161 patients were enrolled in the study. 7 patients were excluded due to changes in the treatment plan. Complete data sets of 154 patients were subsequently analyzed.
Demographic data of all patients is displayed in .
Overall success rate of SpA in the group of young trainees was 72% versus 100% in the group of consultants. 51 (35%) patients were rated to have a “difficult” anatomy/habitus. Trainees succeeded to perform SpA in patients with an easy habitus in 83.3% of cases versus 52.4% when patients had a difficult anatomy (P = 0.005). When trainees failed a SpA, an operator from group C took over, and they were successful in 100% of the cases hence all patients enrolled in the study had the planned surgical procedure done under SpA.
lists specific complications encountered in both operator groups and the two patient groups. Obese patients with a BMI ≥ 32 were significantly higher at risk to experience complications during SpA. Duration of puncture was longer, trainees failed SpA in almost half the cases, and there were significantly more bloody punctures and a higher incidence of paresthesias. Furthermore, even consultants required 3 or more punctures to perform successful SpA in 42.5% of the patients with a BMI ≥ 32.
Incidences of immediate complications for patients with “easy” and “difficult” habitus and the respective operator experience.
The height of the achieved sensory and motor block was not related to weight or BMI of the patient.
Consultants caused less paraesthesias when performing SpA as compared to trainees; however, the difference was not statistically significant (P = 0.31). Patients that were rated to have a difficult habitus had significantly more paresthesias during puncture than patients with identifiable landmarks (13.2 versus 2%; P = 0.005). Furthermore, patients with a difficult habitus had significantly more pain during the procedure than patient with an easy habitus (11.3 versus 1.9%; P = 0.02).
Isobaric bupivacaine 0.5% in equipotent doses caused significantly more hypotensive episodes after intrathecal injection as compared to isobaric ropivacaine 0.5% (21 (25%) versus 2 (3.1%); P = 0.0002). There was no significant difference in hypotensive episodes between patients with a BMI < 30 versus ≥30 (P = 0.05).
Bradycardia with a heart rate of 45 beats per minute or below was observed in 9 (6%) patients and was not significantly related to the local anaesthetic used but was significantly correlated with the level of puncture.
Interestingly, patients who required 4 or more punctures to place a successful SpA had a significantly greater drop in blood pressure.
On day one postoperatively, two patients (1.3%) showed typical features of a transient neurologic syndrome, 6 patients (3.9%) reported difficulties passing urine during the first 12 hours, but no patient required bladder catheterization. 15 patients (9.7%) had one or more episodes of PONV ().
Incidences of complications on day one postoperatively and respective operator experience.
No major complications such as severe hemodynamic disturbances, cardiac arrest, cauda equina syndrome, or permanent neurologic complications were observed.