Spinal cord stimulation for non-reconstructable chronic critical leg ischaemia

BACKGROUND

Patients suffering from inoperable chronic critical leg ischaemia (NR-CCLI), face amputation of the leg. Spinal cord stimulation (SCS) has been proposed as a helpful treatment in addition to standard conservative treatment.

OBJECTIVES

To find evidence for an improvement of limb salvage, pain relief and clinical situation using SCS compared to conservative treatment alone.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases Group's Specialised Register, (last searched May 2005), and the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched Issue 2, 2005). Additional data were obtained from research institutes.

SELECTION CRITERIA

Controlled studies comparing additional SCS with any form of conservative treatment in patients with NR-CCLI.

DATA COLLECTION AND ANALYSIS

Both authors independently assessed the quality of the studies and extracted data.

MAIN RESULTS

Six studies comprising nearly 450 patients were included. In general, the quality of the studies was good. None was blinded due to the nature of the intervention. Limb salvage after 12 months was significantly higher in the SCS group (relative risk (RR) 0.71, 95% confidence interval (CI) 0.56 to 0.90; risk difference (RD) -0.11, 95% CI -0.20 to -0.02). Significant pain relief occurred in both treatment groups, but was more prominent in the SCS group, in which the patients required significantly less analgesics. In the SCS group, significantly more patients reached Fontaine stage II than in the conservative group (RR 4.9, 95% CI 2.0 to 11.9; RD 0.33, 95% CI 0.19 to 0.47). Overall, no significantly different effect on ulcer healing was observed between the two treatments. Complications of SCS treatment consisted of implantation problems (9%, 95% CI 4 to 15%) and changes in stimulation requiring re-intervention (15%, 95% CI 10 to 20%). Infections of the lead or pulse generator pocket occurred less frequently (3%, 95% CI 0 to 6%). The overall risk of complications of additional SCS treatment was 17% (95% CI 12 to 22%), indicating a number needed to harm of 6 (95% CI 5 to 8).A cost comparison was made in only one study. The average overall costs at two years were 36,500 Euros, (SCS group) and 28,600 Euros, (conservative group). The difference (7900 Euros) was significant (P<0.009).

AUTHORS' CONCLUSIONS

There is evidence to favour SCS over standard conservative treatment to improve limb salvage and clinical situation in patients with NR-CCLI. The benefits of SCS against the possible harm of relatively mild complications and costs must be considered.

A comparative study to validate the use of ultrasonography and computed tomography in patients with post-operative intra-abdominal sepsis

PURPOSE

To validate abdominal ultrasonography and helical computed tomography in detecting causes for sepsis in patients after abdominal surgery and to determine improved criteria for its use.

MATERIALS AND METHODS

Eighty-five consecutive surgical patients primarily operated for non-infectious disease were included in this prospective study. Forty-one patients were admitted to the intensive care unit. All patients were suspected of an intra-abdominal sepsis after abdominal surgery. Both ultrasonography (US) and helical abdominal computed tomography (CT) were performed to investigate the origin of an intra-abdominal sepsis. The images of both US and CT were interpreted on a four-point scale by different radiologists or residents in radiology, the investigators were blinded of each other's test. Interpretations of US and CT were compared with a reference standard which was defined by the result of diagnostic aspiration of suspected fluid collections, (re)laparotomy, clinical course or the opinion of an independent panel. Likelihood ratios and post-test probabilities were calculated and interobserver agreement was determined using kappa statistics.

RESULTS

The overall prevalence of an abdominal infection was 0.49. The likelihood ratio (LR) of a positive test-result for US was 1.33 (95% CI: 0.8-2.5) and for CT scan 2.53 (95% CI: 1.4-5.0); corresponding post-test probabilities for US 0.57 (95% CI: 0.42-0.70) and for CT 0.71 (95% CI: 0.57-0.83). The LR of a negative test-result was, respectively, 0.60 (95% CI: 0.3-1.3) and 0.18 (95% CI: 0.06-0.5); corresponding post-test probabilities for US 0.37 (95% CI: 0.20-0.57) and for CT 0.15 (95% CI: 0.06-0.32) were calculated.

