The association between nurse-administered midazolam following cardiac surgery and incident delirium: An observational study

The association between midazolam premedication and postoperative delirium - a retrospective cohort study

STUDY OBJECTIVE

To evaluate the association between midazolam premedication and postoperative delirium in a large retrospective cohort of patients ≥70 years.

DESIGN

Retrospective cohort study.

SETTING

A single tertiary academic medical center.

PATIENTS

Patients ≥70 years having elective non-cardiac surgery under general anesthesia from 2020 to 2021.

INTERVENTIONS

Midazolam premedication, defined as intravenous midazolam administration prior to induction of general anesthesia.

MEASUREMENTS

The primary outcome, postoperative delirium, was a collapsed composite outcome including at least one of the following: a positive 4A's test during post-anesthesia care unit stay and/or the initial 2 postoperative days; physician or nursing records reporting new-onset confusion as captured by the CHART-DEL instrument; or a positive 3D-CAM test. The association between midazolam premedication and postoperative delirium was assessed using multivariable logistic regression, adjusting for potential confounding variables. As secondary analysis, we investigated the association between midazolam premedication and a composite of other postoperative complications. Several sensitivity analyses were performed using similar regression models.

MAIN RESULTS

In total, 1973 patients were analyzed (median age 75 years, 47% women, 50% ASA score ≥ 3, 32% high risk surgery). The overall incidence of postoperative delirium was 15.3% (302/1973). Midazolam premedication was administered to 782 (40%) patients (median [IQR] dose 2 [1,2] mg). After adjustment for potential confounding variables, midazolam premedication was not associated with increased odds of postoperative delirium, with adjusted odds ratio of 1.09 (95% confidence interval 0.82-1.45; P = 0.538). Midazolam premedication was also not associated with the composite of other postoperative complications. Furthermore, no association was found between midazolam premedication and postoperative delirium in any of the sensitivity analyses preformed.

CONCLUSIONS

Our results suggest that low doses of midazolam can be safely used to pre-medicate elective surgical patients 70 years or older before non-cardiac surgery, without significant effect on the risk of developing postoperative delirium.

Postoperative cognitive recovery and prevention of postoperative cognitive complications in the elderly patient

Elderly patients undergoing surgery are at higher risk of life-altering and costly complications. This challenge is increasingly recognized with the growing geriatric surgical population. Advanced age and comorbid conditions, such as disability and frailty that often develop with age, are all independent risk factors of postoperative morbidity and mortality. A common factor in this age group is cognitive impairment, which poses a challenge for the patient and clinician in the perioperative setting. It affects the capacity for informed consent and limits optimization before surgery; furthermore, an existing impairment may progress in severity during the perioperative period, and new onset of signs of delirium or postoperative cognitive dysfunction may arise during postoperative recovery. In this article, we aim to review the current literature examining the latest definitions, diagnostic criteria, and preventive strategies that may ameliorate postoperative cognitive complications.

Effect of perioperative benzodiazepine use on intraoperative awareness and postoperative delirium: a systematic review and meta-analysis of randomised controlled trials and observational studies

BACKGROUND

Benzodiazepine use is associated with delirium, and guidelines recommend avoiding them in older and critically ill patients. Their perioperative use remains common because of perceived benefits.

METHODS

We searched CENTRAL, MEDLINE, CINAHL, PsycInfo, and Web of Science from inception to June 2021. Pairs of reviewers identified randomised controlled trials and prospective observational studies comparing perioperative use of benzodiazepines with other agents or placebo in patients undergoing surgery. Two reviewers independently abstracted data, which we combined using a random-effects model. Our primary outcomes were delirium, intraoperative awareness, and mortality.

RESULTS

We included 34 randomised controlled trials (n=4354) and nine observational studies (n=3309). Observational studies were considered separately. Perioperative benzodiazepines did not increase the risk of delirium (n=1352; risk ratio [RR] 1.43; 95% confidence interval [CI]: 0.9-2.27; I2=72%; P=0.13; very low-quality evidence). Use of benzodiazepines instead of dexmedetomidine did, however, increase the risk of delirium (five studies; n=429; RR 1.83; 95% CI: 1.24-2.72; I2=13%; P=0.002). Perioperative benzodiazepine use decreased the risk of intraoperative awareness (n=2245; RR 0.26; 95% CI: 0.12-0.58; I2=35%; P=0.001; very low-quality evidence). When considering non-events, perioperative benzodiazepine use increased the probability of not having intraoperative awareness (RR 1.07; 95% CI: 1.01-1.13; I2=98%; P=0.03; very low-quality evidence). Mortality was reported by one randomised controlled trial (n=800; RR 0.90; 95% CI: 0.20-3.1; P=0.80; very low quality).

CONCLUSIONS

In this systematic review and meta-analysis, perioperative benzodiazepine use did not increase postoperative delirium and decreased intraoperative awareness. Previously observed relationships of benzodiazepine use with delirium could be explained by comparisons with dexmedetomidine.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42019128144.

