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Sudden Collapse During Upper Gastrointestinal Endoscopy: Expect the Unexpected

Minna Wieck, MD | August 25, 2021
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The Case

A seven-year-old girl had esophageal stenosis due to ingestion of a caustic substance as an infant (Note: although not specified in this case, the most common caustic substances ingested by children are household cleaning agents). She required recurrent upper endoscopy with esophageal dilation under general anesthesia. During the procedure, she was fully monitored with a continuous arterial oxygen saturation probe, heart rate monitors, two-lead electrocardiography, continuous capnography, and non-invasive arterial blood pressure measurements.

The attending gastroenterologist and endoscopist were serially dilating the esophagus with larger and larger rigid dilators when the patient suddenly developed hypotension with a marked decrease in end-tidal carbon dioxide (CO2). She was immediately given a fluid bolus, phenylephrine, and 100% oxygen but still developed cardiac arrest. Cardiopulmonary resuscitation (CPR) was initiated with cardiac massage, but she could not be resuscitated and died.

The Commentary

By Minna Wieck, MD

Gastrointestinal Endoscopy: Understanding the Risks

Gastrointestinal (GI) endoscopy has evolved significantly in the past few decades into a critical and widely available tool for treating many diseases in children.1 Like all tools in a physician’s armamentarium, it is not without risk of serious complications. This risk varies depending on the indication, patient, type of procedure, and experience of the proceduralist. Consequently, discussions among all involved health care providers on how to provide the safest, most cost effective, and least traumatizing care for children are crucial.

The most common complications of endoscopy are bleeding, bowel perforation, infection, and reactions to administered medications.2,3 The Pediatric Clinical Outcomes Research Initiative reports an overall complication rate of 2.3% during upper GI procedures.4 The most serious major complication of endoscopic dilation is perforation with a reported incidence ranging from 0-9%, depending on the underlying etiology of the stricture.5 Complications related to sedation are more common than these technical complications, however.3,6,7 The incidence of adverse cardiopulmonary events during GI endoscopy in children has been reported to range from 1.5-4.8%.3,8,9 These adverse events include respiratory arrest, myocardial infarction, hypoxia, apnea, laryngeal spasm, bradycardia, hypotension, aspiration, and vomiting.5 Risk factors for cardiopulmonary events include patient age (infants are at higher risk than older children); pre-existing pulmonary, cardiac, and/or neurologic disease; “difficult” airways (due to congenital abnormalities, anatomic variants, or comorbidities such as reactive airway disease, etc.); and obesity.6,8-10

Upper endoscopy affects children’s respiratory function through several mechanisms. The required insufflation leads to an increase in peak inspiratory pressures, and this increase is more pronounced during dilation as the balloon pressure increases tracheal stress. Younger children (under age 2) demonstrate greater peak pressure increases than older children, possibly due to a more compliant and smaller, immature trachea.11 Air insufflation also distends the stomach, which can further decrease lung compliance. Unintended extubation during upper endoscopy, and mechanical obstruction of the airway due to bleeding or other objects, have also been reported.11

Although no autopsy was performed and thus the cause of death cannot be proven, the child in this case most likely had a massive air embolism and cardiac arrest. This complication is considered a “never event” or “serious reportable event” by the National Quality Forum (“2C. Patient death or serious injury associated with intravascular air embolism that occurs while being cared for in a healthcare setting”).12 In this situation, healthcare organizations should perform further analysis to identify causes and contributing factors. Failures of this type almost always have multiple contributing factors. Methods such as root cause analysis, interviews, and human and environmental factor analysis are used to examine what happened from different perspectives. One of the main goals is to understand the healthcare work processes that could be changed to eliminate or decrease the risk of this event ever happening again. High reliability organizations recognize that process variability is the underlying source of failures and minimizing variability lowers the incidence of catastrophic events.

Air embolism is a particularly serious complication that results from pressurized air entering into an exposed vessel during insufflation.13 The vessel may be exposed due to underlying disease (e.g., ulcers, mucosal inflammation), scope-induced injury, and/or muscular wall disruption from dilation or other interventions.

