Analysis of anaesthesia incidents during caesarean section reported to webAIRS between 2009 and 2022

Anaesthesia for caesarean section occurs commonly and places specific demands on anaesthetists. We analysed 469 narratives concerning anaesthesia for caesarean section, entered by Australian and New Zealand anaesthetists into the webAIRS incident reporting system between 2009 and 2022. As expected, compared with the remaining 8978 database entries, the 469 incidents were more likely to be emergency cases (relative risk (RR) 1.95), more likely to occur between 18:00 and 22:00 hours (RR 1.81) and between 22:00 and 07:59 hours (RR 4.40) and more likely to be undertaken using neuraxial anaesthesia (RR 9.18). Most incidents involved more than one event. The most commonly reported incidents included intraoperative neuraxial anaesthesia complications (180, 38%), medication errors or issues (136, 29%), equipment issues (49, 10%), obstetric haemorrhage (38, 8%), maternal cardiac arrests (28, 6%), endotracheal tube issues (28, 6%) and neonatal resuscitation (24, 5%). Inadequate neuraxial block, reported in 95 incidents, was the most common intraoperative neuraxial complication. Allergic reactions, reported in 30 incidents, were the most common medication issue, followed by 17 associated with oxytocin and 16 syringe swaps. Thirty-eight reports included significant maternal haemorrhage, with eight of those incidents including maternal cardiac arrest. There was one maternal death and eight incidents with neonatal deaths reported, affecting nine neonates. Problems with intraoperative neuraxial anaesthesia were the most commonly reported events. Implementation of specific strategies are encouraged to enhance preparation for conversion to general anaesthesia and to mitigate medication errors, particularly those relating to oxytocic use and neuraxial anaesthesia medications.

Hypercarbia and high-flow nasal oxygen use during anaesthesia - risking a failure to thrive?

Prevention of arterial oxygen desaturation during anaesthesia with high-flow nasal oxygen (HFNO) has gained greater acceptance for a widening range of procedures. However, during HFNO use there remains the potential for development of significant anaesthesia-associated apnoea or hypoventilation and the possibility of hypercarbia, with harmful cardiovascular or neurological sequelae. The aim of this study was to determine whether any HFNO-related hypercarbia adverse incidents had been reported on webAIRS, an online database of adverse anaesthesia-related incidents. Two relevant reports were identified of complications due to marked hypercarbia during HFNO use to maintain oxygenation. In both reports, HFNO and total intravenous anaesthesia were used during endoscopic procedures through the upper airway. In both, the extent of hypoventilation went undetected during HFNO use. An ensuing cardiac arrest was reported in one report, ascribed to acute hypercarbia-induced exacerbation of the patient's pre-existing pulmonary hypertension. In the other report, hypercarbia led to a prolonged duration of decreased level of consciousness post procedure, requiring ventilatory support. During the search, an additional 11 reports of postoperative hypercarbia-associated sedation were identified, unrelated to HFNO. In these additional reports an extended duration of severe acute hypercarbia led to sedation or loss of consciousness, consistent with the known effects of hypercarbia on consciousness. These 13 reports highlight the potential dangers of unrecognised and untreated hypercarbia, even if adequate oxygenation is maintained.

Adult perioperative cardiac arrest: An overview of 684 cases reported to webAIRS

There were 684 perioperative cardiac arrests reported to webAIRS between September 2009 and March 2022. The majority involved patients older than 60 years, classified as American Society of Anesthesiologists Physical Status 3 to 5, undergoing an emergency or major procedure. The most common precipitants included airway events, cardiovascular events, massive blood loss. medication issues, and sepsis. The highest mortality rate was 54% of the 46 cases in the miscellaneous category (this included 34 cases of severe sepsis, which had a mortality of 65%). This was followed by cardiovascular precipitants (n = 424) in which there were 147 deaths (35% mortality): these precipitants included blood loss (53%), embolism (61%) and myocardial infarction (70%). Airway and breathing events accounted for 25% and anaphylaxis 8%. A specialist anaesthetist attended the majority of these cardiac arrests. As webAIRS is a voluntary database, it is not possible to determine the incidence of perioperative cardiac arrest and only descriptive information on factors associated with cardiac arrest can be obtained. Nevertheless, the large number of reports includes a wide range of cases, precipitants, demographics and outcomes, providing ample opportunity to learn from these events. The data also provide rich scope for further research into further initiatives to prevent cardiac arrest in the perioperative period, and to improve outcomes, should a cardiac arrest occur.

Perioperative corneal abrasions: A report of 42 cases from the webAIRS database

Corneal abrasions are an uncommon complication of anaesthesia. The aim of this study was to identify potential risk factors, treatment and outcomes associated with corneal abrasions reported to the web-based anaesthesia incident reporting system (webAIRS), a voluntary de-identified anaesthesia incident reporting system in Australia and New Zealand, from 2009 to 2021. There were 43 such cases of corneal abrasions reported to webAIRS over this period. The most common postoperative finding was a painful eye. Common features included older patients, individuals with pre-existing eye conditions, general anaesthesia and procedures longer than 60 minutes. Most cases were treated with a combination of lubricating eye drops or aqueous antibiotic eye drops. The findings indicate that patients who sustain a perioperative corneal abrasion can be reassured that in many cases it will heal within 48 hours, but they should seek earlier review if symptoms persist or deteriorate. None of the cases in this series resulted in permanent harm. Well established eye protective measures are important to utilise throughout the perioperative period, including the time until the patient has recovered in the post-anaesthesia care unit.