CONCLUSION

Computed tomography can be used as the imaging modality of choice in patients suspected of intra-abdominal sepsis after abdominal surgery. Because of the low discriminatory power ultrasonography should not be performed as initial diagnostic test.

Systematic review of dressings and topical agents for surgical wounds healing by secondary intention

Background

The best dressing for postoperative wounds healing by secondary intention is unknown.

Methods

A systematic review was conducted to assess the effectiveness of dressings and topical agents on such wounds. Main endpoints were wound healing, pain, patient satisfaction, costs and hospital stay. Systematic methodological appraisal and data extraction were performed by independent reviewers.

Results

Fourteen reports of 13 randomized clinical trials on dressings or topical agents (gauze, foam, bead, alginate and hydrocolloid dressing) for postoperative wounds healing by secondary intention were identified; they were of weak methodological quality. In general, no statistically significant differences in wound healing were found for various dressing comparisons (11 of 13 trials). Patients experienced significantly more pain (four of six trials) and were less satisfied when gauze was used (three of six trials). Gauze was inexpensive, but its use was associated with significantly more nursing time than dressing with foam (two of three trials). No substantial differences in hospital stay were found (four of five trials).

Conclusions

Only small, poor-quality trials exist, rendering the evidence insufficient. Foam is best studied as an alternative to gauze and appears to be preferable in terms of pain reduction, patient satisfaction and nursing time.

Systematic review and meta-analysis of controlled trials assessing spinal cord stimulation for inoperable critical leg ischaemia

Background

Spinal cord stimulation (SCS) may have a place in the treatment of patients with inoperable chronic critical leg ischaemia.

Methods

A systematic review and meta-analysis was performed of all controlled studies comparing SCS in addition to any form of conservative treatment for inoperable chronic critical leg ischaemia. Main endpoints were limb salvage, pain relief and clinical situation. Systematic methodological appraisal and data extraction were performed by independent reviewers.

Results

Of the 18 reports found, nine trials, comprising 444 patients, matched the selection criteria. After pooling, limb salvage at 12 months appeared significantly greater in the SCS group (risk difference (RD) − 0·13 (95 per cent confidence interval (c.i.) − 0·04 to − 0·22)). Significant pain relief occurred in both treatment groups, but patients who received SCS required significantly less analgesia and reached Fontaine stage 2 more often than those who did not have SCS (RD 0·33 (95 per cent c.i. 0·19 to 0·47)). Complications of SCS were problems of implantation (8·2 per cent), changes in stimulation requiring reintervention (14·8 per cent) and infection (2·9 per cent).

Conclusion

The addition of SCS to standard conservative treatment improves limb salvage, ischaemic pain and the general clinical situation in patients with inoperable chronic critical leg ischaemia. These benefits should be weighed against the cost and the (minor) complications associated with the technique.

The effect of suprapubic catheterization versus transurethral catheterization after abdominal surgery on urinary tract infection: a randomized controlled trial

BACKGROUND/AIM

Transurethral catheterization is generally associated with a higher incidence of urinary tract infections than suprapubic catheterization; however, suprapubic catheterization is associated with other disadvantages such as higher costs and a more difficult technique, and at the moment there is no consensus about the use of both catheter systems. Therefore, a prospective randomized study was performed to investigate the effects of suprapubic catheterization and transurethral catheterization in patients undergoing surgery on the incidence of urinary tract infections and patient satisfaction.

METHODS

Patients who underwent an elective laparotomy were randomized and received a suprapubic or transurethral catheter. The primary end point was urinary tract infection. Other parameters of urinary tract infection, as well as duration of catheterization, hospital stay, and number of recatheterizations and of relaparotomies were monitored. Treatment 'per protocol' was also analyzed after exclusion of patients receiving another catheter than randomized for. Patients were asked for their satisfaction with the catheters and complaints during and after catheterization.

