Liver transplantation in Mexican older adults: A comparative single-center study

INTRODUCTION

Liver disease is currently one of the leading causes of death in older adults and the only option deemed curative is liver transplantation. However, it is uncertain whether the successful results obtained in older adults that receive a liver transplant in developed countries can be replicated in developing countries.

AIM

To determine if there are differences in the survival time between older (≥60years) and younger adults that underwent liver transplantation at a university-affiliated tertiary care center in Mexico City.

MATERIALS AND METHODS

A 2-year longitudinal study was conducted. It included 244 participants that were divided into 2groups according to age at the time of transplantation: older adults (≥60years) and younger adults (18-59years). Survival time was defined as the number of days that elapsed between transplantation and death. Survival was expressed as Kaplan-Meier curves.

RESULTS

Median age in the older adults (n=52) was 63.0 (IQR=60-69) and 23 participants were females (44.2%). In the younger adults (n=196) median age was 47.0 (IQR=16-59) and 104 were females (52%). The leading indication for transplant was hepatitisC virus. After the follow-up, fifteen participants died (12 younger adults and 3 older adults). No significant differences were observed between older and younger participants in postoperative complications, the number of re-admissions, or mean post-transplantation survival time.

CONCLUSIONS

There were no statistically significant differences in relation to survival times between older and younger adults that received a liver transplant. Older patients in developing countries should not be excluded from the selection process due only to age.

Mortality study in patients at weaning from mechanical ventilation

OBJECTIVE

To explain mortality in the ICU and in hospital among patients subjected to invasive mechanical ventilation.

DESIGN

A prospective, 9-month observational cohort study was carried out.

SETTING

A Department of Intensive Care Medicine.

PATIENTS

Consecutive patients requiring invasive mechanical ventilation were followed-up on until hospital discharge or death.

INTERVENTIONS

None.

INTEREST VARIABLES

Date of admission, day of first spontaneous breathing test, length of mechanical ventilation, final extubation date, days in ICU, days in hospital or discharge from ICU, SAPS-3 score, WIND study classification, day of death, hospital discharge.

RESULTS

There were 266 patients: 40 in group 0 of the WIND classification (15%; 95% CI 11-20%); 166 in group 1 (62%; 95% CI 56-68%); 38 in group 2 (14%; 95% CI 11-19%); and 22 in group 3 (8%; 95% CI 6-12%. Logistic regression analysis showed group 3 to have the highest hospital mortality (group 3 vs. group 1; odds ratio 4.0; 95% CI 1.5-10.8; P=.007). However, Cox regression analysis showed no significant differences (hazard ratio group 3 vs. group 1, 1.6; 95% CI 0.7-3.4; P=ns).

CONCLUSION

In our study, considering exposure time, the probability of mortality was the same among the 3 different groups of patients with at least one spontaneous breathing test.

Have there been changes in the application of mechanical ventilation in relation to scientific evidence? A multicenter observational study in Mexico

OBJECTIVE

The main study objectives were to describe the practice of mechanical ventilation over an 18-year period in Mexico, and estimate changes in mortality among critical patients subjected to invasive mechanical ventilation (IMV).

DESIGN

A retrospective subanalysis of a prospective observational study conducted in 1998, 2004, 2010 and 2016 was carried out.

SETTING

Intensive Care Units (ICUs) in Mexico.

PARTICIPANTS

Adult patients consecutively enrolled in the ICU during one month and who underwent IMV for more than 12hours or noninvasive mechanical ventilation for more than one hour. Follow-up was performed up to a maximum of 28 days after inclusion.

INTERVENTIONS

None.

PRINCIPAL VARIABLES OF INTEREST

Age, sex, severity upon admission as estimated by SAPS II, parameters of daily arterial blood gases, treatment and complication variables, date and status at discharge from the ICU and from hospital.

RESULTS

A total of 959 patients were included in 81 ICUs. Tidal volume (vt) decreased significantly both in patients with acute respiratory distress syndrome (ARDS) criteria (estimated 8.5ml/kg b.w. in 1998 to 6ml/kg in 2016; P<0.001) and in patients without ARDS (estimated 9ml/kg b.w. in 1998 to 6ml/kg in 2016; P<0.001). The ventilatory protective strategy (defined as vt < 6ml/kg or < 8ml/kg and a plateau pressure < 30cmH₂O) was: 19% in 1998, 44% in 2004, 58% in 2010 and 75% in 2016 (P<0.001). The adjusted mortality rate in ICU over the 4 periods was: in 2004, odds ratio (OR) 1.05 (95% confidence interval, 95%CI: 0.73-1.72; P=0.764); in 2010, OR 1.68 (95%CI: 1.13-2.48; P=0.009); in 2016, OR 0.85 (95%CI: 0.60-1.20; P=0.368).

CONCLUSIONS

The clinical practice of IMV in Mexican ICUs has been modified over a period of 18 years. The most significant change is the ventilatory strategy based on low vt. These changes have not been associated with significant changes in mortality.

[The applicability of results]

The ultimate aim of the critical reading of medical literature is to use the scientific advances in clinical practice or for innovation. This requires an evaluation of the applicability of the results of the studies that have been published, which begins with a clear understanding of these results. When the studies do not provide sufficient guarantees of rigor in design and analysis, the conditions necessary for the applicability of the results are not met; however, the fact that the results are reliable is not enough to make it worth trying to use their conclusions. This article explains how carrying out studies in experimental or artificial conditions often moves them away from the real conditions in which they claim to apply their conclusions. To evaluate this applicability, the article proposes evaluating a set of items that will enable the reader to determine the likelihood that the benefits and risks reported in the studies will yield the least uncertainty in the clinical arena where they aim to be applied.