Koen S. Simons

Analysis of the soundscape in an intensive care unit based on the annotation of an audio recording.

The acoustic environments in hospitals, particularly in intensive care units (ICUs), are characterized by frequent high-level sound events which may negatively affect patient outcome. Many studies performed acoustic surveys, but the measurement protocol was not always reported in detail, and the scope of analysis was limited by the selected mode of sound level meters. Fewer studies systematically investigated the noise sources in ICUs by employing an observer in the patient room, which may potentially bias the measurement. In the current study, the soundscape of an ICU was evaluated where acoustic parameters were extracted from a ∼67-h audio recording, and a selected 24-h recording was annotated off-line for a source-specific analysis. The results showed that the patient-involved noise accounted for 31% of the acoustic energy and 11% of the predicted loudness peaks (PLPs). Excluding the patient-involved noise, the remaining acoustic energy was attributed to staff members (57%), alarms (30%), and the operational noise of life-supporting devices (13%). Furthermore, the contribution of each noise category to the PLPs was found to be more uneven: Staff (92%), alarms (6%), and device noise (2%). The current study suggests that most of the noise sources in ICUs may be associated with modifiable human factors.

Dynamic light application therapy to reduce the incidence and duration of delirium in intensive-care patients: a randomised controlled trial

BACKGROUND Disturbed circadian rhythm is a potentially modifiable cause of delirium among patients in intensive-care units (ICUs). Bright-light therapy in the daytime can realign circadian rhythm and reduce the incidence of delirium. We investigated whether a high-intensity dynamic light application (DLA) would reduce ICU-acquired delirium. METHODS This was a randomised, controlled, single-centre trial of medical and surgical patients admitted to the ICU of a teaching hospital in the Netherlands. Patients older than 18 years, expected to stay in the ICU longer than 24 h and who could be assessed for delirium were randomised to DLA or normal lighting (control), according to a computer-generated schedule. The DLA was administered through ceiling-mounted fluorescent tubes that delivered bluish-white light up to 1700 lux between 0900 h and 1600 h, except for 1130-1330 h, when the light was dimmed to 300 lux. The light could only be turned off centrally by investigators. Control light levels were 300 lux and lights could be turned on and off from inside the room. The primary endpoint was the cumulative incidence of ICU-acquired delirium. Analyses were by intention to treat and per protocol. The study was terminated prematurely after an interim analysis for futility. This study is registered with Clinicaltrials.gov, number NCT01274819. FINDINGS Between July 1, 2011, and Sept 9, 2013, 734 patients were enrolled, 361 in the DLA group and 373 in the control group. Delirium occurred in 137 (38%) of 361 DLA patients and 123 (33%) of 373 control patients (odds ratio 1·24, 95% CI 0·92-1·68, p=0·16). No adverse events were noted in patients or staff. INTERPRETATION DLA as a single intervention does not reduce the cumulative incidence of delirium. Bright-light therapy should be assessed as part of a multicomponent strategy. FUNDING None.

Effect of Haloperidol on Survival Among Critically Ill Adults With a High Risk of Delirium: The REDUCE Randomized Clinical Trial

Importance Results of studies on use of prophylactic haloperidol in critically ill adults are inconclusive, especially in patients at high risk of delirium. Objective To determine whether prophylactic use of haloperidol improves survival among critically ill adults at high risk of delirium, which was defined as an anticipated intensive care unit (ICU) stay of at least 2 days. Design, Setting, and Participants Randomized, double-blind, placebo-controlled investigator-driven study involving 1789 critically ill adults treated at 21 ICUs, at which nonpharmacological interventions for delirium prevention are routinely used in the Netherlands. Patients without delirium whose expected ICU stay was at least a day were included. Recruitment was from July 2013 to December 2016 and follow-up was conducted at 90 days with the final follow-up on March 1, 2017. Interventions Patients received prophylactic treatment 3 times daily intravenously either 1 mg (n = 350) or 2 mg (n = 732) of haloperidol or placebo (n = 707), consisting of 0.9% sodium chloride. Main Outcome and Measures The primary outcome was the number of days that patients survived in 28 days. There were 15 secondary outcomes, including delirium incidence, 28-day delirium-free and coma-free days, duration of mechanical ventilation, and ICU and hospital length of stay. Results All 1789 randomized patients (mean, age 66.6 years [SD, 12.6]; 1099 men [61.4%]) completed the study. The 1-mg haloperidol group was prematurely stopped because of futility. There was no difference in the median days patients survived in 28 days, 28 days in the 2-mg haloperidol group vs 28 days in the placebo group, for a difference of 0 days (95% CI, 0-0; P = .93) and a hazard ratio of 1.003 (95% CI, 0.78-1.30, P=.82). All of the 15 secondary outcomes were not statistically different. These included delirium incidence (mean difference, 1.5%, 95% CI, −3.6% to 6.7%), delirium-free and coma-free days (mean difference, 0 days, 95% CI, 0-0 days), and duration of mechanical ventilation, ICU, and hospital length of stay (mean difference, 0 days, 95% CI, 0-0 days for all 3 measures). The number of reported adverse effects did not differ between groups (2 [0.3%] for the 2-mg haloperidol group vs 1 [0.1%] for the placebo group). Conclusions and Relevance Among critically ill adults at high risk of delirium, the use of prophylactic haloperidol compared with placebo did not improve survival at 28 days. These findings do not support the use of prophylactic haloperidol for reducing mortality in critically ill adults. Trial Registration clinicaltrials.gov Identifier: NCT01785290

