Influence of anesthesia on gastrointestinal endoscopy: A large-scale survey of 50 public hospitals in China : Chinese Medical Journal

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Influence of anesthesia on gastrointestinal endoscopy: A large-scale survey of 50 public hospitals in China

Hou, Haijun1; Tian, Ming1; Liu, Fukun1; Xue, Fushan1; Zhang, Shutian2,

Editor(s): Ni, Jing

Author Information
Chinese Medical Journal ():10.1097/CM9.0000000000002664, April 27, 2023. | DOI: 10.1097/CM9.0000000000002664

To the Editor: In recent years, anesthesia for gastrointestinal endoscopy (GIE) has been widely used for early gastrointestinal cancer screening. Approximately 82% of gastroscopies are performed under sedation/anesthesia in Germany, and 98% of colonoscopies are performed under sedation/anesthesia in the United States.[1,2] Increasingly, more studies are proving the beneficial effects of anesthesia on GIE. Nevertheless, patients and even endoscopists still have concerns about performing GIE under anesthesia. We performed a multicenter prospective observational cohort study to identify the effect of anesthesia on compliance, satisfaction, and safety in Chinese patients undergoing GIE.

The study protocol was approved by the ethics committee and institutional review board of the Beijing Friendship Hospital (No. 2016-P2-040-02). Written informed consent was obtained from all patients the day before the endoscopic examination. We included patients who underwent GIE at our endoscopy center from September 5, 2016 to September 18, 2016 in 50 public hospitals in China [Supplementary Table 1,]. The inclusion criteria were an age of 18–80 years, performance of diagnostic gastroscopy or colonoscopy (including biopsy), an American Society of Anesthesiologists (ASA) score of I to III, body mass index (BMI) of 18–30 kg/m2, and the ability to fill out a survey form and provide informed consent. The exclusion criteria were emergency GIE or a combined procedure involving upper and lower endoscopy; difficult airway, such as that in patients with severe obstructive sleep apnea–hypopnea syndrome; severe pyloric obstruction with gastric retention; history of failure of important organs (e.g., heart failure, renal failure, or Child–Pugh class C liver failure), acute upper gastrointestinal hemorrhage with shock, history of intolerance to anesthesia, history of severe anemia, history of serious neurologic disease, or drug abuse; no accompanying guardian; and communication disorders. Based on the operation type (gastroscopy or colonoscopy) and patients' preference (with or without anesthesia), the patients were divided into four groups: anesthetic gastroscopy, non-anesthetic gastroscopy, anesthetic colonoscopy, and non-anesthetic colonoscopy.

Before entering the operation room, defoaming agents and lidocaine were given orally to all patients. After entering the operation room, all patients were provided with pure oxygen to increase their oxygen reserve. The patients in the anesthetic endoscopy groups were intravenously administered 5.0–7.5 μg of sufentanil, followed by 2.0–2.5 mg/kg of propofol or 0.3–0.5 mg/kg of etomidate before the operation, and anesthesia was given with a continuous propofol infusion of 4–8 mg∙kg-1∙h-1 during the procedures. After completion of endoscopy, the patients were transferred to the post-anesthesia care unit for at least 2 h to rule out immediate post-endoscopic complications. The post-anesthesia care unit discharge criterion was a modified Aldrete score of ≥9. The patients in the non-anesthetic endoscopy groups received no intravenous anesthetics. All GIE procedures were performed by experienced digestive endoscopists.

For all patients, vital signs were routinely monitored and recorded every 2 min by anesthesiologists. Anesthesia-related adverse events during endoscopy were recorded including hypertension, hypotension, tachycardia, bradycardia, apnea, injection pain, and myoclonus, as were post-endoscopy discomforts including hiccups, nausea, vomiting, abdominal pain, bloating, dizziness, and headache. Before and after endoscopy, the anesthesiologists administered two short structured questionnaires to all patients and endoscopists to collect data regarding demographics, compliance, and satisfaction.