A predictive scoring system for postoperative delirium in the elderly patients with intertrochanteric fracture

OBJECTIVE

To establish a scoring system to predict the postoperative delirium in elderly patients with intertrochanteric fracture.

MATERIALS AND METHODS

We retrospectively reviewed 159 elderly patients with a diagnosis of intertrochanteric fracture and underwent closed reduction and intramedullary nail fixation, and then divided them into two groups including the delirium group (23 cases) or non-delirium group (136 cases) in our hospital from January 2017 to December 2019. The following clinical characteristics were recorded and analyzed: age, gender, fracture classification, body mass index (BMI), history of diabetes mellitus, history of stroke, preoperative albumin, preoperative hemoglobin (Hb), preoperative arterial partial pressure of oxygen (PaO₂), time between admission and surgery, lower limb thrombosis, American Society of Anesthesiologists (ASA) grade, operative time, operative blood loss, and intraoperative blood transfusion. The prevalence of these clinical characteristics in delirium group was evaluated, and the scoring system was established using logistic regression analysis. The performance of the scoring system was also prospectively validated.

RESULTS

The predictive scoring system was based on five clinical characteristics confirmed as significant predictors of postoperative delirium, namely, age > 75 years, history of stroke, preoperative Hb ≤ 100 g/L, preoperative PaO₂ ≤ 60 mmHg, and time between admission to surgery > 3 days. Delirium group showed a significant higher score than non-delirium (6.26 vs. 2.29, P < 0.001), and the optimal cut-off value for the scoring system was 4 points. The sensitivity and specificity of the scoring system for predicting postoperative delirium were 82.61% and 81.62% in derivation set, respectively, and 72.71% and 75.00% in validation set.

CONCLUSION

The predictive scoring system confirmed with achieve satisfactory sensitivity and specificity in predicting postoperative delirium in the elderly with intertrochanteric fracture. The risk of postoperative delirium in patients with the score of 5 to 11 is high, while the score of 0 to 4 is low.

Predisposing and Precipitating Factors Associated With Delirium: A Systematic Review

IMPORTANCE

Despite discrete etiologies leading to delirium, it is treated as a common end point in hospital and in clinical trials, and delirium research may be hampered by the attempt to treat all instances of delirium similarly, leaving delirium management as an unmet need. An individualized approach based on unique patterns of delirium pathophysiology, as reflected in predisposing factors and precipitants, may be necessary, but there exists no accepted method of grouping delirium into distinct etiologic subgroups.

OBJECTIVE

To conduct a systematic review to identify potential predisposing and precipitating factors associated with delirium in adult patients agnostic to setting.

EVIDENCE REVIEW

A literature search was performed of PubMed, Embase, Web of Science, and PsycINFO from database inception to December 2021 using search Medical Subject Headings (MeSH) terms consciousness disorders, confusion, causality, and disease susceptibility, with constraints of cohort or case-control studies. Two reviewers selected studies that met the following criteria for inclusion: published in English, prospective cohort or case-control study, at least 50 participants, delirium assessment in person by a physician or trained research personnel using a reference standard, and results including a multivariable model to identify independent factors associated with delirium.

FINDINGS

A total of 315 studies were included with a mean (SD) Newcastle-Ottawa Scale score of 8.3 (0.8) out of 9. Across 101 144 patients (50 006 [50.0%] male and 49 766 [49.1%] female patients) represented (24 015 with delirium), studies reported 33 predisposing and 112 precipitating factors associated with delirium. There was a diversity of factors associated with delirium, with substantial physiological heterogeneity.

CONCLUSIONS AND RELEVANCE

In this systematic review, a comprehensive list of potential predisposing and precipitating factors associated with delirium was found across all clinical settings. These findings may be used to inform more precise study of delirium's heterogeneous pathophysiology and treatment.

Delirium-associated medication in people at risk: A systematic update review, meta-analyses, and GRADE-profiles

BACKGROUND

Drug-associated delirium is a common but potentially preventable neuropsychiatric syndrome associated with detrimental outcomes. Empirical evidence for delirium-associated medication is uncertain due to a lack of high-quality studies. We aimed to further investigate the body of evidence for drugs suspected to trigger delirium.

METHODS

A systematic update review and meta-analyses of prospective studies presenting drug associations with incident delirium in adult study populations was conducted. Two authors independently searched MEDLINE, PsycINFO, Embase, and Google Scholar dated from October 1, 2009 to June 23, 2020, after screening a previous review published in 2011. The most reliable results on drug-delirium associations were pooled in meta-analyses using the random-effects model. Quality of evidence was assessed using the GRADE-approach. This study is preregistered with OSF (DOI https://doi.org.10.17605/OSF.IO/4PUHY).

