Pharmacological considerations in the elderly

Pharmacokinetic and Pharmacodynamic Changes in the Elderly: Impact on Anesthetics

Anesthesiologists are increasingly required to care for frail elderly patients. A detailed knowledge of the influence of age on the pharmacokinetics and dynamics of the anesthetic drugs is essential for optimal safety and care. For most of the anesthetic drugs, the elderly need lower doses to achieve the same plasma concentrations, and at any given plasma and effect-site concentration, they will have more profound clinical effects than younger patients. Caution is required, with close monitoring of clinical effects and active titration of dose administration to achieve the desired level of effect, ideally following the "start low, go slow" principle.

Ureteroscopy under conscious sedation: A proof-of-concept study

INTRODUCTION

Ureteroscopy (URS) is commonly performed under general anesthesia (GA) to maximize patient tolerability and minimize surgical complications; however, given the improvements in endoscopic technology and risks associated with GA, alternate forms of anesthesia have been postulated. We aimed to evaluate the outcomes of URS under conscious sedation.

METHODS

We completed a retrospective cohort study from November 2019 to June 2020 at a tertiary-level hospital. All URSs that were performed under urologist-directed conscious sedation were included. Our primary outcome was the ability to complete URS, defined as success rate. Secondary outcomes included: stone-free rate, intraoperative complication rate, hospital admission rate, and sedation requirement. Univariate- and multivariate-adjusted logistic regression analyses were employed.

RESULTS

Ninety-nine URSs were included. Most (73/99, 73.7%) were performed for urolithiasis. The overall success rate was 83.8% (83/99), with 81.0% (34/42) intra-renal and 70.0% (16/23) proximal ureter success rates. The stone-free rate was 80.8% (59/73). No intraoperative complications nor hospital admissions were reported. The mean amount of sedation required was 3 mg (interquartile range [IQR] 2-4] of midazolam and 100 μg (100-150) of fentanyl. On multivariate analysis, midazolam was significantly associated with increased success (odds ratio 2.496, 95% confidence interval 1.057-5.892, p=0.037).

CONCLUSIONS

We have shown that proximal and intrarenal URS under conscious sedation is safe and effective. We were limited by our lack of followup, small sample size, selection bias to chose healthy patients, and lack of patient tolerability data. Patients and healthcare systems may benefit from implementing this innovation more broadly.

Effect of Heptaflourane Inhalation and Anesthesia Induction on Hemodynamics of Elderly Patients Undergoing Elective Gastrointestinal Tumor Surgery

Gastrointestinal stromal tumors (GISTs) are rare malignancies that begin in specific cells in the GI tract’s (also known as the digestive tract’s) wall. The microenvironment of gastrointestinal cancers has gotten a lot of interest in the last decade. There are various obstacles connected with providing care to individuals with gastrointestinal cancers, especially the elderly. The physiological reserves of elderly individuals are generally depleted, and comorbidities might limit treatment options and increase problems. Surgeons and anesthesiologists must be aware of the measures that must be used while dealing with this fragile population. Anesthesia is a term that refers to the use of drugs to alleviate pain during the surgery and other treatments. Anesthesia is crucial to a patient’s successful treatment and recovery. To induce and maintain general anesthesia in the operating room, inhalation anesthetics (isoflurane, halothane, nitrous oxide, sevoflurane, and desflurane, the most commonly used agents in practice today) are utilized. Inhalation anesthetics are drugs used to give general anesthesia for surgery in the operating room. Anesthetics have the potential to cause substantial cardiac depression as well as hemodynamic instability. In this study, we propose the SBWOA (spark bumper whale optimization algorithm), which is used to assess the patient’s risk before surgery. The entire experiment was run through Matlab simulations.

The Impact of Age on Propofol Requirement for Inducing Loss of Consciousness in Elderly Surgical Patients

It is generally accepted that geriatric patients are more sensitive to propofol than adults; thus, a dose-adjusted propofol is recommended for these patients during the induction of anesthesia. However, for patients aged 75 years and over, established guidelines for propofol induction doses do not provide dose references. To this end, we observed 80 surgical patients (female 39, male 41, American Society of Anesthesiologists physical status score I ∼ II) to access the appropriate dose of propofol for inducing loss of consciousness (LOC). Accordingly, patients were subdivided into group A (20 patients, 45–64 years), group B (20 patients, 65–74 years), group C (20 patients, 75–84 years), and group D (20 patients, ≥ 85 years). All patients received propofol (at a rate of 0.3 mg/kg/min) alone for inducing LOC, which was defined by loss of both eyelash reflex and verbal response. Compared with group A, the propofol requirement for LOC in Group B, C and D decreased by 14.8, 25.2 and 38.5%, respectively. Bivariate linear correlation analysis showed that propofol requirement was negatively correlated with age. After adjusting for potential confounders, age was still an independent factor affecting propofol requirement. In conclusion, the propofol requirement for inducing LOC decreased significantly in elderly patients. We demonstrated that age was an independent factor impacting propofol requirement for LOC during the induction of general anesthesia, implying that the propofol dose for anesthesia induction should be further reduced in elderly surgical patients, especially those aged 75 years and over.

