A comparison between propofol and ketamine for anaesthesia in the elderly. Haemodynamic effects during induction and maintenance

Procedural sedation analgesia in the elderly patient

Elderly patients are perceived as a high-risk group for procedural sedation. Procedural sedation analgesia (PSA) is generally safe in older adults. What is not acceptable is undertreating pain or inadequately sedating a stable patient. All the usual precautions should be taken. One should consider any comorbidities that could make the patient more at risk of adverse reactions or complications. Older patients may be at higher risk for oxygen desaturation, but they usually respond quickly to supplemental oxygen. Geriatric patients usually require lower doses of medications. They tend to be more sensitive to medications, with slower metabolism, less physiologic reserve to handle side effects, and a smaller volume of distribution. The use of drugs for sedation in elderly patients requires careful consideration of their age-related changes in physiology and pharmacokinetics. The choice of drug should be based on the patient's medical condition, comorbidities, and potential adverse effects. Moreover, the administration should be done by trained personnel with close monitoring of vital signs and level of consciousness to prevent complications such as respiratory depression.

Comparative Assessment of Propofol and Ketamine on Hemodynamic Indices and Cerebral Oximetry of Pediatric Patients Undergoing Cardiac Catheterization

Background

Propofol and ketamine are widely used in the induction and maintenance of anesthesia and sedation with different cardiovascular and respiratory effects. In cardiac anesthesia (including pediatric cardiac catheterization), due to the high risk of neurologic complications, cerebral oximetry can effectively monitor cerebral blood oxygen saturation to prevent neurological and respiratory complications.

Objectives

This study aimed to compare the effect of propofol and ketamine on hemodynamic indices and cerebral oxygenation results in children undergoing cardiac catheterization.

Methods

This clinical trial study was performed on 48 patients who were candidates for cardiac catheterization by easy and continuous sampling. Patients were randomly divided into 2 groups: ketamine and propofol. In the ketamine group, ketamine was injected at a dose of 1 - 2 mg/kg, and in the propofol group, propofol was injected at a dose of 0.5 - 1.5 mg/kg. In both groups, incremental doses were repeated as needed. The hemodynamic indices, including blood pressure, heart rate, and peripheral SpO₂, were recorded. Cerebral regional oxygen saturation (RSO₂) was recorded using infrared spectroscopic sensors. Data were analyzed using chi-square, independent t-test, paired t-test, and 1-way analysis of variance (ANOVA).

Results

The results showed that all demographic characteristics of patients and also the mean duration of catheterization were homogeneous between the 2 groups. Hemodynamic indices (such as systolic, diastolic, and mean arterial blood pressure) did not show a significant difference between the 2 groups; however, in the ketamine group compared to the propofol group, the heart rate was significantly higher, and mean RSO₂ was lower (P = 0.023).

Conclusions

Propofol has fewer complications than ketamine and is a good drug for sedating children undergoing cardiac catheterization.

Pretreatment with Low-Dose Esketamine for Reduction of Propofol Injection Pain: A Randomized Controlled Trial

Background

Propofol-induced injection pain is a common adverse effect during the induction of general anesthesia. The purpose of this study is to investigate the effect of low-dose esketamine in preventing propofol injection pain.

Methods

In this double-blind, randomized, controlled trial, patients scheduled for elective ear surgery under general anesthesia received either normal saline (NS), or 40 mg lidocaine, or 0.15 mg/kg esketamine 30 seconds before manual injection of propofol. The primary outcome of this study was the incidence of propofol injection pain. The secondary outcomes included injection pain score, vital signs, total dosage of vasoactive drugs used within 5 minutes after induction, and adverse events related to drugs.

Results

A total of 105 patients were included. Compared with the NS group (67%), pretreatment with esketamine and lidocaine significantly reduced the incidence of injection pain to 29% and 33%, respectively (both P < 0.05); however, no significant difference was found between the esketamine and lidocaine groups. The median of injection pain score was significantly lower in the esketamine and lidocaine groups (both median (interquartile range) = 0 (0–1)) than that in the NS group (1 (0–2); P < 0.05). In addition, compared with the NS and lidocaine groups, preinjection esketamine provided more stable hemodynamic parameters within 5 minutes after induction (P < 0.05). No statistical difference was found in adverse events among the three groups.

