Skip to main content
Key Specialties
Cardiology Diabetology Endocrinology Gastroenterology Geriatrics and Gerontology Gynecology and Obstetrics Hematology Infectious Disease Internal Medicine Nephrology Neurology Oncology Pediatrics Respiratory Medicine Rheumatology Surgery
Congress Coverage
2024 ACC Congress 2023 ESMO Congress 2023 EASD Congress 2023 ERS Congress 2023 ESC Congress 2023 EHA Congress 2023 ASCO Annual Meeting
Clinical Collections
Advances in Alzheimer’s

Keynote webinar | Spotlight on sleep in brain health

LIVE: Thursday 2nd May 2024, 18:00-19:30 (CEST)

Quality sleep is essential for health. But what happens to our brains when sleep patterns are disturbed? Join our experts to explore the interplay between sleep disruption and neurological diseases, and the questions that you need to be asking your patients to help you prevent the harmful effects of sleep deprivation.
ADVANCED SEARCH
Log in
Top
Critical Care
Published in: Critical Care 1/2017

Open Access 01-12-2017 | Research

Outcomes of subsyndromal delirium in ICU: a systematic review and meta-analysis

Authors: Rodrigo B. Serafim, Marcio Soares, Fernando A. Bozza, José R. Lapa e Silva, Felipe Dal-Pizzol, Maria Carolina Paulino, Pedro Povoa, Jorge I. F. Salluh

Published in: Critical Care | Issue 1/2017

Login to get access

Abstract

Background

Subsyndromal delirium (SSD) is a frequent condition and has been commonly described as an intermediate stage between delirium and normal cognition. However, the true frequency of SSD and its impact on clinically relevant outcomes in the intensive care unit (ICU) remains unclear.

Methods

We performed a systematic search in PubMed, Embase, CINAHL, Cochrane Library, and PsychINFO, with no language restrictions, up to 1 October 2016 to identify publications that evaluated SSD in ICU patients.

Results

The six eligible studies were evaluated. SSD was present in 950 (36%) patients. Four studies evaluated only surgical patients. Four studies used the Intensive Care Delirium Screening Checklist (ICDSC) and two used the Confusion Assessment Method (CAM) score to diagnose SSD. The meta-analysis showed an increased hospital length of stay (LOS) in SSD patients (0.31, 0.12–0.51, p = 0.002; I 2 = 34%). Hospital mortality was described in two studies but it was not significant (hazard ratio 0.97, 0.61–1.55, p = 0.90 and 5% vs 9%, p = 0.05). The use of antipsychotics in SSD patients to prevent delirium was evaluated in two studies but it did not modify ICU LOS (6.5 (4–8) vs 7 (4–9) days, p = 0.66 and 2 (2–3) vs 3 (2–3) days, p = 0.517) or mortality (9 (26.5%) vs 7 (20.6%), p = 0.55).