RESULTS

The 31 eligible studies, presenting results for 24 medication classes were identified. Meta-analyses and GRADE level of evidence ratings show no increased delirium risk for Haloperidol (OR: 0.96, 95% CI 0.72-1.28; high-quality evidence), Olanzapine (OR: 0.25, 95% CI 0.15-0.40), Ketamine (OR: 0.72, 95% CI 0.35-1.46) or corticosteroids (OR: 0.69, 95% CI 0.32-1.50; moderate quality evidence, respectively). Low-level evidence suggests a three-fold increased risk for anticholinergics (OR: 3.11, 95% CI 1.04-9.26). Opioids, benzodiazepines, H₁ -antihistamines, and antidepressants did not reach reliable evidence levels in our analyses.

CONCLUSION

We investigated the retrievable body of evidence for delirium-associated medication. The results of this systematic review were then interpreted in conjunction with other evidence-based works and guidelines providing conclusions for clinical decision-making.

Effect of Preoperative Oral Saline Administration on Postoperative Delirium in Older Persons: A Randomized Controlled Trial

Objective

Postoperative delirium (POD) seriously affects recovery of older persons, increasing their mortality rate after surgery. We aimed to evaluate preoperative oral saline administration on postoperative delirium in older persons undergoing spinal decompression.

Design

A randomised controlled trial in a large tertiary hospital.

Setting and Participants

A total of 76 older persons (≧65 years old) undergoing spinal surgery from May 2020 to January 2021.

Methods

Older persons (65–83 years old) who underwent elective spinal canal decompression were randomly grouped into either the control group (n = 38) or the intervention group (n = 38). The control group was forbidden from drinking 8 hours prior to the operation while the intervention group was administered 5 mL·kg⁻¹ of normal saline 2 hours before anesthesia. Hemodynamic indicators, diagnostic biomarkers, preoperative mini-mental status scores, and intraoperative fluid dynamics were recorded at baseline and at various postoperative timepoints. Subjects were then scored for POD and postoperative pain.

Results

S100β protein was lowered in S₁ (F_S1 = 12.289, P <0.001) and S₂ (F_S2 = 12.440, P <0.001) in the intervention group while mean arterial blood pressure (F_T1= 42.997, P<0.001) and heart rate (F_T1= 8.974, P=0.004) were increased. The Ln c-reactive protein of the intervention group was lowered 1 day postoperatively (F_S2 = 6.305, P = 0.014). The incidence of postoperative delirium in the control group was higher than in the intervention group (27.8% vs 8.3%, χ² = 4.547, P = 0.033).

Conclusion

Preoperative oral saline can reduce the incidence of postoperative delirium in older persons by minimizing perioperative hemodynamic fluctuations and central nervous system damage.

Review of Postoperative Delirium in Geriatric Patients After Hip Fracture Treatment

Introduction

Postoperative delirium (POD) is a serious complication occurring in 4–53.3% of geriatric patients undergoing surgeries for hip fracture. Incidence of hip fractures is projected to grow 11.9% from 258,000 in 2010 to 289,000 in 2030 based on 1990 to 2010 data. As prevalence of hip fractures is projected to increase, POD is also anticipated to increase.

Signficance

Postoperative delirium remains the most common complication of emergency hip fracture surgery leading to high morbidity and mortality rates despite significant research conducted regarding this topic. This study reviews literature from 1990 to 2021 regarding POD in geriatric hip fracture management.

Results

Potentially modifiable and non-modifiable risk factors for developing POD include, but are not limited to, male gender, older age, multiple comorbidities, specific comorbidities (dementia, cognitive impairment, diabetes, vision impairment, and abnormal blood pressure), low BMI, preoperative malnutrition, low albumin, low hematocrit, blunted preoperative cytokines, emergency surgery, time to admission and surgery, preoperative medical treatment, polypharmacy, delirium-inducing medications, fever, anesthesia time, and sedation depth and type. Although the pathophysiology remains unclear, the leading theories suggest neurotransmitter imbalance, inflammation, and electrolyte or metabolic derangements as the underlying cause of POD. POD is associated with increased length of hospital stay, cost, morbidity, and mortality. Prevention and early recognition are key factors in managing POD. Methods to reduce POD include utilizing interdisciplinary teams, educational programs for healthcare professionals, reducing narcotic use, avoiding delirium-inducing medications, and multimodal pain control.

Conclusion

While POD is a known complication after hip fracture surgery, further exploration in prevention is needed. Early identification of risk factors is imperative to prevent POD in geriatric patients. Early prevention will enhance delivery of health care both pre- and post-operatively leading to the best possible surgical outcome and better quality of life after hip fracture treatment.

Anesthetic Considerations for Patients on Psychotropic Drug Therapies

Psychotropic drugs are used in the treatment of psychiatric and non-psychiatric conditions. Many patients who are on psychotropic medications may present for procedures requiring anesthesia. Psychotropic medications can have dangerous interactions with drugs commonly used in anesthesia, some of which can be life-threatening. In this review, we describe the current anesthetic considerations for patients on psychotropic drug therapies, including antidepressants, antipsychotics, mood stabilizers, anxiolytics, and stimulants. The pharmacology, side effects, and potential drug interactions of the commonly prescribed psychotropic drug therapies with anesthetic agents are described. Further, we highlight the current recommendations regarding the cessation and continuation of these medications during the perioperative period.