Conclusions

Pretreatment with a low-dose esketamine can not only reduce the incidence of propofol injection pain but also provide a more stable circulation in patients after anesthesia induction. This convenient, well-tolerated, and economic treatment appears as an option to be routinely applied in clinic practice. Clinical Trial Registration. This trial is registered with https://www.chictr.org.cn/showproj.aspx?proj=136690 (the number for the trial registration isChiCTR2100052742).

Acute (R,S)-Ketamine Administration Induces Sex-Specific Behavioral Effects in Adolescent but Not Aged Mice

(R,S)-ketamine is an N-methyl-D-aspartate (NMDA) receptor antagonist that was originally developed as an anesthetic. Most recently, (R,S)-ketamine has been used as a rapid-acting antidepressant, and we have reported that (R,S)-ketamine can also be a prophylactic against stress in adult mice. However, most pre-clinical studies have been performed in adult mice. It is still unknown how an acute (R,S)-ketamine injection influences behavior across the lifespan (e.g., to adolescent or aged populations). Here, we administered saline or (R,S)-ketamine at varying doses to adolescent (5-week-old) and aged (24-month-old) 129S6/SvEv mice of both sexes. One hour later, behavioral despair, avoidance, locomotion, perseverative behavior, or contextual fear discrimination (CFD) was assessed. A separate cohort of mice was sacrificed 1 h following saline or (R,S)-ketamine administration. Brains were processed to quantify the marker of inflammation Cyclooxygenase 2 (Cox-2) expression to determine whether the acute effects of (R,S)-ketamine were partially mediated by changes in brain inflammation. Our findings show that (R,S)-ketamine reduced behavioral despair and perseverative behavior in adolescent female, but not male, mice and facilitated CFD in both sexes at specific doses. (R,S)-ketamine reduced Cox-2 expression specifically in ventral CA3 (vCA3) of male mice. Notably, (R,S)-ketamine was not effective in aged mice. These results underscore the need for sex- and age-specific approaches to test (R,S)-ketamine efficacy across the lifespan.

Prophylactic (R,S)-Ketamine Is Effective Against Stress-Induced Behaviors in Adolescent but Not Aged Mice

BACKGROUND

(R,S)-ketamine, an N-methyl-D-aspartate receptor antagonist, is frequently used as an anesthetic and as a rapid-acting antidepressant. We and others have reported that (R,S)-ketamine is prophylactic against stress in adult mice but have yet to test its efficacy in adolescent or aged populations.

METHODS

Here, we administered saline or (R,S)-ketamine as a prophylactic at varying doses to adolescent (5-week-old) and aged (24-month-old) 129S6/SvEv mice of both sexes 1 week before a 3-shock contextual fear-conditioning (CFC) stressor. Following CFC, we assessed behavioral despair, avoidance, perseverative behavior, locomotion, and contextual fear discrimination. To assess whether the prophylactic effect could persist into adulthood, adolescent mice were injected with saline or varying doses of (R,S)-ketamine and administered a 3-shock CFC as a stressor 1 month later. Mice were then re-exposed to the aversive context 5 days later and administered behavioral tests as aforementioned. Brains were also processed to quantify Cyclooxygenase 2 expression as a proxy for inflammation to determine whether the prophylactic effects of (R,S)-ketamine were partially due to changes in brain inflammation.

RESULTS

Our data indicate that (R,S)-ketamine is prophylactic at sex-specific doses in adolescent but not aged mice. (R,S)-ketamine attenuated learned fear and perseverative behavior in females, reduced behavioral despair in males, and facilitated contextual fear discrimination in both sexes. (R,S)-ketamine reduced Cyclooxygenase 2 expression specifically in ventral Cornu Ammonis region 3 of male mice.

