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An Incomplete Anesthesia History Leads to Adverse Outcomes

Christian Bohringer, MD | July 8, 2022
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The Cases

Case 1: A 64-year-old man came in for a routine bronchoscopy with possible biopsies after an abnormal chest CT (computed tomography). The patient completed the consent process with both the pulmonologist and the anesthesiologist before being taken into the bronchoscopy suite. The patient was intubated and underwent the procedure under general anesthesia with no complications. Within a few minutes after extubation, he exhibited signs of respiratory failure requiring reintubation. A relook bronchoscopy was grossly normal with no evidence of bleeding. The chest x-ray did not reveal a pneumothorax. Uncertain of the etiology, the team reached out to the family in the waiting room.

The patient’s wife revealed a remote history of Guillain Barre Syndrome (GBS) after anesthesia in the past was also told that he should avoid a certain anesthetic (although the wife did not mention the name). The patient was kept intubated for the night and successfully extubated the following morning, after good results from a negative inspiratory force test. Fortunately, there were no lingering adverse effects and the patient was discharged home.

On further review of the chart, there was documentation of GBS in the distant past  as well as reported "sensitivity" to succinylcholine. The patient had never mentioned this history, nor was an alert or allergy documented in the chart, and the team had not reviewed older records.

Case 2: A 73-year-old man with a history of pulmonary tuberculosis presented for bronchoscopy after a new nodule was identified on a follow-up CT scan. After review of his history by the team, the patient was taken into the bronchoscopy suite for the biopsy procedure under light sedation. The timeout was done, and the procedure was completed in about 15 minutes.

After the procedure, the bite block was taken out, but the patient could not close his mouth. After he recovered from the light sedation, he was alert and tried to mouth words pointing towards his temporomandibular joint (TMJ). The pulmonologist and anesthesiologist attempted to close his mouth but were unable to do so. At this point, one of the technicians who had transported the patient disclosed that the patient had mentioned something about his mouth being open after the prior bronchoscopy but since this technician was new and did not know this information was important, he did not reveal it to anyone on the surgical team.

The trauma team was called to assist and the patient was given additional sedation and opioid analgesia. The trauma surgeon then manipulated both TMJs and was finally able to unloose the locked jaw. The patient had some residual pain but was safely discharged and scheduled for outpatient follow-up. On later review, the patient confirmed that he had mentioned what had happened in his previous bronchoscopy to the technician, but he assumed that his physicians knew about it. However, the pulmonologist was not aware of this history, as one of his partners had performed the prior procedure and there was no mention of this problem in the chart.

The Commentary

By Christian Bohringer, MD


These two very different complications, under different circumstances, still shared an underlying contributory factor. In Case 1, the patient received general anesthesia to undergo bronchoscopic lung biopsies, which are often performed in patients with chronic lung disease who face a significant risk of complications like bleeding, pulmonary aspiration, pneumothorax, or post-procedure respiratory arrest.1 Mechanical manipulation of the airways is also associated with significant tachycardia and hypertension.2 Pulmonologists therefore often seek the assistance of an anesthesiology team to help them reduce the risk of performing this procedure. General anesthesia with muscle relaxation ensures immobilization of the biopsy site and allows the pulmonologist to precisely delineate the patient’s pathology. Muscle relaxation enables diagnostic and therapeutic maneuvers to be performed with a greater margin of safety than would be possible with the patient coughing and moving under light sedation. The presence of an anesthesiology team can help to increase patient comfort while minimizing hemodynamic disturbances associated with the procedure.

Regardless of the past history of GBS, it’s likely that the patient had an underlying sensitivity to succinylcholine, contributing to the response to this episode of general anesthesia. Unlike myasthenia gravis, which is well known to be associated with an exaggerated response to neuromuscular blocking drugs, GBS does not affect the neuromuscular junction and there is usually no increased sensitivity to these drugs in patients who recover from GBS.3,4,5  Succinylcholine is contraindicated in acute GBS because of the risk of hyperkalemic cardiac arrest.6,7 Hyperkalemic cardiac arrest with succinylcholine administration has even been reported in one case even after the patient seemed to have made a complete recovery from the paralytic syndrome.8

If the prolonged weakness in Case 1 had been caused by an exaggerated response to a non-depolarizing neuromuscular blocking drug, the anesthesiologist could have reversed the paralysis by giving additional doses of sugammadex. The reintubation and ICU admission would then have been avoided. There were therefore two reasons for succinylcholine to be avoided in this patient and a thorough history would have elicited them.