Approach to Improving Safety: Technical Considerations

To minimize the risk of adverse events associated with pediatric GI endoscopy, several steps can be taken. First, like any procedure, endoscopy should only be performed when indicated and the least invasive methods should be used. Esophageal strictures are one of the most common indications for endoscopic intervention in children. Dilations can be performed using a variety of dilators under endoscopic and/or fluoroscopic control with similar efficacy and complication rates.5 The etiology of the stricture and the experience of the proceduralist often determine which technique is chosen. Regardless of the specific dilators used, the operator must proceed cautiously and apply a measured degree of force to minimize overdistension and trauma to the esophagus. If endoscopy is utilized, decreased insufflation and lower dilation pressures may be necessary to avoid desaturation and permit adequate ventilation.

Comprehensive monitoring, as was done for the patient in this case, is also essential. Adult guidelines recommend monitoring blood pressure, oxygenation, and heart rate along with clinical observation of cardiopulmonary status.14 For children, since serious cardiopulmonary events are rare, there are no high-quality data indicating whether specific monitoring protocols decrease the risk of an adverse event.9 At a minimum, however, pulse oximetry and capnography are recommended and have been shown to decrease the incidence of hypoxia in children.6,10,14 These monitors facilitate early recognition of concerning changes that warrant intervention by either the proceduralist or anesthesiologist.

In children, guidelines and several studies recommend performing upper endoscopy under general anesthesia or under deep sedation to minimize patient stress and anxiety while optimizing the performance of the procedure.1,6 No specific sedation protocol has been established as the best, however.5,6 Patient factors, procedural factors, institutional protocols, and the availability of an anesthesiologist all affect the choice and risks of sedation.

The benefits of CO2 insufflation in pediatric gastrointestinal endoscopy are unclear. The bowel does not resorb air well and post-procedural pain is often attributed to gas bloat. CO2 is absorbed much more rapidly and, in adults, CO2 insufflation significantly reduced post-procedural discomfort.15 Data from pediatric patients are scarce and less convincing. A recent meta-analysis of pediatric randomized controlled trials concluded that CO2 insufflation may decrease the incidence of pain and bloating but the results were not statistically significant.15 The authors hypothesized that the difference in effect between children and adults may have been due to the more prevalent use of general anesthesia in children. Of note, CO2 insufflation was associated with higher CO2 levels in two trials but no related pulmonary complications were reported.15 Thus, routine use of CO2 insufflation in children can be considered but has not been recommended.3,5,15  

If an adverse event occurs, treatment starts with recognition. This patient’s hypotension and rising CO2 were appropriately recognized and triggered application of increased oxygen. In such situations, the patient can also be stimulated to take deep breaths or given reversal agents, depending on the level of sedation. This patient already had an endotracheal tube in place but when that is not the case, non-invasive or even invasive devices (e.g., nasal cannula, mask ventilation) may be required for ventilation and airway protection.7 Of course, rapid treatment of adverse events requires that all reversal drugs and airway devices are immediately available.

If gas embolism is suspected, the procedure and insufflation should be stopped immediately. Any residual insufflated area should be suctioned out and the scope should be withdrawn to allow further decompression. Fluid resuscitation and pressors, if needed, should be initiated to treat the hypotension. Placing the patient in Trendelenburg and left lateral position minimizes the risk of cerebral embolization and can facilitate aspiration of a gas embolism via a central venous catheter.13 If needed, CPR should be initiated according to Pediatric Advanced Life Support (PALS) and/or Advanced Cardiac Life Support (ACLS) protocols.

Approach to Improving Systemic Safety: Non-technical Considerations

Even with implementation of all available preventive measures, serious adverse events still occur. In these situations, non-technical skills like team communication become crucial for saving lives. Poor communication has been identified as a key contributor to failure to rescue, defined as mortality after a surgical complication.16,17 Even when standard resuscitation protocols exist, poor communication is highly correlated with inferior protocol compliance.18 Thus, effective communication at multiple time points can minimize the incidence and impact of adverse events.