Incidence and predictors of delirium on the intensive care unit after acute myocardial infarction, insight from a retrospective registry

OBJECTIVES

This study aimed to identify the incidence and potential risk factors for delirium after myocardial infarction (MI).

BACKGROUND

Delirium is a common complication on intensive care units. Data on incidence and especially on predictors of delirium in patients after acute MI are rare.

METHODS

In this retrospective study, all patients hospitalized for MI treated with coronary angiography in an university hospital in 2018 were included and analyzed. Onset of delirium within the first 5 days after MI was attributed to the MI and was defined by a Nursing Delirium screening scale (NuDesc) ≥2. This score is taken as part of daily care in every patient on intensive care unit three times a day by especially trained nurses.

RESULTS

A total of 624 patients with MI (age 68.5 ± 13.2 years, ST-elevation MI 41.6%, hospital mortality 3.2%) were included in the study. Delirium was detected in 10.9% of all patients. In the subgroup of patients with a stay on the intensive care unit (ICU) for more than 24 hr (n = 229), delirium was detected in 29.7%. Hospital and ICU stay were significantly longer in patients with delirium (p < .001). Delirium was an independent predictor of prolonged ICU-stay. Independent predictors of delirium were age, dementia, alcohol abuse, cardiac arrest, hypotension, and leucocytosis. Infarct size or presentation with ST-elevation were not associated with incidence of delirium.

CONCLUSION

Development of delirium is frequent after acute MI and prolongs hospitalization. Incidence of delirium is associated with clinical instability, preexisting comorbidity, and age rather than MI type or size.

Incidence and predictors of delirium on the intensive care unit in patients with acute kidney injury, insight from a retrospective registry

Acute kidney injury (AKI) and delirium are common complications on the intensive care unit (ICU). Few is known about the association of AKI and delirium, as well as about incidence and predictors of delirium in patients with AKI. In this retrospective study, all patients with AKI, as defined by the KDIGO (kidney disease improving global outcome) guideline, treated for more than 24 h on the ICU in an university hospital in 2019 were included and analyzed. Delirium was defined by a NuDesc (Nursing Delirium screening scale) ≥ 2, which is evaluated three times a day in every patient on our ICU as part of daily routine. A total of 383/919 (41.7%) patients developed an AKI during the ICU stay. Delirium was detected in 230/383 (60.1%) patients with AKI. Independent predictors of delirium were: age, psychiatric disease, alcohol abuse, mechanical ventilation, severe shock, and AKI stage II/III (all p < 0.05). The primary cause of illness had no influence on the onset of delirium. Among patients with AKI, the duration of the ICU stay correlated with higher stages of AKI and the presence of delirium (stage I/no delirium: median 1.9 (interquartile range (25th–75th) 1.3–2.9) days; stage II/III/no delirium: 2.6 (1.6–5.5) days; stage I/delirium: 4.1 (2.5–14.3) days; stage II/III/delirium: 6.8 (3.5–11.9) days; all p < 0.01). Delirium, defined as NuDesc ≥ 2 is frequent in patients with AKI on an ICU and independently predicted by higher stages of AKI.

Preoperative individualized education intervention reduces delirium after cardiac surgery: a randomized controlled study

Background

Postoperative delirium dramatically increases the mortality and morbidity of patients undergoing cardiac surgery. Preoperative education has been proven to be effective in improving recovery and reducing complications. However, there is rare evidence of individualized education for the delirium. This study aimed to investigate the effect of preoperative personalized education on postoperative delirium of patients undergoing cardiac surgery.

Methods

A total of 133 adult patients receiving cardiac surgery in a single center were enrolled in this study and randomized into the experimental group (n=67) and the control group (n=66), who were given the preoperative individualized education intervention and routine care respectively. The primary endpoint of delirium and other clinical outcomes were observed and compared.

Results

All patients completed this trial without a significant difference between the two groups in baseline characteristics. The incidence of the delirium of the experimental group was significantly lower than that of the control group (10.4% vs. 24.2%, P=0.038). There was no statistical difference between two groups in hospital-stay and other complications, while the mechanical ventilation time and ICU stay of the experimental group was significantly lower (MV time: 13.7±7.6 vs. 18.6±9.8 h, P=0.002; ICU stay: 31.3±9.1 vs. 36.5±10.4 h, P=0.003).

Conclusions

Preoperative individualized education intervention can reduce the incidence of postoperative delirium and promote the recovery of patients receiving cardiac surgery.

Restricted versus liberal intraoperative benzodiazepine use in cardiac anaesthesia for reducing delirium (B-Free Pilot): a pilot, multicentre, randomised, cluster crossover trial

BACKGROUND

Delirium is common after cardiac surgery and is associated with adverse outcomes. Perioperative benzodiazepine use is associated with delirium and is common during cardiac surgery, which may increase the risk of postoperative delirium. We undertook a pilot study to inform the feasibility of a large randomised cluster crossover trial examining whether an institutional policy of restricted benzodiazepine administration during cardiac surgery (compared with liberal administration) would reduce delirium.