Comparison of a Nasal Mask and Traditional Nasal Cannula During Intravenous Anesthesia for Gastroscopy Procedures: A Randomized Controlled Trial

BACKGROUND:

Hypoxemia can occur during gastroscopy under intravenous anesthesia. The aim of this randomized controlled trial was to evaluate whether oxygenation using a nasal mask can reduce the incidence of hypoxemia during gastroscopy under intravenous anesthesia compared with a traditional nasal cannula.

METHODS:

A total of 574 patients scheduled for gastroscopy under intravenous anesthesia were enrolled and randomly assigned to receive either a nasal mask or a traditional nasal cannula for oxygenation. The primary outcome was the incidence of hypoxemia. The secondary outcomes included the incidence of severe hypoxemia, duration of hypoxemia, minimum oxygen saturation, the proportion of emergency airway management, length of procedure, recovery time, and the satisfaction of the anesthetist and gastroenterologists as well as other adverse events (including cough, hiccups, nausea and vomiting, reflux, aspiration, and laryngospasm).

RESULTS:

A total of 565 patients were included in the analysis: 282 patients in the nasal cannula group and 283 patients in the nasal mask group. The incidence of hypoxemia was lower in the nasal mask group (18.0%) than in the nasal cannula group (27.7%; relative risk [RR] = 0.65; 95% confidence interval [CI], 0.48–0.89; P = .006), and the hypoxemia lasted a median of 18.0 seconds (interquartile range, 10.0–38.8) in the nasal mask group and 32.5 seconds (20.0–53.5) in the nasal cannula group (median difference –14.50; 95% CI, −22.82 to −1.34; P = .047). The proportion of patients requiring emergency airway management was significantly lower in the nasal mask group (8.8%) than in the nasal cannula group (19.1%; RR, 0.46; 95% CI, 0.30–0.73; P < .001). No difference was found in the overall incidence of other adverse events between the 2 groups (nasal mask 20.8%; nasal cannula 17.0%; RR, 1.23; 95% CI, 0.87–1.73; P = .25). Satisfaction was higher with the nasal mask than with the nasal cannula from the perspective of anesthetists (96.1% for nasal mask versus 84.4% for nasal cannula; RR, 1.14; 95% CI, 1.08–1.20; P < .001) and gastroenterologists (95.4% for mask versus 81.9% for cannula; RR, 1.17; 95% CI, 1.10–1.24; P < .001). There were no significant differences in the incidence of severe hypoxemia, minimum oxygen saturation, length of procedure, or recovery time between the 2 groups.

CONCLUSIONS:

Nasal mask oxygenation reduced the incidence of hypoxemia during anesthesia for gastroscopy under intravenous anesthesia.

Personalization of drug dose thematic issue: introduction article

INTRODUCTION

The need to individualize a drug dosage and adjust it to a patient's physiological and/or pathophysiological status is rarely satisfied in routine clinical practice, primarily because of complexity of the adjustment task.

AREAS COVERED

The aim of this article is to shed light to basic principles of drug dosage individualization in the most frequent clinical states that affect pharmacokinetics of drugs. The principles are derived from published clinical studies conducted on diverse patient populations, using non-compartmental pharmacokinetic model.

EXPERT OPINION

Simple, but sufficiently exact, way to calculate appropriate drug dose for a patient is the one based on target average steady-state concentration and non-compartmental pharmacokinetic model. If target steady-state drug concentration and dosage interval are considered fixed, maintenance dose could be adjusted on the basis of expected changes of total drug clearance and bioavailability, while loading dose should be related to changes of volume of distribution and bioavailability. Relative increase or decrease of these pharmacokinetic parameters in regard to normal values in healthy persons is translated to relative (percentual) increase or decrease of maintenance and loading doses recommended in the drug monograph.

Adverse Outcomes after Advanced EVAR in Patients with Sarcopaenia

PURPOSE

To determine whether low total psoas muscle area (tPMA), as a surrogate for sarcopaenia, is a predictor of adverse outcomes in patients undergoing advanced EVAR.

MATERIALS AND METHODS

A retrospective review of medical records was performed for 257 patients who underwent advanced EVAR (fenestrated or branched technique) in a single tertiary centre from 1 January 2008 to 1 September 2019. The study cohort was divided into tertiles based on tPMA measurement performed independently by two observers from a peri-procedural CT scan at the level of mid-L3 vertebral body. The low tertile was considered sarcopaenic. Logistic regression analysis was used to assess the association of tPMA with 30-day mortality and post-procedural complications. Univariable analysis and adjusted multivariable Cox regression were used to assess the association of tPMA with all-cause mortality.

