Factors Influencing Weaning Older Adults From Mechanical Ventilation: An Integrative Review

Continuous Versus Intermittent Control Cuff Pressure for Preventing Ventilator-Associated Pneumonia: An Updated Meta-Analysis

OBJECTIVE

This study aimed to evaluate the effect of continuous control cuff pressure (CCCP) versus intermittent control cuff pressure (ICCP) for the prevention of ventilator-associated pneumonia (VAP) in critically ill patients.

METHODS

Relevant literature was searched in several databases, including PubMed, Embase, Web of Science, ProQuest, the Cochrane Library, Wanfang Database and China National Knowledge Infrastructure between inception and September 2022. Randomized controlled trials were considered eligible if they compared CCCP with ICCP for the prevention of VAP in critically ill patients. This meta-analysis was performed using the RevMan 5.3 and Trial Sequential Analysis 0.9 software packages. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to assess the level of evidence.

RESULTS

We identified 14 randomized control trials with a total of 2080 patients. Meta-analysis revealed that CCCP was associated with a significantly lower incidence of VAP compared with ICCP (relative risk [RR] = 0.52; 95% confidence interval [CI]: 0.37-0.74; P < 0.001), although considerable heterogeneity was observed (I2 = 71%). Conducting trial sequential analysis confirmed the finding, and the GRADE level was moderate. Subgroup analysis demonstrated that CCCP combined with subglottic secretion drainage (SSD) had a more significant effect on reducing VAP (RR = 0.39; 95% CI = 0.29-0.52; P < 0.001). The effect of CCCP on ventilator-associated respiratory infection (VARI) incidence was uncertain (RR = 0.81; 95% CI = 0.53-1.24; P = 0.34; I2 = 61%). Additionally, CCCP significantly reduced the duration of mechanical ventilation (MV) (mean difference [MD] = -2.42 days; 95% CI = -4.71-0.12; P = 0.04; I2 = 87%). Descriptive analysis showed that CCCP improved the qualified rate of cuff pressure. However, no significant differences were found in the length of intensive care unit (ICU) stay (MD = 2.42 days; 95% CI = -1.84-6.68; P = 0.27) and ICU mortality (RR = 0.86; 95% CI = 0.74-1.00; P = 0.05).

CONCLUSION

Our findings suggest that the combination of CCCP and SSD can reduce the incidence of VAP and the duration of MV and maintain the stability of cuff pressure. A combination of CCCP and SSD applications is suggested for preventing VAP.

Investigating the differences in nutritional status between successfully weaned and unsuccessfully weaned respirator patients

Long-term respirator users admitted to intensive care units need to be transferred to a respiratory care center (RCC) for weaning. It may cause malnutrition in critical care patients, which may manifest as a reduction in respiratory muscle mass, lower ventilatory capacity, and decreased respiratory tolerance. This study aimed to assess that if the patients' nutritional status were improved, it could help RCC patients to wean from respirators. All participants were recruited from the RCC of a medical foundation in the city and Taipei Tzu Chi Hospital. The indicators include serum albumin level, respirator detachment index, maximum inspiratory pressure (PImax), rapid shallow breathing index, and body composition measurements. We recorded the length of hospital stay, mortality, and RCW (respiratory care ward) referral rate for these participants and analyzed the differences in relevant research indicators between those who were and weren't weaned off. 43 of 62 patients were weaned from respirators, while 19 failed. The resuscitation rate was 54.8%. Patients with respirator weaning had a lower number of RCC admission days (23.1 ± 11.1 days) than respirator-dependent patients (35.6 ± 7.8 days, P < 0.05). The PImax of successfully weaned patients had a greater reduction (- 27.09 ± 9.7 cmH₂O) than unsuccessful ones (- 21.4 ± 10.2 cmH₂O, P < 0.05). The Acute Physiology and Chronic Health Evaluation II (APACHE II) scores of successfully weaned patients (15.8 ± 5.0) were lower than those who were not (20.4 ± 8.4, P < 0.05). There was no significant difference in serum albumin levels between the two groups. In the successfully weaned patients, the serum albumin concentration was increased from 2.2 ± 0.3 to 2.5 ± 0.4 mg/dL, P < 0.05. Improved nutritional status can help RCC patients to wean from respirators.

The effects of external diaphragmatic pacing on diaphragm function and weaning outcomes of critically ill patients with mechanical ventilation: a prospective randomized study

BACKGROUND

Diaphragmatic pacing can improve diaphragm function, which is beneficial for the prognosis of patients treated with prolonged mechanical ventilation (MV). While most previous studies have focused on the role of implanted diaphragm pacing (IDP), our study is the first to examine the effects of external diaphragmatic pacing (EDP) in mechanically ventilated patients. Specifically, the effect of EDP on diaphragm function, the success rate of weaning, the duration of MV (DMV), and the intensive care unit (ICU) length of stay (ILOS) were assessed.