In Case 2, the bronchoscopy was performed using sedation in combination with local anesthesia. The use of sedative medication is a valuable adjunct for this procedure because it prevents tachycardia and hypertension. It may also prevent the patient pulling the bronchoscope out of the trachea because local anesthesia by itself is often insufficient to obliterate all the noxious stimuli from the bronchoscopy. Whenever a procedure is performed under sedation, at least two staff members must be present to optimize the patient’s safety. One team member should be dedicated to titrating sedative medication and monitoring the patient’s breathing and blood flow, while the other staff member performs the procedure. It is very difficult to pay sufficient attention to administering sedation and monitoring the patient while performing a complex medical procedure. Calamities due to unrecognized airway obstruction with ensuing hypoxic cardiac arrest have occurred when the person performing the procedure did not have the help of a second staff member monitoring the patient. The person administering sedative medications and monitoring the patient currently does not need to be a licensed anesthesia care provider. A sedation certificate is regarded as sufficient to gain credentialing in many institutions. A historical cohort study, however, showed that complication rates fell after an academic medical center began providing expert anesthesia care for all advanced endoscopic procedures.9

The temporomandibular joint (TMJ) dislocation experienced by this patient is a rare, but well-recognized, postoperative complication.10,11,12 It usually occurs after procedures that require the mouth to be maintained in an open position. Propping the mouth open with a bite block for a long period of time is unphysiologic for the TMJ because the joint’s baseline resting position is when the mouth is closed. Prolonged mouth opening may therefore result in ongoing TMJ pain after a procedure.  Anesthesiologists are aware of the risk of aggravating preexisting TMJ pathology when they perform jaw thrust to maintain a patent airway or when they use a conventional direct laryngoscope to intubate the trachea. Applying excessive force to the mandible during laryngoscopy should be avoided in these patients. Intubating with a video-laryngoscope is preferred because this approach requires less mouth opening and transmits less force on the TMJ than conventional direct laryngoscopy.13 If an inadvertent TMJ dislocation is suspected during the procedure, an X-ray should be taken to confirm the diagnosis and a physician experienced in reducing the TMJ should be consulted to minimize the risk of injury during the reduction. An anesthesiologist may be helpful because sedation and neuromuscular block will facilitate the reduction.

Approach to Improving Safety

Take a thorough preoperative history and carefully review the past medical record

A thorough preoperative anesthesia consultation is important when performing ambulatory outpatient anesthesia.14 A more comprehensive review of past anesthetic history in Case 1 would have led the anesthesia care provider to avoid the use of succinylcholine. It is particularly important for anesthesia care providers to elicit any history of an unexpected reintubation or unexpected intensive care unit (ICU) admission after a previous procedure. The reasons for this type of event should be clearly documented in the patient’s medical record. The problem also needs to be highlighted in the problem list and discharge summary of the patient’s medical record so that health care providers can easily find this information in the future. In retrospect, this patient probably had an atypical pseudocholinesterase enzyme and was not able to metabolize succinylcholine in the normal way. This genetic enzyme variant resulted in the patient experiencing an unexpected, prolonged period of paralysis. Significantly prolonged paralysis after succinylcholine administration due to genetic variance of the pseudocholinesterase enzyme occurs in about one in 3,000 people. A cholinesterase plasma phenotype test can confirm this diagnosis.15 The paralysis in Case 1 could have been reversed by administering fresh frozen plasma (FFP), which contains sufficient normal pseudocholinesterase from the blood donor. However, this treatment is not usually employed because of the risk of viral transmission and fluid overload associated with administering FFP. The risk of prolonged paralysis that cannot readily be reversed is the main reason that succinylcholine is now avoided by most anesthesiologists, especially for outpatient procedures for which unexpected admission is a major inconvenience for both the patient and the health care facility.16

In Case 2, a more diligent preoperative assessment by the anesthesia care provider or the pulmonologist would have elicited the history of previous TMJ dislocation. A review of the previous bronchoscopy record may also have revealed this information. The procedure could then have been performed by passing the bronchoscope through the patient’s nose without having to prop the patient’s mouth open with a bite block. Bite blocks are usually used when the bronchoscope is passed through the mouth so that the patient cannot bite on the scope and damage it. When the scope is passed via the nasal cavity, the bite block is unnecessary and the mouth can remain closed during the procedure.

Allow adequate time for pre-op assessment

Turnover times in operating and procedure rooms are keenly monitored by hospital administrators to maximize operating room utilization, and thus to accommodate more patients while improving the financial performance of their organizations. As health care providers, we have a responsibility to ensure that the quality of health care is not sacrificed for financial gain. Thorough preoperative assessment takes a little extra time but may have prevented the unnecessary admission to the ICU and overnight ventilation in Case 1, and the unnecessary surgical referral and repeat sedation in Case 2. Treatment of these complications  placed these patients at risk for other iatrogenic complications (i.e., from mechanical ventilation) and required additional staff time and other resources. Placing staff under too much time pressure can, at times, be counterproductive and can adversely affect both clinical outcomes and financial performance.

