Moderate-to-deep sedation technique, using propofol and ketamine, allowing synchronised breathing for magnetic resonance high-intensity focused ultrasound (MR-HIFU) treatment for uterine fibroids: a pilot study

Hypnosis in High-Intensity Focused Ultrasound for Thyroid Nodule Ablation

BACKGROUND Current medical technologies enable physicians to treat patients outside operating rooms using minimally invasive techniques. Non-operating room anesthesia (NORA) represents a growing field of medicine, with an increasing number of cases performed over the last decade. As a result, anesthesia providers will need to enhance their understanding of the resources, medical and paramedical staff, and environment outside the operating room. Patients undergoing such procedures under light conscious sedation still experience discomfort such as pain and anxiety, thus requiring the use of pain control medication or sedative drugs. At the same time, the use of hypnosis is spreading in medical practice, particularly with minimally invasive procedures. Many studies have investigated the use of hypnosis in cases of minimally invasive procedures, showing an effective reduction of patients' discomfort and consumption of pain control medication, thus improving patient safety. CASE REPORT We describe the case of a woman in her 70s who underwent a thyroid nodule thermal ablation through high-intensity focused ultrasound (HIFU) performed under hypnosis in a NORA setting. The procedure was well endured; the patient experienced comfort and was satisfied with having avoided general anesthesia. Post-HIFU follow-up showed a 30% decrease of thyroid nodule volume. The patient was completely satisfied with the esthetic result. The operator did not encounter any difficulties with the awoken patient or movements during the procedure. CONCLUSIONS Our case confirms the effective role of hypnosis in relaxation and coping with painful procedures and highlights patient satisfaction without the use of sedative drugs in the context of NORA procedures.

Research advances in the clinical application of esketamine

Esketamine is dextrorotatory ketamine, which is an enantiomer of ketamine. Compared with ketamine, it has the advantages of a fast metabolism, fewer side effects, and strong pharmacological effects, so it is more suitable for clinical use. Esketamine has a powerful analgesic effect and has little effect on breathing. It has a wide range of applications in the fields of pediatric anesthesia, conscious sedation anesthesia, and emergency analgesia. In addition, it is also used for pain that is difficult to relieve with conventional drugs and to prevent postoperative pain. Various routes of administration are also suitable for patients who need short-term analgesia and sedation. As a drug, esketamine inevitably brings some side effects when it is used clinically. In this article, by introducing the mechanism of action and pharmacological characteristics of esketamine, its clinical application is reviewed, and it provides a reference for the more reasonable and safe clinical application of esketamine.

Efficacy and safety of the combination of propofol and S(+)-ketamine for procedural sedation in pediatric patients undergoing totally implantable venous access port implantation: A prospective randomized controlled study

BACKGROUND

Totally implantable venous access port (TIVAP) implantation is usually performed under general anesthesia with endotracheal intubation in children. Procedural sedation without endotracheal intubation has been applied to minor pediatric surgeries like central venous catheter insertion. To explore a more efficient and less invasive anesthesia mode to implant TIVAPs for children, we aimed to evaluate the efficacy and safety of procedural sedation using propofol and S(+)-ketamine compared with general anesthesia.

METHODS

Sixty-six patients aged 6 months to 10 years undergoing TIVAP implantation were randomly allocated to two groups. Patients under procedural sedation [S(+)-ketamine-propofol (sketofol) group] were given target-controlled infusion of propofol 4 μg/ml using the Paedfusor model and S(+)-ketamine 0.5 mg/kg as induction, and had target-controlled infusion of propofol 3-4 μg/ml as maintenance. Patients in sketofol group received medium-flow oxygen inhalation through facemasks during surgery. Patients under general anesthesia (control group) were given propofol 2 mg/kg, cisatracurium 0.2 mg/kg, fentanyl 3 μg/kg as induction, and sevoflurane 0.8 minimum alveolar concentration as maintenance after endotracheal intubation. Primary outcome was the postoperative emergence agitation evaluated 5 min after awakening.

RESULTS

Postoperative emergence agitation evaluated 5 min after awakening was lower in sketofol group versus control group [1.0 (0.5, 1.0) vs. 3.0 (2.0, 4.0); median difference (95% CI): 2.0 (1.0, 2.0); P < 0.001]. Time to awakening was significantly lower in sketofol group versus control group [15.0 (5.0, 23.0) vs. 26.0 (20.5, 37.5); median difference (95% CI): 11.0 (7.0, 19.0); P < 0.001], as well as time to discharge from post anesthesia care unit [35.0 (24.0, 45.0) vs. 45.0 (37.5, 59.5); median difference (95% CI): 10.0 (10.0, 23.0); P < 0.001]. Postoperative complications or adverse events were not reported in sketofol group.

