Low-Dose Ketamine for Outpatient Hysteroscopy: A Prospective, Randomised, Double-Blind Study

Enhanced recovery protocols for ambulatory surgery

INTRODUCTION

In the United States, ambulatory surgeries account for up to 87% of all surgical procedures. (1) It was estimated that 19.2 million ambulatory surgeries were performed in 2018 (https://www.hcup-us.ahrq.gov/reports/statbriefs/sb287-Ambulatory-Surgery-Overview-2019.pdf). Cataract procedures and musculoskeletal surgeries are the most common surgical interventions performed in ambulatory centers. However, more complex surgical interventions, such as sleeve gastrectomies, oncological, and spine surgeries, and even arthroplasties are routinely performed as day cases or in a model of an ambulatory extended recovery. (2-5) The ambulatory surgery centers industry has grown since 2017 by 1.1% per year and reached a market size of $31.2 billion. According to the Ambulatory Surgery Center Association, there is a potential to save $57.6 billion in Medicare costs over the next decade (https://www.ibisworld.com/industry-statistics/market-size/ambulatory-surgery-centers-united-states/). These data suggest an expected rise in the volume of ambulatory (same day) or extended ambulatory (23 h) surgeries in coming years. Similar increases are also observed in other countries. For example, 75% of elective surgeries are performed as same-day surgery in the United Kingdom. (6) To reduce costs and improve the quality of care after those more complex procedures, ambulatory surgery centers have started implementing patient-centered, high-quality, value-based practices. To achieve those goals, Enhanced Recovery After Surgery (ERAS) protocols have been implemented to reduce the length of stay, decrease costs, increase patients' satisfaction, and transform clinical practices. The ERAS fundamentals for ambulatory surgery are based on five pillars, including (1) preoperative patient counseling, education, and optimization; (2) multimodal and opioid-sparing analgesia; (3) nausea and vomiting, wound infection, and venous thromboembolism prophylaxis; (4) maintenance of euvolemia; and (5) encouragement of early mobility. Those pillars rely on interdisciplinary teamwork led by anesthesiologists, surgery-specific workgroups, and safety culture. (2) Research shows that a team of ambulatory anesthesiologists is crucial in improving postoperative nausea and vomiting (PONV) and pain control. (7) This review will summarize the current evidence on the elements and clinical importance of implementing ERAS protocol for ambulatory surgery.

Conscious sedation for office hysteroscopy: A systematic review and meta-analysis

OBJECTIVE

To evaluate the role of conscious sedation on pain control in office hysteroscopy.

METHODS

MEDLINE, EMBASE, CINAHL and CENTRAL were searched from inception to the 30th October 2020 in order to perform a systematic review and meta-analysis of all randomized controlled trials investigating women undergoing office hysteroscopic procedures, allocated to either conscious sedation or a suitable comparator, where the outcome was pain. Data regarding adverse events, feasibility and satisfaction/acceptability were also collected. The Risk of Bias 2 tool was used to assess study quality. Standard mean differences (SMD) or Odds Ratios (OR), and their 95% confidence intervals (CIs) were calculated for continuous (e.g. mean pain) and dichotomous (e.g. side-effects) outcomes, respectively.

RESULTS

The literature search returned 339 results, of which seven studies were included for systematic review, with five studies having data suitable for meta-analysis. Intravenous conscious sedation, when compared with local anesthesia, reduced pain during (SMD -0.26, 95% CI -0.51 to -0.01), but not after (SMD -0.18, 95% CI -0.43 to 0.07) office hysteroscopy. No significant difference in side-effects were noted (OR 15.58, 95% CI 0.08 to 2891.91). Intravenous conscious sedation, when compared to an oral analgesic and antispasmodic, was associated with increased pain, both during (SMD 1.03, 95% CI 0.56 to 1.49) and after (SMD 0.49, 95% CI 0.04 to 0.93) hysteroscopy and had significantly more side-effects (OR 134.33, 95% CI 16.14 to 1118.17). Inhalational conscious sedation (70% N₂O/30% O₂), when compared to oral analgesia and anxiolysis, showed the greatest reduction in pain during hysteroscopy (SMD -1.04, 95% CI -1.57 to -0.52), however side-effects were not reported. Whilst patients and hysteroscopists were more satisfied with deeper levels of sedation, resulting side-effects, such as delirium, increased the level of post-procedural attention required, leading to a significantly lower level of satisfaction amongst nursing staff.

CONCLUSION

The routine use of conscious sedation in contemporary hysteroscopic practice should be avoided in the absence of any clear reduction in pain and a higher risk of side-effects.

Effects of Low-Dose Ketamine Infusion on Alleviating the Opioid Burden for Patients Undergoing Myomectomy Surgery

Objective

Recent research has focused on the use of N-methyl-D-aspartate (NMDA) receptor antagonists for pain management. Several drugs are known to have this action, including ketamine, which exerts its main analgesic effect through NMDA receptor antagonism. This study aimed to evaluate the effect of low-dose ketamine infusion on opioid exposure for patients undergoing myomectomy surgery under general anaesthesia.

Methods

A total of 70 women were included in this prospective double-blind trial study. The patients included in this study were American Society of Anaesthesiologists physical status I-II, aged between 18 and 50 years and scheduled for laparotomy myomectomy surgery. Patients were randomised to receive either a bolus of 0.2 mg kg^-1 of ketamine followed by a continuous infusion of 0.2 mg kg^-1 hr^-1 during the operation or a placebo of normal saline. Both groups also received morphine as needed for pain relief. The primary outcome was the total amount of morphine used during the intraoperative and postoperative periods. Intraoperative and postoperative mean blood pressure, heart rate and postoperative visual analogue scale for pain were assessed.

Results

Total mean morphine consumption was significantly lower in the ketamine group than in the control group (26±3.5 mg vs. 34.7±3.3 mg, respectively, p<0.05). However, there were no statistical differences between the groups regarding haemodynamics, postoperative pain score and complications.

Conclusion

The use of ketamine in low infusion doses intraoperatively during an elective myomectomy procedure produced an opioid-sparing effect by reducing perioperative morphine consumption without significant side effects.