Before the procedure, a “checklist” conversation between the proceduralist and anesthesiologist (if applicable) is recommended to discuss the optimal location (i.e., main operating room or procedural suite), timing, type of sedation, and patient readiness. A systematic assessment can help to identify patient and procedural risk factors that warrant additional workup, consultations, or interventions. A suggested pre-endoscopy checklist from the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition is available for review.3 Failure to appropriately assess the patient and establish a unified plan before the procedure begins may increase the risk for unexpected adverse events.

Once a complication occurs, escalation of care requires three fundamental communication steps as identified by Johnston et al.: (1) Recognition of patient deterioration; (2) Prompt communication to the appropriate providers; and (3) Initiation of definitive management.15 Barriers to successful completion of these steps include clinical inexperience, hierarchy, overconfidence, and poor inter-professional communication. Delayed escalation of care is associated with higher mortality rates,19 emphasizing the importance of effective communication to patient safety. Implementing interventions to address these barriers, such as requiring multidisciplinary education for junior team members, establishing formal protocols for escalation of care, carrying out simulation training, or utilizing more streamlined communication technologies, can help at both an individual and system-wide level.

Features of effective communication during resuscitation are an area of burgeoning research. Communication during resuscitation suffers from an abundance of irrelevant talking, medically colloquial statements, non-specific requests, and repeated calls for interventions.18,20 In contrast, examples of ideal communication include calling team members by name or clinical role; actively sharing information to generate a shared mental model; ordering medications by name, dose, and route; and verifying that information has been communicated.18 Ideally, all team members, not just physicians or team leaders, actively participate in sharing information. Closed-loop communication has been identified as a key characteristic that results in faster task completion during pediatric trauma resuscitation.21

To prevent rare but serious adverse events, simulation is an effective means for improving both technical and non-technical skills such as communication, leadership, and teamwork.22 For example, utilization of a standardized resuscitation lexicon during neonatal resuscitation exercises was associated with a trend toward faster initiation of appropriate interventions and fewer errors.23 In acute trauma resuscitation, simulation was associated with increased resuscitation knowledge, more completed tasks, and faster completion of those tasks.22 Thus, increased utilization of simulation may enhance patient safety by improving not only the technical aspects of endoscopy and resuscitation, but also the non-technical aspects such as communication.

Loop Closure

Regardless of the outcome of a procedure, the most important conversations are those held with the patient and their family. Beforehand, the proceduralist and anesthesiologist should proceed only after an honest and clear discussion of the indications, risks, benefits, and alternatives. If an adverse event has occurred and been recognized, it must be disclosed to the patient’s family or legal guardian as soon as possible. Communicating bad news is an important skill that forces us as physicians to put our commitment to our patients’ well-being above our own discomfort or guilt. It may well be the only conversation that really matters, for “if we do it badly, the patients or family members may never forgive us; if we do it well, they may never forget us.”24,25

Take-Home Points

  • Upper endoscopy in children is a generally safe, medically necessary, and effective procedure but does carry risk of significant harm.
  • Technical steps like using appropriate monitoring, minimizing insufflation and dilation pressures to the lowest level necessary, and, possibly, insufflating with CO2 can help mitigate these risks.
  • Additional education and training for care team members in escalation of care can also help mitigate the risks.
  • Improving communication both before and during the procedure may improve the success of rescue after medical complications.

Minna Wieck, MD
Assistant Professor of Surgery
Department of Surgery, Division of Pediatric Surgery
UC Davis Health


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This project was funded under contract number 75Q80119C00004 from the Agency for Healthcare Research and Quality (AHRQ), U.S. Department of Health and Human Services. The authors are solely responsible for this report’s contents, findings, and conclusions, which do not necessarily represent the views of AHRQ. Readers should not interpret any statement in this report as an official position of AHRQ or of the U.S. Department of Health and Human Services. None of the authors has any affiliation or financial involvement that conflicts with the material presented in this report. View AHRQ Disclaimers
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