CONCLUSIONS

These findings demonstrate that prophylactic (R,S)-ketamine efficacy is sex, dose, and age dependent and will inform future studies investigating (R,S)-ketamine efficacy across the lifespan.

Consensus Guidelines on the Use of Intravenous Ketamine Infusions for Chronic Pain From the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, and the American Society of Anesthesiologists

BACKGROUND

Over the past 2 decades, the use of intravenous ketamine infusions as a treatment for chronic pain has increased dramatically, with wide variation in patient selection, dosing, and monitoring. This has led to a chorus of calls from various sources for the development of consensus guidelines.

METHODS

In November 2016, the charge for developing consensus guidelines was approved by the boards of directors of the American Society of Regional Anesthesia and Pain Medicine and, shortly thereafter, the American Academy of Pain Medicine. In late 2017, the completed document was sent to the American Society of Anesthesiologists' Committees on Pain Medicine and Standards and Practice Parameters, after which additional modifications were made. Panel members were selected by the committee chair and both boards of directors based on their expertise in evaluating clinical trials, past research experience, and clinical experience in developing protocols and treating patients with ketamine. Questions were developed and refined by the committee, and the groups responsible for addressing each question consisted of modules composed of 3 to 5 panel members in addition to the committee chair. Once a preliminary consensus was achieved, sections were sent to the entire panel, and further revisions were made. In addition to consensus guidelines, a comprehensive narrative review was performed, which formed part of the basis for guidelines.

RESULTS

Guidelines were prepared for the following areas: indications; contraindications; whether there was evidence for a dose-response relationship, or a minimum or therapeutic dose range; whether oral ketamine or another N-methyl-D-aspartate receptor antagonist was a reasonable treatment option as a follow-up to infusions; preinfusion testing requirements; settings and personnel necessary to administer and monitor treatment; the use of preemptive and rescue medications to address adverse effects; and what constitutes a positive treatment response. The group was able to reach consensus on all questions.

CONCLUSIONS

Evidence supports the use of ketamine for chronic pain, but the level of evidence varies by condition and dose range. Most studies evaluating the efficacy of ketamine were small and uncontrolled and were either unblinded or ineffectively blinded. Adverse effects were few and the rate of serious adverse effects was similar to placebo in most studies, with higher dosages and more frequent infusions associated with greater risks. Larger studies, evaluating a wider variety of conditions, are needed to better quantify efficacy, improve patient selection, refine the therapeutic dose range, determine the effectiveness of nonintravenous ketamine alternatives, and develop a greater understanding of the long-term risks of repeated treatments.

Propofol Use in the Elderly Population: Prevalence of Overdose and Association With 30-Day Mortality

PURPOSE

Geriatric patients are more sensitive to the anesthetic effects of propofol and its adverse effects, such as hypotension, than is the general population; thus, a reduced dose (1-1.5 mg/kg) is recommended for the induction of anesthesia. The extent to which clinicians follow established dosing guidelines has not been well described. Therefore, we investigated the prevalence of propofol overdose in the elderly population to determine whether propofol overdose occurs and is associated with increased hypotension and 30-day mortality.

METHODS

In this retrospective study in patients who received propofol for the induction of general anesthesia, data on demographic characteristics, preoperative medications, intraoperative management, and 30-day mortality were collected. The dose of propofol used for the induction of anesthesia and the median blood pressure in the pre- and immediate postinduction periods were determined. Hypotension was defined as either: (1) a decrease in mean arterial pressure (MAP) of >40% concurrent with a MAP of <70 mm Hg; or (2) a MAP of <60 mm Hg.

FINDINGS

A total of 17,540 patients were included in the analysis; 4033 (23.0%) were aged >65 years. The median (interquartile range) propofol dose in the group aged >65 years was 1.8 (1.4-2.2) mg/kg, above the recommended dose, in comparison to 2.2 (1.9-2.5) mg/kg in younger patients. On multivariate analysis, increased propofol dose was associated with increased postinduction hypotension, especially in patients over 70 years of age, but not 30-day mortality.