The use of sugammadex in critical events in anaesthesia: A retrospective review of the webAIRS database

Sugammadex has been used for more than ten years in Australia and New Zealand and has been implicated as an effective treatment, and in some cases a potential cause, of a critical incident. We aimed to identify and analyse critical incidents involving sugammadex reported to webAIRS, a de-identified voluntary online critical incident reporting system in Australia and New Zealand. We identified 116 incidents where the reporter implicated sugammadex as either a cause (23 cases) or a treatment (93 cases) during anaesthesia. There were 17 incidents suggestive of sugammadex anaphylaxis, although not all were confirmed by skin testing. There were six incidents when bradycardia was temporally related to sugammadex administration, although it was not possible to exclude other causes or contributory factors. There were nine incidents in which sugammadex was used to reverse aminosteroid-related neuromuscular blockade successfully in a 'can't intubate, can't oxygenate' (CICO) situation, and a further 67 incidents in which sugammadex was used to reverse aminosteroid neuromuscular blockade as part of the management of other critical incidents. While sugammadex was used during the management of 16 cases of anaphylaxis, there was no clear indication that this altered the course of the anaphylaxis in any of the cases. These reports indicate that sugammadex can be a potential trigger for anaphylaxis and that its use may be associated with the development of significant bradycardia. However, it is not possible to estimate or even speculate on the incidence of these sugammadex-related incidents on the basis of voluntary reporting to a database such as webAIRS. The reports also indicate that sugammadex has been used successfully to reverse residual or deep aminosteroid neuromuscular blockade in critical incident situations and to help rescue CICO scenarios. These findings provide further support for ensuring the ready availability of sugammadex wherever aminosteroid muscle relaxants are used.

A cross-sectional overview of the second 4000 incidents reported to webAIRS, a de-identified web-based anaesthesia incident reporting system in Australia and New Zealand

This cross-sectional overview of the second 4000 incidents reported to webAIRS has findings that are very similar to the previous overview of the first 4000 incidents. The distribution of patient age, body mass index and American Society of Anesthesiologists physical status was similar, as was anaesthetist gender, grade, location and time of day of incidents. About 35% of incidents occurred during non-elective procedures (vs. 33% in the first 4000 incidents). The proportion of incidents in the various main categories was also similar, with respiratory/airway being most common, followed by cardiovascular, medication-related and medical device or equipment-related incidents. Together these categories made up about 78% of all incidents in both overviews. The immediate outcome was comparable with reports of harm in about a quarter of incidents and a similar rate of deaths (4.7% vs. 4.2%). However, the proportion of patients who had received total intravenous anaesthesia was higher (17.6% vs. 7.7%) and the proportion of patients who received combined intravenous and inhalational anaesthesia was lower (52.3% vs. 58.4%), as was the proportion receiving local anaesthesia alone (1.6% vs. 6.7%). There was a small increase in the number of incidents resulting in unplanned admission to a high dependency or intensive care unit (18.1% vs. 13.5%). It is not clear whether these differences represent trends or random observations. About 48% of incidents were considered preventable by the reporters (vs. 52% in the first 4000). These findings support continued emphasis on human and system factors to promote and improve patient safety in anaesthesia care.

Analysis of medication errors during anaesthesia in the first 4000 incidents reported to webAIRS

Medication error is a well-recognised cause of harm to patients undergoing anaesthesia. From the first 4000 reports in the webAIRS anaesthetic incident reporting system, we identified 462 reports of medication errors. These reports were reviewed iteratively by several reviewers paying particular attention to their narratives. The commonest error category was incorrect dose (29.4%), followed by substitution (28.1%), incorrect route (7.6%), omission (6.5%), inappropriate choice (5.8%), repetition (5.4%), insertion (4.1%), wrong timing (3.5%), wrong patient (1.5%), wrong side (1.5%) and others (6.5%). Most (58.9%) of the errors resulted in at least some harm (20.8% mild, 31.0% moderate and 7.1% severe). Contributing factors to the medication errors included the presence of look-alike medications, storage of medications in the incorrect compartment, inadequate labelling of medications, pressure of time, anaesthetist fatigue, unfamiliarity with the medication, distraction, involvement of multiple people and poor communication. These data add to current evidence suggesting a persistent and concerning failure effectively to address medication safety in anaesthesia. The wide variation in the nature of the errors and contributing factors underline the need for increased systematic and multifaceted efforts underpinned by a strengthening of the current focus on safety culture to improve medication safety in anaesthesia. This will require the concerted and committed engagement of all concerned, from practitioners at the clinical workface, to those who fund and manage healthcare.

