Analgesic efficacy of selective tibial nerve block versus partial local infiltration analgesia for posterior pain after total knee arthroplasty: a randomized, controlled, triple-blinded trial

BACKGROUND

The adductor canal block provides pain relief on the anterior aspect of the knee after arthroplasty. Pain on the posterior aspect may be treated either by partial local infiltration analgesia of the posterior capsule or by a tibial nerve block. This randomized, controlled, triple-blinded trial tests the hypothesis that a tibial nerve block would provide superior analgesia compared to posterior capsule infiltration in patients scheduled for total knee arthroplasty under spinal anesthesia with an adductor canal block.

METHODS

Sixty patients were randomized to receive either infiltration of the posterior capsule by the surgeon with ropivacaine 0.2%, 25 mL, or a tibial nerve block with 10 mL of ropivacaine 0.5%. Sham injections were performed to guarantee proper blinding. The primary outcome was intravenous morphine consumption at 24 h. Secondary outcomes included intravenous morphine consumption, pain scores at rest and on movement, and different functional outcomes, measured at up to 48 h. When necessary, longitudinal analyses were performed with a mixed-effects linear model.

RESULTS

The median (interquartile range) of cumulative intravenous morphine consumption at 24 h was 12 mg (4-16) and 8 mg (2-14) in patients having the infiltration or the tibial nerve block respectively (p = 0.20). Our longitudinal model showed a significant interaction between group and time in favor of the tibial nerve block (p = 0.015). No significant differences were present between groups in the other above-mentioned secondary outcomes.

CONCLUSION

A tibial nerve block does not provide superior analgesia when compared to infiltration. However, a tibial nerve block might be associated with a slower increase in morphine consumption over time.

[Poppyseed anaphylaxis]

We describe 3 patients with a severe allergic immediate-type reaction to poppy-seeds, diagnosed from clinical findings, skin tests and specific IgE antibodies (CAP). All show a serologic positivity to sesame seed, possibly due to a cross reactivity to similar allergens. From 1978 until 1987 402 food allergy patients seen at the Allergy Unit, Department of Dermatology, University Hospital Zurich, Switzerland, included no case of allergy to poppy-seeds. Because of today's trend to vegetarian food such immediate type reactions can be expected to occur more frequently.

Peripheral blood mononuclear cells in patients with nonleukemic cutaneous T-cell lymphoma. Reduced proliferation and preferential secretion of a T helper-2-like cytokine pattern on stimulation

BACKGROUND AND DESIGN

Since patients with cutaneous T-cell lymphoma (CTCL) demonstrate several immunologic abnormalities such as elevated serum immunoglobulin levels or reduced natural killer cell activity, we analyzed functional properties of the peripheral blood mononuclear cells in patients with nonleukemic CTCL and healthy donors.

RESULTS

After priming with phytohemagglutinin for 3 days, a reduced proliferation in the presence of interleukin 2 and interleukin 4 was found. Limiting dilution technique revealed a diminished number of peripheral blood mononuclear cells from patients with CTCL that were capable of proliferating on interleukin 2 but not on interleukin 4 stimulation. Phytohemagglutinin induced a significantly higher release of interleukin 4 (mean +/- SD, 196 +/- 149.8 pg/mL [n = 19] vs 76.4 +/- 16.4 pg/mL [n = 248]) and a significantly lower secretion of interferon-gamma (24.9 +/- 30.7 U/mL [n = 17] vs 47.5 +/- 43.5 U/mL [n = 18]) in the peripheral blood mononuclear cells of patients with CTCL compared with the peripheral blood mononuclear cells of healthy donors (P < or = .02, U test).

CONCLUSION

These functional characteristics can be explained by an imbalanced T helper-1/T helper-2 system and allow speculations concerning clinical features such as elevated immunoglobulin serum levels and reduced cytotoxic activity in patients with CTCL.

[Pneumocystis carinii pneumonia in HIV infection: better prognosis because of early diagnosis]

The clinical presentation of 60 consecutive Pneumocystis carinii pneumonias in 58 HIV-infected patients (48 men, 10 women, mean age 34 [22-53] years) was prospectively evaluated from April to August 1989 and compared with 60 consecutive P. carinii pneumonias in 59 HIV-infected patients (55 men, 4 women, mean age 37.5 [22-60] years) between 1981-88. Mortality rates within 14 days after diagnosis of P. carinii pneumonia were 50% (8 of 16 patients) until 1985, 20.5% (9 of 44) between 1986 and August 1988, and 1.7% (one of 60) in 1989. The degree of severity of the pneumonias at time of diagnosis was markedly lower in 1989, as shown by following parameters (averages of 1989, compared with averages of 1981-88): lactate dehydrogenase 540 (250-1419) U/l versus 680 (235-1920) U/l (not significant); alveolo-arterial difference of partial oxygen tension (pA-aO2) 22.9 (0.5-73.5) mmHg versus 39.7 (19-70) mmHg (P less than 0.001); score of radiological findings 1.4 (0-3) versus 2.7 (0-4) (P less than 0.001). In 1989, mainly clinical symptoms (dry cough: 57 of 60 cases, dyspnea: 44 of 60 cases, fever: 43 of 60 cases) initiated the diagnostic procedure: chest radiographs, lactate dehydrogenase and pA-aO2 were normal in 13, 25 and 33 episodes, respectively. The lower mortality rate of P. carinii pneumonia could not primarily be explained by therapeutical progress since the treatment of choice did not change fundamentally since 1981. Above all, early diagnosis fundamentally determined the probability of survival.