Effects of caudal sufentanil supplemented with levobupivacaine on blocking spermatic cord traction response in pediatric orchidopexy

Estimation of the plasma effect site equilibration rate constant of sufentanil in children using the time to peak effect of heart rate and blood pressure

Objectives:

Although targeting the effect site concentration may offer advantages over the traditional forms of administering intravenous anesthetics, it is not applicable for sufentanil in children because its plasma effect site equilibration rate constant (k_e0) is not known yet. We estimated k_e0 of sufentanil in children using the time to peak effect (t_peak) method.

Materials and Methods:

Under general anesthesia, sufentanil t_peak was measured after administration of a submaximal bolus dose by means of the decrease in heart rate, blood pressure and calculated approximate entropy (ApEn) of electroencephalogram in 105 children (age range: 3–11 years). k_e0 was estimated using t_peak and known sufentanil pharmacokinetic parameters in normal children.

Results:

The mean t_peaks were measured as 44 ± 22 s and 227 ± 91 s by heart rate and by mean blood pressure respectively. The estimated k_e0 were 5.16/min and 0.49/min by heart rate and blood pressure respectively. t_peak could not be measured using the ApEn, thus k_e0 could not be calculated by ApEn in children.

Conclusions:

Shorter measured sufentanil t_peak by heart rate compared to blood pressure indicate that the heart rate decrease faster than decreasing of blood pressure. Moreover, the calculated sufentanil k_e0 in children depends on the pharmacodynamics parameters.

Comparison between the intravenous and caudal routes of sufentanil in children undergoing orchidopexy and further evaluation of the association of caudal adrenaline and neostigmine

Background:

The aim of this study was to compare the intravenous (IV) and caudal routes of administration of sufentanil for children undergoing orchidopexy and also to evaluate the effects on addition of caudal adrenaline and neostigmine.

Materials and Methods:

Sixty patients scheduled for orchidopexy were divided into the following groups: 1) Group IVSu received IV 0.5 μg/kg sufentanil and caudal saline; 2) Group CSu received caudal 0.5 μg/kg sufentanil and IV saline; 3) Group CSuAdr received caudal sufentanil plus adrenaline 5 μg/ml (1:200,000) and IV saline; 4) Group CSuNeo received caudal sufentanil plus neostigmine, and IV saline; and 5) Group CSuNeoAdr received caudal sufentanil plus neostigmine plus adrenaline, and IV saline. Heart rate and mean blood pressure >15% was treated with increasing isoflurane concentration. Consumption of isoflurane, side effects, quality of sleep, time to first administration of analgesic, and number of doses of 24-h rescue analgesic were recorded.

Results:

Groups were demographically similar. Isoflurane consumption showed the following association: Group IVSu = Group CSuNeo = Group CSuNeoAdr < Group CSu = Group CSuAdr (P < 0.02). VAS for sedation on reversal of anesthesia showed the following association: Group CSuNeo = Group CSuNeoAdr < Group CSu = Group CSuAdr = Group IVSu (P < 0.005). Time to the first administration of dipyrone showed the following association: Group IVSu = Group CSu = Group CSuAdr (3-4 h) < Group CSuNeo = Group CSuNeoAdr (10-11 h) (P < 0.05). Number of doses of rescue analgesic showed the following association: Group IVSu = Group CSu = Group CSuAdr > Group CSuNeo = Group CSuNeoAdr (P < 0.005). Incidence of adverse effects was similar among groups.

Conclusion:

Caudal sufentanil alone was no better than when administered in the IV route, and would just be justified by the association of neostigmine, but not adrenaline. Neostigmine association resulted in better perioperative analgesia.