METHODS

We conducted a two-centre, pilot, randomised cluster crossover trial with four 4 week crossover periods. Each centre was randomised to a policy of restricted or liberal use, and then alternated between the two policies during the remaining three periods. Our feasibility outcomes were adherence to each policy (goal ≥80%) and outcome assessment (one delirium assessment per day in the ICU in ≥90% of participants). We also evaluated the incidence of intraoperative awareness in one site using serial Brice questionnaires.

RESULTS

Of 800 patients undergoing cardiac surgery during the trial period, 127/800 (15.9%) had delirium. Of these, 355/389 (91.3%) received benzodiazepines during the liberal benzodiazepine periods and 363/411 (88.3%) did not receive benzodiazepines during the restricted benzodiazepine periods. Amongst the 800 patients, 740 (92.5%) had ≥1 postoperative delirium assessment per day in the ICU. Of 521 patients screened for intraoperative awareness, one patient (0.2%), managed during the restricted benzodiazepine period (but who received benzodiazepine), experienced intraoperative awareness.

CONCLUSIONS

This pilot study demonstrates the feasibility of a large, multicentre, randomised, cluster crossover trial examining whether an institutional policy of restricted vs liberal benzodiazepine use during cardiac surgery will reduce postoperative delirium.

CLINICAL TRIAL REGISTRATION

NCT03053869.

Postoperative cognitive decline: the nurse's role in identifying this underestimated and misinterpreted condition

BACKGROUND

postoperative cognitive changes can increase morbidity and mortality, demand for postoperative care and social and health costs, and can lead to dementia.

AIM

this article discusses perioperative variables that can be used to identify patients who are more vulnerable to experiencing cognitive decline after surgery. It also highlights some screening tools that could be useful for early detection and for planning nursing care.

METHOD

a literature search was conducted using the Medline, CINAHL, PsychINFO and Cochrane Library databases from 2010 to 2018. Google Scholar was also consulted. The reference lists of relevant articles covering postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) were reviewed for further relevant papers.

CONCLUSION

assessment and evaluation of a patient's cognitive resources before and after surgery can lead to clinical interventions to support the person's coping mechanisms; health professionals can reduce the short- and long-term effects of cognitive decline. Screening tools could be used as part of a strategy to minimise postoperative cognitive changes.

The relationship of delirium and risk factors for cardiology intensive care unit patients with the nursing workload

AIMS AND OBJECTIVES

To evaluate the relationship of delirium and risk factors for cardiology intensive care unit (ICU) patients with the nursing workload.

BACKGROUND

Delirium is a common syndrome in patients with cardiac problems. The risk factors causing delirium and the presence and type of delirium affect the nurse workload and patient care quality adversely.

DESIGN

This cross-sectional study was conducted with 133 patients staying at the cardiology ICU of a university hospital between 5 January-31 March 2017.

METHOD

The study data were collected using the Patient Information Form, Delirium Risk Factors' Form and Therapeutic Intervention Scoring System-28 (TISS-28) scale to identify the nurse workload. The statistical analysis of the data was performed using frequency, chi-square, Mann-Whitney U, correlation and regression analyses.

RESULTS

It was found that patients who developed delirium were 65 years or older, they had more nasogastric/total parenteral nutrition (NG/TPN), benzodiazepine and physical restraints in comparison with those with no delirium development, and that the prevalence of hypoxia and hypoalbuminemia were higher in these patients. The mean TISS-28 score was higher in patients with delirium, compared with those without delirium. There was a positive correlation between the mean Acute Physiology and Chronic Health Evaluation II (APACHE II) scores and the mean TISS-28 score of the patients. The mean TISS-28 score was found to significantly increase with being at the age of 65 and above and the administration of mechanical ventilation. The patients with delirium required a mean of 60-min additional care.

CONCLUSIONS

Our study results suggest that the presence of delirium and the delirium risk factors, irrespective of delirium, increase the nurse workload.

RELEVANCE TO CLINICAL PRACTICE

An effective management of delirium risk factors can improve the patient care quality by reducing delirium occurrence and nurse workload.

Delirium after cardiac surgery. Incidence, phenotypes, predisposing and precipitating risk factors, and effects

BACKGROUND

In cardiac surgical patients little is known about different phenotypes of delirium and how the symptoms fluctuate over time.

OBJECTIVES

Evaluate risk factors, incidence, fluctuations, phenotypic characteristics and impact on patients' outcomes of delirium.

METHODS

Prospective longitudinal study. In postoperative intensive care unit 199 patient were assessed three-times a day through an adapted versions of the Intensive Care Delirium Screening Checklist.

RESULTS

Delirium and subsyndromal delirium incidence were 30.7% and 31.2%, respectively. Delirium manifested mostly in the hypoactive form and showed a fluctuating trend for several days. Atrial fibrillation, benzodiazepine/opioids dosages, hearing impairment, extracorporeal circulation length, SAPS-II and mean arterial pressure were independent predictors for delirium. Delirium was a statistically significant predictor of chemical/physical restraint use and hospital length of stay.

