ABSTRACT
OBJECTIVE: To determine the median effective concentration (EC50) of remifentanil to inhibit pupillary reflex dilation (PRD) induced by endotracheal intubation using a modified sequential test method. METHODS: In this prospective study, 34 patients undergoing elective surgery under general anesthesia were selected. The induction of anesthesia was started using propofol with an effect-site concentration (Ce(pro)) of 4.0 µg/mL. The effect-site concentration of remifentanil (Ce(Remi)) was set according to the modified sequential test method, with 0.42 ng/mL as the initial concentration for the first patient. The gradient ratio was 1.1. The Ce(Remi) of each patient was determined by whether the PRD of the previous patient disappeared during endotracheal intubation. If the PRD disappeared, a lower concentration was applied. Otherwise, a higher concentration was applied. The experiment ended after 9 crosses of PRD disappearance-presence and PRD presence-disappearance. The EC50 of remifentanil and 95% confidence interval (CI) were calculated using the Dixon and Massey's method. The Probit regression procedure was used to derive the EC50, 95% effective concentration (EC95) of remifentanil and their 95% CIs. RESULTS: The EC50 of remifentanil to inhibit PRD induced by endotracheal intubation was 4.41 ng/mL (95% CI, 4.32 to 4.49 ng/mL) and the EC95 was 5.24 ng/mL (95% CI, 4.78 to 7.68 ng/mL). In 34 patients, the time to reach the maximum change in heart rate, systolic blood pressure, mean arterial pressure and Bispectral index was 75.00 (60.00-98.00) s, 95.00 (75.00-133.00) s, 95.00 (75.00-135.00) s, and 100.00 (78.00-113.00) s, respectively, which was significantly longer than the time (42.00 (25.00-47.00) s) needed for pupillary diameter (P<0.05). CONCLUSION: The EC50 of remifentanil to inhibit PRD induced by endotracheal intubation was 4.41 ng/mL and the EC95 was 5.24 ng/mL. The time to reach the maximum pupillary diameter change was shorter than the time needed for heart rate, blood pressure, and Bispectral index. This prospective study was registered in the China Clinical Trials Registration Center (ChiCTR2100043771, https://www.chictr.org.cn).
ABSTRACT
OBJECTIVE: To evaluate the effect of dexmedetomidine on intracranial pressure (ICP) in patients undergoing gynecological laparoscopic surgery in Trendelenburg position through ultrasonographic measurement of optic nerve sheath diameter (ONSD). METHODS: Ninety patients underwent total laparoscopic hysterectomy were selected as research subjects in this prospective study. These patients were divided into a dexmedetomidine group (n=45) and a control group (n=45) using a random number table. The dexmedetomidine group was pumped with 0.5 µg/kg dexmedetomidine (20041731, Yangtze River Pharmaceutical Group, China) 10 min before the anesthesia induction, followed by a continuous pump of 0.5 µg/(kg·h) until the end of the surgery, and the control group was pumped with 0.5 µg/(kg·h) 0.9% sodium chloride solution. Patients in both groups were assisted with mechanical ventilator after endotracheal intubation by rapid induction. Intraoperatively, the pneumoperitoneum pressure was maintained at 14 mmHg, and the bispectral index was maintained at 40 to 60. We recorded ONSD measured with ultrasonography in both groups at 5 min before induction of anesthesia in supine position (T1), 5 min after CO2 pneumoperitoneum in Trendelenburg position (T2), 30 min after CO2 pneumoperitoneum in Trendelenburg position (T3), 60 min after CO2 pneumoperitoneum in Trendelenburg position (T4) and 5 min after the close of pneumoperitoneum in supine position (T5). The cerebral oxygen metabolism indicators of the two groups at different time periods were compared, including jugular venous oxygen saturation (SjvO2), arterial content and arterial-to-internal jugular difference (Da-jvO2), cerebral oxygen extraction rate (CERO2). Heart rate (HR) and mean arterial pressure (MAP) were also recorded at T1-T5. Besides, American Society of Anesthesiologists (ASA) grade, time of endotracheal extubation, recovery time for orientation and postoperative adverse reactions were recorded in each group. RESULTS: There were significant differences in ONSD at T2 ((4.77±0.14) mm vs. (4.98±0.13) mm), T3 ((5.19±0.15) mm vs. (5.53±0.14) mm), T4 ((5.10±0.11) mm vs. (5.27±0.13) mm) and T5 ((4.71±0.12) mm vs. (4.4±0.16) mm) between the two groups (all P<0.05), and obvious differences were also found within groups when comparing the ONSD at T2-T5 to that at T1 (P<0.05). There were also significant differences in SjvO2, Da-jvO2 and CERO2 between the