IMPLICATIONS

Older patients received greater-than-recommended doses of propofol for induction, which may have led to significant dose-dependent hypotension. Despite this finding, the dose of propofol for induction was not independently associated with a greater 30-day mortality rate. More education regarding geriatric concerns is needed for encouraging anesthesiologists to tailor the plan for anesthesia in geriatric patients. However, overall postsurgical mortality is a function of preoperative risk and type surgical procedure.

Scandinavian clinical practice guidelines on general anaesthesia for emergency situations

Emergency patients need special considerations and the number and severity of complications from general anaesthesia can be higher than during scheduled procedures. Guidelines are therefore needed. The Clinical Practice Committee of the Scandinavian Society of Anaesthesiology and Intensive Care Medicine appointed a working group to develop guidelines based on literature searches to assess evidence, and a consensus meeting was held. Consensus opinion was used in the many topics where high-grade evidence was unavailable. The recommendations include the following: anaesthesia for emergency patients should be given by, or under very close supervision by, experienced anaesthesiologists. Problems with the airway and the circulation must be anticipated. The risk of aspiration must be judged for each patient. Pre-operative gastric emptying is rarely indicated. For pre-oxygenation, either tidal volume breathing for 3 min or eight deep breaths over 60 s and oxygen flow 10 l/min should be used. Pre-oxygenation in the obese patients should be performed in the head-up position. The use of cricoid pressure is not considered mandatory, but can be used on individual judgement. The hypnotic drug has a minor influence on intubation conditions, and should be chosen on other grounds. Ketamine should be considered in haemodynamically compromised patients. Opioids may be used to reduce the stress response following intubation. For optimal intubation conditions, succinylcholine 1-1.5 mg/kg is preferred. Outside the operation room, rapid sequence intubation is also considered the safest method. For all patients, precautions to avoid aspiration and other complications must also be considered at the end of anaesthesia.

General anaesthesia in elderly patients with cardiovascular disorders: choice of anaesthetic agent

Our population is aging; currently 15% of the Western population are aged >65 years, and represent 25% of those undergoing surgery. The proportion of the population aged >or=65 years is rapidly growing, and an increasing number are affected with cardiovascular disease. The older person is a high-risk patient. This is because of their altered physiology and associated co-morbidities, as well as the pharmacokinetic and pharmacodynamic changes that may alter drug responses. There is considerable variability seen in the physical and physiological states of individual patients within the older population. This has an important impact on choosing a safe anaesthetic technique for each individual, which in turn can influence the morbidity and mortality in this population. The physiological changes in the aging cardiovascular system affect the arterial and venous vasculature, myocardium and autonomic nervous system, making the older person more prone to cardiovascular instability. In addition to the physiological changes, the cardiovascular status of the older person tends to be compromised by associated pathological conditions that are more common with increasing age. Pharmacokinetic and pharmacodynamic changes must be taken into account when deciding about drug dosing in this age group. Aspects of dose reduction, titration of drugs, dosing intervals and the pharmacodynamic effects of each class of drug are explained in detail in the text. The major challenge in anaesthesia for the older person with cardiovascular disease is maintenance of haemodynamic stability, particularly in the face of reduced physiological reserve and capability to respond to periods of instability. An appropriate anaesthetic technique must be selected to minimize haemodynamic changes and maintain near normal physiological status. The other key objective is to minimize the incidence of adverse outcomes, such as perioperative myocardial ischaemia/infarction, arrhythmias, heart failure, postoperative cognitive dysfunction and stroke. No single anaesthetic regimen or agent can be advocated. Knowledge of the pharmacokinetic and pharmacodynamic principles of anaesthetic agents and their altered response in elderly patients is essential when selecting an anaesthetic agent. This article provides a practical guide to the selection and use of general anaesthetic agents in older patients with cardiovascular disorders, highlighting the differences among various agents.