CONCLUSIONS

Given the fluctuating and phenotypic characteristics, delirium screening should be a systematic/intentional activity. Multidisciplinary prevention strategies should be implemented to identify and treat the modifiable risk factors.

Benzodiazepine administration during adult cardiac surgery: a survey of current practice among Canadian anesthesiologists working in academic centres

BACKGROUND

Benzodiazepines are commonly administered during cardiac surgery because of their limited effect on hemodynamics and presumed role in preventing intraoperative awareness. Recent concerns about an increased risk of delirium with benzodiazepines have resulted in decreased usage in the intensive care unit and in geriatric perioperative practice. Little is known, however, about current benzodiazepine usage in the setting of adult cardiac surgery.

METHODS

We contacted all academic anesthesia departments in Canada to identify practicing attending cardiac anesthesiologists; this group constituted our sampling frame. Information regarding participant demographics, benzodiazepine usage, type, dose, and other administration details were obtained by electronic survey. Responses were analyzed descriptively.

RESULTS

The survey was completed by 243/346 (70%) of cardiac anesthesiologists. Eleven percent of respondents do not administer benzodiazepines. Midazolam was the most commonly used benzodiazepine, with a mean (standard deviation) dose of 4.9 (3.8) mg given to an average patient. When respondents were asked the proportion of patients that they gave benzodiazepines, the response was bimodal. The most common considerations that influenced benzodiazepine use were patient age (73%), patient anxiety (63%), history of alcohol/drug/benzodiazepine use (60%), and the presence of risk factors for intraoperative awareness (44%).

CONCLUSIONS

Benzodiazepine use is common among academic cardiac anesthesiologists in Canada. Nonetheless, heterogeneity exists between individual practices, suggesting clinical equipoise between restrictive and liberal administration of benzodiazepines for cardiac anesthesia. L'administration de benzodiazépines pendant la chirurgie cardiaque chez l'adulte: évaluation de la pratique actuelle des anesthésiologistes canadiens exerçant en milieu universitaire.

Risk factors for postoperative delirium after spine surgery in middle- and old-aged patients

BACKGROUND

Postoperative delirium is a common complication following various operative procedures with an incidence rate of 10-77 %.

AIM

To analyze various risk factors for postoperative delirium after spine surgery in the middle- and old-aged patients.

METHODS

This study retrospectively reviewed 451 patients (226 males and 225 females, an average age of 65.1 ± 18.3 years) who underwent spinal surgery in our hospital between January 2010 and August 2015. Patients who had features of acute onset and fluctuating course and any two of the other features were diagnosed with delirium. Cognitive tests consisting of Clinical Dementia Rating and Global Deterioration Scale were performed to evaluate delirium. T tests were used for statistical analysis of the difference between the two groups, and logistic regression analyses were used for determining the risk factors.

RESULTS

A total of 42 (9.3 %) patients were diagnosed with delirium. Delirious and non-delirious patients had no difference in age, gender, BMI, education level, drug treatment, comorbid disease history, surgical history, preoperative blood pressure, intraoperative blood loss, blood transfusion, use of surgical implants, surgical site, use of fentanyl and propofol, and preoperative VAS score. Intraoperative hypotension and use of dezocine were related to postoperative delirium (P = 0.03 and P = 0.07). The multiple regression equation was Y = -0.11 + 0.52 × X ₀ + 0.21 × X ₁, where X ₀ = amount of dezocine, X ₁ = instances of intraoperative hypotension.

CONCLUSION

Postoperative delirium commonly occurs after spine surgery. Intraoperative hypotension <80 mmHg and intraoperative use of dezocine represent valuable new predictors of the risk of delirium.

Predicting, preventing, and identifying delirium after cardiac surgery

Delirium after cardiac surgery is a major problem. The exact mechanisms behind delirium are not understood. Potential pathways of delirium include neurotransmitter interference, global cognitive disorder, and neuroinflammation. Several predisposing and precipitating risk factors have been identified for postoperative delirium. The development of delirium following cardiac surgery is associated with worse outcomes in the perioperative period. Multiple interventions are being explored for the prevention and treatment of delirium. Studies investigating the potential roles of biomarkers in delirium as well as pharmacological interventions to reduce the incidence and duration of delirium are necessary to mitigate this negative outcome.

Risk factors for delirium after on-pump cardiac surgery: a systematic review

Introduction

As evidence-based effective treatment protocols for delirium after cardiac surgery are lacking, efforts should be made to identify risk factors for preventive interventions. Moreover, knowledge of these risk factors could increase validity of etiological studies in which adjustments need to be made for confounding variables. This review aims to systematically identify risk factors for delirium after cardiac surgery and to grade the evidence supporting these associations.