RESULTS

165 patients were eligible, of whom 19 patients had to be excluded. 75 patients were allocated to receive the suprapubic catheter and 71 the transurethral catheter. There was no difference in the incidence of a urinary tract infection between the suprapubic group (n = 9/75; 12%) and the transurethral group (n = 8/71; 11%). Most patients (6/9) who developed a urinary tract infection in the suprapubic group, however, underwent recatheterization because of postoperative complications/sepsis and relaparotomy. The incidence of urinary tract infections in patients who received a suprapubic catheter and not a transurethral catheter was 3/59 (5%). The patients did not differ with respect to satisfaction and complaints. Being a men, recatheterization and duration of catheterization are risk factors.

CONCLUSIONS

The incidence of a urinary tract infection between a suprapubic catheter and a transurethral catheter in patients undergoing major surgery was not different. A potential advantage of the suprapubic catheter (reduction of urinary tract infections) is probably partly negated, because transurethral catheters were used if recatheterization was indicated during the postoperative stay or due to complications.

Spinal cord stimulation for non-reconstructable chronic critical leg ischaemia

BACKGROUND

Patients suffering from inoperable chronic critical leg ischaemia (NR-CCLI), face amputation of the leg. Spinal cord stimulation (SCS) has been proposed as a helpful treatment in addition to standard conservative treatment.

OBJECTIVES

To find evidence for an improvement of limb salvage, pain relief and clinical situation by means of SCS over conservative treatment alone.

SEARCH STRATEGY

The reviewers searched the Cochrane Peripheral Vascular Diseases Group Specialised Register, (last searched November 2002), the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched Issue 4, 2002). Additional data were obtained from research institutes.

SELECTION CRITERIA

Controlled studies comparing additional SCS with any form of conservative treatment in patients with NR-CCLI.

DATA COLLECTION AND ANALYSIS

Two reviewers (DU, HV), independently assessed the quality of the studies and extracted the data.

MAIN RESULTS

Six studies comprising nearly 450 patients were included. In general the quality of the studies was good, although none of them was blinded due to the nature of the intervention. Limb salvage after 12 months was significantly higher in the SCS group (RR 0.71, 95%CI: 0.56 to 0.90; RD -0.13, 95%CI: -0.22 to -0.04). Significant pain relief occurred in both treatment groups, but was more prominent in the SCS group, in which the patients required significantly less analgesics. In the SCS group significantly more patients reached Fontaine stage II than in the conservative group (RR 4.9, 95%CI: 2.0 to 11.9; RD 0.33, 95%CI: 0.19 to 0.47). Overall, no significantly different effect on ulcer healing was observed between the two treatments. Complications of SCS treatment consisted of implantation problems (9%; 95%CI: 4 to 15%) and changes in stimulation requiring reintervention, (15%; 95%CI: 10 to 20%). Infections of the lead or pulse generator pocket occurred less frequently (3%; 95%CI: 0 to 6%). The overall risk of complications of additional SCS treatment was 17%, 95%CI: 12 to 22%, indicating a number needed to harm of six (95%CI: 5 to 8).A cost comparison was made in only one study. The average overall costs at two years were 36,500 euros, in the SCS group and 28,600 euros, in the conservative group. The difference (7,900 euros) was significant (p<0.009).

REVIEWER'S CONCLUSIONS

There is evidence to favour SCS over standard conservative treatment to improve limb salvage and clinical situation in patients with NR-CCLI. The benefits of SCS against the possible harm of relatively mild complications, and costs must be considered.

Urine interleukin-8 is a marker for urinary tract infection in postoperative patients

BACKGROUND

Urine of patients with urinary tract infection (UTI) contains high levels of interleukin (IL)-6 and IL-8. However, knowledge of the kinetics of their release in urine is limited. We therefore compared the appearance of IL-6 and IL-8 in urine after uncomplicated surgery and surgery complicated by UTI.

PATIENTS AND METHODS

165 patients undergoing abdominal surgery who received a urinary catheter were studied. Urine IL-6 and IL-8 were prospectively measured in patients who did (n = 10) or did not (n = 20) develop UTI. Statistical analysis was done by one-way ANOVA and the Mann-Whitney test.

RESULTS

Although urine IL-6 increased in the 2 to 4 days preceding the bacteriological documentation of UTI, a similar increase was observed in patients who did not develop UTI. Urine IL-8 was elevated on the day UTI was diagnosed, while remaining low in controls.

