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Detection of intravascular injection of regional anaesthetics in children
Q A Fisher1, D H Shaffner, M Yaster
1Department of Anaesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287-5842, USA.
Insights
Electrocardiogram (ECG) changes are reliable indicators for detecting accidental intravascular injection of local anesthetics during pediatric epidural blocks. Continuous ECG monitoring, especially T-wave amplitude and rhythm, alongside epinephrine in test doses, enhances safety.
Area of Science:
- Pediatric Anesthesiology
- Cardiovascular Monitoring
- Regional Anesthesia Safety
Background:
- Traditional methods for detecting intravascular injection of local anesthetics during pediatric epidural blocks, such as epinephrine-induced tachycardia or hypertension, may yield inaccurate results.
- This highlights the need for more reliable detection methods to ensure patient safety.
Purpose of the Study:
- To evaluate the effectiveness of electrocardiogram (ECG) changes as markers for detecting intravascular injection of local anesthetics with epinephrine during pediatric epidural block placement.
- To compare ECG findings with traditional vital sign monitoring.
Main Methods:
- An observational study was conducted in a teaching hospital, analyzing ECG rhythm strips from pediatric patients undergoing epidural anesthesia over one year.
- ECG parameters, including heart rate, rhythm, and T-wave configuration, were analyzed during test dose injections.
Main Results:
- Of 742 pediatric epidural blocks, 5.6% involved detected intravascular injections.
- Electrocardiogram monitoring showed significant changes: 83% exhibited T-wave amplitude increases (>25%), and 97% had T-wave or rhythm alterations in response to epinephrine.
- No false positives were recorded, indicating high specificity.
Conclusions:
- Continuous ECG monitoring for heart rate, rhythm, and T-wave amplitude changes is recommended for detecting intravascular injection during pediatric epidural anesthesia.
- Adding epinephrine to the local anesthetic test dose and administering injections in small increments are crucial safety measures.
Purpose:
Detection of intravascular injection of local anaesthetic during placement of regional blocks in children by using epinephrine-induced tachycardia or hypertension may produce false positive and false negative findings. This study evaluates ECG changes as markers of intravascular injection of local anaesthetics with epinephrine, during placement of epidural blocks in children.
Methods:
Observational study in a teaching hospital of all epidural anaesthetics administered to paediatric patients during one year. General anaesthesia, where used, was not controlled. An ECG rhythm strip was recorded during test dose injection and analyzed for changes in rate, rhythm, and T-wave configuration.
Results:
During the study period, 742 paediatric epidural blocks were administered. There were 644 caudal (284 without catheters), 97 lumbar, and one thoracic epidural anaesthetics. Satisfactory placement was achieved in 97.7% of patients. Intravascular injection was detected in 42 (5.6%) of epidural anaesthetics (3.8% and 6.7% of straight needle and catheter injections, respectively). Detection was by immediate aspiration of blood in six patients, and by heart rate increases > 10 bpm in 30. Five had heart rate decreases suggesting a baroreceptor response. Five had heart rate increases < 10 bpm that were possible responses to noxious stimuli. Of 30 patients with known intravascular injection and for whom ECG strips were available, 25 (83%) had T-wave amplitude increases > 25%, and 29 (97%) had ECG changes in T-wave or rhythm in response to the epinephrine injection. There were no false positives.
Conclusion:
In order to reduce risks associated with epidural anaesthesia in children, epinephrine should be added to the local anaesthetic test dose, the ECG should be monitored continuously for changes in heart rate, rhythm, and T-wave amplitude. Epidural injections should be given in small increments.