Ketamine eliminates propofol pain but does not affect hemodynamics during induction with double-lumen tubes

BACKGROUND AND OBJECTIVE

Propofol injection during induction of anesthesia induces pain. Ketamine has been shown to reduce the injection pain. However, ketamine has unfavorable adverse effects, including increased secretion production and hemodynamic responses, which might induce pulmonary or hemodynamic adverse events, especially in patients undergoing lung surgery who require a double-lumen tube (DLT). The aim of this study was to determine whether ketamine can safely reduce propofol injection pain during induction of anesthesia for lung surgery.

METHODS

Forty-five patients scheduled for elective lung surgery requiring DLT were randomly allocated into three groups. Patients received saline (control), ketamine 0.5 mg kg(-1) (0.5 ketamine), or ketamine 1.0 mg kg(-1) (1.0 ketamine), followed by 5 ml propofol 30 s later. An anesthesiologist blinded to the study group assessed pain score during induction, hemodynamics during DLT placement, and secretion production during anesthetic management.

RESULTS

Pretreatment of 0.5 mg kg(-1) ketamine reduced the incidence and intensity of propofol injection pain, whereas 1.0 mg kg(-1) ketamine completely eliminated the pain. There were no significant differences regarding oxygenation during one-lung ventilation (OLV) and hemodynamics during induction among the three groups, although ketamine increased secretion production.

CONCLUSIONS

One milligram per kilogram of ketamine completely eliminated pain associated with propofol injection without affecting hemodynamics during induction of anesthesia and oxygenation during OLV.

Adverse events associated with ketamine for procedural sedation in adults

STUDY OBJECTIVES

Ketamine is widely used as a procedural sedation agent in pediatrics, where its safety and efficacy are supported by numerous studies. Emergency physicians use ketamine infrequently in adults, as it is believed to have a more significant side effect profile in this population. However, adult data on ketamine use in the emergency medicine literature are sparse. Our objective was to determine ketamine's adverse effect profile in adults when used for procedural sedation.

METHODS

We performed a literature review based on adverse effect research methodology recommendations. PubMed, EMBASE, TOXNET, and a variety of specialized databases were queried without regard to publication date or language. Experts were contacted to locate additional data. Inclusion criteria included adult study; ketamine used to facilitate the performance of painful procedures; dose of at least 1 mg/kg intravenous or at least 2 mg/kg intramuscular; original data and adverse events reported; spontaneously breathing patient, and no continuous cotherapies. Studies that met inclusion criteria were abstracted onto structured forms and their results qualitatively summarized.

RESULTS

Of the 5512 unique citations that were evaluated, 87 met criteria for inclusion. Most studies were performed in the 1970s and published in the anesthesia literature. Contexts, end points, and methodological quality varied widely across studies. Ketamine reliably produces conditions that facilitate the performance of painful procedures. Pharyngeal reflexes are generally preserved and cardiovascular tone stimulated, including a rise in blood pressure and myocardial oxygen demand. Laryngospasm and airway obstruction are reported, and though ketamine is a respiratory stimulant, a brief period of apnea around the time of injection is common. Reports of significant cardiorespiratory adverse events are rare, despite ketamine's frequent use in austere, poorly monitored settings. Dysphoric emergence phenomena occur in 10% to 20% of cases; sedating medications are effective in preventing and managing these reactions.

CONCLUSION

When ketamine is used for procedural sedation in adults, emergence phenomena occur in 10% to 20% of patients. Although providers must be prepared to recognize and manage airway obstruction, cardiorespiratory adverse events are rare and typically do not affect outcomes.

