Anaesthesia with midazolam and S-(+)-ketamine in spontaneously breathing paediatric patients during magnetic resonance imaging

Esketamine: Less Drowsiness, More Analgesia

Racemic ketamine is a 1:1 mixture of 2 enantiomers that turn light in opposite direction: Dextrorotatory esketamine is approximately 4 times more affine for the N-methyl-D-aspartate (NMDA) receptor than levorotatory arketamine, which may explain why esketamine is about twice as potent as an analgesic and anesthetic as the racemate. Esketamine has attracted renewed interest in view of the opioid crisis, racemic ketamine's abuse, and esketamine's approval for expanded use. We evaluated the anesthesia literature concerning mental, cardiovascular, cerebral, and antinociceptive effects of esketamine published in English between 1980 and 2022. The review shows that esketamine and racemic ketamine are not "the same" at clinically equivalent analgesic and anesthetic dose: Psychomimetic effects seem to be essentially related to NMDA receptor blockade and esketamine is not devoid of unwanted mental impact. However, it probably involves less cholinergic inhibition. Cognitive disturbances during arousal, awakening, and recovery from the drug are less, and less pronounced with esketamine. The drug allows for an approximately 50% dose reduction in anesthesia and analgesia which goes along with a higher clearance and shorter recovery time as compared to racemic ketamine. In comparison of esketamine with placebo, esketamine shows cardiocirculatory stabilizing and neuroprotective effects which can be seen in anesthesia induction, cardiac surgery, and analgesia and sedation in brain injury. Evidence of esketamine's antinociceptive efficacy is inconsistent, although a recent meta-analysis reports improved pain relief after surgery in a study with short observation time. To better define esketamine's place, direct head-to-head comparison with the racemate at equi-analgesic/anesthetic dose is warranted.

The effect of "multiphase sedation" in the course of computed tomography and magnetic resonance imaging on children, parents and anesthesiologists

BACKGROUND AND OBJECTIVES

We aimed to investigate the effect on children undergoing Computed Tomography (CT) or Magnetic Resonance Imaging (MRI), their parents and attending anesthesiologist of "multiphase sedation" which we define as "the intended sedation level achieved with one or more agents through the same or different routes with more than one administration".

MATERIAL AND METHODS

One hundred children and their parents were randomly allocated to one of two study groups. In phase 1; in Group I the patients were given midazolam (0.5mg.kg(-1)) in 5 mL fruit juice, and the ones in control group (Group II) were given only fruit juice. After intravenous (iv) cannulation; in phase II, boluses of propofol were given to achieve the adequate sedation for imaging. Anxiety scores of children and their parents were recorded using Oucher scale and STAI, respectively, and parental satisfaction was evaluated by visual analogue scale (VAS). The number of attempts for iv cannulation, length of time for preparation, and amount of hypnotics were recorded.

RESULTS

Anxiety state of children was similar between groups before premedication, but later it was lower in Group I. Before procedure, STAI score of parents was similar and later it was lower in Group I. Parental satisfaction in Group I was higher. The number of attempts for iv cannulation and required propofol dose was less in Group I.

CONCLUSION

"Multiphase sedation" procedure provides children to feel less pain and anxiety, and decreases parental anxiety while increasing their satisfaction. It supplies a comfortable and safe sedation, as it provides a short and problem-free preparation process for the attending anesthetist as well.

Impact of psychological interventions on reducing anxiety, fear and the need for sedation in children undergoing magnetic resonance imaging

Children undergoing magnetic resonance imaging examination frequently experience anxiety and fear before and during the scanning. The aim of the present study was to assess: i) whether and to what extent psychological interventions might reduce anxiety and fear levels; ii) whether the intervention is related to a decrease in the need for sedation. The interventions consisted of three activities: a clown show, dog interaction and live music. The emotional status (anxiety and fear) of the children was evaluated before and after the activities through a rating scale questionnaire. The results showed that the activities had high effectiveness in reducing the level of anxiety and fear and decreased the need for sedation in the experimental group compared to the control group. This approach proved to be a positive patient experience, helping to alleviate children's anxiety and fear, decreasing the need for sedation, and was cost-effective.