CONCLUSION

In this patient group with postoperative UTI, urine IL-8 was a better marker for the early host response than urine IL-6.

Enhancement of polymorphonuclear cell-mediated tumor cell killing on simultaneous engagement of fcgammaRI (CD64) and fcalphaRI (CD89)

Antibodies can efficiently induce antitumor responses via recruitment of Fc receptor-bearing cytotoxic cells. Polymorphonuclear (PMN) cells represent attractive effector cells for antibody-directed immunotherapy. This, because activated PMN cells coexpress the class I receptors for IgG (FcgammaRI, CD64) and IgA (FcalphaRI, CD89), which are potent cytotoxic trigger molecules. Both receptors, however, require the FcR gamma chain for signaling. In this study, we show that FcgammaRI and FcalphaRI can trigger function independently of one another and do not cross-compete for the FcR gamma chain. FcalphaRI proved more efficient in initiating early signaling events and effector functions, such as redirected tumor cell killing and generation of superoxide. In addition, simultaneous engagement of FcgammaRI and FcalphaRI resulted in enhanced tumor cell lysis. These data support the development of concepts in which both FcgammaRI and FcalphaRI on PMN cells are targeted for tumor therapy.

L1-specific protection from tumor challenge elicited by HPV16 virus-like particles

A single injection of HPV16 L1 virus-like particles induced potent CD8-mediated protection from tumor challenge by C3 cells, a line derived from embryonic mouse cells transfected with the HPV16 genome. L1 RNA, but not protein, was detected biochemically in C3 cells. These results indicate that low-level expression of HPV16 L1 can occur in proliferating cells and serve as a tumor vaccine target. Although L1 expression is generally thought to be restricted to terminally differentiated epithelial cells, these results suggest that additional analysis for low-level L1 expression in proliferating cells of HPV-induced lesions is warranted and might help in predicting the clinical potential of HPV L1 virus-like particle-based vaccines.

Immunization with human papillomavirus type 16 (HPV16) oncoprotein-loaded dendritic cells as well as protein in adjuvant induces MHC class I-restricted protection to HPV16-induced tumor cells

Human papillomavirus (HPV) E6 and E7 oncoproteins are attractive targets for T-cell-based immunotherapy of cervical cancer. In this study, we demonstrate that dendritic cells (DCs) pulsed with HPV16 E7 protein are not only recognized in vitro by E7-specific CTLs but also elicit E7-specific CTL responses in vivo, associated with protection against a challenge with syngeneic HPV16-induced tumor cells. Vaccination with soluble E7 protein in incomplete Freund's adjuvant likewise induces E7-specific CTL responses associated with tumor protection. The presence of HPV16 E7-specific CTLs in vivo and the observation that depletion of CD8+ cells completely abolishes tumor protection demonstrate that CTLs are the major effector cells in mediating antitumor activity. The in vivo involvement of DCs in the activation of protective CTLs is suggested by the surface display of E7 peptide-loaded MHC class I molecules on these cells after E7 protein immunization. These data show that HPV16 E7 protein-pulsed DCs, as well as the administration of E7 protein antigen in adjuvant, can effectively stimulate tumor-specific MHC class I-restricted CD8+ T-cell-mediated protective immunity to HPV16-induced cancers.

Accumulation of foreign gases during closed-system anaesthesia

In a previous study, accumulation of methane was found at the end of closed-system ventilation. As on-line analysis of gas concentrations is now available, we examined the progressive increase in concentrations of methane, carbon monoxide and acetone during modern, closed-system conditions, and their influence on infrared halothane analysis, in 26 non-pregnant, gynaecological patients. A computer-controlled closed-system anaesthesia apparatus (PhysioFlex) was used for ventilation during total i.v. anaesthesia (excluding nitrous oxide or potent inhalation anaesthetics) for gynaecological laparoscopy. Methane, carbon monoxide and acetone concentrations were analysed every 15 min in a photoacoustic infrared monitor and halothane concentrations by built-in infrared spectrometry. Mean methane concentrations increased progressively after 105 min to 941 (SD 1094) ppm, but concentrations of carbon monoxide and acetone did not increase significantly. In 18 patients, the infrared measurement falsely indicated 0.79 (0.52)% "halothane" after 60 min, but no reading appeared in the other eight patients. We conclude that methane accumulated progressively under strict closed-system conditions in higher concentrations than reported previously. In two-thirds of patients it induced false "halothane" readings.

