有创-无创序贯机械通气救治非COPD急性严重呼吸衰竭的护理

目的：探讨有创一无创序贯机械通气救治非COPD病因所致急性严重呼吸衰竭的临床效果及护理。方法：选择非COPD病因所致急性严重呼吸衰竭患者20例为序贯通气组,先经口气管插管有创通气,根据病情在3～7d内拔除气管插管改为无创正压通气;选择相似病情病例20例作为对照组,经Kr气管插管有创通气,以同步间歇强制通气＋压力支持通气方式撤机。对2组患者均进行密切观察、精心护理以配合治疗。观察两组病例的机械通气时间、呼吸机相关性肺炎（VAP）发生率、撤机成功率、住院死亡率、总住院时间等,并对护理资料进行分析。结果：序贯通气组VAP发生率、有创通气时间、总机械通气时间、总住院时间明显低于对照组（P〈0．05）。结论：有创一无创序贯机械通气策略不仅可应用于COPD所致的重症呼吸衰竭,结合有效的护理措施,对非COPD病因所致急性严重呼吸衰竭的救治也具有一定优势。     

Noninvasive positive-pressure ventilation in clinical practice at a large university-affiliated Brazilian hospital

OBJECTIVES:

To describe noninvasive positive-pressure ventilation use in intensive care unit clinical practice, factors associated with NPPV failure and the associated prognosis.

METHODS:

A prospective cohort study.

RESULTS:

Medical disorders (59%) and elective surgery (21%) were the main causes for admission to the intensive care unit. The main indications for the initiation of noninvasive positive-pressure ventilation were the following: post-extubation, acute respiratory failure and use as an adjunctive technique to chest physiotherapy. The noninvasive positive-pressure ventilation failure group was older and had a higher Simplified Acute Physiology Score II score. The noninvasive positive-pressure ventilation failure rate was 35%. The main reasons for intubation were acute respiratory failure (55%) and a decreased level of consciousness (20%). The noninvasive positive-pressure ventilation failure group presented a shorter period of noninvasive positive-pressure ventilation use than the successful group [three (2-5) versus four (3-7) days]; they had lower levels of pH, HCO₃ and base excess, and the FiO₂ level was higher. These patients also presented lower PaO2:FiO2 ratios; on the last day of support, the inspiratory positive airway pressure and expiratory positive airway pressure were higher. The failure group also had a longer average duration of stay in the intensive care unit [17 (10-26) days vs. 8 (5-14) days], as well as a higher mortality rate (9 vs. 51%). There was an association between failure and mortality, which had an odds ratio (95% CI) of 10.6 (5.93 – 19.07). The multiple logistic regression analysis using noninvasive positive pressure ventilation failure as a dependent variable found that treatment tended to fail in patients with a Simplified Acute Physiology Score II≥34, an inspiratory positive airway pressure level≥15 cmH2O and pH<7.40.

CONCLUSION:

The indications for noninvasive positive-pressure ventilation were quite varied. The failure group had a longer intensive care unit stay and higher mortality. Simplified Acute Physiology Score II≥34, pH<7.40 and higher inspiratory positive airway pressure levels were associated with failure.     

Asynchrony and cyclic variability in pressure support noninvasive ventilation

Noninvasive mechanical ventilation is an effective procedure to manage patients with acute or chronic respiratory failure. Most ventilators act as flow generators that assist spontaneous respiratory cycles by delivering inspiratory and expiratory pressures. This allows the patient to improve alveolar ventilation and subsequent pulmonary gas exchanges. The interaction between the patient and his ventilator are therefore crucial for tolerance and acceptability and part of this interaction is the facility to trigger the ventilator at the beginning of the inspiration. This is directly related to patients' discomfort which is not quantified today. Phase portraits reconstructed from the airflow and first-return maps built on the total breath duration were used to investigate the quality of the patient-ventilator interaction. Phase synchronization can be identified from phase portrait and the breath-to-breath variability is well characterized by return maps. This paper is a first step in the direction of automatically estimating the comfort from measurements and not from a necessarily subjective answer given by the patient. These tools could be helpful for the physicians to set the ventilator parameters.     