Magnetic Resonance Imaging in Children under Anesthesia: The Relationship between the Degree of Information Provided to Parents and Parents’ Anxiety Scores

Background. We aimed to investigate the correlation between the anxiety scores of parents whose children are administered anesthesia for magnetic resonance imaging (MRI) and the level of information provided to them before the MRI. The study included 146 children and their parents. The demographic information of the children and their parents was recorded. The parents were divided into two groups. In Group I, the patient's medical history and physical exam findings were recorded on a standard consultation form by an anesthesiologist. In Group II, the parents were additionally provided with more detailed information on how the anesthesia would be administered and the drugs to be used and their side effects and complications. The anxiety scores of the parents were found to be lower in Group II. A higher level of education was associated with higher anxiety scores. Intergroup comparison detected lower anxiety scores for Group II parents whose education levels were up to high school. However, no change upon receiving detailed information was detected in the anxiety scores of parents with higher education levels. In conclusion, this may lower the anxiety scores in parents informed about details of anesthesia administration and may raise parents' sense of confidence in the doctor.

Sedation with ketamine and low-dose midazolam for short-term procedures requiring pharyngeal manipulation in young children

BACKGROUND

Pediatric intestinal biopsy procedures including considerable transpharyngeal manipulation of a wire-guided metal capsule require adequate sedation or anesthesia. This retrospective cohort study was designed to evaluate intravenous sedation with ketamine and low-dose midazolam in young children undergoing these procedures before and also after discharge from the hospital.

METHODS

A total of 244 biopsy procedures in 217 children under the age of 16 years were evaluated. All anesthesia records were reviewed according to a defined study protocol and in 145 cases the parents were also interviewed by telephone to obtain further information on possible adverse effects before and after discharge.

RESULTS

Ketamine and low-dose midazolam were carefully titrated by an experienced anesthesia team at an approximate dose ratio of 40 : 1 (total doses 2.3 and 0.05 mg.kg(-1)) in continuously monitored spontaneously breathing children. Possibly associated problems before discharge were salivation (5.7%), vomiting (4.9%), oxygen desaturation (3.3%), laryngospasm (2.5%) and rash (1.2%) according to the patient records and blurred vision (27%), nausea and vomiting (19%), vertigo (13%) and hallucinations or nightmares (3.5%) according to telephone interviews. Few, mild and transient problems remained after discharge from the hospital.

CONCLUSIONS

Careful titration of ketamine and low-dose midazolam provides adequate sedation for nonsurgical pediatric short-term procedures also requiring considerable pharyngeal manipulation, particularly considering the low number of serious airway problems such as laryngospasm. The high incidence of late postoperative problems suggests that prospective studies should be designed for long-term follow-up of young children subjected to sedation or anesthesia.

Anästhesie außerhalb des Zentral-OP

The number of diagnostic and surgical procedures being performed outside the core operating area is growing disproportionately. Due to the higher perioperative risk for such patients, anesthesia should only be provided by a very experienced anesthesiologist, even for supposedly small interventions. At these locations, timely and direct access to the anesthesia machine and/or the patient is often limited and if additional personnel or supplies are required, substantial time delays usually occur and should be allowed for. Standard operating procedures that are optimized to local requirements and providing a specially equipped anesthesia trolley for diagnostic and surgical procedures outside of the core operating area, may decrease the likelihood of complications induced by poorly equipped anesthesia workplaces. For electroconvulsive therapy (ECT), the standard drugs are methohexital in combination with short-acting opioids, such as remifentanil and succinylcholine. Significant variations in arterial blood pressure and heart rate are possible. Anesthesia induction in children with a known difficult airway or difficult intravascular access should initially be performed in a location with optimal infrastructure with subsequent transfer to the diagnostic or surgical suite outside the core operating area. Before entering the magnetic resonance imaging (MRI) suite, personal ferromagnetic items (e.g. pens, credit cards, stethoscopes, keys, telephones, USB sticks) should be removed to prevent injury and data loss; a MRI-compatible anesthesia machine and equipment is compulsory. Patients with cardiac pacemakers, cochlea implants, aneurysm or other clips, metallic-based tattoos or make-up are not normally compatible with MRI. General anesthesia should be preferred over conscious sedation for magnetic resonance imaging and ear protection is necessary for anesthetized patients. Gastroscopy in children should be performed under general anesthesia; and when concluding the procedure, air insufflated into the gastrointestinal tract should be suctioned in all patients. For angiography, maximum monitoring needs to be available to provide hemodynamically unstable patients with adequate anesthesia care; comprehensive radiation protection for patients and staff as well as temperature monitoring for prolonged diagnostic procedures is also necessary. Monitoring oxygen saturation and end-tidal carbon dioxide as well as employing visual and audible alarms is an essential requirement even during conscious sedation. In summary, the number of diagnostic and surgical procedures performed outside the core operating area should be reduced to a minimum and, whenever possible, diagnostic or surgical procedures should be performed within the core operating area.

