Effectiveness of diaphragmatic ultrasound as a predictor of successful weaning from mechanical ventilation: a systematic review and meta-analysis

BACKGROUND

Several measurements have been used to predict the success of weaning from mechanical ventilation; however, their efficacy varies in different studies. In recent years, diaphragmatic ultrasound has been used for this purpose. We conducted a systematic review and meta-analysis to evaluate the effectiveness of diaphragmatic ultrasound in predicting the success of weaning from mechanical ventilation.

METHODS

Two investigators independently searched PUBMED, TRIP, EMBASE, COCHRANE, SCIENCE DIRECT, and LILACS for articles published between January 2016 and July 2022. The methodological quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool; additionally, the certainty of the evidence is evaluated using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) methodology. Sensitivity and specificity analysis was performed for diaphragmatic excursion and diaphragmatic thickening fraction; positive and negative likelihood ratios and diagnostic odds ratios (DOR) with their confidence intervals (95% CI) were calculated by random effects analysis, summary receiver operating characteristic curve was estimated. Sources of heterogeneity were explored by subgroup analysis and bivariate meta-regression.

RESULTS

Twenty-six studies were included, of which 19 were included in the meta-analysis (1204 patients). For diaphragmatic excursion, sensitivity was 0.80 (95% CI 0.77-0.83), specificity 0.80 (95% CI 0.75-0.84), area under the summary receiver operating characteristic curve 0.87 and DOR 17.1 (95% CI 10.2-28.6). For the thickening fraction, sensitivity was 0.85 (95% CI 0.82-0.87), specificity 0.75 (95% CI 0.69-0.80), area under the summary receiver operating characteristic curve 0.87 and DOR 17.2 (95% CI 9.16-32.3). There was heterogeneity among the included studies. When performing a subgroup analysis and excluding studies with atypical cutoff values, sensitivity and specificity increased for diaphragmatic thickening fraction; sensitivity increased and specificity decreased for diaphragmatic excursion; when comparing studies using pressure support (PS) versus T-tube, there was no significant difference in sensitivity and specificity; bivariate meta-regression analysis shows that patient position at the time of testing was a factor of heterogeneity in the included studies.

CONCLUSIONS

Measurement of diaphragmatic excursion and diaphragmatic thickening fraction predict the probability of successful weaning from mechanical ventilation with satisfactory diagnostic accuracy; however, significant heterogeneity was evident in the different included studies. Studies of high methodological quality in specific subgroups of patients in intensive care units are needed to evaluate the role of diaphragmatic ultrasound as a predictor of weaning from mechanical ventilation.

Neutralizing Antibodies from Convalescent Chikungunya Virus Patients Can Cross-Neutralize Mayaro and Una Viruses

Most alphaviruses are mosquito-borne and can cause severe disease in domesticated animals and humans. The most notable recent outbreak in the Americas was the 2014 chikungunya virus (CHIKV) outbreak affecting millions and producing disease highlighted by rash and arthralgia. Chikungunya virus is a member of the Semliki Forest (SF) serocomplex, and before its arrival in the Americas, two other member of the SF complex, Una (UNAV) and Mayaro (MAYV) viruses, were circulating in Central and South America. This study examined whether antibodies from convalescent CHIKV patients could cross-neutralize UNAV and MAYV. Considerable cross-neutralization of both viruses was observed, suggesting that exposure to CHIKV can produce antibodies that may mitigate infection with UNAV or MAYV. Understanding the impact of CHIKV exposure on population susceptibility to other emerging viruses may help predict outbreaks; moreover, identification of cross-reactive immune responses among alphaviruses may lead to the development of vaccines targeting multiple viruses.

Co-circulation of dengue, chikungunya, and Zika viruses in Colombia from 2008 to 2018

Objective.

This study aimed to identify the co-circulation patterns of three viruses (dengue, Zika, and ­chikungunya) in Colombia from 2008 to 2018 by using notification reports provided to the national surveillance system.

Methods.

This cross-sectional study was conducted through a review of data for 2008 through 2018 from Colombia’s Public Health Surveillance System (SIVIGILA).

Results.

In 2015, when chikungunya was first detected, it had a higher incidence (1 359.0 cases per 100 000 persons) than did the two other diseases. In 2016, when the circulation of Zika virus was first found, the incidence was 296.4 cases per 100 000 persons; that incidence declined dramatically in the next two years. Between 2015 and 2018, there was a substantial decrease in the frequency of dengue circulation, with it going from 334.1 cases per 100 000 persons in 2015 to 90.7 cases per 100 000 in 2017 and 173.1 cases per 100 000 in 2018.

Conclusions.

The decrease in the number of dengue cases after co-circulation of the three viruses could indicate possible cross-protection. This finding should be further analyzed.

Clinical characteristics of patients hospitalized with severe respiratory illness during influenza seasons in the cities of Bogota and Manizales, Colombia 2000-2006

OBJECTIVE

Identifying clinical factors associated with respiratory tract diseases during human influenza circulation seasons in children aged less than two years old and adults aged over 65 years in two hospitals in the cities of Manizales and Bogota, Colombia.

METHODS

A retrospective case study in patients hospitalized with acute respiratory illness was carried out during influenza circulation seasons from 2000 to 2006 in Bogota and Manizales. Complication frequency was studied, including death, and its relationship with baseline diseases.

RESULTS

535 children under two years of age and 288 adults over 65 years old were studied. 38.9 % of the children and 27 % of the adults had at least one complication. The presence of underlying disease in children was associated with complications such as hospital death (OR=16.5; 4.7-57.7 95%CI), being admitted to an intensive care unit (OR=6.3; 3.5-11.3 95%CI), respiratory distress needing FIO2> 40 % (OR=2.4; 1.6-3.7 95 %CI), mechanical ventilation (OR=2.4; 1.6-3.7 95 %CI) and multilobar pneumonia (OR=2.1; 1.3-3.4 95 %CI). This association remained after adjusting for confounding factors such as age and socioeconomic status, whilst such relationship was not observed in older adults.

CONCLUSION

Children with underlying chronic diseases were more susceptible to clinical complications during influenza seasons. Those under 6 months of age were particularly prone to dying or being admitted to an ICU. These results suggested that vaccination policies need to be adjusted.

[Cost effectiveness of influenza vaccination in children under 2 years old and elderly in Colombia]

OBJECTIVE

Estimating the burden of disease associated with influenza virus season and modelling the epidemiological and economic impacts of introducing an inactivated vaccine to Colombia.

METHODOLOGY

A complete economic evaluation was done in children aged less than 2 and adults aged over 65. The outcomes evaluated in the under 2-year olds included: the yearly number of cases of acute respiratory infection (ARI), medical visits, hospitalisations and deaths by ARI. The outcomes measured in adults were the number of yearly deaths and hospitalisations due to cardiocirculatory diseases (CCD).

RESULTS

Influenza infection in children under 2 years old not having had vaccination may cause 4,300 cases, 2,700 medical visits, 900 hospitalisations and 230 deaths by ARI yearly. Amongst the elder group, influenza infection would be associated with 670 deaths by pneumonia and 1,870 deaths from CCD. The incremental cost effectiveness ratio (ICER) for flu vaccination among children under 2 ranged from USD$ 1,900 to USD$ 2,967 per averted death. ICER was cost saving in adults aged over 65.

CONCLUSIONS

This study's results supported the Colombian Ministry of Health's initiative for introducing yearly flu vaccination amongst small children and older adults in Colombia.