As per the study protocol, 4296 patients were recruited for the study. This prospective, large-sample, and multicenter study was performed to report the influence of anesthesia on GIE in China. All participating hospitals were public hospitals, and the enrolled patients were largely representative of the general population of Chinese patients undergoing GIE. Hence, this study could provide some important insights into clinical decision-making.

For demographic data, there was no statistical difference in age, BMI and ASA physical status between each two groups. Female patients in gastroscopy group (57.2%, 887/1550) and in colonoscopy group (53.4%, 326/611) both showed a greater preference for anesthetic endoscopy than did male patients in these two groups (gastroscopy, 42.8%, 663/1550, χ2 = 12.79, P <0.001; colonoscopy, 46.6%, 285/611, χ2 = 9.19, P = 0.002). Similarly, the proportion of highly educated patients (high school or above) in anesthetic gastroscopy group (70.3%, 1089/1550) and in anesthetic colonoscopy group (78.7%, 481/611) were both higher than those in non-anesthesia groups (gastroscopy, 63.2%, 973/1539, χ2 = 17.22, P <0.001; colonoscopy, 73.3%, 437/596, χ2 = 9.19, P = 0.002). This suggests that women and patients with a higher education background have a greater demand for high-comfort medical care.

Data regarding compliance, satisfaction, and safety in the four groups are shown in Table 1. Specifically,willingness to repeat endoscopy on time for all patients was significantly higher in anesthetic than in non-anesthetic endoscopy groups (gastroscopy, 96.8% [1500/1550] vs. 91.5% [1408/1539], χ2 = 39.12; colonoscopy, 95.4%[583/611] vs. 89.6%[534/596], χ2 = 14.81; P both <0.001). The anesthetic endoscopy groups also had higher patient and endoscopist satisfaction rates. These results suggest that anesthesia improves patients' compliance with GIE and enhances their satisfaction. These findings are consistent with those of Abraham et al[3] who reported that 79% of patients in the anesthesia group were satisfied with their level of comfort (vs. 47% in the non-anesthesia group) and that 81% of the patients in the anesthesia group were willing to undergo repeat endoscopy (vs. 65% in the non-anesthesia group). Baudet and Aguirre-Jaime[4] also showed that satisfaction survey scores were significantly higher in patients with anesthesia than in patients without anesthesia (22.8 ± 2.7 vs. 18.6 ± 2.3). The degree of willingness to undergo repeat endoscopy was significantly greater in patients with anesthesia than in those without anesthesia (70% vs. 25%, P <0.001). These results confirmed patients' demand for pain-free medical services and high-comfort medical treatment. Additionally, the higher biopsy rate and lesion detection rate but shorter inspection time found in the anesthesia groups further increased the patients' and endoscopists' satisfaction.

Table 1 - Compliance, satisfaction, and safety of patients in four endoscopy groups (N = 4296)
Gastroscopy Colonoscopy
Variables Non-anesthesia (N = 1539) Anesthesia (N = 1550) Statistics value P value Non-anesthesia (N = 596) Anesthesia (N = 611) Statistics value P value
Compliance data
Willingness to repeat endoscopy on time for all patients 1408 (91.5) 1500 (96.8) 39.12* <0.001 534 (89.6) 583 (95.4) 14.81 <0.001
First-visit patients 786 (51.1) 756 (48.8) 1.63 0.202 393 (65.9) 401 (65.6) 0.01 0.910
Willingness to repeat endoscopy on time 711 (90.5) 726 (96.0) 18.87 <0.001 360 (91.6) 383 (95.5) 5.04 0.025
Willingness to repeat endoscopy with anesthesia 376 (52.9) 715 (98.5) 408.62 <0.001 182 (50.6) 378 (98.7) 231.66 <0.001
Re-visit patients 753 (48.9) 794 (51.2) 1.63 0.202 203 (34.1) 210 (34.4) 0.01 0.910
Repeated endoscopy on time 601 (79.8) 667 (84.0) 4.59 0.032 162 (79.8) 184 (87.6) 4.64 0.031
Previous endoscopy with anesthesia 54 (9.0) 612 (91.8) 868.53 0.000 22 (13.6) 163 (86.4) 194.81 0.000
Satisfaction data
Patients' satisfaction 1176 (76.4) 1510 (97.4) 300.38 <0.001 467 (78.4) 591 (96.7) 94.10 <0.001
Endoscopists' satisfaction 1132 (73.6) 1485 (95.8) 295.38 <0.001 479 (80.4) 572 (93.6) 47.05 <0.001
Safety data
Adverse events during endoscopy 680 (44.2) 158 (10.2) 451.33 <0.001 77 (12.9) 36 (5.9) 17.56 <0.001
Discomforts after endoscopy 690 (44.8) 311 (20.1) 216.31 <0.001 241 (40.4) 115 (18.8) 67.78 <0.001
Biopsy rate 695 (45.2) 829 (53.5) 21.41 0.000 191 (32.0) 233 (38.1) 4.91 0.027
Lesion detection rate 486 (69.9) 622 (75.0) 4.96 0.026 160 (83.8) 211 (90.6) 4.42 0.036
Inspection time (min) 8.8 ± 2.4 5.9 ± 1.9 11.68* <0.001 19.1 ± 6.5 15.8 ± 4.3 13.69* <0.001
Data are presented as n (%) or mean ± standard deviation.* indicates values calculated using independent-samples t test, while other statistics value are calculated using chi-square test.