巨细胞病毒肺炎患者实行无创通气的监测与护理观察

目的 对入住重症监护室(ICU)接受无创通气的巨细胞病毒肺炎(CMV)患者,通过监测护理,为临床相关应用提供证据.方法 2010年1月-2014年5月入住我院ICU病房接受无创通气的巨细胞病毒肺炎患者共计96例,常规应用抗病毒、免疫抑制剂及肠内外营养支持等综合治疗措施,在应用呼吸机期间对患者行心电监测及呼吸机管道护理,并积极预防及护理患者的不良反应.结果 96例患者中72例经无创通气治疗后好转出院,治疗有效率为69.1％;例患者在行无创通气后需进一步行有创呼吸机通气治疗,其中11例治愈出院,13例死亡.呼吸机治疗期间共有42例患者出现胃肠胀气者16例,面部皮肤压迫损伤28例,气胸者4例,皮下气肿者3例,鼻黏膜干燥、糜烂、出血者36例,刺激性结膜炎者2例.结论 在患者接受无创正压通气期间做好患者相关监测及护理是确保患者接受无创通气并确保通气成功与否的重要因素,通过正确积极的护理可以有效的减少患者接受呼吸机治疗期间出现的相关并发症并能有效的提高患者的治疗疗效.     

Infections in patients requiring ventilation in intensive care: application of a new classification

Objective: To classify infections according to the carrier state determined by surveillance cultures of throat and rectum, rather than by the traditional criterion of the time of onset after admission.
Methods: An observational cohort study of 3 months' duration was performed in a mixed medical-surgical intensive care unit (ICU) in a district general hospital of a subset of patients requiring mechanical ventilation for ≥3 days. Surveillance cultures from throat and rectum were obtained on admission to the ICU and then twice weekly to distinguish carriage of potentially pathogenic microorganisms (PPM) brought in by the patient from microorganisms acquired during the ICU stay.
Results: Out of the total population of 104 patients, 21 patients were enrolled over 3 months. Eight patients (38%) developed 12 infections, half of which were of primary endogenous pathogenesis and caused by Haemophilus influenzae, Candida albicans and Pseudomonas aeruginosa carried by the patients on admission. The remaining six were of secondary endogenous pathogenesis and caused by Acinetobacter baumannii and Pseudomonas aeruginosa acquired in the unit.
Conclusions: Traditional classifications of hospital infection are challenged. If the traditional 48-h cut-off point was used, then 9 of 12 cases (75%) of infection would have been classified as nosocomial, whereas using the method based on the carrier state, 50% of all infections were caused by microorganisms carried by the patient on admission to the ICU. Moreover, we believe that the distinction between primary endogenous, secondary endogenous and exogenous is valid because these three types of infection each require different control methods.     

Mechanical ventilation in patients in the intensive care unit of a general university hospital in southern Brazil: an epidemiological study

OBJECTIVES:

To determine the characteristics, the frequency and the mortality rates of patients needing mechanical ventilation and to identify the risk factors associated with mortality in the intensive care unit (ICU) of a general university hospital in southern Brazil.

METHOD:

Prospective cohort study in patients admitted to the ICU who needed mechanical ventilation for at least 24 hours between March 2004 and April 2007.

RESULTS:

A total of 1,115 patients admitted to the ICU needed mechanical ventilation. The mortality rate was 51%. The mean age (± standard deviation) was 57±18 years, and the mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 22.6±8.3. The variables independently associated with mortality were (i) conditions present at the beginning of mechanical ventilation, age (hazard ratio: 1.01; p<0.001); the APACHE II score (hazard ratio: 1.01; p<0.005); acute lung injury/acute respiratory distress syndrome (hazard ratio: 1.38; p=0.009), sepsis (hazard ratio: 1.33; p=0.003), chronic obstructive pulmonary disease (hazard ratio: 0.58; p=0.042), and pneumonia (hazard ratio: 0.78; p=0.013) as causes of mechanical ventilation; and renal (hazard ratio: 1.29; p=0.011) and neurological (hazard ratio: 1.25; p=0.024) failure, and (ii) conditions occurring during the course of mechanical ventilation, acute lung injuri/acute respiratory distress syndrome (hazard ratio: 1.31; p<0.010); sepsis (hazard ratio: 1.53; p<0.001); and renal (hazard ratio: 1.75; p<0.001), cardiovascular (hazard ratio: 1.32; p≤0.009), and hepatic (hazard ratio: 1.67; p≤0.001) failure.

CONCLUSIONS:

This large cohort study provides a comprehensive profile of mechanical ventilation patients in South America. The mortality rate of patients who required mechanical ventilation was higher, which may have been related to the severity of illness of the patients admitted to our ICU. Risk factors for hospital mortality included conditions present at the start of mechanical ventilation conditions that occurred during mechanical support.     