RESULTS

A total of 257 patients comprised 193 males and 64 females with the mean age of 75.4 years (± 6.8) were included. Adjusted multivariable Cox regression revealed an 8% reduction in all-cause mortality for every 1 cm² increase in tPMA, P < 0.05. TPMA was associated with 30-day mortality (OR 0.85, 95% CI 0.75-0.96, P < 0.05) and spinal cord ischaemia (SCI) (OR 0.89, 95% CI 0.82-0.97, P < 0.05). For remaining post-procedural complications, tPMA was not a useful predictive tool. TPMA correlated negatively with hospital stay length (r_s-0.26, P < 0.001). Patients with lower tPMA were more likely to be discharged to a rehabilitation center (OR 0.93, 95% CI 0.87-0.98 , P < 0.05).

CONCLUSION

Measurement of tPMA can be a useful predictive tool for adverse outcomes after advanced EVAR.

LEVEL OF EVIDENCE

Level 3, Retrospective cohort study.

Perioperative pharmacotherapy to prevent cardiac complications in patients undergoing noncardiac surgery

Introduction: Despite advances in surgical and anesthetic techniques, perioperative cardiovascular complications are a major cause of 30-day perioperative mortality. Major cardiovascular complications after noncardiac surgery include myocardial ischemia, congestive heart failure, arrhythmias, and cardiac arrest. Along with surgical risk assessment, perioperative medical optimization can reduce the rates and clinical impact of these complications.Areas Covered: In this review, the authors discuss the pharmacological basis, existing evidence, and professional society recommendations for drug management in preventing cardiovascular complications in patients undergoing noncardiac surgery.Expert opinion: Perioperative management of cardiovascular disease is an increasingly important and growing area of clinical practice. Societal guidelines regarding the use of most routine cardiovascular medications are based on a number of large clinical studies and provide a basic foundation to guide management. However, the heterogeneous nature of patients, as well as surgeries, makes it practically impossible to devise a 'one size fits all' recommendation in this setting. Thus, the importance of a more individualized approach to perioperative risk stratification and management is being increasingly recognized. The underlying comorbidities and cardiac profile as well as the risk of cardiac complications associated with the planned surgery must be factored in to understand the nuance of the management strategies.

Anaesthetic considerations in nonagenarians and centenarians

PURPOSE OF REVIEW

The ageing population is a global public health issue and we can expect to encounter more and more older patients requiring anaesthetic care. Age itself is no longer the sole reason for declining a patient for anaesthesia and surgery. Undoubtedly, managing patients at the extremities of age is challenging and demanding, not only because of multiple comorbidities, but also the poorer functional status, frailty and decline in general well being that must be managed during the perioperative journey. In this article, we will focus on three important aspects of anaesthetic care for this patient group, namely, comorbidity, frailty and perioperative cognitive dysfunction; and give recommendations on how anaesthetists should tackle these aspects for the 'older old' and the 'oldest old', based on current best evidence.

RECENT FINDINGS

The 'oldest old' (nonagerians and centenarians) are the fastest-growing geriatric population worldwide. Evidence has demonstrated that an enhanced care programme designed for elderly patients is safe, feasible and could diminish both complications and length of stay after surgery. Studies are emerging on frailty measurement and the association with outcomes of anaesthesia and surgery and have resulted in new recommendations on best practices for postoperative brain health and nomenclature of perioperative neurocognitive disorder.

SUMMARY

Comorbidity, frailty and perioperative cognitive dysfunction are significant perioperative concerns specific to elderly patients and clearly associated with adverse outcomes after surgery. These anaesthetic concerns should be anticipated and properly managed through the perioperative pathway so that their potential complications can be mitigated.

Pharmacodynamics and pharmacokinetics in older adults

PURPOSE OF REVIEW

With the growing of the aging population, increased and new methods of anesthesia and surgery allow for surgery and other interventions in older adults.Pharmacokinetics and pharmacodynamics of drugs in older adults differ from those in younger and middle-aged adults. However, the geriatric population is frequently neglected in the context of clinical trials. The present review focuses on the consequences of multimorbidity and pharmacokinetic and pharmacodynamic alterations and their implications on anesthesia.

RECENT FINDINGS

Physiologically based pharmacokinetic and pharmacodynamic modeling may serve as an option to better understand the influence of age on drugs used for anesthesia. However, difficulties to adequately characterize geriatric patients are described.

SUMMARY

Further research of drug effects in the aging population may include physiologically based pharmacokinetic and pharmacodynamic complex models and randomized controlled trials with thoroughly conducted geriatric assessments.