Paediatric anaesthesia outside the operating room

Anaesthesiologists are regularly consulted to provide anaesthesia for children in settings other than an operating room. Current debate focuses on the appropriateness of the presence of an anaesthesiologist versus a non-anaesthesiologist. There is mounting evidence that the presence of an anaesthesiologist is safer. We will review the recent literature concerning paediatric anaesthesia outside the operating room and offer recommendations that may impact on efficacy and safety.

Sedation and analgesia for brief diagnostic and therapeutic procedures in children

The number of diagnostic and therapeutic procedures done outside of the operating room and the intensive care unit has increased substantially in recent years. In parallel, the management of acute pain and anxiety in children undergoing therapeutic and diagnostic procedures has developed considerably in the past two decades. The primary goal of procedural sedation and analgesia is the safe and efficacious control of emotional distress and pain. The availability of non-invasive monitoring, short-acting opioids and sedatives has broadened the possibilities of sedation and analgesia in children in diverse settings. While most of these procedures themselves pose little risk to the child, the administration of sedation or analgesia may add substantial risk to the patient. This article reviews the current status of sedation and analgesia for invasive and non-invasive procedures in children providing an evidence-based approach to several topics of importance, including patient assessment, personnel requirements, equipment, monitoring, and drugs.

Oral sedation with midazolam and diphenhydramine compared with midazolam alone in children undergoing magnetic resonance imaging

BACKGROUND

The purpose of this study was to compare the safety and efficacy of oral midazolam and midazolam-diphenhydramine combination to sedate children undergoing magnetic resonance imaging (MRI).

METHODS

We performed a prospective randomized double-blind study in 96 children who were randomly allocated into two groups. Group D received oral diphenhydramine (1.25 mg x kg(-1)) with midazolam (0.5 mg x kg(-1)), and Group P received oral placebo with midazolam (0.5 mg x kg(-1)) alone. Sedation scores, onset and duration of sleep were evaluated. Adverse effects, including hypoxemia, failed sedation, and the return of baseline activity, were documented.

RESULTS

Diphenhydramine facilitated an earlier onset of midazolam sedation (P < 0.01), and higher sedation scores (P < 0.01). In children who received midazolam alone, 20 (41%) were inadequately sedated, compared with 9 (18%) children who received midazolam and diphenhydramine combination (P < 0.01). Time to complete recovery was not significantly different between the two groups.

CONCLUSIONS

Our study indicates that the combination of oral diphenhydramine with oral midazolam resulted in safe and effective sedation for children undergoing MRI. The use of this combination might be more advantageous compared with midazolam alone, resulting in less sedation failure during MRI.

The management of infants and children for painless imaging

The ability of a child to remain sufficiently immobile for painless imaging depends upon their behaviour and the imaging itself. Anaesthesia allows imaging to be optimised but it is expensive, scarce and inappropriate for many situations. Fortunately, sedation and behavioural techniques are sufficiently successful for the majority of scanning, and success rates are high provided that suitable children are selected. Sedation, however, administered by non-anaesthetists, may have catastrophic complications such as airway obstruction. Current UK recommendations demand that any sedation technique has a 'wide margin of safety', but in addition to this, safety is dependent on trained, skillful and experienced staff. Magnetic resonance imaging frightens many children and special planning is necessary for sedation and anaesthesia. When planning an imaging service for children, all the management techniques should be considered in order to achieve maximum efficiency, quality and safety.

Effects of low dose ketamine before induction on propofol anesthesia for pediatric magnetic resonance imaging

BACKGROUND

We aimed to investigate effects of low dose ketamine before induction on propofol anesthesia for children undergoing magnetic resonance imaging (MRI).