CONCLUSIONS

Compared to general anesthesia with endotracheal intubation, procedural sedation using propofol and S(+)-ketamine improves the postoperative emergence agitation right after the recovery of consciousness, and has advantage in shortening anesthetic recovery time for pediatric patients undergoing TIVAP implantation.

Lessons learned during implementation of MR-guided High-Intensity Focused Ultrasound treatment of uterine fibroids

BACKGROUND

Although promising results have been reported for Magnetic Resonance image-guided High-Intensity Focused Ultrasound (MR-HIFU) treatment of uterine fibroids, this treatment is not yet widely implemented in clinical practice. During the implementation of a new technology, lessons are learned and an institutional learning-curve often has to be completed. The primary aim of our prospective cohort study was to characterize our learning-curve based on our clinical outcomes. Secondary aims included identifying our lessons learned during implementation of MR-HIFU on a technical, patient selection, patient counseling, medical specialists and organizational level.

RESULTS

Our first seventy patients showed significant symptom reduction and improvement of quality of life at 3, 6 and 12 months after MR-HIFU treatment compared to baseline. After the first 25 cases, a clear plateau phase was reached in terms of failed treatments. The median non-perfused volume percentage of these first 25 treatments was 44.6% (range: 0-99.7), compared to a median of 74.7% (range: 0-120.6) for the subsequent treatments.

CONCLUSIONS

Our findings describe the learning-curve during the implementation of MR-HIFU and include straightforward suggestions to shorten learning-curves for future users. Moreover, the lessons we learned on technique, patient selection, patient counseling, medical specialists and organization, together with the provided supplements, may be of benefit to other institutions aiming to implement MR-HIFU treatment of uterine fibroids. Trial registration ISRCTN14634593. Registered January 12, 2021-Retrospectively registered, https://www.isrctn.com/ISRCTN14634593 .

The median effective concentration of propofol with different doses of esketamine during gastrointestinal endoscopy in elderly patients: A randomized controlled trial

AIMS

Propofol may result in hypotension, bradycardia and loss of protective reflexes, especially in elderly patients, while esketamine, a N-methyl-D-aspartate receptor antagonist, has analgesic, anaesthetic and sympathomimetic properties and is known to cause less cardiorespiratory depression. We hypothesized that esketamine may reduce the median effective concentration (EC₅₀ ) of propofol and coadministration is less likely to produce hypotension during gastrointestinal endoscopy in elderly patients.

METHODS

Ninety elderly patients, aged 65-89 years, undergoing gastrointestinal endoscopy were randomly assigned into 3 groups: SK0 (control) group (0 mg/kg esketamine); SK0.25 group (0.25 mg/kg esketamine); and SK0.5 group (0.5 mg/kg esketamine). Anaesthesia was achieved by plasma target-controlled infusion of propofol with different bolus doses of esketamine. The EC₅₀ of propofol for gastrointestinal endoscopy was determined by using the up-and-down method of Dixon. The initial plasma target concentration is 2.5 μg/mL and the adjacent concentration gradient is 0.5 μg/mL. Cardiovascular variables were also measured.

RESULTS

Propofol EC₅₀ s and its 95% confidence interval for gastrointestinal endoscopy in elderly patients were 3.69 (2.59-4.78), 2.45 (1.85-3.05) and 1.71 (1.15-2.27) μg/mL in the SK0, SK0.25 and SK0.5 groups, respectively (P < .05). The average percent change from baseline mean arterial pressure was -19.7 (7.55), -15.2 (7.14) and -10.1 (6.73), in the SK0, SK0.25 and SK0.5 groups, respectively (P < .001).

CONCLUSION

Combination medication of propofol with esketamine reduced the propofol EC₅₀ during gastrointestinal endoscopy in elderly patients compared with administration of propofol without esketamine. Increasing doses of SK with propofol are less likely to produce hypotension with shorter recovery time.