Conclusions

SSD occurs in one-third of the ICU patients and has limited impact on the outcomes. The current literature concerning SSD is composed of small-sample studies with methodological differences, impairing a clear conclusion about the association between SSD and progression to delirium or worse ICU clinical outcomes.
Appendix
Available only for authorised users
Literature
1.
Cole MG, Ciampi A, Belzile E, Dubuc-Sarrasin M. Subsyndromal delirium in older people: a systematic review of frequency, risk factors, course and outcomes. Int J Geriatr Psychiatry. 2013;28(8):771–80.CrossRefPubMed
2.
Bergeron N, Dubois MJ, Dumont M, Dial S, Skrobik Y. Intensive Care Delirium Screening Checklist: evaluation of a new screening tool. Intensive Care Med. 2001;27(5):859–64.CrossRefPubMed
3.
Ely EW, Inouye SK, Bernard GR, Gordon S, Francis J, May L, et al. Delirium in mechanically ventilated patients: validity and reliability of the confusion assessment method for the intensive care unit (CAM-ICU). JAMA. 2001;286(21):2703–10.CrossRefPubMed
4.
Sachdev PS, Blacker D, Blazer DG, Ganguli M, Jeste DV, Paulsen JS, et al. Classifying neurocognitive disorders: the DSM-5 approach. Nat Rev Neurol. 2014;10(11):634–42.CrossRefPubMed
5.
American Psychiatric Association. Task Force on DSM-V. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington: American Psychiatric Association; 2013. p. 947.CrossRef
6.
Ouimet S, Riker R, Bergeron N, Cossette M, Kavanagh B, Skrobik Y. Subsyndromal delirium in the ICU: evidence for a disease spectrum. Intensive Care Med. 2007;33(6):1007–13.CrossRefPubMed
7.
Breu A, Stransky M, Metterlein T, Werner T, Trabold B. Subsyndromal delirium after cardiac surgery. Scand Cardiovasc J. 2015;49(4):207–12.CrossRefPubMed
8.
Li HC, Chen YS, Chiu MJ, Fu MC, Huang GH, Chen CC. Delirium, subsyndromal delirium, and cognitive changes in individuals undergoing elective coronary artery bypass graft surgery. J Cardiovasc Nurs. 2015;30(4):340–5.CrossRefPubMed
9.
Al-Qadheeb NS, Skrobik Y, Schumaker G, Pacheco MN, Roberts RJ, Ruthazer RR, et al. Preventing ICU subsyndromal delirium conversion to delirium with low-dose IV haloperidol: a double-blind, placebo-controlled pilot study. Crit Care Med. 2016;44(3):583–91.CrossRefPubMedPubMedCentral
10.
Hakim SM, Othman AI, Naoum DO. Early treatment with risperidone for subsyndromal delirium after on-pump cardiac surgery in the elderly: a randomized trial. Anesthesiology. 2012;116(5):987–97.CrossRefPubMed
11.
Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, et al. Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis Of Observational Studies in Epidemiology (MOOSE) group. JAMA. 2000;283(15):2008–12.CrossRefPubMed
12.
Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gotzsche PC, Ioannidis JP, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. J Clin Epidemiol. 2009;62(10):e1–34.CrossRefPubMed
13.
Inouye SK, van Dyck CH, Alessi CA, Balkin S, Siegal AP, Horwitz RI. Clarifying confusion: the confusion assessment method. A new method for detection of delirium. Ann Intern Med. 1990;113(12):941–8.CrossRefPubMed
14.
American Psychiatric Association. Task Force on DSM-IV. Diagnostic and statistical manual of mental disorders: DSM-IV-TR. 4th ed. Washington, DC: American Psychiatric Association; 2000. p. 943. xxxvii.
15.
Wells GA, Shea B, O'Connell D, Peterson J, Welch V, Tugwell P. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses. 2006. Available from: http://​www.​ohri.​ca/​programs/​clinical_​epidemiology/​oxford.​htm.​
16.
Review Manager [Computer program]. Version 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration; 2014.
17.
Tan MC, Felde A, Kuskowski M, Ward H, Kelly RF, Adabag AS, et al. Prevalence and predictors of post-cardiotomy delirium. Am J Geriatr Psychiatry. 2008;16(7):575–83.CrossRefPubMed
18.
Salluh JI, Wang H, Schneider EB, Nagaraja N, Yenokyan G, Damluji A, et al. Outcome of delirium in critically ill patients: systematic review and meta-analysis. BMJ. 2015;350:h2538.CrossRefPubMedPubMedCentral
19.
Ely EW, Shintani A, Truman B, Speroff T, Gordon SM, Harrell Jr FE, et al. Delirium as a predictor of mortality in mechanically ventilated patients in the intensive care unit. JAMA. 2004;291(14):1753–62.CrossRefPubMed
20.
Jeon K, Jeong BH, Ko MG, Nam J, Yoo H, Chung CR, et al. Impact of delirium on weaning from mechanical ventilation in medical patients. Respirology. 2016;21(2):313–20.CrossRefPubMed
21.
Cole M, McCusker J, Dendukuri N, Han L. The prognostic significance of subsyndromal delirium in elderly medical inpatients. J Am Geriatr Soc. 2003;51(6):754–60.CrossRefPubMed
22.
Levkoff SE, Liptzin B, Cleary PD, Wetle T, Evans DA, Rowe JW, et al. Subsyndromal Delirium. Am J Geriatr Psychiatry. 1996;4(4):320–9.CrossRefPubMed
23.
24.
Zaal IJ, Devlin JW, Peelen LM, Slooter AJ. A systematic review of risk factors for delirium in the ICU. Crit Care Med. 2015;43(1):40–7.CrossRefPubMed
25.
Pitrowsky MT, Shinotsuka CR, Soares M, Lima MA, Salluh JI. The importance of delirium monitoring in the intensive care unit. Rev Bras Ter Intensiva. 2010;22(3):274–9.CrossRefPubMed
26.
Patel SB, Poston JT, Pohlman A, Hall JB, Kress JP. Rapidly reversible, sedation-related delirium versus persistent delirium in the intensive care unit. Am J Respir Crit Care Med. 2014;189(6):658–65.CrossRefPubMed
27.
Serafim RB, Bozza FA, Soares M, do Brasil PE, Tura BR, Ely EW, et al. Pharmacologic prevention and treatment of delirium in intensive care patients: a systematic review. J Crit Care. 2015;30(4):799–807.CrossRefPubMed
28.
Lowery DP, Wesnes K, Brewster N, Ballard C. Subtle deficits of attention after surgery: quantifying indicators of sub syndrome delirium. Int J Geriatr Psychiatry. 2010;25(10):945–52.CrossRefPubMed
29.
Inouye SK, Kosar CM, Tommet D, Schmitt EM, Puelle MR, Saczynski JS, et al. The CAM-S: development and validation of a new scoring system for delirium severity in 2 cohorts. Ann Intern Med. 2014;160(8):526–33.CrossRefPubMedPubMedCentral
30.
Khan BA, Perkins AJ, Gao S, Hui SL, Campbell NL, Farber MO, et al. The Confusion Assessment Method for the ICU-7 Delirium Severity Scale: a novel delirium severity instrument for use in the ICU. Crit Care Med. 2017;45(5):851–7.CrossRefPubMed
Metadata
Title
Outcomes of subsyndromal delirium in ICU: a systematic review and meta-analysis
Authors
Rodrigo B. Serafim
Marcio Soares
Fernando A. Bozza
José R. Lapa e Silva
Felipe Dal-Pizzol
Maria Carolina Paulino
Pedro Povoa
Jorge I. F. Salluh
Publication date
01-12-2017
Publisher
BioMed Central
Published in
Critical Care / Issue 1/2017
Electronic ISSN: 1364-8535
DOI
https://doi.org/10.1186/s13054-017-1765-3

Other articles of this Issue 1/2017

Critical Care 1/2017 Go to the issue

Research

Can body mass index predict clinical outcomes for patients with acute lung injury/acute respiratory distress syndrome? A meta-analysis

Letter

The usability of ventilators: a comparative evaluation of use safety and user experience—an editorial response

Research

Systemic impact on secondary brain aggravation due to ischemia/reperfusion injury in post-cardiac arrest syndrome: a prospective observational study using high-mobility group box 1 protein

Letter

Skin autofluorescence in acute kidney injury

Research

A supplemental intravenous amino acid infusion sustains a positive protein balance for 24 hours in critically ill patients

Research

Transthoracic echocardiography: an accurate and precise method for estimating cardiac output in the critically ill patient