[Discussion on optimal duration of pegylated interferon α combined with ribavirin for chronic hepatitis C in HIV-infected patients]

Objective: To investigate the optimal duration of pegylated-alpha interferon (Peg-INFα) combined with ribavirin (RBV) in treating chronic hepatitis C infection in human immunodeficiency virus (HIV)-infected patients. Methods: A multicenter prospective study was conducted. The study subjects were divided into two groups; HIV/HCV co-infections (Group A, n = 158) and control with HCV-monoinfections (Group B, n = 60). All recruited patients received standard Peg-INFα plus RBV therapy. Group A was divided into 3 subgroups according to CD4(+) cell counts: A1 subgroup, 79 cases, CD4(+) counts > 350 cells /μl, who received anti-HCV before combination antiretroviral therapy(cART); A2 subgroup, 45 cases, CD4(+) counts between 200 and 350 cells/μl, who did not start anti-HCV until they could tolerate cART well; A3 subgroup, 34 cases, CD4(+) counts < 200 cells /μl, cART was administered first, and anti-HCV therapy was started when CD4(+) counts > 200 cells/μl. The anti-HCV efficacy of two groups and 3 subgroups were compared. Statistical analysis for normal distribution and homogeneity of variance data was calculated by t-test and the counting data was analyzed by χ (2) test. The Mann-Whitney U test was used for non-normal data. A one-way analysis of variance (ANOVA) was used for the comparison of multiple groups, followed by SNK method. Multiple independent samples were used for non-parametric tests. Results: There was no significant difference in age and baseline HCV RNA levels between groups and subgroups (P > 0.05). By an intent-to-treat (ITT) analysis, in Group A, the ratio of complete early virological response (cEVR) rate was 75.3% (119/158), the ratio of end of treatment virological response (eTVR) rate was 68.4% (108/158), and the ratio of sustained virological response (SVR) rate was 48.7% (77/158); in Group B, the ratio of cEVR rate was 93.3% (56/60), the ratio of eTVR rate was 90.0% (54/60), and the ratio of SVR rate was 71.7% (43/60); The therapeutic index of Group A were lower than those of Group B (P≤0.05). By per-protocol (PP) analysis, the ratio of cEVR rate in Group A [75.2% (88/112)] was still lower than that in Group B [93.3% (56/60)], but no significant differences were found in the ratio of eTVR rate and SVR rate between 2 groups (P > 0.05). Comparing the efficacy of subgroups (A1, A2 and A3) by ITT analysis, the ratios of cEVR rate were respectively 78.5% (62/79), 75.6% (34/45) and 67.6% (23/34); the ratios of eTVR rate were respectively 68.4%(54/79), 80.0%(36/45)and 52.9%(18/34); and the ratios of SVR rate were respectively 41.8%(33/79), 64.4%(29/45)and 44.1%(15/34). The ratio of eTVR in subgroup A2 was obviously higher than that in subgroup A3 and the ratio of SVR in subgroup A2 was statistically higher than that of subgroup A1(P≤0.05). However, by PP analysis, no significant differences of the therapeutic indexes were found among the respective subgroups (P > 0.05). Conclusion: HIV-HCV co-infected patients would have better anti-HCV efficacy with Peg-INFα-2a plus RBV than HCV- monoinfected patients. The best time for initiating anti-HCV therapy in HIV-HCV co-infected patients is when CD4(+) counts 200 cells/ μl.

[Clinical efficacy of pegylated interferon in patients co-infected with HIV and HCV who failed standard interferon therapy]

OBJECTIVE

To investigate the efficacy and safety of pegylated interferon-alpha (PEG-INF-α) combined with ribavirin in patients co-infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) who failed prior standard interferon therapy.

METHODS

A prospective study was performed to analyze HCV RNA load, liver function, and CD4+ count at weeks 0 (baseline), 12, 24, and 48 of treatment and at 24 weeks after drug discontinuation in 20 patients co-infected with HIV and HCV who failed standard interferon therapy and were then treated with PEG-INF-αand ribavirin.

RESULTS

Among the 20 patients, 14 were infected with HCV genotype 1b, 3 with HCV genotype 2a, and 3 failed sequencing. At baseline, the mean CD4(+)count, mean CD8(+)count, and mean CD4(+)/CD8(+)ratio were 406.45 ± 210.83 cells/ml, 1 076.45 ± 716.18 cells /ml, and 0.43 ± 0.17, respectively; the mean HCV RNA load was 6.01 ± 1.13 log10IU/ml; 12 patients (60%) had abnormal liver function. A total of 14 patients (70%) achieved complete early virologic response, 15 (75%) achieved end-of-treatment virologic response, 7 (35%) achieved sustained virologic response (SVR), and 8 (40%) experienced recurrence. The incidence rate of drug-related adverse events during the treatment was 50% (10/20); no serious adverse events occurred, and no patient withdrew from the treatment due to adverse events. At week 48, both CD4(+)and CD8(+)counts of all patients declined significantly compared with the baseline values (P= 0.001 and 0.001), but the CD4(+)/CD8(+)ratio increased significantly (P= 0.032). The SVR group had a significantly lower mean baseline HCV RNA load than the non-SVR group (4.95 ± 1.18 log10IU/ml vs 6.59 ± 0.53 log10IU/ml,t= 3.49,P= 0.009).