Method

A prior registered systematic review was performed using EMBASE, CINAHL, MEDLINE and Cochrane from 1990 till January 2015 (http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42014007371). All studies evaluating patients for delirium after cardiac surgery with cardiopulmonary bypass (CPB) using either randomization or multivariable data analyses were included. Data was extracted and quality was scored in duplicate. Heterogeneity impaired pooling of the data; instead a semi-quantitative approach was used in which the strength of the evidence was graded based on the number of investigations, the quality of studies, and the consistency of the association reported across studies.

Results

In total 1462 unique references were screened and 34 were included in this review, of which 16 (47 %) were graded as high quality. A strong level of evidence for an association with the occurrence of postoperative delirium was found for age, previous psychiatric conditions, cerebrovascular disease, pre-existent cognitive impairment, type of surgery, peri-operative blood product transfusion, administration of risperidone, postoperative atrial fibrillation and mechanical ventilation time. Postoperative oxygen saturation and renal insufficiency were supported by a moderate level of evidence, and there is no evidence that gender, education, CPB duration, pre-existent cardiac disease or heart failure are risk factors.

Conclusion

Of many potential risk factors for delirium after cardiac surgery, for only 11 there is a strong or moderate level of evidence. These risk factors should be taken in consideration when designing future delirium prevention strategies trials or when controlling for confounding in future etiological studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1060-0) contains supplementary material, which is available to authorized users.

Delirium in Prolonged Hospitalized Patients in the Intensive Care Unit

Background:

Prolonged hospitalization in the intensive care unit (ICU) can impose long-term psychological effects on patients. One of the most significant psychological effects from prolonged hospitalization is delirium.

Objectives:

The aim of this study was to assess the effect of prolonged hospitalization of patients and subsequent delirium in the intensive care unit.

Patients and Methods:

This conventional content analysis study was conducted in the General Intensive Care Unit of the Shariati Hospital of Tehran University of Medical Sciences, from the beginning of 2013 to 2014. All prolonged hospitalized patients and their families were eligible participants. From the 34 eligible patients and 63 family members, the final numbers of actual patients and family members were 9 and 16, respectively. Several semi-structured interviews were conducted face-to-face with patients and their families in a private room and data were gathered.

Results:

Two main themes from two different perspectives emerged, 'patients' perspectives' (experiences during ICU hospitalization) and 'family members' perspectives' (supportive-communicational experiences). The main results of this study focused on delirium, Patients' findings were described as pleasant and unpleasant, factual and delusional experiences.

Conclusions:

Family members are valuable components in the therapeutic process of delirium. Effective use of family members in the delirium caring process can be considered to be one of the key non-medical nursing components in the therapeutic process.

Cardiovascular surgery nurses' level of knowledge regarding delirium

BACKGROUND

Studies have shown that nurses have a crucial role in the recognition of delirium; however, they have insufficient knowledge regarding the issue.

OBJECTIVE

The aim of the study is to determine the knowledge level of cardiovascular surgery nurses regarding delirium.

METHODS

A survey design was used. The population of the study consisted of 124 nurses employed at the cardiovascular surgery wards and intensive care units of universities as well as state and private hospitals located in two different cities in Turkey between May and June 2014. The sample consisted of 97 nurses employed at the aforementioned institutions and time. Data were collected using the questionnaire form depicting the demographic characteristics of the nurses and the knowledge form including the level of nurses' knowledge regarding delirium. For the evaluation of data, number, percentage, Kruskal-Wallis, Mann-Whitney U- and independent-samples t-test were used.

RESULTS

Nurses were between 18 and 47 years of age with a mean 29·8 (SD = 6·80, the youngest = 18 and the oldest = 47) years. They spent a minimum of 1, a maximum of 25 and a median value of 3 (interquartile range, IQR: 5) years working in cardiovascular surgery. As for the scores received from the knowledge form regarding delirium, the lowest was zero, the highest was 60, and the average score was 41·18 ± 12·50 (a moderate level of knowledge). It was found that the nurses working in intensive care units, those who were chief nurses and those who received in-service training scored higher than the others.

CONCLUSIONS

Cardiovascular surgery nurses had a moderate level of knowledge regarding delirium. This may result in the neglect of delirium or a misdiagnosis.

RELEVANCE TO CLINICAL PRACTICE

It is recommended that training is provided that includes recognition, assessment and application of appropriate interventions to minimise the incidence of delirium.

Emergence from general anaesthesia and evolution of delirium signs in the post-anaesthesia care unit

BACKGROUND

Emergence from anaesthesia is often accompanied by signs of delirium, including fluctuating mental status and inattention. The evolution of these signs of delirium requires investigation since delirium in the post-anaesthesia care unit (PACU) may be associated with worse outcomes.

METHODS

Adult patients emerging from anaesthesia were assessed for agitated emergence in the operating room using the Richmond Agitation-Sedation Scale (RASS). The Confusion Assessment Method for the Intensive Care Unit was then used to evaluate delirium signs at PACU admission and during PACU stay at 30 min, 1 h, and discharge. Signs consistent with delirium were classified as hyperactive vs hypoactive based upon a positive CAM-ICU assessment and the concomitant RASS score. Multivariable logistic regression was utilized to assess potential risk factors for delirium during PACU stay including age, American Society of Anesthesiologists classification, and opioid and benzodiazepine exposure.