Noise pollution in the ICU: time to look into the mirror

No abstract

Metrics of circadian lighting for clinical investigations

There are currently no accepted metrics for summarising lighting conditions in studies aimed at investigating effects mediated by the circadian system. The objectives of this paper are to propose a set of metrics for capturing circadian variations in environmental lighting conditions and to compare two different lighting regimes applied to patient rooms. Our metric design emphasises the characterisation of light stimuli over time, e.g. their spread over one or more days. Lighting measurements for comparative assessment were taken in 20 beds in the intensive care unit of the Jeroen Bosch Hospital. Lighting conditions between the intensive care unit beds differed significantly across a number of circadian metrics. The proposed set of metrics offers a simple yet comprehensive approach to characterising lighting conditions from the circadian perspective with direct application in clinical studies investigating the effects of light on health.

Effect of preadmission sunlight exposure on intensive care unit–acquired delirium: A multicenter study

PURPOSE It is assumed that there is a relation between light exposure and delirium incidence. The aim of our study was to determine the effect of prehospital light exposure on the incidence of intensive care unit (ICU)-acquired delirium. MATERIALS AND METHODS Data from 3 ICUs in the Netherlands were analyzed retrospectively. Delirium was assessed with the Confusion Assessment Method for the ICU. Daily light intensity data were obtained from meteorological stations in the vicinity of the 3 hospitals. The association between light intensity and delirium incidence was analyzed using logistic regression analysis adjusting for known covariates for delirium. RESULTS Data of 3198 patients, aged (mean ± SD) 61.9 ± 15.3 years with Acute Physiology and Chronic Health Evaluation II score 16.4 ± 6.6 were analyzed. Delirium incidence was 31.2% and did not vary significantly throughout the year. Twenty-eight-day preadmission photoperiod was highest in spring and lowest in winter; however, no association between light exposure and delirium incidence was found (odds ratio, 1.00; 95% confidence interval, 0.99-1.00; P = 0.72). Furthermore, delirium was significantly associated with age, infection, use of sedatives, Acute Physiology and Chronic Health Evaluation II score, and diagnosis of neurological disease or trauma. CONCLUSIONS The incidence of delirium does not differ per season and prior sunlight exposure does not play a role of importance in the development of ICU-acquired delirium.

The Influence of End-of-Life Care on Organ Donor Potential

Many patients with acute devastating brain injury die outside intensive care units and could go unrecognized as potential organ donors. We conducted a prospective observational study in seven hospitals in the Netherlands to define the number of unrecognized potential organ donors outside intensive care units, and to identify the effect that end‐of‐life care has on organ donor potential. Records of all patients who died between January 2013 and March 2014 were reviewed. Patients were included if they died within 72 h after hospital admission outside the intensive care unit due to devastating brain injury, and fulfilled the criteria for organ donation. Physicians of included patients were interviewed using a standardized questionnaire regarding logistics and medical decisions related to end‐of‐life care. Of the 5170 patients screened, we found 72 additional potential organ donors outside intensive care units. Initiation of end‐of‐life care in acute settings and lack of knowledge and experience in organ donation practices outside intensive care units can result in under‐recognition of potential donors equivalent to 11–34% of the total pool of organ donors. Collaboration with the intensive care unit and adjusting the end‐of‐life path in these patients is required to increase the likelihood of organ donation.

Reducing sensory input in critically ill patients: are eyemasks a blind spot?

