Anaesthesia for the patient with dementia undergoing outpatient surgery

Strategies to improve end-of-life decision-making and palliative care following hip fracture in frail older adults: a scoping review

BACKGROUND

Although surgery is the gold standard following a hip fracture, the potential for rehabilitation and survival rates are low in frail older patients. Some patients may derive more benefit from palliative care. The objectives of this review were to identify the available strategies to improve end-of-life decision-making and palliative care for frail patients with hip fractures and to synthetise their level of support.

METHODS

We conducted a scoping review of the scientific and grey literature, searching seven databases and websites of associations. We included all study designs, expert opinion articles and clinical practice guidelines (CPGs). Data were synthetised according to the Approach to Patient with Limited Life Expectancy and Hip Fracture framework. The number of research items and their level of evidence were tabulated for each of the recommended strategies.

RESULTS

Of the 10 591 items identified, 34 were eligible. The majority of included articles were original research studies (n = 15). Half of the articles and CPGs focused on intervention categories (55%) such as goals of care discussion and comfort care, followed by factors to consider in the end-of-life decision-making process (25%) and prognosis assessments (20%), mainly through the estimation of life expectancy. The level of evidence for these strategies remains low, given the limited number of prospective studies supporting them.

CONCLUSIONS

This scoping review highlighted that end-of-life care in frail older patients with a hip fracture remains understudied. The strategies identified could be prioritised for future research to improve the well-being of the target population while promoting sustainable resource management.

Basal Forebrain Cholinergic Activity Modulates Isoflurane and Propofol Anesthesia

Cholinergic neurons in the basal forebrain (BF) have long been considered to be the key neurons in the regulation of cortical and behavioral arousal, and cholinergic activation in the downstream region of the BF can arouse anesthetized rats. However, whether the activation of BF cholinergic neurons can induce behavior and electroencephalogram (EEG) recovery from anesthesia is unclear. In this study, based on a transgenic mouse line expressing ChAT-IRES-Cre, we applied a fiber photometry system combined with GCaMPs expression in the BF and found that both isoflurane and propofol inhibit the activity of BF cholinergic neurons, which is closely related to the consciousness transition. We further revealed that genetic lesion of BF cholinergic neurons was associated with a markedly increased potency of anesthetics, while designer receptor exclusively activated by designer drugs (DREADD)-activated BF cholinergic neurons was responsible for slower induction and faster recovery of anesthesia. We also documented a significant increase in δ power bands (1-4 Hz) and a decrease in β (12-25 Hz) power bands in BF cholinergic lesioned mice, while there was a clearly noticeable decline in EEG δ power of activated BF cholinergic neurons. Moreover, sensitivity to anesthetics was reduced after optical stimulation of BF cholinergic cells, yet it failed to restore wake-like behavior in constantly anesthetized mice. Our results indicate a functional role of BF cholinergic neurons in the regulation of general anesthesia. Inhibition of BF cholinergic neurons mediates the formation of unconsciousness induced by general anesthetics, and their activation promotes recovery from the anesthesia state.

Identifying a Personalized Anesthetic with Fuzzy PROMETHEE

Objective

During an anesthetic evaluation, the individual's medical history and overall fitness for the whole medical procedure should be carefully examined. The objective of this study was to apply a multi-criteria decision-making technique to determine the proper anesthetic agent for specific patients.

Methods

The fuzzy PROMETHEE (Preference Ranking Organization Method for Enrichment of Evaluations) method was applied to determine the most appropriate agent. Minimum alveolar concentration, blood:gas and oil:gas partition coefficients, onset of action, recovery time, duration, induction and maintenance doses, and washout time were used as the criteria for the analysis. After defining the values of each criteria, the criteria weights and the preference function were set, and finally the results for two different examples, one for general ranking and one for a specific individual were obtained.

RESULTS

The results show that nitrous oxide and xenon are among the preferred inhaled anesthetics in the ranking of the inhaled anesthetics, whereas midazolam was identified as the preferred injected agent. When the weights are selected according to a specific patient's condition, namely a 70-year-old woman to undergo an emergent laparoscopic appendectomy with comorbidities, including severe chronic obstructive pulmonary disease as a consequence of a life-long smoking habit, morbid obesity, and type II diabetes, the results changed significantly. In this case, desflurane and etomidate come first in the ranking of inhaled and injected anesthetics, respectively, while nitrous oxide is the least preferred anesthetic agent.

