The use of inhaled sevoflurane during operative hysteroscopy is associated with increased glycine absorption compared to intravenous propofol for maintenance of anesthesia

Pharmacologic Interventions to Minimize Fluid Absorption at the Time of Hysteroscopy: A Systematic Review and Meta-analysis

OBJECTIVE

To assess which interventions are effective in reducing fluid absorption at the time of hysteroscopy.

DATA SOURCE

Ovid MEDLINE, Ovid EMBASE, PubMed (non-MEDLINE records only), EBM Reviews-Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov , and Web of Science were searched from inception to February 2022 without restriction on language or geographic origin.

METHODS OF STUDY SELECTION

Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, all English-language, full-text articles reporting fluid balance, with an intervention and comparator arm, were included. Title and abstract screening and full-text review were completed independently by two authors. Conflicts were resolved through discussion and consensus. Studies' risk of bias was assessed using the Cochrane Risk of Bias Tool for RCTs and the Newcastle-Ottawa Scale for observational studies.

TABULATION, INTEGRATION, AND RESULTS

The search identified 906 studies, 28 of which were eligible for inclusion, examining the following interventions: gonadotropin-releasing hormone (GnRH) agonist; ulipristal acetate; vasopressin; danazol; oxytocin; and local, general, and regional anesthesia. A significant reduction in mean fluid absorption was seen in patients preoperatively treated with danazol (-175.7 mL, 95% CI -325.4 to -26.0) and a GnRH agonist (-139.68 mL, 95% CI -203.2, -76.2) compared with patients in a control group. Ulipristal acetate and type of anesthesia showed no difference. Data on type of anesthesia and vasopressin use were not amenable to meta-analysis; however, four studies favored vasopressin over control regarding fluid absorption. Mean operative time was reduced after preoperative treatment with ulipristal acetate (-7.1 min, 95% CI -11.31 to -2.9), danazol (-7.5 min, 95% CI -8.7 to -6.3), and a GnRH agonist (-3.3 min, 95% CI -5.6 to -0.98).

CONCLUSION

Preoperative treatment with a GnRH agonist and danazol were both found to be effective in reducing fluid absorption and operative time across a range of hysteroscopic procedures. High-quality research aimed at evaluating other interventions, such as combined hormonal contraception, progestin therapy, and vasopressin, are still lacking in the literature.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021233804.

Minimal alveolar concentration of sevoflurane in combination with dexmedetomidine in patients with hysteroscopy: An up-down sequential allocation study

BACKGROUND

Dexmedetomidine is commonly used in hysteroscopy surgery due to its analgesia and sedation without respiratory depression. Many studies have shown that dexmedetomidine can reduce the consumption of sevoflurane. However, the optimal end-tidal concentration of sevoflurane when it is co-administered with dexmedetomidine has not been established. The primary purpose of this study was to investigate the minimal alveolar concentration (MAC) of sevoflurane for cervical dilatation combined with different doses of dexmedetomidine in patients with hysteroscopy surgery.

METHODS

One-hundred patients undergoing hysteroscopy surgery were enrolled in this clinical trial. All the patients were randomly assigned into four groups (C, D₁ , D₂ , D₃ ) and received a loading dose of dexmedetomidine (0, 0.6, 0.8 and 1.0 μg/kg) over 10 min before anaesthesia induction, respectively. Anaesthesia was induced in each patient with 5% sevoflurane in 100% oxygen via a facemask. A laryngeal mask (LMA) was inserted when the patient had lost consciousness and the BIS value decreased below 40. The response to cervical dilatation stimulus (movement vs non-movement) by the insert of hysteroscope was recorded. The MAC of sevoflurane was measured by up and down sequential method of Dixon and Mood and centred isotonic regression analysis.

RESULTS

The calculated MAC of sevoflurane using up-and-down method of Dixon and Mood in patients with hysteroscopy surgery was (1.90 ± 0.13)%, (1.23 ± 0.16)%, (1.03 ± 0.10)% and (0.93 ± 0.08)% in groups C, D₁ , D₂ and D₃ , respectively.