We read with interest the article by Van Rompaey and colleagues [1] reporting that earplugs may be useful in the prevention of delirium in non-ventilated ICU patients. Unfortunately, they did not report any potentially negative effects of earplugs related to sensory deprivation - for example, restlessness, discomfort, or anxiety. In non-ventilated critical care patients the combination of earplugs and eyemasks were effective to improve sleep [2], and the use of eyemasks, in healthy volunteers, in a simulated ICU environment led to improved nighttime sleep and higher nocturnal melatonin levels [3]. Whether or not these positive results also apply to intubated ICU patients is not known and the mentioned possible disadvantages might especially occur in this vulnerable patient group. Nevertheless, the Dutch guideline on delirium management states that the use of nighttime eyemasks should be considered [4]. As the use of eyemasks in intubated patients could very well lead to a feeling of sensorial deprivation and its feasibility in critically ill patients is not clear, we analyzed 18 ICU patients who were offered the choice of wearing a nightmask from 10 p.m. to 6 a.m. (Table ​(Table1).1). The need for informed consent was waived since the use of eyemasks is a part of national delirium guidelines and participation was on a voluntary basis. Table 1 Patient characteristics Eleven patients (61%) were willing to wear a nightmask on average on 28% (median 4 nights, range 1 to 5) of nights on the ICU. In these patients self-perceived quality of sleep, using a visual analog scale (VAS), improved from 6.6 (5.9 to 8.2) to 7.5 (7.0 to 8.0) (P = 0.041) when the mask was worn. In 72% of cases, the mask was refused or taken off prematurely due to restlessness (30%), discomfort (20%), or anxiety (11%). While eyemasks might improve sleep in selected patients, it also may lead to feelings of discomfort and anxiety in mechanically ventilated ICU patients and therefore its standardized use should be used with caution and only on a voluntary basis in this specific group.

Association between the Hanging Chin Sign and Mortality in Critically Ill Patients, a Retrospective Observational Study

Purpose: Define a new sign called the ‘Hanging Chin Sign’ (HCS) and discuss its clinical significance by evaluating if it is associated with poor hospital outcome in critically ill patients.Methods: A retrospective observational study was performed. 331 adult patients presenting to the emergency department (ED) between 1 April 2011 and 31 July 2013, for which an Intensive Care Unit (ICU) physician was consulted and a supine chest X-ray was taken, were included. HCS was defined as radiological projection of the jawbone (os mandibula) over one or more ribs on the chest X-ray. In-hospital mortality, ICU admission and hospital length of stay (LOS) was compared between patients with and without a HCS.Results: In patients presenting with a HCS, mortality was significantly higher. After case mix correction for age, gender, Glascow Coma Scale and neurological pathology, there was no significant independent association between the HCS and mortality, ICU admission, hospital LOS, ICU LOS and APACHE II score.Conclusion: Critically ill patients presenting to the ED with a HCS have higher in-hospital mortality. Although there is no independent association between the HCS and severity of disease, it can be used as an additional clinical marker for mortality and frailty.

Effect of Dynamic Light Application on Cognitive Performance and Well-being of Intensive Care Nurses

Background Exposure to bright light has alerting effects. In nurses, alertness may be decreased because of shift work and high work pressure, potentially reducing work performance and increasing the risk for medical errors. Objectives To determine whether high‐intensity dynamic light improves cognitive performance, self‐reported depressive signs and symptoms, fatigue, alertness, and well‐being in intensive care unit nurses. Methods In a single‐center crossover study in an intensive care unit of a teaching hospital in the Netherlands, 10 registered nurses were randomly divided into 2 groups. Each group worked alternately for 3 to 4 days in patients’ rooms with dynamic light and 3 to 4 days in control lighting settings. High‐intensity dynamic light was administered through ceiling‐mounted fluorescent tubes that delivered bluish white light up to 1700 lux during the daytime, versus 300 lux in control settings. Cognitive performance, self‐reported depressive signs and symptoms, fatigue, and well‐being before and after each period were assessed by using validated cognitive tests and questionnaires. Results Cognitive performance, self‐reported depressive signs and symptoms, and fatigue did not differ significantly between the 2 light settings. Scores of subjective well‐being were significantly lower after a period of working in dynamic light. Conclusions Daytime lighting conditions did not affect intensive care unit nurses’ cognitive performance, perceived depressive signs and symptoms, or fatigue. Perceived quality of life, predominantly in the psychological and environmental domains, was lower for nurses working in dynamic light.