Total intravenous anaesthesia with propofol-racemic ketamine and propofol-S-ketamine: a comparative study and haemodynamic evaluation in dogs undergoing ovariohysterectomy

Total intravenous anaesthesia (TIVA) with propofol and ketamine proved to be very satisfactory from a clinical point of view. This blind randomised controlled trial was designed to compare induction and maintenance of anaesthesia under continuous infusion of propofol-racemic ketamine (PRK) with that of propofol-S-ketamine (PSK) and evaluate their haemodynamic, metabolic and ventilatory effects. Seven female dogs undergoing ovariohysterectomy were involved in each group. Anaesthesia was induced: in Group PRK, with propofol (4.0mg kg-1) and racemic ketamine (2.0mg kg-1) intravenous (i.v.), followed by i.v. infusion of propofol (initial dose of 0.5mg kg-1 min-1) and racemic ketamine (0.2mg kg-1 min-1); in Group PSK, with propofol (4.0mg kg-1) and S-ketamine (1.0 mg kg¹) i.v., followed by i.v. infusion of propofol (initial dose of 0.5mg kg-1 min-1) and S-ketamine (0.1mg kg-1 min-1). Parameters were assessed before anaesthesia and in 6 time points after induction. In both groups, heart rate increased significantly at all time points. There was a slight decrease in systemic blood pressure, cardiac output and cardiac index in both groups. The systolic index decrease significantly and intense respiratory depression was observed in all groups, making assisted ventilation necessary.

Hemodynamics in elderly coronary artery disease patients undergoing propofol sedation

PURPOSE

The purpose of this study was to evaluate noninvasive intraoperative hemodynamics in an elderly population with coronary artery disease (CAD) undergoing midazolam/fentanyl intravenous sedation-analgesia, with or without propofol for dentoalveolar surgery.

PATIENTS AND METHODS

A retrospective chart analysis of 24 consecutive male patients aged 60 years or greater, with coronary artery disease, undergoing midazolam/fentanyl intravenous sedation-analgesia with or without propofol for dentoalveolar surgery. Data recorded included noninvasive baseline and intraoperative hemodynamic measurements at 5-minute intervals for systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), and pulse (P).

RESULTS

The addition of propofol to elderly CAD patients resulted in statistically significant lower averages for SBP (126.1 mm Hg vs 131.3 mm Hg, P < .01), DBP (64.1 mm Hg vs 74.3 mm Hg, P < .001), MAP (84.3 mm Hg vs 94.2 mm Hg, P < .001) and PP (57.7 mm Hg vs 61.8 mm Hg, P = .01) with statistically insignificant differences in pulse (74.2 beats per minute vs 75.8 beats per minute, P = .1). Baseline changes in elderly CAD patients who received propofol were within +/-20% (range: -13.8% to +6.9%).

CONCLUSION

Midazolam/fentanyl intravenous sedation provided stable intraoperative hemodynamics in elderly CAD patients. The addition of propofol to elderly CAD patients also resulted in stable intraoperative hemodynamics and may be a safe adjunct to intravenous sedation in elderly CAD patients.

The pharmacology of anesthetic drugs in elderly patients

Elderly patients are more sensitive to anesthetic drugs than younger patients. This increased sensitivity has a pharmacokinetic basis if the dose produces a higher drug concentration in an elderly patient than in a younger patient. The increased sensitivity has a pharmacodynamic basis if the same concentration produces a more profound drug effect in elderly patients. This article reviews the mechanisms of increased sensitivity of elderly patients to opioids, hypnotics, amnestica, and muscle relaxants.

Ketamine in the ED: medical politics versus patient care

The safe and effective use of ketamine for sedation/analgesia by emergency physicians has been validated in the medical literature. Nonetheless, arbitrary restrictions of this medication to anesthesia practitioners have prohibited emergency physician use in some locations. We explore the scientific evidence related to the use of ketamine by emergency physicians for sedation/analgesia, the history of sedation, the operational definitions of conscious sedation and dissociative anesthesia, and the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) related standards. We conclude that ketamine sedation/ analgesia offers many specific advantages for emergency patients and that it is safely administered by emergency physicians in the appropriately monitored setting.

The use of propofol in a child with hepatitis A

Propofol was used for the induction and maintenance of anaesthesia in a 4-year-old girl with hepatitis A and haematemesis. The anaesthetic was uneventful with no postoperative sequelae.