取得良好的内固定治疗效果,并能有效改善肺挫伤低氧血症,减少ARDS、MODS等并发症,缩短机械通气治疗时间及ICU时间,提高治愈率。     

Non-invasive negative and positive pressure ventilation in the treatment of acute on chronic respiratory failure

Objective To investigate in clinical practice the role of non-invasive mechanical ventilation in the treatment of acute respiratory failure on chronic respiratory disorders.Design An 18 months prospective cohort study.Setting A specialised respiratory intensive care unit in a university-affiliated hospital.Patients A total of 258 consecutive patients with acute respiratory failure on chronic respiratory disorders.Interventions Criteria for starting non-invasive mechanical ventilation and for endotracheal intubation were predefined. Non-invasive mechanical ventilation was provided by positive pressure (NPPV) ventilators or iron lung (NPV).Results The main characteristics of patients (70% with chronic obstructive pulmonary disease) on admission were (mean, SD or median, 25th–75th centiles): pH 7.29 (0.07), PaCO₂ 83 mm Hg (19), PaO₂/FiO₂ 198 (77), APACHE II score 19 (15–24). Among the 258 patients, 200 (77%) were treated exclusively with non-invasive mechanical ventilation (40% with NPV, 23% with NPPV, and 14% with the sequential use of both), and 35 (14%) with invasive mechanical ventilation. In patients in whom NPV or NPPV failed, the sequential use of the alternative non-invasive ventilatory technique allowed a significant reduction in the failure of non-invasive mechanical ventilation (from 23.4 to 8.8%, p=0.002, and from 25.3 to 5%, p=0.0001, respectively). In patients as a whole, the hospital mortality (21%) was lower than that estimated by APACHE II score (28%).Conclusions Using NPV and NPPV it was possible in clinical practice to avoid endotracheal intubation in the large majority of unselected patients with acute respiratory failure on chronic respiratory disorders needing ventilatory support. The sequential use of both modalities may increase further the effectiveness of non-invasive mechanical ventilation.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00134-003-2145-9     

Paralysis has no effect on chest wall and respiratory system mechanics of mechanically ventilated,sedated patients

Objective To evaluate the separate effects of sedation and paralysis on chest wall and respiratory system mechanics of mechanically ventilated, critically ill patients.Setting: ICU of the University La Sapienza Hospital, Rome.Patients and participants 13 critically ill patients were enrolled in this study. All were affected by disease involving both lungs and chest wall mechanics (ARDS in 4 patients, closed chest trauma without flail chest in 4 patients, cardiogenic pulmonary oedema with fluidic overload in 5 patients).Measurements and results Respiratory system and chest wall mechanics were evaluated during constant flow controlled mechanical ventilation in basal conditions (i. e. with the patients under apnoic sedation) and after paralysis with pancuronium bromide. In details, we simultaneously recorded airflow, tracheal pressure, esophageal pressure and tidal volume; with the end-inspiratory and end-expiratory airway occlusion technique we could evaluate respiratory system and chest wall elastance and resistances. Lung mechanics was evaluated by subtracting chest wall from respiratory system data. All data obtained in basal conditions (with the patients sedated with thiopental or propofol) and after muscle paralysis were compared using the Student'st test for paired data. The administration of pancuronium bromide to sedated patients induced a complete muscle paralysis without producing significant modification both to the viscoelastic and to the resistive parameters of chest wall and respiratory system.Conclusions This study demonstrates the lack of additive effects of muscle paralysis in mechanically ventilated, sedated patients. Also in view of the possible side effects of muscle paralysis, our results question the usefulness of generalyzed administration of neuromuscular blocking drugs in mechanically ventilated patients.     

Epidural analgesia or mechanical ventilation for multiple rib fractures?

