Efficacy of carbon dioxide versus air insufflation according to different sedation protocols during therapeutic endoscopic retrograde cholangiopancreatography: prospective, randomized, double-blind study

Is Carbon Dioxide Insufflation During Endoscopy in Children as Safe and as Effective as We Think?

OBJECTIVES

Distension of the gastrointestinal lumen is crucial for visualization and advancement during endoscopic procedures. An increasing number of pediatric centers now use carbon dioxide (CO2) preferentially over air as many adult studies and a few pediatric studies have concluded that CO2 is better tolerated than air, especially for colonoscopy.

AIMS

The aim of the study was to determine if CO2 is as safe and as effective as air and if it reduces abdominal discomfort and distension in children undergoing upper endoscopy and colonoscopy.

METHODS

Double blinded, prospective, randomized clinical study. Patient- and nursing-reported outcomes of pain and distension were recorded. End tidal CO2 (EtCO2) was monitored continuously with a CO2-sampling nasal cannula for patients undergoing procedural sedation and via the endotracheal tube for those who were intubated.

RESULTS

One hundred seventy-eight patients with 180 procedures were enrolled, 91 procedures were randomized to receive CO2, and 89 to air. Groups did not differ significantly with respect to nursing-assessed abdominal discomfort, change in girth from baseline, or endoscopist-perceived ease of inflation. Use of CO2 was associated with transient spikes in the EtCO2 (≥60 mmHg) in a significant number of patients during sedated upper endoscopy without endotracheal intubation. There was a reduction of bloating and flatulence for all procedures in the CO2 group.

CONCLUSIONS

The benefits of using CO2 for insufflation were minimal in our patients. The observed transient elevations of EtCO2 during sedated upper endoscopy raise concerns of possible systemic hypercarbia. The wisdom of its routine use for all pediatric endoscopic procedures is questioned.

Efficacy and safety of carbon dioxide insufflation versus air insufflation during endoscopic retrograde cholangiopancreatography in randomized controlled trials: a systematic review and meta-analysis

Background and study aims  Ambient air is the most commonly used gas for insufflation in endoscopic procedures worldwide. However, prolonged absorption of air during endoscopic examinations may cause pain and abdominal distension. Carbon dioxide insufflation (CO ₂ i) has been increasingly used as an alternative to ambient air insufflation (AAi) in many endoscopic procedures due to its fast diffusion properties and less abdominal distention and pain. For endoscopic retrograde cholangiopancreatography (ERCP), use of CO ₂ for insufflation is adequate because this procedure is complex and prolonged. Some randomized controlled trials (RCTs) have evaluated the efficacy and safety of CO ₂ as an insufflation method during ERCP but presented conflicting results. This systematic review and meta-analysis with only RCTs evaluated the efficacy and safety of CO ₂ i versus AAi during ERCP. Methods  A literature search was performed using online databases with no restriction regarding idiom or year of publication. Data were extracted by two authors according to a predefined data extraction form. Outcomes evaluated were abdominal pain and distension, complications, procedure duration, and CO ₂ levels. Results  Eight studies (919 patients) were included. Significant results favoring CO ₂ i were less abdominal distension after 1 h (MD: -1.41 [-1.81; -1.0], 95 % CI, I² = 15 %, P  < 0.00001) and less abdominal pain after 1 h (MD: -23.80 [-27.50; -20.10], 95 %CI, I² = 9 %, P  < 0.00001) and after 6 h (MD: -7.00 [-8.66; -5.33]; 95 % CI, I² = 0 %, P  < 0.00001). Conclusion  Use of CO ₂ i instead of AAi during ERCP is safe and associated with less abdominal distension and pain after the procedure.