METHODS

From September 2019 to December 2020, a total of 51 mechanically ventilated patients in the ICU of the Sun Yat-sen Memorial Hospital, Sun Yat-sen University were enrolled and randomly divided into an EDP group of 27 patients and a control group of 24 patients. The control group received routine treatment, and the EDP group received EDP treatment in addition to routine treatment. The diaphragm excursion (DE), diaphragm thickening fraction (DTF), DMV, ILOS, and average survival time were recorded to evaluate efficacy.

RESULTS

Patients treated with EDP had increased DE [exp(B) =1.86, 95% CI: 1.39 to 2.50, P<0.001] and DTF [exp(B) =1.35, 95% CI: 1.05 to 1.76, P=0.022], shortened weaning time (P=0.026) and prolonged average survival time (P<0.001) compared to patients who did not receive EDP therapy. Especially in cases with difficult weaning, the improvement of DE and DTF in the EDP treatment group was more obvious than that in the control group (P=0.013 and P=0.032). Moreover, the DTF upon attempted spontaneous breathing trial (SBT) was negatively correlated with the fraction of inspired oxygen (FiO2) [r=-0.54; 95% confidence interval (CI): -0.77 to -0.19; P=0.004], the arterial partial pressure of oxygen (PaO2) (r=-0.58; 95% CI: -0.79 to -0.25; P=0.001), the PaO2/FiO2 ratio (r=-0.52; 95% CI: -0.75 to -0.16; P=0.006), and the serum lactate concentration (Lac) (r=-0.39; 95% CI: -0.68 to 0.003; P=0.046).

CONCLUSIONS

EDP treatment can effectively reduce the DMV and prolong the average survival time of mechanically ventilated patients.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR1900024096.

Early prediction of extubation failure in patients with severe pneumonia: a retrospective cohort study

Backgroud: Severe pneumonia is one of the most common causes for mechanical ventilation. We aimed to early identify severe pneumonia patients with high risk of extubation failure in order to improve prognosis.

Methods: From April 2014 to December 2015, medical records of intubated patients with severe pneumonia in intensive care unit were retrieved from database. Patients were divided into extubation success and failure groups, and multivariate logistic regressions were performed to identify independent predictors for extubation failure.

Results: A total of 125 eligible patients were included, of which 82 and 43 patients had extubation success and failure, respectively. APACHE II score (odds ratio (OR) 1.141, 95% confident interval (CI) 1.022–1.273, P = 0.019, cutoff at 17.5), blood glucose (OR 1.122, 95%CI 1.008–1.249, P = 0.035, cutoff at 9.87 mmol/l), dose of fentanyl (OR 3.010, 95%CI 1.100–8.237, P = 0.032, cutoff at 1.135 mg/d), and the need for red blood cell (RBC) transfusion (OR 2.774, 95%CI 1.062–7.252, P = 0.037) were independent risk factors for extubation failure.

Conclusion: In patients with severe pneumonia, APACHE II score > 17.5, blood glucose > 9.87 mmol/l, fentanyl usage > 1.135 mg/d, and the need for RBC transfusion might be associated with higher risk of extubation failure.

Clinical study of Dysfunctional Ventilatory Weaning Response in critically ill patients

Objective:

to clinically validate the nursing diagnosis of Dysfunctional Ventilatory Weaning Response in adult patients admitted to Intensive Care Units.

Method:

a concurrent cohort performed with 93 patients admitted to Intensive Care Units. The incidence and incidence density of the diagnosis were estimated, its related factors were identified based on bivariate analysis and clinical indicators for determining its occurrence, according to the global and temporal presentation.

Results:

the overall incidence of the diagnosis was 44.09% and the incidence density was 14.49 occurrences for every 100 extubations/day. The factors related to the diagnosis were the following: age, clinical severity, fluid balance, oliguria, hemodialysis, edema in upper/lower limbs, anasarca, number of antibiotics, hypothermia, hyperthermia, amount of secretion, muscle retraction, anxiety score, heart rate, use of vasopressors and non-invasive ventilation after extubation. The clinical indicators most frequently identified for determining the diagnosis were the following: tachypnea, drop of saturation and tachycardia. Temporal progression in the severity of these manifestations was found.

Conclusion:

the Dysfunctional Ventilatory Weaning Response is a common finding in critically ill patients. Some components of the diagnosis of the NANDA-International (2018) version could be clinically validated. It is noteworthy that there are variables not yet described in the taxonomy, demonstrating the need to review this nursing diagnosis.