Recognize persistent neuromuscular blockade prior to extubation

In retrospect, the persistent weakness of the patient in Case 1 should have been recognized prior to extubation. Persistent neuromuscular blockade can be recognized clinically by low tidal volume, fast respiratory rate, and lid lag (or inability to voluntarily open the eyelids). There is also a lack of antigravity power in the limbs.17 Frowning the forehead may be the patient’s only motor response during residual neuromuscular blockade because the frontalis muscle is more resistant to the effects of neuromuscular blocking drugs than most other muscles in the body. A nerve stimulator could have been used to verify adequate recovery of neuromuscular function prior to extubating the patient. However, it is very important to ensure that the patient is sedated when using a nerve stimulator because the application of a tetanic stimulus to a peripheral nerve is excruciatingly painful for an awake patient. Recognition of persistent weakness would have prevented a period of hypoxia and hypercarbia as well as an unnecessary reintubation in this case. If the patient had not been reintubated expeditiously, he could have suffered a hypoxic cardiac arrest.      

Clearly highlight the problem in the medical record

A reintubation or unexpected ICU admission due to persistent neuromuscular blockade after administration of a neuromuscular blocking drug should always be highlighted in the patient’s medical record. The presence of an atypical pseudocholinesterase enzyme should be listed as a succinylcholine allergy in the allergy section on the snapshot page to ensure that the patient never receives this drug again. A MedicAlert bracelet with the words “succinylcholine apnea” may also be helpful to prevent a recurrence of this scenario.

The inadvertent dislocation of the TMJ should also be clearly documented in the patient record to warn subsequent anesthesia care providers of the risk of this complication occurring again during another procedure.

Use online registers for anesthetic problems

Some health care systems offer online anesthetic problem registers to help prevent potentially recurring anesthesia-related problems.18 These online registers clearly describe the anesthesia problem, and the patient is given a plastic card with instructions on how anesthesia care providers should access the information in the future. This type of online register is useful when a patient receives care in different health care systems with electronic medical record systems that are not linked with one another or after the patient has moved to a different community.

Understandably, patients often do not remember the details of an adverse event that they experienced. An online report by an anesthesia care provider is therefore much more informative than relying upon recall by the patient. Affected patients usually remember that they had a significant problem during a previous procedure; however, they may not recall the details that would help an anesthesiologist to avoid recurrence of the problem. Letters given by anesthesiologists to patients are often lost. Online registers that can be accessed by anesthesiologists before embarking on another procedure can therefore be useful to impart vital information.

In Case 2, an online report of TMJ dislocation during an earlier bronchoscopy may have led the pulmonologist to choose the nasal instead of the oral route and could have prevented the recurrent dislocation.

Take advantage of the entire patient care team

The contributions of the junior transport technologist are interesting. The patient told the junior transport technologist that his jaw was locked open during a previous bronchoscopy, but this information was not relayed to either the pulmonologist or the anesthesiologist because the junior staff member did not recognize the importance of this information, or perhaps assumed that the physicians were already aware of it. This information may also have not been passed on because the junior technologist felt uncomfortable speaking out. It is very important that all members of the health care team, regardless of their level of experience, feel comfortable bringing up any issues that may affect patient safety without having to fear criticism or ridicule from senior staff members. We must strive to create a work environment that empowers all hospital personnel to draw attention to potential safety issues. It is also important to ensure that new or junior staff have appropriate onboarding that emphasizes the importance of communicating all patient information, even if it is thought to be minor.

Educate and empower patients about the nature of the anesthesia problem

After an avoidable anesthesia problem has been identified, it is paramount that the patient is informed about the nature of the problem. Clear advice should be given on how to prevent a recurrence of the issue in the future. MedicAlert bracelets with important information (e.g., “succinylcholine apnea”) may be helpful.

During procedures patients often receive a benzodiazepine anxiolytic, such as midazolam, which often prevents them from remembering information given in the recovery room. Family members should therefore be present when the issue is discussed after the procedure, and a written summary of the event should be given to the patient. If the patient does not recognize the significance of the event, it is unlikely that the problem will be prevented during a subsequent procedure in a different hospital.

Take Home Points

  • A thorough preoperative history and review of the past medical record is always important.
  • Sufficient time needs to be allocated for an adequate preoperative evaluation.
  • All team members need to feel empowered to bring up issues without fear of reprisal.
  • An online register for anesthesia problems can be helpful—especially when the patient changes health care systems.
  • Educating the patient about the nature of the problem is of key importance to prevent it from occurring again.

Christian Bohringer, MBBS

Professor of Clinical Anesthesiology
Department of Anesthesiology and Pain Medicine
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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