CO 2 vs. air insufflation in endoscopic ultrasonography: a prospective study

Background and study aims  Carbon dioxide (CO ₂ ) is being increasingly used for insufflation during endoscopy for safety and better tolerance. The role of CO ₂ during endoscopic ultrasonography (EUS) has not been studied yet. Our main aim was to compare the effects of CO ₂ vs. air insufflation on abdominal discomfort in patients undergoing EUS. Our secondary outcomes were to ascertain the effects of CO ₂ insufflation on image quality/visual artifacts and on the amount of sedation. Patients and methods  This was a prospective, controlled, single-blind, observational study. Abdominal discomfort was assessed before diagnostic EUS, and 1 and 3 hours post-procedure and recorded as a visual analogue scale. Image quality was also recorded as a 4-point scale from optimal to poor at four different scanning sites (esophagus, stomach, duodenal bulb and second portion). Results  A total of 198 patients were enrolled. We observed that CO ₂ resulted in less abdominal discomfort than air insufflation that was statistically significant at 3 hours ( P  = 0.048) but not at 1 hour after EUS ( P  = 0.112), probably due to the ongoing effects of sedation at the latter stage. On the other hand, no differences were found in the dose of sedation administered in the two groups. Image quality was significantly better in the CO ₂ group compared to the air group at all four different scanning sites ( P  < 0.01). Similarly, CO ₂ correlated with less visual artifacts and need of suction ( P  < 0.01). Conclusions  Similarly to previous findings with other endoscopic procedures, EUS was associated with improved scores for abdominal discomfort with CO ₂ rather than air insufflation. Moreover, overall EUS image quality was improved using CO ₂ insufflation. Future studies are warranted to ascertain whether CO ₂ insufflation should be regarded as the standard of care for diagnostic EUS.

Etomidate Sedation for Advanced Endoscopic Procedures

BACKGROUND AND STUDY AIM

Although propofol is widely used for sedation for endoscopic procedures, concerns remain regarding cardiopulmonary adverse events. Etomidate has little effect on the cardiovascular and respiratory systems, but patient satisfaction analysis is lacking. We compared the efficacy and safety of balanced propofol and etomidate sedation during advanced endoscopic procedures.

METHODS

As a randomized noninferiority trial, balanced endoscopic sedation was achieved using midazolam and fentanyl, and patients were randomly assigned to receive propofol (BPS) or etomidate (BES) as add-on drug. The main outcomes were sedation efficacy measured on a 10-point visual analog scale (VAS) and safety.

RESULTS

In total, 186 patients (94 in the BPS group and 92 in the BES group) were evaluated. BES did not show noninferiority in terms of overall patient satisfaction, with a difference in VAS score of -0.35 (97.5 % confidence interval -1.03 to ∞, p = 0.03). Among endoscopists and nurses, BES showed noninferiority to BPS, with differences in VAS scores of 0.06 and 0.08, respectively. Incidence of cardiopulmonary adverse events was lower in the BES group (27.7 versus 14.1 %, p = 0.023). Hypoxia occurred in 5.3 and 1.1 % of patients in the BPS and BES group (p = 0.211). Myoclonus occurred in 12.1 % (11/92) in the BES group. BES had lower risk of overall cardiopulmonary adverse events (odds ratio 0.401, p = 0.018).

CONCLUSIONS

BES was not noninferior to BPS in terms of patient satisfaction. However, BES showed better safety outcomes in terms of cardiopulmonary adverse events.

Efficacy of midazolam- versus propofol-based sedations by non-anesthesiologists during therapeutic endoscopic retrograde cholangiopancreatography in patients aged over 80 years

BACKGROUND AND AIM

As society ages, the need for endoscopic retrograde cholangiopancreatography (ERCP) is increasing. This prospective comparative study evaluated the safety and efficacy of midazolam- versus propofol-based sedations by non-anesthesiologists during therapeutic ERCP in patients over 80 years of age.

METHODS

A total of 100 patients over 80 years of age who required therapeutic ERCP were enrolled and randomly received midazolam + fentanyl (MF group) or propofol + fentanyl (PF group) sedation. Endoscopic sedation was titrated to a moderate level and carried out by trained registered nurses. Main outcome measurements were sedation safety in terms of cardiopulmonary components and efficacy measured on a 10-point visual analogue scale (VAS).

RESULTS

Regarding safety, hypoxia occurred in seven (14%) in the MF group and in eight patients (16%) in the PF group (P = 0.779). Increased O₂ supply was more frequent in the PF group (32% vs 42%), albeit not significantly so. There were no differences in the frequency of hypotension, bradycardia or tachycardia between the two groups. Mean VAS score for overall satisfaction with sedation by patients, endoscopists, and nurses and the scores for pain during the procedures were not different between the two groups. There was no significant difference in the procedure outcomes or rate of ERCP-related complications.

CONCLUSIONS

There were no significant differences of safety and efficacy between midazolam- and propofol-based sedation in patients over 80 years of age. Increased O₂ supply was more frequent in the propofol group, but the prevalence of hypoxia did not differ significantly.