CONCLUSIONS

The administration of dexmedetomidine can significantly decrease the MAC of sevoflurane for hysteroscopy surgery. However, a ceiling effect of the reduction was observed when the dose of dexmedetomidine was higher than 0.8 μg/kg.

The active fragments of ghrelin cross the blood-brain barrier and enter the brain to produce antinociceptive effects after systemic administration

G (1-5)-NH₂, G (1-7)-NH₂, and G (1-9) are the active fragments of ghrelin. The aim of this study was to investigate the antinociceptive effects, their ability to cross the blood-brain barrier, and the receptor mechanism(s) of these fragments using the tail withdrawal test in male Kunming mice. The antinociceptive effects of these fragments (2, 6, 20, and 60 nmol/mouse) were tested at 5, 10, 20, 30, 40, 50, and 60 min after intravenous (i.v.) injection. These fragments induced dose- and time-related antinociceptive effects relative to saline. Using the near infrared fluorescence imaging experiments, our results showed that these fragments could cross the brain-blood barrier and enter the brain. The antinociceptive effects of these fragments were completely antagonized by naloxone (intracerebroventricular, i.c.v.); however, naloxone methiodide (intraperitoneal, i.p.), which is the peripheral restricted opioid receptor antagonist, did not antagonize these antinociceptive effects. Furthermore, the GHS-R1α antagonist [D-Lys³]-GHRP-6 (i.c.v.) completely antagonized these antinociceptive effects, too. These results suggested that these fragments induced antinociceptive effects through central opioid receptors and GHS-R1α. In conclusion, our studies indicated that these active fragments of ghrelin could cross the brain-blood barrier and enter the brain and induce antinociceptive effects through central opioid receptors and GHS-R1α after intravenous injection.

The use of hysteroscopy in endometrial cancer: old questions and novel challenges

Endometrial cancer is the most common gynecological malignancy with a relatively good overall prognosis. It traditionally has two subtypes: type 1 (endometrioid carcinoma) and type 2 (non-endometrioid carcinoma). The prognosis is excellent for stage I endometrioid cancer, with a 5-year survival rate of 96%. However, the prognosis is much worse for women with high-risk endometrial cancer. Effective preoperative staging is important in order to tailor treatment and achieve optimal long-term survival. The majority of asymptomatic polyps detected by ultrasound are treated surgically. Conventionally, dilatation and curettage was performed to obtain a histological diagnosis, but nowadays hysteroscopy with biopsy is starting to be considered as the gold standard. Hysteroscopic resection seems to reduce the risk of underdiagnosed (atypical endometrial hyperplasia) endometrial cancer. To avoid the spread of malignant cells, hysteroscopy should be performed with concern to keep intrauterine pressure low. In comparison with cervical injection, the hysteroscopic method has a better detection rate in the para-aortic area during sentinel lymph node mapping. In the assessment of cervical involvement, the accuracy of magnetic resonance imaging is significantly higher than the accuracy of hysteroscopy. In fertility-sparing cases, hysteroscopic endometrium resection with progesterone therapy is an acceptable option.

The Impact of Spinal Anesthesia and Use of Oxytocin on Fluid Absorption in Patients Undergoing Operative Hysteroscopy: Results from a Prospective Controlled Study

Objective

The aim of this study was to determine if combining intravenous oxytocin infusion and spinal anesthesia will reduce the amount of glycine absorption in patients undergoing operative hysteroscopy.

Patients and Methods

A prospective controlled study was conducted in premenopausal patients who had hysteroscopic surgery including endometrial resection, endometrial polypectomy, myomectomy resection and uterine septal resection. The effect of combined spinal anesthetic with oxytocin infusion on fluid deficit was studied.