Few studies have discriminated the frequency of visits. In our study, first-visit patients in the anesthetic endoscopy group were willing to undergo anesthesia during the next visit. Additionally, more re-visit patients in the anesthetic endoscopy groups had previously undergone endoscopy with anesthesia. These results indicate patients' actual situations regarding their willingness to undergo repeat endoscopy with anesthesia and confirm that anesthesia can significantly improve patients' compliance with GIE under anesthesia on time.

No serious adverse events occurred in this study. The incidences of adverse events during endoscopy (gastroscopy, 44.2% [680/1539] vs. 10.2%158/1500, χ2 = 451.33; colonoscopy, 12.9% [77/596] vs. 5.9% [36/611], χ2 = 17.56; both P <0.001) and discomforts after endoscopy (gastroscopy, 44.8% [690/1539] vs. 20.1% [311/1550], χ2 = 216.31; colonoscopy, 40.4% [241/596] vs.18.8% [115/611], χ2 = 67.78; both P <0.001) were higher in the non-anesthetic than in the anesthetic endoscopy groups. These prove the safety of anesthesia for GIE. Prior studies have indicated that anesthesia-related cardiovascular and respiratory complications in patients undergoing GIE were attributed to excessive sedation/anesthesia.[5]

Based on our questionnaire data and clinical observations, anesthesia increased patients' compliance, as shown by greater willingness to undergo the next GIE procedure under anesthesia; improved patients' and endoscopists' satisfaction; and reduced adverse events. GIE under anesthesia should be advocated.

This study has some limitations. First, this study was unblinded because the grouping was mostly based on the patients' preference. Second, there were possible confounding factors with respect to the patients' willingness to undergo repeat endoscopy and patients' satisfaction, such as satisfaction with the medical environment, service provided by the doctor and nurse, and disease severity. The impact of economic factors on patients' willingness to choose anesthetic endoscopy has not yet been established. Some patients did not acknowledge that they refused anesthetic endoscopy because of the cost. Third, the study did not make a detailed distinction between adverse events and discomforts. The patients' symptoms were diverse, coexisting, and short term; symptoms were thus difficult to summarize. Fourth, the study lacked a cost-effectiveness analysis. Fifth, anesthetic agents are associated with potential risk compared with non-anesthetic endoscopy. Non-anesthetic procedures are recommended for some special individuals such as elderly patients and high-risk patients with cardiopulmonary disease. However, we did not elaborate on this aspect. We have conducted a study on the impact of different sedation depths on adverse cardiovascular events in elderly patients, and further reports will be evaluated by our team in future studies.


We thank all the co-workers from the Departments of Anesthesiology and Endoscopy centers in 50 public hospitals.

Conflicts of interest



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