Relationship between state anxiety and delirium

Bastiaan Van Grootven, RN, MSNElke Detroyer, RN, MSNEls Devriendt, RN, MSNAn Sermon, MD, PhDMieke Deschodt, RN, PhDJohan Flamaing, MD, PhDChristophe Dubois, MD, PhDKoen Milisen, RN, PhD

Definitions

• State anxiety = Reflects a temporary, acute anxious reaction with feelings of tension and apprehension.

(De Vries et al. J Clin Psychol Med Settings 2013)

• Delirium = Characterized by an acute and fluctuating disturbance in attention and awareness with a change in cognition or the development of a perceptual disturbance.

(American Psychiatric Association. DSM-5 criteria 2013)

Current state of knowledge (1)

• Delirium = – High incidence– Negative outcomes– Risk factors = target for intervention– Psychological factors underexplored

(Inouye et al. Lancet 2014)

• State anxiety = target for intervention1. Preoperative education

(Bradt et al. Cochrane Database Syst Rev 2013)

2. Preoperative music therapy(McDonald et al. Cochrane Database Syst Rev 2004)

Current state of knowledge (2)

• Previous studies: No relationship (Simpson et al. J Psychosom Res 1987; Bowman AM. J Gerontol Nurs 1992; Detroyer et al. J Am Geriatr Soc

2008)

• Methodological considerations:1. Small sample size

(Simpson et al. J Psychosom Res 1987; Bowman AM. J Gerontol Nurs 1992; Detroyer et al. J Am Geriatr Soc 2008)

2. Unreliable assessment delirium(Simpson et al. J Psychosom Res 1987; Bowman AM. J Gerontol Nurs 1992

Design

• RQ = Is preoperative state anxiety a risk factor for postoperative delirium in elderly hip fracture patients?

• Secondary data-analysis of non-randomised studie– Traumatic hip fracture patients ≥ 65 years

(Deschodt et al. J Am Geriatr Soc. 2011; Deschodt et al. J Am Geriatr Soc. 2012)

• Exclusion criteria:– Preoperative delirium– Missed preoperative state anxiety assessment– Missed postoperative delirium assessment

State-Trait Anxiety Inventory (STAI)

(Marteau et al. Br J Clin Psychol 1992)

Delirium

• Confusion Assessment Method (CAM)– Delirious vs Non delirious

• Delirium Index (DI)– Severity

• Measured postoperatively day 1,3,5,8

Other risk factors & background variables

• Cognition: 12- item Mini-Mental Status Examination (MMSE)

• Functional status: Katz ADL index

• Depression: 10-item Geriatric Depression Scale (GDS)

• Comorbidity: Charlson Comorbidity Index

• Other by chart review: – Demographics– Intraoperative variables: e.g. blood pressure, …

Sample (1)

1. Patients available for analysis: 171

2. Patients excluded– Preoperative delirium: 37– Missing state anxiety assessment: 59– Missing delirium assessment: 7

3. Patients included for analysis: 86

Sample (2)Sample characteristics Sample (n= 86)

- Age, mean ± SD

- Incidence postoperative delirium, n (%)

- Duration postoperative delirium, median (IQR)

- Delirium Index, median (IQR) (range 0-21)

- STAI, mean ± (SD) (range 6-24)

- 12-item MMSE median (IQR) (range 0-12)

-Katz index of ADL, median (IQR) (range 6-12)

- Risk for depression (≥ 4 GDS), n (%)

80.1 ± 6.8

24 (27.9)

2 (1)

4 (3)

12.3 ± 2.1

10 (4)

7 (2)

53 (61.6)

Bivariate correlations: state anxiety - delirium

Preoperative state anxiety Correlation P-value

- Incidence of postoperative delirium

- Duration of postoperative delirium

- Severity of postoperative delirium

rb = 0.135

Rho = 0.038

Rho = 0.153

0.353

0.861

0.160

Delirium risk factorsVariables OR (95%CI)

- Mini-Mental Status Examination

- Osteosynthesis surgery

- Lowest diastolic blood pressure

- Moderate level of education

- State-Trait Anxiety Inventory

- Highest systolic blood pressure

0.75 (0.60-0.95)

3.66 (1.02-13.15)

0.92 (0.85-0.99)

0.61 (0.14-2.62)

1.18 (0.89-1.56)

0.97 (0.94-1.00)

Conclusion

1. State anxiety NOT associated with delirium.

2. Delirium risk factors:– Baseline cognitive impairment– Decreasing intraoperative diastolic blood

pressure values– Having osteosynthesis surgery

Methodological considerations1. Considerable missing data (i.e. 34.5%) observed for state anxiety

assessment. - Associated with lower baseline cognitive functioning. - STAI may not be reliable in an older frail population.

2. Postoperative delirium underestimated (i.e. 27.9% versus 44.5%): 49 cases of postoperative delirium excluded.

3. Selection bias in study sample.

4. No postoperative risk factors explored.

5. Additional exclusion (n= 85, 49.7%) for secondary analysis reduced sample size.

Implications for research

• Need for a valid and reliable assessment of state anxiety in an older population.

• Further exploration of osteosynthesis surgery as specific risk factor of postoperative delirium.

Thank youNo conflict of interest