Efficacy and safety of carbon dioxide insufflation versus air insufflation for endoscopic retrograde cholangiopancreatography: A meta-analysis update

BACKGROUND AND OBJECTIVE

Endoscopic retrograde cholangiopancreatography (ERCP) is essential for visualising the biliary tree and pancreatic ducts, and carbon dioxide (CO₂) insufflation during ERCP is considered an alternative technique to air insufflation for relieving post-procedural abdominal discomfort (abdominal pain and distension). The aim of the present study was to evaluate the effect of CO₂ insufflation on the remission of abdominal discomfort and the potential side effects by conducting a meta-analysis.

METHODS

The method recommended by the Cochrane Collaboration was employed to conduct a meta-analysis of randomised controlled trials (RCTs) of CO₂ insufflation versus air insufflation during ERCP. The PubMed, EMBASE, Cochrane Library, ISI Web of Science and China Biology Medicine disc (CBMdisc) databases were comprehensively searched.

RESULTS

Nine high-quality RCTs were reviewed. The updated meta-analysis showed that the CO₂ groups achieved a lower abdominal pain score [1-hour (SMD: -1.44, 95% CI: -2.76, -0.15), 3-hour (SMD: -1.17, 95% CI: -2.18, -0.16) and 6-hour (SMD: -1.39, 95% CI: -2.68, -0.10)], a lower abdominal distension score [1-hour (SMD: -1.05, 95% CI: -1.73, -0.38), 3-hour (SMD: -0.63, 95% CI: -1.10, -0.16) and 6-hour (SMD: -0.54, 95% CI: -0.99, -0.08)] and a lower overall rate of complications (OR: 0.59; 95% CI: 0.37, 0.93). There was no significant difference between the groups regarding abdominal discomfort immediately after recovery or 24-hour post-procedure. There was no evidence to indicate higher pressure of CO₂ (pCO₂) values in the CO₂ groups during the procedure when the patients were under sedation anaesthesia.

CONCLUSIONS

Compared to air insufflation, CO₂ insufflation is currently the preferred method for ERCP and decreases post-procedural abdominal pain and distension without significant side effects.

Effects of carbon dioxide insufflation during direct cholangioscopy on biliary pressures and vital parameters: a pilot study in porcine models

BACKGROUND AND AIMS

Direct per-oral cholangioscopy allows endoscopic visualization of the biliary tract. Insufflation with carbon dioxide (CO₂) is an alternative to saline solution irrigation during direct cholangioscopy. There are no data on maximal CO₂ insufflation in direct cholangioscopy without causing biliary barotrauma or fatal gas embolism. We aimed to evaluate the safety of increasing CO₂ insufflation in direct cholangioscopy without causing biliary barotrauma or fatal gas embolism.

METHODS

This was an in vivo animal study. Four domestic pigs, under general endotracheal anesthesia, were used. The first animal was used to validate the feasibility of direct cholangioscopy and biliary pressure measurements, after which all animals underwent laparotomy, insertion of a pressure transducer in the cystic duct, and direct transpapillary placement of the cholangioscope. The common bile duct (CBD) and cystic duct were ligated to contain the instilled gas and exclusively expose the biliary tree. Insufflation of CO₂ started at 200 mL/min and was continuously increased until there was evidence of bile duct rupture (as measured by a drop in intraductal pressures) or instability of vital signs (hypotension, bradycardia, bradypnea, O₂ desaturation). Necropsy was performed on all animals to assess the liver and biliary system for evidence of barotrauma.

RESULTS

CO₂ was insufflated up to 8 L/min without causing bile duct rupture or instability in vital signs despite increasing CBD pressure with insufflation. There was significant correlation between CO₂ flow with partial pressure of CO₂ in arterial blood (PaCO₂) (coefficient, 0.96-1.00; P < .01) and end tidal expired CO₂ (EtCO₂) (coefficient, 0.94-1.00; P < .01). However, the pulse rate, respiratory rate, arterial blood pressure, and O₂ did not correlate with the amount of CO₂ flow. There was no evidence of hepatic or biliary barotrauma on necropsy.

CONCLUSIONS

This pilot experience in porcine models suggests that CO₂ insufflation is safe for direct cholangioscopy and does not result in biliary barotrauma or vital signs instability.