NAP6 Messages for Patients
What is NAP6?
NAP6 is the 6th National Audit Project of the Royal College of Anaesthetists. It was a 4- year collaboration between specialist doctors (anaesthetists, allergists and clinical immunologists) and patient representatives to study life-threatening allergic reactions (anaphylaxis) during anaesthesia and surgery. The project is the largest study of this topic ever undertaken. It included identifying all life-threatening allergic reactions occurring in the UK over a period of 1 year and examining each one in detail. The aim of the project was to establish accurate information on this issue to be able to give to patients and to improve patient safety.
What did NAP6 find?
NAP6 examined 256 life-threatening allergic reactions occurring during anaesthesia and surgery. Although this may sound concerning, more than 3 million patients have anaesthesia and surgery each year. The risk of life-threatening allergy during anaesthesia and surgery was found to be 1 in 10,000 cases.
In 192 cases the doctors conducting the study established which drug caused the allergic reaction. The commonest cause was antibiotics, given at the time of surgery to reduce the risk of infection. The next commonest group of drugs were the neuromuscular blocking agents (used to relax the muscles during surgery) followed by the skin antiseptic chlorhexidine and a dye most commonly used in breast surgery called ‘patent blue dye’.
The allergic reactions led to severe falls in blood pressure in all patients and severe asthma or wheezing in approximately half of. The reactions occurred very soon after the drugs were given, usually within 15 minutes; most likely because anaesthetists need to give drugs directly into the blood steam (intravenously). In contrast, allergic reactions to foods or tablets may start more gradually and commonly lead to rash, stomach upset, swellings and difficulty breathing.
Anaesthetists acted very promptly to diagnose anaphylaxis and to start life-saving treatment. Although the study only included ‘life-threatening’ allergy, the vast majority of patients survived. Ten patients died in the one year studied, meaning that 24 out of every 25 patients with this life-threatening emergency were successfully resuscitated by the anaesthetists and those working with them. Life-saving treatment included giving intravenous fluid, adrenaline and other powerful drugs to support the blood pressure and managing other important features of anaphylaxis such as giving oxygen, treating severe asthma attacks and establishing patients on a ventilator. The patients who died did so in spite of extensive efforts by anaesthetists to save their lives. Patients who died were more likely to be elderly, obese, have chronic illness and to be taking cardiac medicines than those who survived and we believe their underlying conditions played an important part in their deaths.
Most patients had their operations cancelled or curtailed and were transferred to Intensive Care after initial treatment. Typically, patients spent one day recovering in intensive care and another on a hospital ward before going home. The vast majority of patients made a complete physical recovery. About one in six patients had longer lasting effects, the most common being anxiety about future operations.
Every anaphylaxis event needs investigation by a Specialist Drug Allergy Clinic to find out what caused the anaphylactic reaction. NAP6 identified that these clinics are under-resourced and patients have to wait a long time to be seen. Ideally patients should typically wait about 6 weeks (this gives time for the body’s immune system to ‘reset’ after the reaction) but we found patients usually waited at least three months and in many cases much longer. The study also identified that the testing in these clinics could be more reliable and standardised.
Patients receive on average eight drugs during their anaesthetic, but some receive 20! Iidentifying which one triggered the anaphylactic reaction requires investigation in a Specialist Drug Allergy Clinic. It is essential that all patients attend their clinic appointment. Before they leave hospital the patient should be given written advice on what has happened, what drugs they received and the plan for investigation. The drug allergy clinic will perform a number of tests that include a careful conversation about the events, some skin tests and sometimes further blood tests or advanced investigations. After attending the Specialist Drug Allergy Clinic, the patent should receive written information telling them:
• The type of reaction they have had
• The drug that is likely to have caused it
• Drugs to avoid in future healthcare
• Safe alternatives to the drugs that need to be avoided.
• Whether they need to wear or carry an allergy alert and if so, where to get it
This information should also be sent to the patient’s GP. In NAP6 we found that this information was not reliably given to patients. NAP6 has produced standardised letters that Anaesthetists and allergy doctors can use to improve communication with patients and their general practitioners.
Sometimes anaphylaxis led to cancellation of urgent operations. These may need to be re-scheduled before there has been time for the patient’s reaction to be investigated. Urgent operations can be safely performed in these circumstances by following some straightforward rules. The NAP6 team has provided specific guidance for doctors on how this may be achieved.
The project made an in-depth analysis of antibiotics and anaphylaxis. Antibiotics were given to more than half of patients having operations and procedures. It emerged that a disproportionate number of allergic reactions were to an antibiotic called ‘teicoplanin’, which is often given to patients who report penicillin allergy. Other studies have shown that, although 1 in 10 people think they are allergic to penicillin, in reality only 1 in 100 is. This means that for every 10 patents who tell the anaesthetist they are allergic to penicillin only 1 is. The report made recommendations to improve the safety of antibiotic use during operations and further work is under way to examine this further.
NAP6 was designed to improve the reliability and safety of care for patients. The project team made more than 100 recommendations to improve safe practice. These recommendations are directed to national organisations, hospitals and individual practitioners, particularly anaesthetists and allergists/immunologists. The results of NAP6 show that these life-threatening events are generally managed very well but we hope that with our recommendations anaesthesia and surgery will be even safer.
What can I do as a patient?
Serious allergic reactions to drugs are rare but are serious. If you have a known allergy to an antibiotic or anaesthetic drug it is important you inform all those caring for you before you have a procedure. Some patients would benefit from investigation of allergy before undergoing anaesthesia. This would need to be arranged well in advance of your procedure and should be discussed with your GP. Patients who may benefit from this include those with multiple reported allergies to antibiotics who are due for major surgery. Further national guidance on this is given here. If in doubt, please discuss this with your GP.