Focused Ultrasound (FUS) for Chronic Pain Management: Approved and Potential Applications

Chronic pain is one of the leading causes of disability and disease burden worldwide, accounting for a prevalence between 6.9% and 10% in the general population. Pharmacotherapy alone results ineffective in about 70-60% of patients in terms of a satisfactory degree of pain relief. Focused ultrasound is a promising tool for chronic pain management, being approved for thalamotomy in chronic neuropathic pain and for bone metastases-related pain treatment. FUS is a noninvasive technique for neuromodulation and for tissue ablation that can be applied to several tissues. Transcranial FUS (tFUS) can lead to opposite biological effects, depending on stimulation parameters: from reversible neural activity facilitation or suppression (low-intensity, low-frequency ultrasound, LILFUS) to irreversible tissue ablation (high-intensity focused ultrasounds, HIFU). HIFU is approved for thalamotomy in neuropathic pain at the central nervous system level and for the treatment of facet joint osteoarthritis at the peripheral level. Potential applications include HIFU at the spinal cord level for selected cases of refractory chronic neuropathic pain, knee osteoarthritis, sacroiliac joint disease, intervertebral disc nucleolysis, phantom limb, and ablation of peripheral nerves. FUS at nonablative dosage, LILFUS, has potential reversible and tissue-selective effects. FUS applications at nonablative doses currently are at a research stage. The main potential applications include targeted drug and gene delivery through the Blood-Brain Barrier, assessment of pain thresholds and study of pain, and reversible peripheral nerve conduction block. The aim of the present review is to describe the approved and potential applications of the focused ultrasound technology in the field of chronic pain management.

A planning strategy for combined motion-assisted/gated MR guided focused ultrasound treatment of the pancreas

Objective: To develop and evaluate a combined motion-assisted/gated MRHIFU heating strategy designed to accelerate the treatment procedure by reducing the required number of sonications to ablate a target volume in the pancreas. Methods: A planning method for combined motion-assisted/gated MRHIFU using 4D-MRI and motion characterization is introduced. Six healthy volunteers underwent 4D-MRI for target motion characterization on a 3.0-T clinical scanner. Using displacement patterns, simulations were performed for all volunteers for three sonication approaches: gated, combined motion-assisted/gated, and static. The number of sonications needed to ablate the pancreas head was compared. The influence of displacement amplitude and target volume size was investigated. Spherical target volumes (8, 15, 20 and 34 mL) and displacement amplitudes ranging from 5 to 25 mm were evaluated. For this case, the number of sonications required to ablate the whole target was determined. Results: The number of required sonications was lowest for a static target, 62 on average (range 49-78). The gated approach required most sonications, 126 (range 97-159). The combined approach was almost as efficient as the hypothetical static case, with an average of 78 (range 53-123). Simulations showed that with a 5-mm displacement amplitude, the target could be treated by making use of motion-assisted MRHIFU sonications only. In that case, this approach allowed the lowest number of sonication, while for 10 mm and above, the number of required sonications increased. Conclusion: The use of a combined motion-assisted/gated MRHIFU strategy may accelerate tumor ablation in the pancreas when respiratory-induced displacement amplitudes are between 5 and 10 mm.

Evaluation of pain during high-intensity focused ultrasound ablation of benign thyroid nodules

OBJECTIVE

To assess severity and factors of pain during high-intensity focused ultrasound (HIFU) ablation of benign thyroid nodules.

METHODS

128 patients who underwent a HIFU ablation for a benign thyroid nodule were analysed. All patients received a bolus of intravenous pethidine and diazepam before treatment. After treatment, patients were asked to rate their overall pain experience on a visual analogue scale (0-100) (0 = no pain; 100 = worse possible pain) during treatment, 2 h after treatment and the following morning. Binary logistic regression was performed to evaluate associated factors for pain including patient demographics, nodule size, body mass index (BMI) and treatment parameters.

RESULTS

At T1, median (range) pain score was 65.0 (0.00-100.00). Only 16 (12.5 %) patients had a pain score of zero. In multivariate analysis, only lower BMI (OR 1.265, 95 % CI 1.102-1.452, p=0.001) and longer nodule diameter (OR 1.462, 95 % CI 1.071-1.996, p=0.017) were independent factors for pain score at T1 ≤ 65.0.

CONCLUSIONS

A moderate to severe amount of pain was reported during ablation of benign thyroid nodules in over 50 % of patients. Patients' BMI and length of nodule diameter were independent variables for pain during HIFU ablation.

KEY POINTS

• Pain was moderate to severe during HIFU ablation of thyroid nodules. • Only one in eight patients reported no pain during ablation. • Level of energy per pulse did not affect pain. • Patients with lower BMI and larger nodules had less pain.