control group and the dexmedetomidine group at T2-T5 (all P<0.05), and obvious differences were found within groups when comparing the indices at T2-T5 to those at T1 (P<0.05). The incidences of postoperative dizziness (20.00%), nausea and vomiting (17.78%), and headache (13.33%) in the dexmedetomidine group and were significantly lower than those in the control group (55.56%, 48.89% and 42.22%, respectively; all P<0.05). At T2-T5, dexmedetomidine group had lower HR than control group (P<0.05), while no differences were found in MAP between the two groups (P>0.05). There were also no differences in ASA grade, time of endotracheal extubation, and recovery time for orientation between the two groups (both P>0.05). CONCLUSION: Dexmedetomidine can effectively decrease the occurence of increased ICP in patients undergoing gynecological laparoscopic surgery in Trendelenburg position, improve brain oxygen metabolism, and reduce the incidences of postoperative dizziness, nausea and vomiting as well as headache (China Clinical Trials Registration Center, registration number: ChiCTR2100052046, https://www.chictr.org.cn).
ABSTRACT
OBJECTIVE: To investigate the effects of ultrasound-guided stellate ganglion block (SGB) on the supply and demand balance of cerebral oxygen in patients with permissive hypercapnia (PHC) undergoing shoulder arthroscopy in a beach chair position (BCP). METHOD: In this prospective study, a total of 86 patients who had shoulder arthroscopy were enrolled and divided into the stellate ganglion block group (SG group, n=43) and the control group (CN group, n=43) using a random number table method. Ultrasound-guided SGB was performed on patients' operation side at the 6th cervical vertebra (C6) anterior transverse tubercle level. Patients in the SG group were injected with 6ml mixture of 0.25% ropivacaine hydrochloride and 1% lidocaine hydrochloride, and those in the CN group with an equal amount of 0.9% normal saline (NS). The patients of both groups were placed in BCP for shoulder arthroscopy, and rapid induction of endotracheal intubation was performed for assisted or mechanical ventilation. Ventilation strategy was adjusted to gradually increase pulmonary end-tidal CO2 (PETCO2) during surgery. The rSO2 levels of patients in both groups were recorded 10 min after being placed in supine position in the operation room (T0), 10 min after SGB (T1), 10 min after anesthesia induction in supine position (T2), 10 min after anesthesia induction in beach chair position (T3), 30 min after PETCO2 was stabilized at 35 to 40 mmHg (T4) during surgery, and 30 min after PETCO2 was stabilized at 45 to 50 mmHg (T5), respectively. The cerebral oxygen metabolic measures, including saturation of jugular bulb venous oxygen (SjvO2), difference in artery-jugular venous oxygen content (DajvO2) and cerebral oxygen extraction rate (CERO2) of patients in the two groups at the time point mentioned above were compared. Hemodynamic parameters including arterial carbon dioxide partial pressure (PaCO2), mean arterial pressure (MAP), heart rate (HR) and Saturation of Pulse Oxygen (SpO2) were recorded. Cerebral desaturation episodes, nausea, vomiting and the use of vasoactive drugs during surgery were also recorded. The Mini-Mental State Examination score (MMSE) was recorded 1 day before and after surgery. RESULTS: There was no significant difference in the comparison of SjvO2, Da-jvO2, CERO2, PaCO2, MAP, HR and SpO2 between the two groups at T0-T5 (P>0.05); no significant differences were found in intra-group comparison of SjvO2, Da-jvO2, CERO2 at T0-T4 (P>0.05); the level of SjvO2 at T5 was higher than that at T4, and the levels of Da-jvO2 and CERO2 at T5 were markedly lower than those at T4 (P<0.05). No significant differences were found in the inter-group comparison of MAP, HR and SpO2 at T0-T5 (P>0.05), while PaCO2 was significantly higher at T4 than that at T5 (P<0.05). The rSO2 levels of patients in both groups significantly decreased at T3, as compared with those at T0 (P<0.05); the rSO2 levels markedly increased at T5 than those at T4 (P<0.05); and the rSO2 levels showed more significant increase in SGB group than those in the CN group as the level of PETCO2 rose. CONCLUSION: Permissive hypercapnia resulting from proper ventilation can significantly increase the rSO2 levels in patients who undergo shoulder arthroscopy in BCP, the effect of which was enhanced by SGB on patients' operation side to maintain well-balanced demand and supply of cerebral oxygen. (China Clinical Trial Registry, registration number ChiCTR2000033385, https://www.chictr.org.cn).
