The influence of anesthesia on intraoperative neurophysiological monitoring during spinal surgeries.

BACKGROUND: Intraoperative neuromonitoring using tc-MEPs satisfactorily detects motor tract integrity changes during spinal surgery. However, tc-MEP is affected by anesthesia and other factors, in which the stimulation threshold increases because the waveform amplitude decreases over time with the accumulation and boluses of anesthetics. METHODS: We conducted a retrospective study of 139 patients. The average age was 30 years. Tc-MEPs were recorded bilaterally from the tibialis anterior muscle and the abductor hallucis muscle. Statistical tests were used to investigate the changes to evaluate anesthetic effects. RESULTS: There were no significant differences in tc-MEP amplitude change (%) between the groups of propofol (13 %), remifentanil (22 %) and sufentanil (26 %, p < 0.01). Significant differences were found between the groups of propofol, remifentanil, and sufentanil (20 %) and bolus sufentanil (‒30 %), and bolus ketamine (730 %, p < 0.008). Major differences were observed between bolus sufentanil (‒30 %) and bolus ketamine (730 %, p < 0.001). When comparing tc-MEPs with no amplitude, no significant difference was found between the groups of propofol (26 %), remifentanil (24 %), and sufentanil (28 %, p < 0.007). Substantial difference was found between the groups of propofol, remifentanil, and sufentanil (mean 26 %) and the group where ketamine boluses were administered. We didn't observe any loss of amplitude (0 %, p < 0.0002). CONCLUSION: IONM may be useless in patients where boluses of sufentanil are administered and also with Medical Research Council grades 3 and below. Consider applying IONM in patients with severe spinal deformity along with a higher age of over 50 and neurological deficit. Increasing stimulus intensity or facilitation techniques may be considered to improve the usefulness of tc-MEP. Our concept of findings supports the neurophysiological monitoring findings in other studies (Tab. 10, Ref. 45).

Quality of life after elective lumbar spinal fusions.

OBJECTIVES: Our goal was to evaluate the quality of life in patients who underwent an elective lumbar stabilization and fusion. MATERIALS AND METHODS: We treated 208 patients (120 females and 88 males) for degenerative lumbar spine conditions. In 165 cases we performed the transforaminal lumbar interbody fusion (TLIF), in 38 the posterolateral lumbar fusion (PLF) and in 5 the anterior lumbar interbody fusion (ALIF). Before and after the surgery, pain was evaluated with the VAS and the quality of life with the second version of the SF-6. Follow up was from six months to two years. We used the statistical tests chi-square, t-test and ANOVA. RESULTS: Satisfied were 62.5% of patients, partially satisfied were 19.7% and dissatisfied were 17.8% of patients. The average VAS decreased from 68 to 35. There was a significant improvement in mobility and decrease of consumption of analgetics after the surgery. Clinically significant improvements were in all domains of sf-36 except the mental health, social function and mental composite score. We had 30 complications in 28 patients. A revision surgery was necessary in 18 cases. Complications had no significant effect on the SF-36 and VAS score. CONCLUSION: The results are comparable with published data. Correctly indicated spinal operations are effective in reducing pain and improvement of the function. We have noted a significant decrease of pain, improvement of mobility, and a reduction of analgetics consumption. Despite the improvements, post-operatively all values of the SF-36 were lower than standards for the population. Complications and reoperations in our group are relatively common problems, surprisingly did not affected the quality of life after surgery (Tab. 9, Ref. 38). Full Text (Free, PDF) www.bmj.sk.

[The effect of complications on the quality of life after surgery for lumbar spine degenerative disease]. / Vplyv komplikácií na kvalitu zivota po stabilizacných operáciách degeneratívnych ochorení lumbálnej chrbtice.

PURPOSE OF THE STUDY: To evaluate the effect of complications on the quality of life in patients after elective stabilisation surgery on the lumbar spine. MATERIAL AND METHODS: Between January 2005 and June 2007, 208 patients (120 women and 88 men) were included in the prospective study carried out at our department. These patients were undergoing elective surgery for lumbar spinal disease, namely, central and lateral stenosis, degenerative disc disease and degenerative and isthmic spondylolisthesis. All patients were treated by transpedicular fixation and fusion involving transforaminal lumbar interbody fusion (TLIF) in 165 patients, anterior lumbar interbody fusion (ALIF) in five and posterolateral fusion (PLF) in 38 patients. Satisfaction of the patients with surgery outcomes was assessed on a three-point scale, using the Visual Analogue Scale (VAS), and the Short Form health survey questionnaire (SF-36v2) for life quality evaluation. The follow-up period ranged from 6 months to 2 years. The results were statistically analysed using the chi-square test and t-test. RESULTS: A total of 30 complications were recorded in 28 patients (13.5 %). Revision surgery was necessary in 18 patients (8.7%). Pedicle screw misplacement was found in eight patients and permanent neurological deficit with paresis of the unilateral lower limb in three patients. Carbon cage break-down during surgery occurred in one patient, misinsertion of the cage was in one patient. The dural sac was damaged in five patients, superficial and deep wound infection was found in four and two patients, respectively. Broken screws were detected in seven patients. Donor-site pain persisted in two patients. The patients free from complications were more satisfied (partial or full satisfaction in 86%) than the patients with complications, who reported satisfaction in 78%. However, the difference was not statistically significant. The complications had no significant effect on either any of the SF-36v2 health domains or the total physical and mental score or pain intensity. The ALIF procedure was associated with no complications, PLF with three (13%) and TLIF with 23 (14%) complications, but the differences were not statistically significant. DISCUSSION: Complications and revision surgery were relatively frequent in our group, but not excessive compared with the published data which report their occurrence from 3% to 30%. This large range is related to an ambiguous definition and specification of complications. A significantly fewer complications have been reported in the studies supported by companies, or in those in which the author/s participate in instrumentation development. Some studies suggest that novel and more complex techniques bring about a higher risk of complications and repeat surgery, others report better results and fewer reoperations following a 360-degree fusion than after PLF. The difference in complications between TLIP and PLF in our group was not significant. CONCLUSIONS: Complications are a serious issue of spinal surgery. The majority of complications in our group were associated instrumentation--most frequently with incorrect screw misinsertion. On the whole, the complications did not significantly influence the quality of life and pain intensity after surgery. Most of them were treated successfully with no permanent consequences. The permanent neurological deficit in three patients, because of the small number, had no effect on the whole group results. A reduction in the number of complications would not produce any expected improvement of functional out- come.