Preoperative medication use and postoperative delirium: a systematic review

Abstract

BackgroundMedications are frequently reported as both predisposing factors and inducers of delirium. This review evaluated the available evidence and determined the magnitude of risk of postoperative delirium associated with preoperative medication use.MethodsA systematic search in Medline and EMBASE was conducted using MeSH terms and keywords for postoperative delirium and medication. Studies which included patients 18 years and older who underwent major surgery were included. The methodological quality of included studies was assessed independently by two authors using the Newcastle-Ottawa quality assessment scale for cohort studies.ResultsTwenty-nine studies; 25 prospective cohort, three retrospective cohort and one post hoc analysis of RCT data were included. Only four specifically aimed to assess medicines as an independent predictor of delirium, all other studies included medicines among a number of potential predictors of delirium. Of the studies specifically testing the association with a medication class, preoperative use of beta-blockers (OR = 2.06[1.18–3.60]) in vascular surgery and benzodiazepines RR 2.10 (1.23–3.59) prior to orthopedic surgery were significant. However, evidence is from single studies only. Where medicines were included as one possible factor among many, hypnotics had a similar risk estimate to the benzodiazepine study, with one significant and one non-significant result. Nifedipine use prior to cardiac surgery was found to be significantly associated with delirium. The non-specific grouping of psychoactive medication use preoperatively was generally higher with an associated two-to-seven-fold higher risk of postoperative delirium, while only two studies included narcotics without other agents, with one significant and one non-significant result.ConclusionsThere was a limited number of high quality studies in the literature quantifying the direct association between preoperative medication use and postsurgical delirium. More studies are required to evaluate the association of specific preoperative medications on the risk of postoperative delirium so that comprehensive guidelines for medicine use prior to surgery can be developed to aid delirium prevention.Trial registrationThis systematic review has been registered on PROSPERO International prospective register of systematic reviews (Registration number: CRD42016051245).Electronic supplementary materialThe online version of this article (10.1186/s12877-017-0695-x) contains supplementary material, which is available to authorized users.

Use of medicines that may precipitate delirium prior to hospitalisation in older Australians with delirium: An observational study

“…Patient characteristics assessed at the time of hospital admission included age, sex and residential aged care status. Medicines associated with delirium were identified from two systematic reviews 7,8 and three narrative reviews (Appendix S1). 9,15,16 We classified the medicines into two groups: medicines with known risk of delirium and medicines suspected to be associated with delirium based on evidence from two systematic reviews.…”

“…Various classes of medicines are associated with delirium in medical and surgical patients. 7,8 These include anaesthetic agents, sedative/hypnotics, barbiturates, antidepressants, anticholinergics, opioid analgesics, antipsychotics, antihistamines, corticosteroids, fluoroquinolone antibiotics and antiparkinsonian agents. 9 An Australian cohort study found that individuals aged 65 years or older exposed to two anticholinergic medications were at a 2.5-fold increased risk (relative risk = 2.58, 95% confidence interval = 1.91-3.48) of hospital admission for acute confusion, delirium or dementia during the periods when they were taking these medicines compared to when they were not taking them .…”

Multicomponent Interventions Reduce High‐Risk Medications for Delirium in Hospitalized Older Adults

“…Medications are frequently implicated in the development of delirium and may account for 12% to 39% of all delirium cases. 3,[7][8][9][10][11][12] Agents with anticholinergic activity, including first-generation antihistamines and muscle relaxants, are known to cause delirium in vulnerable brains like those of acetylcholine-compromised individuals with Alzheimer's disease. [13][14][15] Sedative-hypnotics such as benzodiazepines have also been implicated in the development of delirium.…”

Incidence and risk factors of PostopeRativE delirium in intensive care unit patients: A study protocol for the PREDICt study

“…The demographic variables and related information on potential risk factors identified by three systematic review (Gosselt, Slooter, Boere, & Zaal, ; Kassie, Nguyen, Kalisch Ellett, Pratt, & Roughead, ; Oh et al, ) and two guidelines (Aldecoa et al, ; Devlin et al, ) related to POD will be used. We will also include other variables based on clinical experience.…”

“…Errors are counted when the patient incorrectly answers a question Command: Say to patient "Hold up this many fingers" (Hold two fingers in front of patient). "Now do the same with the other hand" (Do not repeat number of fingers) An error is counted if patient is unable to complete the entire command Note: Abbreviations: ICU, intensive care unit; RASS, Richmond Agitation-Sedation Scale.Slooter,Boere, & Zaal, 2015;Kassie, Nguyen, Kalisch Ellett, Pratt, & Roughead, 2017;Oh et al, 2015) and two guidelines(Aldecoa et al, 2017;Devlin et al, 2018) related to POD will be used. We will also include other variables based on clinical experience.…”