Accessory cell-derived IL-12 and prostaglandin E2 determine the IFN-gamma level of activated human CD4+ T cells

IL-12 and PGE2 are two immunomodulators produced by accessory cells (AC) in response to various stimuli. IL- 12 enhances IFN-gamma production by activated CD4+ T cells, whereas PGE2 inhibits the secretion of this cytokine. Because these AC-derived factors exert clearly opposite modulatory effects on IFN-gamma production, we examined 1) the net-IFN-gamma production of CD4+ T cells, stimulated in the presence of both IL-12 and PGE2, 2) the susceptibility of activated CD4+ T cells in time by adding these modulators at different timepoints after stimulation, and 3) the relative contributions of AC-derived IL-12 and PGE2 to IFN-gamma levels by stimulating CD4+ T cells in the presence of LPS-activated monocytes and inhibitors of PGE2 or IL-12. Here, we demonstrate that 1) IL-12 and PGE2 do not abrogate the modulatory action of each other and that the net-IFN-gamma production is determined by their concentration ratio, 2) T cells become insensitive to PGE2, whereas susceptibility to IL-12 is retained after activation, and 3) activated monocytes potently modulate IFN-gamma levels of stimulated CD4+ T cells via release of IL-12 and PGE2. The relative contributions of these AC-derived factors shift in time, due to different production kinetics, from a dominant IL-12 effect to a mixed IL-12/PGE2 effect. Because the net IFN-gamma production of CD4+ T cells is largely determined by the ratio of IL-12 and PGE2 at the timepoint of T cell activation, an imbalance in the production of these immunomodulators may, therefore, lead to immunologic dysfunction.

Accessory cell-derived IL-12 and prostaglandin E2 determine the IFN-gamma level of activated human CD4+ T cells

IL-12 and PGE2 are two immunomodulators produced by accessory cells (AC) in response to various stimuli. IL- 12 enhances IFN-gamma production by activated CD4+ T cells, whereas PGE2 inhibits the secretion of this cytokine. Because these AC-derived factors exert clearly opposite modulatory effects on IFN-gamma production, we examined 1) the net-IFN-gamma production of CD4+ T cells, stimulated in the presence of both IL-12 and PGE2, 2) the susceptibility of activated CD4+ T cells in time by adding these modulators at different timepoints after stimulation, and 3) the relative contributions of AC-derived IL-12 and PGE2 to IFN-gamma levels by stimulating CD4+ T cells in the presence of LPS-activated monocytes and inhibitors of PGE2 or IL-12. Here, we demonstrate that 1) IL-12 and PGE2 do not abrogate the modulatory action of each other and that the net-IFN-gamma production is determined by their concentration ratio, 2) T cells become insensitive to PGE2, whereas susceptibility to IL-12 is retained after activation, and 3) activated monocytes potently modulate IFN-gamma levels of stimulated CD4+ T cells via release of IL-12 and PGE2. The relative contributions of these AC-derived factors shift in time, due to different production kinetics, from a dominant IL-12 effect to a mixed IL-12/PGE2 effect. Because the net IFN-gamma production of CD4+ T cells is largely determined by the ratio of IL-12 and PGE2 at the timepoint of T cell activation, an imbalance in the production of these immunomodulators may, therefore, lead to immunologic dysfunction.