Perioperative care of geriatric patients

The older population is expected to nearly double across the globe by 2050, and the baby boom cohort is expected to represent at least 20% of the US population by 2030. Geriatric patients will increasingly utilize the health-care system, and therefore surgical and perioperative care must be tailored to this sensitive group given the increased risk for perioperative complications. The literature was reviewed to highlight fundamental components of the preoperative evaluation as well as cardiac, pulmonary, and renal complications. Frailty is a multidimensional process that can lead to the physiologic effects of aging and estimates the risk of perioperative morbidity and mortality better than chronologic age alone. Health-care providers should assess a geriatric patient's cognitive status, decision-making capacity, frailty, advance care planning, medications, and anesthetic approach in a multidisciplinary fashion to ensure optimal care. The risks of postoperative cardiac, pulmonary, and renal complications should be evaluated and optimized preoperatively to reduce the potential for adverse outcomes.

The development of a test battery to assess the hand-eye functions relevant in predicting easy and accurate tablet subdivision in older people: A pilot study

AIMS

Tablets may be subdivided for dose adaptations or to ease swallowing. The handling is common in older patients but can be difficult and inaccurate. Currently, it is not known which hand-eye functions determine the ability of older people to break tablets by hand and to do so with acceptable ease and accuracy. The aim of this study was to develop a test battery to assess the hand-eye functions relevant in predicting easy and accurate tablet subdivision in older people.

METHODS

A mixed methods study was conducted including literature reviews and a pilot experiment. The reviews were conducted in Pubmed, Google Scholar, Dutch journals and professional standards. The first review tried to identify the hand-eye functions relevant to tablet subdivision and the second the associated measuring instruments, testing protocols and normative data. A test battery was empanelled. A pilot experiment was conducted in 30 adult volunteers to optimize and evaluate the test battery.

RESULTS

Five domains were considered relevant: hand size, hand strength, flexibility/manual dexterity, vision and coordination. Hand size could best be measured by finger circumference, hand strength by pinch- and grip strength, flexibility by active range of joint motion, manual dexterity (and flexibility, coordination, cognition, vision) by pegboard function, vision by near visual acuity. Older people preferred the use of tablet splitters over hand breaking.

CONCLUSION

Easy and accurate tablet subdivision is essential to the good use of medicines. We developed a test battery for older people, but probably of value to all age groups.

Computational Approaches to Anesthetic Drug Discovery

All currently available general anesthetics produce potentially deadly side effects. Unfortunately, few approaches have been developed to design safer ones, despite important advances in anesthetic mechanisms research. Cayla and colleagues recently showed that computational methods can be used to identify anesthetic lead compounds devoid of specific side effects.

Replacement of dexmedetomidine loading with midazolam for sedation in elderly patients with spinal anesthesia

BACKGROUND

Dexmedetomidine is an effective sedative during spinal anesthesia. However, it requires a loading dose, which can result in transient hypertension, hypotension, bradycardia, and/or sinus arrest. In addition, the time required to reach an appropriate depth of sedation may cause anxiety to the patients. Therefore, we examined whether an intravenous bolus of midazolam could replace the loading dose of dexmedetomidine for sedation during surgery in elderly patients who received spinal anesthesia.

METHODS

Patients aged over 60 years who scheduled to undergo total knee arthroplasty under spinal anesthesia were enrolled in this study. The patients were randomized into 2 groups. Patients in dexmedetomidine group (group D) (n = 20) were administered a loading dose of dexmedetomidine (1.0 μg/kg over 10 min) intravenously followed by dexmedetomidine maintenance (0.5 μg/kg/h). Patients in group MD (n = 20) were administered an intravenous midazolam (0.05 mg/kg) followed by dexmedetomidine maintenance (0.5 μg/kg/h) intravenously. Heart rate (HR), mean arterial blood pressure (MBP), peripheral oxygen saturation (SpO2), and patient state index (PSI) were recorded. Ramsay sedation scale (RSS) scores were evaluated at 10 minutes after drug administration and the end of surgery.

RESULTS

A total of 40 subjects were enrolled in the present study. At baseline, there was no between-group difference in HR. Ten minutes after drug administration, group D had lower HR than group MD (62.1 ± 9.4 versus 69.6 ± 13.4, P = .047). PSI was significantly lower in group MD at 10 minutes after drug administration (82.8 ± 13.0 versus 72.0 ± 16.0, P = .024); there was no between-group difference at 30 and 60 minutes, and lower values in group D at the end of surgery (70.2 ± 22.6 versus 79.7 ± 10.9, P = .011). The RSS score showed statistically significantly deeper sedation in group MD 10 minutes after drug administration, but no difference at the end of surgery.

CONCLUSIONS

An intravenous bolus of midazolam is a viable alternative to dexmedetomidine loading for sedation during surgery in elderly patients who received spinal anesthesia. This is especially effective for patients who are at high risk for bradycardia or who want a faster sedation.