Conclusion

Expert opinion is always needed. Assigning weights to criteria and grading alternatives are the major challenges in multi-criteria decision-making studies. Fuzzy PROMETHEE is proposed to solve a multi-criteria decision-making problem in selecting a general anesthetic.

Effects site concentrations of propofol using target-controlled infusion in dental treatment under deep sedation among different intellectual disability types

Background

We aimed to assess the dose needed to achieve the propofol effect-site concentration using target-controlled infusion in intellectually disabled patients and to detail the most effective method for achieving a safe level of consciousness without hemodynamic changes as well as detail any resulting adverse effects.

Methods

We performed a retrospective review of sedation service records of 138 intellectually disabled patients (51, mental retardation; 36, autism; 30, brain lesion, 12 genetic diseases, 9 dementia) aged over 15 years and weighing over 30 kg. These patients had received propofol via target-controlled infusion in the special care dental clinic of Seoul National University Dental Hospital from May 2008 to September 2018 for restorative treatment (112), minor surgery (13), prosthodontics (7), periodontics treatment (5), and implant (1).

Results

For all groups, the duration of dental treatments was 43 ± 18 minutes, total sedation time was 73 ± 23 minutes, and total BIS values was 57 ± 12. The propofol maintenance dosage values for each group were: mental retardation, 3 ± 0.5 (2–4) µg/ml; autism, 3.1 ± 0.7 (2–5) µg/ml; brain lesion, 2.8 ± 0.7 (1.5–5) µg/ml; genetic disease, 2.9 ± 0.9 (1–4) µg/ml; and dementia 2.3 ± 0.7 (1–3.4) µg/ml.

Conclusions

The dementia group needed a lower dosage to reach a safe, effective propofol effect-site concentration than the other groups. Since there were no complications, deep sedation is a great alternative to general anesthesia for dental treatment of intellectually disabled patients.

Palliative Care in the Hip Fracture Patient

Introduction:

Older patients with hip fracture have a 20% to 30% mortality rate in the year after surgery. Nonoperative care has higher 1-year mortality rates and is generally only pursued in those with an extraordinarily high surgical risk. As the population ages, more patients with hip fracture may fall into this category. The orthopedic surgeon is typically the main consultant responsible for deciding between surgery and conservative management, and the reasoning behind one decision over the other is often poorly understood. We undertook a review to determine decision-making tools for surgery in high-risk patients with hip fracture.

Materials and Methods:

A review was conducted using PubMed to determine articles published using the terms palliative care, conservative care, nonoperative, hip fracture, orthopedic procedures, fracture fixation, and surgery. Our search resulted in 13 articles to review. These were further screened to determine tools for use in surgical decision-making.

Results:

Several potential decision-making tools were found in our search. The potential tools to identify patients who would benefit from nonoperative treatment included the Palliative Performance Scale for severe dementia, the Lawton Instrumental Activities of Daily Living and Katz Activities of Daily Living scales for prefracture immobility, a combination of clinical signs and laboratory tests to determine risk of imminent death, and the Charlson Comorbidity Score for additional serious comorbidities. No tools have been prospectively tested in a clinical setting.

Discussion:

Evaluation of each patient using a variety of decision making tools should help the orthopedic surgeon determine which patients would be better suited to non-operative management. After determining the benefit of non-operative care, they must effectively allow the fracture to heal while ameliorating pain. Palliative care physicians can fulfill this role by providing support and symptom relief.

Conclusions:

Surgical decision-making for hip fracture repair in the elderly patients is not straight forward. Several tools may be helpful to the surgeon in determining who may be better suited for nonoperative care or a palliative care referral. Prospective data do not exist in these decision-making tools.

Anesthesia and the risk of dementia in the elderly

Cognitive complications are common after surgery in the elderly, and with an increased number of elderly patients undergoing surgery, a potential impact of anaesthesia and surgery on long term cognition, and especially dementia would be concerning. The question whether anaesthesia and surgery in itself induce structural changes in the brain and thereby cognitive deterioration, or reveal a preexisting cognitive impairment remains unresolved. Several studies show an increased risk of reversible cognitive impairment after surgery in the elderly, but the risk of inducing dementia remains speculative. Further studies are needed to elucidate this potential association. Meanwhile, elderly frail patients need to be closely followed including preoperative cognitive screening, since they are at increased risk of cognitive deterioration after surgery and discharge.