RESULTS

Among 400 patients enrolled, 19% had agitated emergence. Delirium signs were present at PACU admission, 30 min, 1 h, and PACU discharge in 124 (31%), 59 (15%), 32 (8%), and 15 (4%) patients, respectively. In patients with delirium signs, hypoactive signs were present in 56% at PACU admission and in 92% during PACU stay. Perioperative opioids were associated with delirium signs during PACU stay (P=0.02).

CONCLUSIONS

A significant proportion of patients develop delirium signs in the immediate postoperative period, primarily manifesting with a hypoactive subtype. These signs often persist to PACU discharge, suggesting the need for structured delirium monitoring in the PACU to identify patients potentially at risk for worse outcomes in the postoperative period.

Exploring the impact of augmenting sedation assessment with physiologic monitors

BACKGROUND

Pharmacological sedation is a necessary tool in the management of critically ill, mechanically ventilated patients. The intensive care unit (ICU) sedation strategy is to use the least amount of medication to meet safety and comfort goals. Titration of pharmacological agents is currently guided by clinical assessment tools. The purpose of this study was to determine whether the addition of a neurophysiological monitor, bispectral index (BIS), aided the ICU nurse in reducing the amount of drug used, compared to a clinical tool alone, in a general critical care population.

METHODS

In this prospective clinical trial, mechanically ventilated adults (N=300) were randomised to sedation assessment using only the observational assessment tool (RASS) or a combination of observational and physiologic measures (RASS+BIS). Subjects were enrolled from a medical ICU (N=154), a trauma ICU (N=72) and a general mixed-use ICU (N=74).

RESULTS

BIS-augmented sedation was only associated with the reduction of drug use when patients were sedated with propofol or narcotic agents (propofol [1.61 mg/kg/h vs. 1.77 mg/kg/h; p<0.0001], fentanyl [54.73 mcg/h vs. 66.81 mcg/h; p<0.0001], and hydromorphone [0.97 mg/h vs. 4.00 mg/h: p<0.0001] compared to RASS alone. In contrast, patients sedated with dexmedetomidine or benzodiazepines were given higher doses under the BIS-augmented dexmedetomidine [0.46 mcg/kg/h vs. 0.33 mcg/kg/h; p<0.0001], lorazepam [4.13 mg/h vs. 3.29 mg/h p<0.0001], and midazolam [3.73 mg/h vs 2.86 mg/h; p<0.0001]) protocol compared to clinical assessment alone.

CONCLUSION

The clinical evaluation of depth of sedation remains the most reliable method for the titration of pharmacological sedation in the critical care unit. However, BIS-augmented assessment is helpful in reducing the amount of propofol and narcotic medication used and may be considered an adjunct when these agents are utilised.

Risk Factors for Acute Delirium in Critically Ill Adult Patients: A Systematic Review

Background. Delirium is characterized by disturbances of consciousness, attention, cognition, and perception. Delirium is a serious but reversible condition associated with poor clinical outcomes. This has implications for the critically ill patient; the effects of delirium cause long term sequelae, principally cognitive deficits, and functional decline. Objectives. The objective of the paper was to describe risk factors associated with delirium in critically ill adult patients. Methods. Published and unpublished literature from 1990 to 2012, limited to English, was searched using ten databases. Results. Twenty-two studies were included in this paper. A large number of risk factors were presented in the literature; some of these were common across all settings whilst others were exclusive to the type of setting. Benzodiazepines and opioids were shown to be risk factors for delirium independent of setting. Conclusion. With regard to patients admitted to medical and surgical intensive care units, risk factors of older age and comorbidity were common. In the cardiac ICU, older age and lower Mini-Mental Status Examination scores were cited most often as risk factors for delirium, but other risk factors exclusive to the setting were also significant. Benzodiazepines were identified as the most significant pharmacological risk factor for delirium.

Epidemiology and risk factors for delirium across hospital settings

Delirium is one of the most common causes of acute end-organ dysfunction across hospital settings, occurring in as high as 80% of critically ill patients that require intensive care unit (ICU) care. The implications of this acute form of brain injury are profound. Across many hospital settings (emergency department, general medical ward, postoperative and ICU), a patient who experiences delirium is more likely to experience increased short- and long-term mortality, decreases in long-term cognitive function, increases in hospital length of stay and increased complications of hospital care. With the development of reliable setting-specific delirium-screening instruments, researchers have been able to highlight the predisposing and potentially modifiable risk factors that place patients at highest risk. Among the large number of risk factors discovered, administration of potent sedative medications, most notably benzodiazepines, is most consistently and strongly associated with an increased burden of delirium. Alternatively, in both the hospital and ICU, delirium can be prevented with the application of protocols that include early mobility/exercise. Future studies must work to understand the epidemiology across settings and focus upon modifiable risk factors that can be integrated into existing delirium prevention and treatment protocols.