Value of Combination of Heart, Lung, and Diaphragm Ultrasound in Predicting Weaning Outcome of Mechanical Ventilation

Background

Postextubation distress is detrimental to the prognosis of critically ill patients with successful spontaneous breathing trial. The known risk factors of failed weaning are associated with the heart, lungs, and diaphragm. The aim of this study was to explore the role of a combined model including indicators of heart, lung, and diaphragm ultrasound in predicting the weaning outcome.

Material/Methods

Patients’ clinical data and ultrasonic features of heart, lungs, and diaphragm were recorded. Patients were included in either the failed weaning group (n=24) or the successful weaning group (n=81). The association of potential variables with the risk of weaning failure was determined using multivariate logistic regression analysis. The accuracy of potential indicators for predicting the weaning outcome were evaluated and a multiindicator combined model was established to improve the predictive accuracy.

Results

Brain natriuretic peptide (odds ratio [OR]=1.120, P=0.004), left-atrial pressure (LAP) (OR=1.333, P=0.005), lung ultrasound score (LUS) (OR=1.736, P=0.001), and hemidiaphragm dysfunction (OR=3.942, P=0.014) were associated with an increased risk of weaning failure. However, all of these indicators could not accurately predict the weaning outcome independently (all areas under the curve [AUCs] <0.9). The combination of LAP, LUS, and hemidiaphragm dysfunction showed the highest AUC (AUC=0.919).

Conclusions

The combined model including LAP, LUS, and hemidiaphragm dysfunction were the most accurate method for the prediction.

Analysis of functional status and muscle strength in adults and older adults in an intensive care unit: a prospective cohort study

The aim of this study was to analyze and assess the association between functional status (FS) and muscle strength (MS) in young adults, adults and older adults in an intensive care unit (ICU). We conducted a prospective cohort study with 48 patients. FS was assessed using the Functional Status Score for the Intensive Care Unit (FSS-ICU) and MS was measured using the Medical Research Council Sum-Score (MRC-SS) and by testing handgrip strength (HS). The assessments were performed on awakening and ICU discharge. The data were analyzed using the Kruskall-Wallis, chi-squared, Wilcoxon and Spearman's correlation tests. FS and MRC-SS scores were higher on ICU discharge in all groups. Gains were lowest in the older adult group. HS was greater in both hands on ICU discharge in all groups except the adults. FSS-ICU on both awakening and ICU discharge was highest in the adults; HS-R was lowest in the older adults. There was a strong association between FS and MS in the young adults and adults. FS and MS showed progressive improvement during ICU stay. Gains in FS and MS on awakening and ICU discharge were lowest among the older adults. Important associations were found between these variables in all groups except the older adults. This can be explained by the multifactorial nature of illness and incapacity in this group.

Electrical impedance tomography for predicting failure of spontaneous breathing trials in patients with prolonged weaning

Background

Spontaneous breathing trials (SBTs) on a T-piece can be difficult in patients with prolonged weaning because of remaining de-recruitment phenomena and/or insufficient ventilation. There is no clinically established method existent other than experience for estimating whether an SBT is most probably beneficial. Electrical impedance tomography (EIT) is a clinical useful online monitoring technique during mechanical ventilation, particularly because it enables analysis of effects of regional ventilation distribution. The aim of our observational study was to examine if EIT can predict whether patients with prolonged weaning will benefit from a planned SBT.

Methods

Thirty-one patients were examined. Blood gas analysis, vital parameter measurements, and EIT recordings were performed at three time points: (1) baseline with pressure support ventilation (PSV) (t0), (2) during a T-piece trial (t1), and (3) after resumption of PSV (t2). Calculation of EIT parameters was performed, including the impedance ratio (IR), the tidal variation of impedance (TIV), the changes in end-expiratory lung impedance (ΔEELI), the global inhomogeneity index (GI), and the regional ventilation delay (RVD) index with use of different thresholds of the percentage inspiration time (RVD40, RVD60, RVD80). The predictive power of the baseline GI with regard to clinical impairment of an SBT was analyzed by means of ROC curves. Clinical deterioration was assumed when tidal volume was decreased by at least 20 ml after the T-piece trial, measured at t2.

Results

Partial pressure of arterial oxygen significantly decreased at t1 (71 ± 15 mmHg) compared with t0 (85 ± 17 mmHg, p < 0.05) and t2 (82 ± 18 mmHg, p < 0.05). The IR trended toward higher values during t1. At t1, TIV and ΔEELI significantly decreased. The GI was significantly increased at t1 (t0 59.3 ± 46.1 vs t1 81.5 ± 62.5, p = 0.001), as were all RVD indexes. Assuming a GI cutoff value of >40, sensitivity of 85% and specificity of 50% were reached for predicting an increased future tidal volume.

Conclusions

EIT enables monitoring of regional ventilation distribution during SBTs and is suitable to estimate whether an SBT probably will be beneficial for an individual patient. Therefore, the application of EIT can support clinical decisions regarding patients in the phase of prolonged weaning.