Case 7 An iatrogenic problem
Andreas, a 6-day-old preterm infant born at 33 weeks gestation, is recovering from the respiratory distress syndrome and Group B streptococcal (GBS) sepsis. However, he remains on oxygen and has renal failure which developed as a complication of his septicaemia but which is improving. His potassium is raised at 6.7 mmol/L (3.5–5.5 mmol/L), his urea is 17.2 mmol/L (1.0–5.0 mmol/L) and his creatinine is 202 μmol/L (24–112 μmol/L). He is normotensive. The night shift registrar discusses the treatment of the hyperkalaemia with the consultant on call who suggests intravenous salbutamol. The registrar prescribes 4 mg/kg iv over 5 minutes and repeats the potassium 3 hours later, at which time it has fallen to 6.3 mmol/L.
What do you think of the treatment so far?
The following morning, a Saturday, the day shift registrar, Dr McKenzie, who is close to completing her registrar training, is told by the nursing staff that Andreas has deteriorated. She examines him and notes that he is tachycardic at 212 beats/minute, hypertensive at 82/54 mmHg and appears to be stiff. Dr McKenzie reviews Andreas’ medications and notes that he was given 4 mg/kg of salbutamol instead of 4 mcg/kg, 1000 times the appropriate dose.
What would you do now?
Dr McKenzie immediately contacts the National Poisons Centre who inform her that tachycardia, hypertension and muscle stiffness can be caused by a salbutamol overdose. They state that the half life is 4–6 hours but may be slightly longer in a preterm infant in renal failure (salbutamol is partly renally excreted). They suggest that Andreas remains in intensive care, with close monitoring for arrhythmias and of his serum potassium level. As 8 hours have elapsed since the dose was given, which is likely to equate to more than 1 half life, they suggest conservative, symptomatic management and that Andreas should improve over the next 24–48 hours.
Dr McKenzie contacts Andreas’ parents and asks them to come to the hospital, explaining that the infant has had too high a dose of a medication given to decrease the raised potassium level. She sees both parents on her own. They are extremely angry, shout abuse at her and threaten to call their lawyer and sue the hospital during a heated discussion. Dr McKenzie then calls the consultant who comes in and also discusses the overdose with the parents together with the neonatal sister. The consultant also contacts the consultant neonatologist at the regional neonatal unit who echoes the advice of the Poisons Centre. The consultant also informs the manager on call and arranges to discuss the case with the doctor who prescribed the salbutamol and the nurse who actually gave the injection. He also reports this adverse event using the hospital’s online incident reporting system.
Andreas remains unwell for 48 hours, during which time he is closely monitored. Fortunately, the tachycardia settles, there are no other arrhythmias, he does not develop hypokalaemia, and he gradually improves.
Following discharge from hospital Andreas remains well.
One year later, the parents complain to the hospital and subsequently sue due to the severe distress that Andreas suffered because of the overdose, including the multiple painful additional blood tests.
Expert opinion
Hyperkalaemia requiring treatment is rare in general paediatrics and neonatology. When using unfamiliar drugs, or familiar drugs in an unfamiliar setting, the dose should be double checked by the doctor and ideally also double checked with another doctor or a senior nurse. Salbutamol is very frequently used in childhood asthma when the dose, when using nebulizers, is in milligrams and it is this that led to the error. Fortunately for the doctor, salbutamol is a very safe drug.
Though Dr McKenzie, the registrar who discovered this error, was close to the completion of her paediatric training, she should have told the consultant about the error as soon as she had finished discussing the case with the Poisons Centre. Consultants are more experienced at talking to parents about errors and will also know more about the procedures that need to be followed. In cases such as this the parents should be seen by a consultant together with a senior nurse; the manager on call should be contacted and may wish to inform the hospital’s chief executive. The doctor who prescribed the salbutamol should be contacted to discuss the error and in some cases may need counselling. The nurse who gave the injection should also be spoken to. In the case of parents who threaten to contact the media, the hospital’s Public Relations officer may need to be informed. The hospital’s legal advisor may also need to be contacted.
Although difficult to quantify, Andreas probably suffered moderate rather than severe discomfort during the 2 days that he was unwell and more closely monitored.
Legal comment
This case is clearly indefensible. However, Andreas was not seriously affected by the mistake. The case should be settled as quickly as possible. A year has passed since the incident. It may be appropriate to call a meeting with the family to discuss the case. This would be an opportunity to show what lessons have been learned, and to offer an apology and compensation.
The value of the claim will be low, in the region of £1000–£2000.