CONCLUSION

In the patients co-infected with HIV and HCV who failed standard interferon therapy, PEG-INF-αcombined with ribavirin has good efficacy and safety, and the patients with a low baseline HCV RNA load are more likely to achieve SVR.

Closed-circuit anesthesia preserves skin blood flow during surgery

BACKGROUND

Closed-circuit anesthesia (CCA) has been suggested to provide better hemodynamic stability, but the relative contribution of CCA to the control of blood flow in microcirculation is not defined. It is hypothesized that isoflurane-based CCA provides a favorable skin blood flow mediating via lesser circulatory response to surgical stimulation. This study was purposed to compare the effects of isoflurane conveyed by CCA with that by semiclosed anesthesia (SCA) on the preservation of skin blood flow in the forearm.

METHODS

Twenty seven patients scheduled for colorectal surgery were enrolled for the study and randomly assigned to one of two groups, either receiving CCA (n=14) or SCA (n=13). Anesthesia was induced with fentanyl (100 ig) and thiopental (4-5 mg/kg), and intubation was facilitated with pancuronium priming (0.015 mg/kg) and succinylcholine (1.25 mg/kg). Two percent isoflurane in high O2 flow (3 L/min) was given for 10 min to each patient initially to wash isoflurane in the functional residual capacity of both lungs and the breathing circuit. In the CCA group, after insoflurane wash-in the 02 flow was reduced less than 250 mL/min with isoflurane vaporizer setting adjusted to 3-5% to keep inspired isoflurane at 2% for maintenance of anesthesia. In patients of in the SCA group, anesthesia was maintained with isoflurane in 3 L/min O2 flow keeping the inspired isoflurane concentration at 2% throughout the surgery. A laser Doppler flowmetry (Moore instrument, Axminster, England) was used to measure skin blood flow (SBF) at the thenar eminence of left hand. Skin blood flow was determined and was taken as baseline (100%) at the 10th min after tracheal intubation. Thereafter, the magnitude of SBF was determined likewise every 30 minutes over the two-hour study. The hemodynamic and respiratory parameters were measured at every 5 minutes in both groups.

RESULTS

In comparison with the SCA group, the CCA group had a greater magnitude of skin blood flow (106 +/- 13% vs. 75 +/- 17%; 104 +/- 14% vs. 68 +/- 14% P < 0.01) at the 60th and 120th min. Also, patients who received SCA had higher mean arterial pressure (MABP) (82 +/- 8 vs. 78 +/- 8; 89 +/- 6 vs. 77 +/- 10, P < 0.05) and heart rate (HR) (80 +/- 9 vs. 73 +/- 9; 82 +/- 15 vs. 71 +/- 14, P < 0.05) at the 60th and 120th min.

CONCLUSIONS

Closed circuit technique for isoflurane anesthesia is feasible and advantageous. It not only facilitates favorable skin blood flow but also provides better hemodynamic stability in comparison with semiclosed technique for isoflurane anesthesia.

Clipping of the appendix induced cardiac arrest during appendectomy under spinal anesthesia

Bradycardia is commonly seen in high spinal anesthesia, however, evolution of cardiac arrest from sudden onset of severe bradycardia is infrequent. Prompt recognization and resuscitative measures are of paramount importance because they may insure a complete recovery without sequela as an aftermath. We report herein a case of severe sinus bradycardia induced by clipping of the appendix during appendectomy under spinal anesthesia with the sensory block up to T5 dermatome. Prompt intravenous atropine failed to regain normal sinus rhythm, and cardiac arrest ensued. Cardiac massage, manual ventilation with oxygen and low-dose epinephrine successfully resuscitated the patient. The possible mechanisms and management of this complication are also discussed.

Property changes of UHMW polyethylene hip cup endoprostheses during implantation

In this study it is demonstrated that the combined chemical and mechanical influences of the implant situation cause property changes of ultra-high-molecular-weight polyethylene (UHMW PE) hip joint cups. Nearly 30 out of 48 loosened cups, retrieved 3 weeks to 11 years after implantation, were investigated. Density measurements show a density increase with implantation time and a dependence of these changes from implant position and loading conditions. The rate of extractable constituents also increases with course of time. An increased in vivo conditioned oxidation of the UHMW PE can be demonstrated by infrared (IR) spectrometry. The density increase can be explained by post-crystallization, which is the result of oxidative chain scission. This leads to a reduction of the average molecular weight of the PE and to an increased extractability of constituents. Since these changes have been recognized as the reasons for aging and failing of UHMW PE, the methods of material characterization used in this study for retrieved implants will help to develop suitable in vitro testing and simulating methods. They are the prerequisite for the necessary improvements of the material properties of UHMW PE.