Iatrogenic uvular injury related to airway instrumentation: A report of 13 cases from the webAIRS database and a review of uvular necrosis following inadvertent uvular injury

Published reports of uvular necrosis are uncommon and it is possibly an under-reported complication of oropharyngeal manipulation. Uvular necrosis is thought to develop due to ischaemia secondary to mechanical compression of the uvula from oropharyngeal devices. Patients typically present with symptoms of a sore throat within 48 hours postoperatively. It is unclear whether there are any preventable factors, or any specific management strategies that might reduce this complication. Treatment is most commonly conservative management, including observation and simple analgesia. We present 13 cases of uvular injury that were reported to a web-based anaesthesia incident reporting system (webAIRS), a voluntary de-identified anaesthesia incident reporting system in Australia and New Zealand. While the postoperative findings varied, sore throat was the most frequent symptom. Most of the cases resolved spontaneously; the remainder with supportive treatment only. The findings suggest that patients who sustain a uvular injury can be reassured, but they should be advised to seek review early if sore throat persists or any difficulty with breathing develops.

Difficult and failed intubation in the first 4000 incidents reported on webAIRS

A review of the first 4000 reports to the webAIRS anaesthesia incident reporting database was performed to analyse cases reported as difficult or failed intubation. Patient, task, caregiver and system factors were evaluated. Among the 4000 reports, there were 170 incidents of difficult or failed intubation. Difficult or failed intubation incidents were most common in the 40-59 years age group. More than half of cases were not predicted. A total of 40% involved patients with a body mass index >30 kg/m² and 41% involved emergency cases. A third of the reports described multiple intubation attempts. Of the reports, 18% mentioned equipment problems including endotracheal tube cuff rupture, laryngoscope light failure, dysfunctional capnography and delays with availability of additional equipment to assist with intubation. Immediate outcomes included 40 cases of oxygen desaturation below 85%; of these cases, four required cardiopulmonary resuscitation. The majority of the incidents resulted in no harm or minor harm (45%). However, 12% suffered moderate harm, 3.5% severe harm and there were three deaths (although only one related to the airway incident). Despite advances and significant developments in airway management strategies, difficult and failed intubation still occurs. Although not all incidents are predictable, nor are all preventable, the information provided by this analysis might assist with future planning, preparation and management of difficult intubation.

A prospective six-month audit of airway incidents during anaesthesia in twelve tertiary level hospitals across Australia and New Zealand

This audit of airway incidents was conducted over six months in 12 tertiary level hospitals across Australia and New Zealand. During that time, 131,233 patients had airway management and 111 reports were submitted (incidence 0.08%). The airway incidents included a combination of difficult airway management (83), oxygen desaturation (58), aspiration (19), regurgitation (14), laryngospasm (16), airway bleeding (10), bronchospasm (5) and dental injury (4), which gave a total of 209 events in 111 reports. Most incidents occurred during general anaesthesia (GA; 83.8%) and normal working hours (81.1%). Forty-three percent were associated with head and neck surgery and 12.6% with upper abdominal procedures. Of these patients, 52% required further medical treatment or additional procedures and 16.2% required unplanned admission to an intensive care unit or a high dependency unit. A total of 31.5% of patients suffered from temporary harm and 1.8% from permanent harm. There was one death. The factors associated with a high relative risk (RR) of an airway incident included American Society of Anesthesiologists Physical Status (ASA PS) (ASA PS 2 versus 1, RR 1.75; ASA PS 3 versus 1, RR 3.56; ASA PS 4 versus 1, RR 6.1), and emergency surgery (RR 2.16 compared with elective). Sedation and monitored anaesthesia care were associated with lower RRs (RR 0.49 and RR 0.73 versus GA, respectively). Inadequate airway assessment, poor judgement and poor planning appeared to be contributors to these events. Future teaching and research should focus on these areas to further improve airway management and patient safety.

Aspiration during anaesthesia in the first 4000 incidents reported to webAIRS

The first 4000 reports to the webAIRS anaesthesia incident reporting database were used to evaluate pulmonary aspiration in patients undergoing procedures under general anaesthesia or sedation. Demographic data, predisposing factors, outcome and potential preventative measures were evaluated. In these reports, 121 cases of aspiration were identified. Aspirated substances included gastric contents, bile type fluids, blood and solids; 60 (49.6%) patients were admitted to the intensive care unit/high dependency unit, and 43 (35.5%) required mechanical ventilation. Aspiration was associated with significant harm in >50% of reports, and eight (6.6%) patients died. Factors associated with a risk ratio of aspiration >1.5 and outside the 95% confidence interval for no event included: age >80 years, emergency procedure, procedure undertaken in freestanding day unit or gastroenterology department, procedure undertaken between 1800 and 2200 hours and endoscopy procedures. Only 11 (9%) cases appeared to be inadequately fasted, and 77 (64%) were definitely fasted. In the remaining 33 (27%), fasting was not mentioned. In 18 (14.9%) cases, aspiration occurred in the presence of cricoid pressure. Potential measures to prevent aspiration included using a cuffed endotracheal tube rather than a laryngeal mask airway in cases at high risk of aspiration and being made more aware of potential risk factors by improvements in team communication. Aspiration continues to be an important complication of anaesthesia, and one that can be difficult to predict and to prevent.