SummaryThis is the first research to evaluate cough frequency continuously over 24-hour periods and to characterize associations with mycobacterial load and treatment. This study provides novel information on the circadian cycle of cough frequency and risk factors for increased cough frequency.

Objectives We sought to study the association between sedation status, medications (benzodiazepines, opioids, and antipsychotics), and clinical outcomes in a resource-limited setting. Design A longitudinal study of critically ill participants on mechanical ventilation. Setting Five intensive care units (ICUs) in four public hospitals in Lima, Peru. Patients One thousand six hundred fifty-seven critically ill participants were assessed daily for sedation status during 28 days and vital status by day 90. Results After excluding data of participants without a Richmond Agitation Sedation Scale score and without sedation, we followed 1338 (81%) participants longitudinally for 18,645 ICU days. Deep sedation was present in 98% of participants at some point of the study and in 12,942 ICU days. Deep sedation was associated with higher mortality (interquartile odds ratio (OR) = 5.42, 4.23–6.95; p < 0.001) and a significant decrease in ventilator (− 7.27; p < 0.001), ICU (− 4.38; p < 0.001), and hospital (− 7.00; p < 0.001) free days. Agitation was also associated with higher mortality (OR = 39.9, 6.53–243, p < 0.001). The most commonly used sedatives were opioids and benzodiazepines (9259 and 8453 patient days respectively), and the latter were associated with a 41% higher mortality in participants with a higher cumulative dose (75th vs 25th percentile, interquartile OR = 1.41, 1.12–1.77; p < 0.01). The overall cumulative dose of benzodiazepines and opioids was high, 774.5 mg and 16.8 g, respectively, by day 7 and by day 28; these doses approximately doubled. Haloperidol was only used in 3% of ICU days; however, the use of it was associated with a 70% lower mortality (interquartile OR = 0.3, 0.22–0.44, p < 0.001). Conclusions Deep sedation, agitation, and cumulative dose of benzodiazepines were all independently associated with higher 90-day mortality. Additionally, deep sedation was associated with less ventilator-, ICU-, and hospital-free days. In contrast, haloperidol was associated with lower mortality in our study. Electronic supplementary material The online version of this article (10.1186/s13054-019-2394-9) contains supplementary material, which is available to authorized users.