Aromaa et al. [5]
Pitkänen et al. [6]
Cardiac arrest
2/0
0/0
Total spinal anesthesia
0
0/2
Neurologic complication
19/4
7/17
Infection
4/2
7/6
Acute toxicity
0/2
0
Drug error
0/1
0/2
The calculation of incidences when trusting the patient insurance claims can be unreliable. Even though the patient insurance system should be well known and ombudsmen in the hospitals help patients with claims, all complications will not be registered. This is well expressed in a retrospective study by Moen et al., where they gathered information from the Swedish health care system [7]. The study was based on a mailed enquiry to anesthesia departments confirmed through search of adequate administrative files dealing with malpractice or insurance matters. They found 127 complications, including 33 hematomas. Only two out of these 33 hematomas were found in the Swedish patient insurance claims.
On the other hand, when we compare the Finnish studies we can see that there has been a marked increase in the activity of reporting claims. During the period 2000–2009, the annual number of claims has been stable, at about 8000. During the period 1987–1993 when the insurance system was relatively new, the annual number of claims rose from 2500 to 5700. Therefore, we can assume that the increase in claims has produced more reliable results.
Moen et al.’s study is from severe neurologic complications after central neuraxial blockades in Sweden 1990–1999 [7]. At that time the population in Sweden was approximately 8.8 million. In the 10-year period, they found 127 severe complications: spinal hematoma (33 cases), cauda equine syndrome (32 cases), meningitis (29 cases), epidural abscess (13 cases), and miscellaneous (20 cases). Only serious neurologic complications were included in that study. Less serious and transient complications or those attributed to systemic local anesthetic toxicity and cardiovascular side effects were not covered. They succeeded in acquiring a comprehensive retrospective study in serious neurologic complications. The number of complications as well as the denominators in their study seems to be accurately achieved. There are several interesting results which can be compared between these three studies. The numbers of neuraxial anesthesia procedures per capita are rather similar (Table 30.2).
Table 30.2
Morbidity after neuraxial blocks , Nordic studies
Moen et al. Sweden [7] | Aromaa et al. Finland [5] | Pitkänen et al. Finland [6] | |
|---|---|---|---|
Study period (year) | 1990–1999 | 1987–1993 | 2000–2009 |
Population | 8,800,000 | 5,100,000 | 5,300,000 |
Spinal anesthesia | 1,260,000 | 550,000 | 840,000 |
Epidural anesthesia | 450,000 | 170,000 | 520,000 (incl CSE) |
Spinal Hematomas
Hematoma after neuraxial block occurs most commonly in epidural space. It can appear also subarachnoidally and even subdurally (between dura and arachnoidea). Moen et al. and Aromaa et al. did not differentiate the anatomical location [5, 7]. Moen et al. used the term spinal hematoma , which can be assumed to mean all hematomas [7]. In Pitkänen et al.’s study, there were nine epidural, two subdural, and two subarachnoid hematomas in the lumbar area [6]. The spinal hematomas are presented in Table 30.3. In Finland, the number of hematomas increased between the two studies; however, the relative number is smaller than in the Swedish study.
Table 30.3
Spinal hematomas (number of patients)