Differential modulation of T helper type 1 (Th1) and T helper type 2 (Th2) cytokine secretion by prostaglandin E2 critically depends on interleukin-2

Prostaglandin E2 (PGE2) favors T helper type 2 (Th2)-like cytokine secretion profiles in murine and human CD4+ T cells by inhibiting the production of the Th1-associated cytokines interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) and up-regulating the production of the Th2-associated cytokines IL-4 and IL-5 in a dose-dependent way. However, the potent inhibition of IL-2 production by PGE2 seems to be in contrast with the simultaneous up-regulation of IL-4 and IL-5 production, because the induction of these cytokines requires IL-2. We, therefore, investigated to which extent the net modulatory effect of PGE2 is determined by the availability of IL-2. To this aim, we examined the effects of PGE2 on the cytokine secretion profiles of a panel of human Th0 clones upon stimulation via different activation pathways, resulting either in high or low IL-2 production. The differential modulation of Th1 and Th2 cytokines by PGE2 was observed only upon modes of stimulation resulting in high IL-2 production. When IL-2 production was low, PGE2 inhibited the secretion of all four cytokines. These different modulation patterns were directly related to the IL-2 availability, because (i) neutralizing antibody to IL-2 abrogated the up-regulatory effect of PGE2 on IL-4 and IL-5 secretion in experiments with high endogenous IL-2 levels, (ii) lack of differential cytokine modulation by PGE2 in conditions with low levels of endogenous IL-2 could be restored with exogenous IL-2, and (iii) cell viability was comparable in all conditions. These results demonstrate that the net modulatory effect of PGE2 on the cytokine secretion profile of T cells critically depends on the availability of IL-2. Since this parameter varies with the experimental conditions and the T cell population studied, this finding may explain why certain immune responses may be either up- or down-regulated by PGE2 under different conditions.

Immunoadjuvant activity of a liposomal IL-6 formulation

The adjuvant effect of interleukin 6 (IL-6) entrapped in liposomes was evaluated using a 65 kDa heat shock protein as a model antigen. The secondary humoral immune response either to antigen alone, or incorporated into liposomes, and the effect of IL-6 entrapped in liposomes, on this response were studied in Balb/c mice. The adjuvanticity of these formulations was compared with that of potent adjuvants such as Ribi and dimethyldioctadecylammoniumbromide (DDA). The importance of IL-6 during adjuvant activity was supported by the observation that high serum IL-6 levels were induced in Balb/c mice by all members of a panel of adjuvants tested. Following incorporation into liposomes, IL-6 retained its full biological activity, as shown by its capacity to sustain growth of the IL-6-dependent B9 cell line. At antigen dosages where Ribi and DDA gave minimal or no secondary antibody titres, incorporation of antigen into liposomes resulted in measurable secondary antibody titres. Interestingly, this adjuvant activity was significantly enhanced when liposomes containing IL-6 were co-injected with the liposomal antigen formulation. These results illustrate the potential adjuvant properties of this formulation, which seem especially useful for vaccines containing weak or non-immunogenic antigens.

Effect of intravenous hypnotics on the actions of pipecuronium

Seventy-five ASA Grades I-III patients (18-85 years, 45-90 kg) were randomized into five groups. All patients received N2O/O2 (2/1) and alfentanil: loading dose (LD) 0.015 mg kg-1 and maintenance dose (MD) 0.045 mg kg-1 h-1 (groups 1-4). Group 1 received propofol (LD 2 mg kg-1 and MD 6 mg kg-1 h-1); Group 2 etomidate (LD 0.3 mg kg-1 and MD 0.6 mg kg-1 h-1); Group 3 midazolam (LD 0.2 mg kg-1 and MD 0.120 mg kg-1 h-1); Group 4 methohexitone (LD 1.5 mg kg-1 and MD 4 mg kg-1 h-1); Group 5 dehydrobenzperidol 0.05-0.23 mg kg-1 and alfentanil (LD 0.100 mg kg-1 and MD 0.060 mg kg-1 h-1). The neuromuscular block induced by pipecuronium (50 micrograms kg-1) was evaluated. No statistically significant differences were found between the five groups as concerned degree of block (expressed as % twitch amplitude in response to the first of the TOF stimuli (Ta1) at intubation, T1 minimum and recovery to Ta1 = 20%, 25% and 75%. Slightly faster intubation was possible when midazolam was used in comparison with propofol, methohexitone or NLA and when etomidate was used in comparison with propofol. A wide range of individual values of maximal neuromuscular blocking activity was found.