ABSTRACT
BACKGROUND: During the Coronavirus Disease 2019 (COVID-19) pandemic, emergency departments and fever clinics nurses acted as gatekeepers to the health care system. To manage the psychological problems that these nurses experience, we should develop appropriate training and intervention programs. OBJECTIVE: To identify the impact of COVID-19 on the psychology of Chinese nurses in emergency departments and fever clinics and to identify associated factors. METHODS: This online cross-sectional study recruited participants through snowball sampling between 13 February and 20 February 2020. Nurses self-administered the online questionnaires, including a general information questionnaire, the Self-Rating Anxiety Scale, the Perceived Stress Scale-14, and the Simplified Coping Style Questionnaire. RESULTS: We obtained 481 responses, of which 453 were valid, an effective response rate of 94.18%. Participants who had the following characteristics had more mental health problems: female gender, fear of infection among family members, regretting being a nurse, less rest time, more night shifts, having children, lack of confidence in fighting transmission, not having emergency protection training, and negative professional attitude. CONCLUSION: Effective measures are necessary to preserve mental health of nurses in emergency departments and fever clinics. These include strengthening protective training, reducing night shifts, ensuring adequate rest time, and timely updating the latest pandemic situation.
ABSTRACT
OBJECTIVE: To investigate the effect of individualized positive end-expiratory pressure (PEEP) titration on intraoperative respiration and circulation in elderly patients undergoing spinal surgery in prone position under general anesthesia. METHODS: We prospectively selected 80 elderly patients (39 males and 41 females) aged over 65 years old, at American Society of Anesthesiologists (ASA) grade II or III, who underwent elective prone spinal surgery under general anesthesia, for this study. These patients were randomly divided into titration group and control group, with 40 cases in each group. PEEP of the titration group was increased from 0 to 20 cmH2O by steps of 2 cmH2O. For the control group, PEEP was constantly at 5 cmH2O and ventilation was maintained throughout the surgery. Dynamic pulmonary compliance (Cdyn) measurements were recorded when each PEEP level was kept for 1 min during titration, and individualized PEEP was determined by maximal Cdyn. MAP (mean arterial pressure), heart rate (HR), and CVP (Central venous pressure) were recorded at the set of prone position (T0), PEEP ventilation for 10 min (T1), 30 min (T2), 60 min (T3), end of surgery (T4), and 20 min after extubation (T5). Mean airway pressure (Pmean) and Cdyn were recorded from T0 to T4. Blood gas analysis was performed from T0 to T5 to calculate intrapulmonary shunt fraction (Qs/Qt) and OI (PaO2/FiO2). The rate of phenylephrine use during mechanical ventilation and the incidence of postoperative pulmonary complications were also recorded. RESULTS: The individualized PEEP obtained by titration for 1 min in the titration group was (12.38±2.67) cmH2O, which was significantly higher than the 5 cmH2O in constant PEEP of the control group (P<0.05). There was no significant difference in MAP, HR, and CVP between the two groups at different time points, and no significant difference was noted in Pmean between the two groups from T0 to T4 (all P>0.05). From T2 to T4, Cdyn was significantly higher, and Qs/Qt was lower in the titration group than those in the control group (all P<0.05). From T2 to T5, the OI in the titration group was significantly higher than that in the control group (P<0.05). The rate of phenylephrine use was significantly higher in the titration group than that in the control group (10 patients (25%) vs. 3 patients (8%), P<0.05). The incidence of postoperative pulmonary complications in the titration group was significantly lower than that in the control group (2 cases (5%) vs. 8 cases (20%), P<0.05). CONCLUSION: Compared with a constant PEEP of 5 cmH2O, intraoperative individualized PEEP titration in elderly patients undergoing spinal surgery in prone position can improve oxygenation, reduce intrapulmonary shunt and postoperative pulmonary complications. (Chinese Clinical Trial Registry, registration number ChiCTR2000040722, https://www.chictr.org.cn).