A protocol for treating thoracic trauma is proposed. Severe pulmonary lesion with increased venous admixture (e.g. contusio, atelectasis, aspiration) is treated by mechanical ventilation. Rib fractures with minor pulmonary lesion and therefore with only moderately abnormal gas exchange but with remarkably reduced vital capacity (even with flail chest) are controlled by thoracic epidural analgesia following vital capacity, tidal volume and respiratory rate. If both a severe pulmonary lesion and serial rib fractures are present, the patient is ventilated for 2–3 days and then extubated to breathe spontaneously with epidural analgesia. The indication for a mechanical ventilation or for spontaneous breathing with thoracic epidural analgesia is therefore deducted more from functional variables than from morphological facts. The course of consecutive series of 283 patients is presented. 155 patients were treated with primary ventilation and 112 patients with primary epidural analgesia, while 16 patients could be managed with general analgesia. The duration of treatment morbidity and mortality show this protocol to be very useful.     

Clinical applications of high-frequency jet ventilation

Six patients with acute respiratory failure were treated with high-frequency jet ventilation (HFJV): 3 because they developed barotrauma while on conventional mechanical ventilation (CMV), 2 because of sedative- or PEEP-induced hypotension on CMV, and 1 because of bronchopleural fistula. In all patients, except the one with bronchopleural fistula, who was treated from the start with HFJV, gas exchange before (while on CMV) and after institution of HFJV could be compared. In these five patients, including the two with acute respiratory failure not complicated by barotrauma, gas exchange was better during HFJV than during CMV for the same levels of F_IO₂ and PEEP. HFJV therefore seems the method of choice for ventilatory support, not only in patients with bronchopulmonary disruption, but also in patients with hemodynamic embarrassment during CMV.     

Invasive and noninvasive ventilation in the emergency department

This article reviews invasive and noninvasive ventilation for emergency physicians. It presents an overview of respiratory physiology principles that will help emergency physicians adapt their ventilation strategies to any clinical situation. The basic modes of ventilation are summarized. The advantages and limitations of certain novel modes of ventilation are presented. This review highlights a variety of ventilation strategies to be used for patients with normal lung mechanics and gas exchange, acute hypoxemic respiratory failure, decreased lung compliance, airflow obstruction, and weakness or restriction of the chest wall. This article will help clinicians prevent, recognize, and treat complications of mechanical ventilation.     

Conventional and high-frequency ventilation in dogs with bronchopleural fistula

Seven anesthetized dogs with bronchopleural fistulas were subjected to a sequence of continuous positive-pressure ventilation (CPPV), volume-controlled high-frequency positive-pressure ventilation (HFPPV), and high-frequency vibratory ventilation (HFVV). Adequate short-term ventilation and oxygenation were possible with all three ventilatory modes. During HFPPV and HFVV, PaCO2 was unchanged, but hypercarbia developed during CPPV. PaO2 decreased during each mode of ventilation, but HFPPV maintained PaO2 at a sufficient and constant level during the 30-min test period. HFPPV was the most efficient technique with respect to delivery of minute ventilation, the relation between fistula flow and delivered ventilation, and maintenance of both ventilation and oxygenation.     

Delayed diagnosis of flail chest

A retrospective review of 99 consecutive patients with flail chest after trauma was conducted to determine the incidence and significance of delayed presentation. Patients ranged in age from 7 to 88 yr (mean 50.3). Hospitalization ranged from 1 to 129 days (mean 23). Mean Injury Severity Score was 30. Sixty (61%) patients were managed with mechanical ventilation. Pulmonary complications developed in 48 (48%) patients and 14 (14%) patients died. The flail chest injury was documented on initial examination of 77 (78%) patients. Delayed presentation occurred in 22 (22%) patients from 1 to 10 days after injury. Reasons for delayed diagnosis included intubation and mechanical ventilation before complete physical examination, development of pulmonary complications with the attendant increased work of breathing, and physician error. The time of presentation was not associated with patient age, sex, severity of injury, need for mechanical ventilation, duration of ventilation, incidence of pulmonary morbidity, or mortality.     