Estimating respiratory mechanical parameters of ventilated patients: a critical study in the routine intensive-care unit

Airflow and pressure were measured post-operatively in eight mechanically ventilated patients in the routine intensive care unit. Analysis of the input impedance spectra versus frequency suggested that respiratory data cannot be adequately reproduced using the classic two-element R-C model, as the real part of input impedance decreases with frequency. To fit in with this behaviour, we adopted a three-element model with an additional parallel compliance. The three parameters of this model were estimated separately in the frequency and time domains by minimising suitable least-square criterion functions. The results demonstrate a good agreement between the parameter estimates in the frequency and time domains, and show that the three-element model reproduces the input impedance frequency pattern in the range 0.2–8 Hz. Comparison of different linear models in the time domain demonstrated that the precision of parameter estimates and the quality of best fitting sharply increase from the two-element to the three-element model. The addition of a fourth resistive parameter, like in the Mead model, does not lead to appreciable improvement and makes the model almost unidentifiable. The possible contribution of a ventilator-patient circuit of the upper airway shunting and of the peripheral airway obstruction are also discussed.     

Communication with Patients on Mechanical Ventilation: A Review of Existing Technologies

How to cite this article: Anand A, Nair RR, Kodamanchili S, Panda R, Bhardwaj KK, Gowthaman TB. Communication with Patients on Mechanical Ventilation: A Review of Existing Technologies. Indian J Crit Care Med 2022;26(6):756–757.     

Effects of deep sedation on sleep in critically ill medical patients on mechanical ventilation

Atypical EEG patterns not consistent with standard sleep staging criteria have been observed in medical intensive care unit (ICU) patients. Our aim was to examine the relationship between sleep architecture and sedation in critically ill mechanically ventilated patients pre‐ and post‐extubation. We performed a prospective observational repeated measures study where 50 mechanically ventilated patients with 31 paired analyses were examined at an academic medical centre. The sleep efficiency was 58.3 ± 25.4% for intubated patients and 45.6 ± 25.4% for extubated patients (p = .02). Intubated patients spent 76.33 ± 3.34% of time in non‐rapid eye movement (NREM) sleep compared to 64.66 ± 4.06% of time for extubated patients (p = .02). REM sleep constituted 1.36 ± 0.67% of total sleep time in intubated patients and 2.06 ± 1.09% in extubated patients (p = .58). Relative sleep atypia was higher in intubated patients compared to extubated patients (3.38 ± 0.87 versus 2.79 ± 0.42; p < .001). Eleven patients were sedated with propofol only, 18 patients with fentanyl only, 11 patients with fentanyl and propofol, and 10 patients had no sedation. The mean sleep times on “propofol”, “fentanyl”, “propofol and fentanyl,” and “no sedation” were 6.54 ± 0.64, 4.88 ± 0.75, 6.20 ± 0.75 and 4.02 ± 0.62 hr, respectively. The sigma/alpha values for patients on “propofol”, “fentanyl”, “propofol and fentanyl” and “no sedation” were 0.69 ± 0.04, 0.54 ± 0.01, 0.62 ± 0.02 and 0.57 ± 0.02, respectively. Sedated patients on mechanical ventilation had higher sleep efficiency and more atypia compared to the same patients following extubation. Propofol was associated with higher sleep duration and less disrupted sleep architecture compared to fentanyl, propofol and fentanyl, or no sedation.     

不同机械通气模式对COPD合并呼吸衰竭患者氧代谢指数及血气分析的影响

目的 探讨不同机械通气模式对COPD合并呼吸衰竭患者氧代谢指数及血气分析的影响。方法 选取2016年5月~2017年12月我院收治的COPD合并呼吸衰竭患者60例,采用随机数字表法分为观察组和对照组,每组30例。两组均行呼吸机支持呼吸,观察组给予适应性压力支持（ASV）,对照组给予同步间歇指令性通气（SIMV）+压力支持通气（PSV）,比较两组治疗开始即刻和治疗后6 d呼吸频率、氧代谢指数、血气分析。结果 治疗后,两组PaO2、pH高于治疗前,PaCO2、RR低于治疗前,且观察组PaO2、PaCO2、RR、pH优于对照组,差异有统计学意义（P＜0.05）。两组CaO2、DO2、SaO2高于治疗前,VO2低于治疗前,且观察组CaO2、VO2、DO2、SaO2优于对照组,差异有统计学意义（P＜0.05）。结论 ASV模式在COPD急性加重合并呼吸衰竭患者中有助于提升肺通气功能、促进自主呼吸回复,改善机体氧供需平衡,具有较好的效果,优于SIMV＋PSV模式。     

Non-invasive Ventilation Delivered by Helmet vs Face Mask in Patients with COVID-19 Infection: Additional Measures to Reap Further Benefits

How to cite this article: Mandal M, Bhattacharya D, Esquinas AM. Non-invasive Ventilation Delivered by Helmet vs Face Mask in Patients with COVID-19 Infection: Additional Measures to Reap Further Benefits. Indian J Crit Care Med 2022;26(10):1159–1160.