Results

A total of 88 patients were studied. Sixty-two cases were done under general anesthesia (control group) and 26 cases were performed with spinal anesthesia and the use of oxytocin infusion (study group). There was a statistically significant less mean fluid deficit in the study group than control group in the endometrial polypectomy patients (220±36 mL vs 392±178 mL, respectively, P value 0.010, 95% C.I.: 163–276) and the myomectomy patients (308±66 mL vs 564±371 mL, respectively, P value 0.003, 95% C.I.: 239–378). In the endometrial resections, there was also a statistically significant less mean fluid deficit in the study than the control group (P value ˂ 0.001). Regarding septal resection, there was no statistically significant difference in the mean fluid deficit between the two groups (P value 0.833).

Conclusion

Spinal anesthesia combined with intravenous oxytocin infusion in operative hysteroscopy results in a statistically significant reduction in the glycine fluid deficit than the general anesthesia. We also recommend studying the effects of this combination in operative hysteroscopy using bipolar devices with isotonic solutions.

Supraglottic jet oxygenation and ventilation for obese patients under intravenous anesthesia during hysteroscopy: a randomized controlled clinical trial

Background

Supraglottic jet oxygenation and ventilation (SJOV) can effectively maintain adequate oxygenation in patients with respiratory depression, even in apnea patients. However, there have been no randomized controlled clinical trials of SJOV in obese patients. This study investigated the efficacy and safety of SJOV using WEI Nasal Jet tube (WNJ) for obese patients who underwent hysteroscopy under intravenous anesthesia without endotracheal intubation.

Methods

A single-center, prospective, randomized controlled study was conducted. The obese patients receiving hysteroscopy under intravenous anesthesia were randomly divided into three groups: Control group maintaining oxygen supply via face masks (100% oxygen, flow at 6 L/min), the WNJ Oxygen Group with WNJ (100% oxygen, flow: 6 L/min) and the WNJ SJOV Group with SJOV via WNJ [Jet ventilator working parameters:100% oxygen supply, driving pressure (DP) 0.1 MPa, respiratory rate; (RR): 15 bpm, I/E; ratio 1:1.5]. SpO₂, P_ETCO₂, BP, HR, ECG and BIS were continuously monitored during anesthesia. Two-Diameter Method was deployed to measure cross sectional area of the gastric antrum (CSA-GA) by ultrasound before and after SJOV in the WNJ SJOV Group. Episodes of SpO₂ less than 95%, P_ETCO₂ less than 10 mmHg, depth of WNJ placement and measured CSA-GA before and after jet ventilation in the WNJ SJOV Group during the operation were recorded. The other adverse events were collected as well.

Results

A total of 102 patients were enrolled, with two patients excluded. Demographic characteristics were similar among the three groups. Compared with the Control Group, the incidence of P_ETCO₂ < 10 mmHg, SpO₂ < 95% in the WNJ SJOV group dropped from 36 to 9% (P = 0.009),from 33 to 6% (P = 0.006) respectively,and the application rate of jaw-lift decreased from 33 to 3% (P = 0.001), and the total percentage of adverse events decreased from 36 to 12% (P = 0.004). Compared with the WNJ Oxygen Group, the use of SJOV via WNJ significantly decreased episodes of SpO₂ < 95% from 27 to 6% (P = 0.023), P_ETCO₂ < 10 mmHg from 33 to 9% (P = 0.017), respectively. Depth of WNJ placement was about 12.34 cm in WNJ SJOV Group. There was no significantly difference of CSA-GA before and after SJOV in the WNJ SJOV Group (P = 0.234). There were no obvious cases of nasal bleeding in all the three groups.

Conclusions

SJOV can effectively and safely maintain adequate oxygenation in obese patients under intravenous anesthesia without intubation during hysteroscopy. This efficient oxygenation may be mainly attributed to supplies of high concentration oxygenation to the supraglottic area, and the high pressure jet pulse providing effective ventilation. Although the nasal airway tube supporting collapsed airway by WNJ also plays a role. SJOV doesn’t seem to increase gastric distension and the risk of aspiration. SJOV can improve the safety of surgery by reducing the incidence of the intraoperative involuntary limbs swing, hip twist and cough.

Trial registration

Chinese Clinical Trial Registry. Registration number, ChiCTR1800017028, registered on July 9, 2018.