METHODS

Forty-three children aged 9 days to 7 years, undergoing elective MRI were randomly assigned to receive intravenously either a 2.5 mg x kg(-1) bolus of propofol followed by an infusion of 100 microg x g(-1) x min(-1) or a 1.5 mg x kg(-1) bolus of propofol immediately after a 0.5 mg x kg(-1) bolus of ketamine followed by an infusion of 75 microg x kg(-1) x min(-1). If a child moved during the imaging sequence, a 0.5-1 mg x kg(-1) bolus of propofol was given. Systolic and diastolic blood pressures, heart rate, peripheral oxygen saturation and respiratory rates were monitored. Apnea, the requirement for airway opening maneuvers, secretions, nausea, vomiting and movement during the imaging sequence were noted. Recovery times were also recorded.

RESULTS

Systolic blood pressure and heart rate decreased significantly in the propofol group, while blood pressure did not change and heart rate decreased less in the propofol-ketamine group. Apnea associated with desaturation was observed in three patients of the propofol group. The two groups were similar with respect to requirements for airway opening maneuvers, secretions, nausea-vomiting, movement during the imaging sequence and recovery time.

CONCLUSIONS

Intravenous administration of low dose ketamine before induction and maintenance with propofol preserves hemodynamic stability without changing the duration and the quality of recovery compared with propofol alone.

Sedation and analgesia for procedures outside the operating room

The volume of literature concerning sedation and analgesia for procedures outside the operating room has increased greatly over the past several years. Information relating to sedation risks and complications, the development of sedation guidelines, and now specific sedation techniques has appeared. The following section will trace the development of the most recent sedation guidelines and identify the key elements for inclusion into institutional sedation guidelines. The risks and complications associated with sedation will be addressed and an approach to providing sedation and analgesia for procedures outside the operating room will be presented. The important characteristics of several common drugs used for sedation and analgesia will also be discussed.

Deep sedation with propofol for children undergoing ambulatory magnetic resonance imaging of the brain: experience from a pediatric intensive care unit

OBJECTIVES

Use of intravenous propofol sedation to facilitate completion of magnetic resonance imaging of the brain in children.

DESIGN

Retrospective, cross-sectional.

SETTING

A university-affiliated pediatric intensive care unit.

PATIENTS

A total of 115 children who received intravenous propofol to complete magnetic resonance imaging of the brain January 1 through December 31, 2001.

INTERVENTIONS

Intravenous propofol infusion.

MEASUREMENTS AND MAIN RESULTS

The mean age was 4.2 +/- 3.1 yrs, and there were 63 boys and 52 girls. Sixty-nine percent of patients belonged to ASA physical status class I, and 31% belonged to ASA class II. All studies were completed with satisfactory image quality. The total dose of propofol used to complete a magnetic resonance image of the brain was 4.3 +/- 1.7 mg/kg body weight. The mean duration of sedation induction was 4.5 +/- 3.5 mins. The mean time to recovery (from the end of the procedure) was 20 +/- 15 mins. The duration of the procedure averaged 39 +/- 20 mins, and the time to discharge from the hospital was 50 +/- 21 mins from the end of the procedure. No episodes of hypoxia, apnea, or a need for artificial airway were noted. Systolic blood pressure decreased 10% +/- 13%, but none of the patients met the criteria for hypotension. A telephone call the next day to the family did not reveal any delayed complications.

CONCLUSIONS

Propofol can safely facilitate ambulatory magnetic resonance imaging of the brain in children, and it is associated with brief induction, recovery, and discharge times from the hospital. A drop in blood pressure, although mild and transient, does occur. Therefore, appropriate monitoring and preparedness for cardiorespiratory support are essential.

Considerations for anaesthesia in children with haematological malignancy undergoing short procedures

As a result of increased use of risk-directed treatment regimes, there is a regular requirement for short-lasting but painful procedures to be performed on children to aid in diagnosis or treatment. The aim of any anaesthetic technique is to provide analgesia and amnesia with minimal side-effects and early return to former activity levels. We review the implications of haematological malignancy in children with regard to anaesthesia and the consequences arising from both the disease and ensuing treatment. We outline some of the current anaesthetic techniques in use and review the advantages and disadvantages of each.