cEEG electrode-related pressure ulcers in acutely hospitalized patients

Abstract

Background: Pressure ulcers resulting from continuous EEG (cEEG) monitoring in hospitalized patients have gained attention as a preventable medical complication. We measured their incidence and risk factors.

Methods: We performed an observational investigation of cEEG-electrode-related pressure ulcers (EERPU) among acutely ill patients over a 22-month period. Variables analyzed included age, sex, monitoring duration, hospital location, application methods, vasopressor usage, nutritional status, skin allergies, fever, and presence/severity of EERPU. We examined risk for pressure ulcers vs monitoring duration using Kaplan-Meyer survival analysis, and performed multivariate risk assessment using Cox proportional hazard model.

Results: Among 1,519 patients, EERPU occurred in 118 (7.8%). Most (n = 109, 92.3%) consisted of hyperemia only without skin breakdown. A major predictor was monitoring duration, with 3-, 5-, and 10-day risks of 16%, 32%, and 60%, respectively. Risk factors included older age (mean age 60.65 vs 50.3, p < 0.01), care in an intensive care unit (9.37% vs 5.32%, p < 0.01), lack of a head wrap (8.31% vs 27.3%, p = 0.02), use of vasopressors (16.7% vs 9.64%, p < 0.01), enteral feeding (11.7% vs 5.45%, p = 0.04), and fever (18.4% vs 9.3%, p < 0.01). Elderly patients (71-80 years) were at higher risk (hazard ratio 6.84 [1.95-24], p < 0.01), even after accounting for monitoring time and other pertinent variables in multivariate analysis.

Conclusions: EERPU are uncommon and generally mild. Elderly patients and those with more severe illness have higher risk of developing EERPU, and the risk increases as a function of monitoring duration.

Figure 1. Examples of continuous EEG (cEEG)–electrode-related pressure ulcers (EERPU)

Lesion staging was determined retrospectively by review of the EEG technician's written descriptions and by review of hospital safety reports, which are routinely filed for any lesions noted by the bedside clinician (usually the nurse) to be of severity greater than stage 1. EERPU stages were assigned following standard definitions, as follows: stage 1 for hyperemia without the presence of ulcers or blisters (A); stage 2 for shallow open ulcers or intact blisters without subcutaneous fat exposure (B–D); stage 3 when there was full-thickness tissue loss with exposure of subcutaneous fat but no visible bone, tendon, or muscles; and stage 4 for full-thickness ulcers with exposure of muscle, tendons, or bones. EEG technicians were trained to report any skin disruption to the primary care team and to the nursing staff. The decision to continue or terminate a cEEG study was made on a case-by-case basis with the involvement of the entire care team. A clinical nurse specialist was consulted by the EEG technician or the nursing staff to examine skin breakdown with attention to lesions of stage 2 or greater. The National Database of Nursing Quality Indicators was used to stage per the hospital's inpatient quality control policy. (E) Pressure implantation effect on the subjacent skin after 24 hours of lead placement. (F) An electrode with blood and paste after removal from a patient with EERPU.

Figure 2. Cumulative probability of continuous EEG (cEEG)–electrode-related pressure ulcers (EERPU) occurrence

Kaplan-Meier estimate of the cumulative probability of EERPU occurrence is plotted as a function of EEG study duration in days (solid line). The number of patients left at risk as time progresses is shown between the red arrows. The 95% confidence interval values are represented by the purple shaded region surrounding the darker blue line. The information for this graph was extracted from the statistical analysis of the effect of EEG duration on pressure ulcers. The risk of EERPU at 3, 5, and 10 days of monitoring was 16% (SE = 0.02), 32% (SE = 0.3), and 60% (SE = 0.7), respectively.