A total of 339 patient injury claims relating to nerve blockade were identified, which comprised 0.8 % of all cases reported to the NPE during this period. In 32 % of cases, the patient had his/her claim upheld. These patients received compensation pay-outs totalling NOK 82 million, or approximately 1 % of the total pay-outs by the NPE. «Lack of causal relation» was the most common justification for rejection of a claim, whereas «substandard care» was the most common reason for a claim being upheld.
There has been a steady increase in the number of cases. This growth in caseload may be attributable to several factors, two of the most important being increasing awareness of the scheme and expansion of the scheme over the years. Parts of the primary health service and psychiatry were included in the scheme in 1992, with the remainder following after the Act on Patient Injury Compensation came into force in 2003. Private health care provision became part of the scheme in 2009 (1).
Cases related to anaesthesia account for a small proportion of those processed. Within the field of anaesthesia, cases related to dental injuries are the most common (5), but a third of cases involve central and peripheral nerve blockade. It has been reported that central and peripheral nerve blockade can cause serious and permanent injuries (6) – (8), and it is therefore important that these are examined.
The NPE summaries of closed cases consisted of short written accounts of varying quality, and therefore provided limited information. The expert reports also varied markedly, but do appear to have improved steadily over the course of the period examined. This meant that the classification of cases was to some degree a matter of judgement. We have not examined systematically either the expert statements or the casework procedures. Full disclosure of all cases would require the consent of each of the 339 applicants, which we did not seek.
Gaps in parts of the standardised information constitute the greatest weakness of our study. However, the study's strength is that it provides a complete picture of the anaesthesia-related cases handled by the NPE over a long period of time. Obtaining an overview of patient injuries related to central and peripheral nerve blockade can be challenging, as such patients are often primarily under the care of other medical disciplines besides anaesthesiology. It is also important for this reason to systematically analyse cases reported to the NPE within this field.
Unfortunately we have no information about the total number of nerve blocks performed in Norway. There are said to be 1.4 million neuraxial blocks (epidural and spinal anaesthesia) per year in Finland (9), and 1.96 million per year in Sweden (10). Taking the average of these two countries and adjusting for population size would mean that in Norway 1.19 million neuraxial blocks are performed each year, which corresponds to 16.6 million blocks in the 14-year period in which 339 cases were reported to the NPE.
On the basis of these data it is not possible to draw any conclusions regarding the incidence of injuries associated with peripheral and central nerve blockade, as there is no systematic recording of injuries and complications resulting from the use of nerve blockade in anaesthesia. Sigurd Fasting has discussed the risks associated with anaesthesia in an article in this journal (11), citing unpublished data on nerve injuries resulting from regional anaesthesia, but in general little is known about this type of injury in Norway.
In the international literature, the incidence of serious neurological injuries resulting from use of central nerve blocks varies, but is in the region of 1 : 10 000 – 20 000 (12) – (14). The incidence in association with peripheral blocks is uncertain, but is said to be around 3 – 4 per 10 000 blocks (13).
A total of 339 patient injury cases over 14 years, a period in which there are likely to have been close to 16 million blocks, is not a huge number. Of these, 107 claims were accepted, while 232 were rejected (after appeal and reconsideration). But when cases were accepted, the injuries were often very severe and resulted in large pay-outs.
The reasonability rule can be used even if there is no error or omission in health care provision, or objective liability, and was used by 27 % of patients who had their initial claim upheld. The size of the awards varied. There was not always a correlation between the extent of the injury and the size of the pay-out – as it is the patient's financial losses that must be covered.
The filing of claims to the NPE is dependent on patients being aware of the possibility to apply for compensation and choosing to avail themselves of this right. Healthcare professionals have an obligation to inform patients about the possibility of seeking compensation if they have suffered an injury or serious complication in association with medical treatment (1). Little is known about whether doctors fail to disclose this information and, if so, why this might be.
The expert evaluation must provide information that will enable the case officer to decide whether or not the criteria for obtaining compensation have been fulfilled. Since there was deemed to be no causal link in 60 % of the claims that were rejected, and no error or omission of treatment in 39 %, this may suggest that many of the patients reported problems and symptoms that were unrelated to our procedures and/or that the nerve blockade was performed in accordance with good clinical practice. However, we appreciate that it may be difficult for patients to grasp an association (or lack of association) between their symptoms and the procedures that were performed in hospital.
The proportion of patients that appeal the decision is between 40 % and 50 %. It costs the patient nothing to appeal and it is not surprising that many take the opportunity to do so. According to the homepage of the Norwegian administrative appeals body for health services (15), approximately 13 % of disputed decisions are reversed. The percentage of reversals is lower for patient injuries related to nerve blockade (personal communication).
Several arenas have been established for the reporting of patient injuries – for the purposes of learning from adverse incidents (local systems for non-compliance reporting, various public reporting systems) (16, 17). But in most of these, it is the medical profession that does the reporting, whereas it is patients and their next of kin who report cases to the NPE. This means that the analysis of cases here is an important supplement to the analysis of cases reported to other systems.
Upon review of the 339 cases, we are left with the impression that documentation of the procedure is often incomplete and assessment of the injury inadequate. This means that it can be difficult to judge how a case was handled.
Where severe acute injury is suspected after neuraxial block (e.g. epidural haematoma), there are good guidelines available which should be followed (18). Good anaesthesia record-keeping is highly important. The records should describe the technique used, the number of injections, the drug and its concentration, problems and any complications. A postoperative follow-up is necessary for every patient who receives a nerve block, with systematic recording of efficacy and any adverse effects (12, 19).
When complications in the form of nerve injury are suspected after a central or peripheral block, the patient should be referred to a neurologist for assessment. This applies to patients with signs of paresis and/or paraesthesia, difficulties with walking and symptoms related to bladder/bowel control.
The neurologist will evaluate the indication for spinal MRI and/or neurophysiological assessment with EMG/neurography (occasionally supplemented with a Thermotest), dependent on whether there are signs of central and/or peripheral deficits in the clinical neurological examination. Signs of peripheral deficits in an extremity constitute an indication for EMG/neurography. A negative EMG/neurography result cannot rule out damage to the nerve root; the clinical neurological examination will be most important in this regard, in combination with spinal MRI.
The Thermotest is a semi-objective assessment and must always be interpreted in combination with a clinical neurological examination. The indication for a Thermotest should be evaluated by a neurologist. The test is offered only by some of the larger hospitals in Norway. None of the neurophysiological assessments alone will allow any definite conclusions to be drawn regarding the mechanism of injury; they only allow a nerve injury to be demonstrated in some cases.