Percutaneous transtracheal jet ventilation for cardiopulmonary resuscitation: evaluation of a new jet ventilator

This study compared percutaneous transtracheal jet ventilation (PTJV) at a frequency (f) of 20/min, with high-frequency positive-pressure ventilation (HFPPV) at f of 60/min, and endotracheal intubation and intermittent positive-pressure ventilation (ET IPPV) at f of 10/min in apneic dogs. Fifty-four emergency medicine trainees (EMTs) attempted PTJV via a 14-gauge Angiocath attached to a hand-held jet ventilator, f of 20/min, and ET IPPV using an Ambu bag, f of 10/min. Twenty-nine other EMTs attempted cricothyrotomy using a prototype nonkinkable catheter (Arrow) and a new jet ventilator, Bronchovent, f of 60/min, equipped with a pressure sensor which stops ventilation at pressures greater than 20 cm H2O. Adequate oxygenation was achieved by all 3 groups, but only the HFPPV group avoided respiratory alkalosis. There was a higher equipment failure rate (catheter kinking and dislodgment) in the PTJV group. In the HFPPV group, the Bronchovent's pressure-limiting sensor stopped ventilation when the catheter was kinked or out of position, reducing the extent of subcutaneous emphysema and barotrauma. With further catheter improvements, HFPPV Bronchovent may offer a safe and reliable method of ventilating patients during CPR in the field.     

Outcomes of morbidly obese patients requiring mechanical ventilation for acute respiratory failure

OBJECTIVE: To examine the outcomes of morbidly obese patients with acute respiratory failure treated with mechanical ventilation. DESIGN: Retrospective study. SETTING: A 14-bed medical intensive care unit in an 800-bed university-based hospital. PATIENTS: A total of 50 morbidly obese subjects with acute respiratory failure requiring ventilatory assistance. INTERVENTIONS: None. MEASUREMENTS: Arterial blood gas measurements, intubation rate, days of mechanical ventilation, intensive care unit length of stay, hospital length of stay, and mortality. RESULTS: From January 1997 to December 2004, 50 morbidly obese patients with acute respiratory failure were treated with mechanical ventilation. Invasive mechanical ventilation was implemented in 17 patients with a mean body mass index of 53.2 +/- 12.2 kg/m2. A total of 33 patients were treated with noninvasive ventilation (NIV), of which 21 avoided intubation (NIV success) and 12 required intubation (NIV failure). Mean body mass index for the NIV success group was significantly less than for the NIV failure group (46.9 +/- 8.9 and 62.5 +/- 16.1 kg/m2, respectively, p = .001). Acute Physiology and Chronic Health Evaluation II scores were similar for patients treated with invasive and noninvasive ventilation. Significant improvements in pH and Paco2 were noted for the invasive mechanical ventilation and NIV success groups. No improvements in gas exchange were noted in the NIV failure group. Of patients treated with NIV, 36% required intubation. Hospital mortality for the invasive ventilation and NIV failure groups was increased. CONCLUSION: The type of ventilatory assistance may influence clinical outcomes in morbidly obese patients with acute respiratory failure.     

无创机械通气治疗老年急性左心衰并呼吸衰竭的效果研究

目的探讨应用无创机械通气治疗老年急性左心衰并呼吸衰竭的效果。方法选取急性左心衰肺水肿并呼吸衰竭患者92例,采用随机数表法分为2组。对照组患者行常规治疗,观察组患者在常规治疗的基础上给予无创机械通气治疗。比较2组患者治疗后临床症状改善、动脉血气分压、RR、p H以及临床效果。结果治疗后,观察组患者临床症状改善情况、p(O_2)、p(CO_2)、RR、p H、总有效率显著优于对照组(P0.05)。结论对急性左心衰肺水肿并呼吸衰竭患者给予无创机械通气治疗,能够有效改善患者的心功能。