A sobering editorial...
- Since 2009 there has been a dramatic increase in reported cases of intrathecal tranexamic acid (TXA), parallel to increasing intraoperative TXA use.
- TXA is powerfully neurotoxic.
- Spinal TXA has a mortality rate > 50%, and high incidence of permanent neurological injury in survivors.
- Almost always results from a drug swap error.
- Because both TXA and bupivacaine are made by many manufacturers, there are many different ampoule designs and drug presentations.
- Risk of harm from TXA error is probably ~ 1 in 10,000 spinals.
- TXA should be physically separated from common spinal drugs and we should consider discarding orphaned ampoules rather than attempting to return to the box.
- Stop and visualise the consequences after your own theoretical spinal drug error: facing the patient, family, colleagues, hospital, regulators...
What did they find?
This review by Patel, Robertson & McConachie identified 21 published cases of inadvertent spinal TXA administration. Notably 10 patients died, and almost all suffered life-threatening side effects.
What are the common signs?
- Block failure.
- Severe back and buttock pain (universal).
- HT, tachycardia, arrhythmias, CVS collapse.
How should it be managed?
There are three components to managing intrathecal TXA:
- Treating TXA-induced seizures with anticonvulsants: magnesium; benzodiazepines; barbiturates (thiopentone); phenytoin; possibly propofol. Thiopentone infusion was frequently required to terminate seizures.
- Mitigate TXA neurotoxic effects: maintain head-up; CSF lavage to dilute TXA, infusing crystalloid at an interspace higher than an IT needle draining CSF, 10mL for 10mL, repeated up to 4 times.
- Haemodynamic monitoring & support
How does this happen?
In almost all cases ampoule identification error was the primary cause.
Human factor contributions identified were:
- Failure to check ampoule label.
- Similar ampoule appearance.
- Spinal catheter mistaken for IV (1).
- Lack of drug handling and storage policies.
- Storage of tranexamic acid with LA or lack of physical separation.
- Underestimating potential for error.
"All errors could have been prevented..."
“Inhalational anaesthetic agents are chlorofluorocarbons, ‘greenhouse gases’ that have between 349 (sevoflurane) and 3714 (desflurane) times the global warming potential over a 20 year time horizon of carbon dioxide (isoflurane 1401), equivalent to driving a car 18 (sevoflurane) to ~350 miles (desflurane) per hour of anaesthetic use (isoflurane 30 miles); these figures do not account for the additional carbon cost of heating desflurane vaporisers. Together with nitrous oxide, inhalational anaesthetic agents contribute ~2.5% of the 22.8 million tonnes of carbon dioxide equivalents the NHS produces annually.” - Whitesummary