Changes in the blood flow and prevention of vasospasm of the femoral artery by topical application of lidocaine in rats.

Free-tissue transfer with anastomosis has become an important microsurgical technique. Sometimes vasospasm occurs after anastomosis. We examined the changes in blood flow and the effect on the treatment of vasospasm of the femoral artery of rats. The rat models of vasospasm were generated by topical application of epinephrine. We topically applied 2% lidocaine as a single dose (0.2 mL) and a continuous infusion (1.0 mL/h). Our results suggest that although the effect lasts for a short period, a single application of 2% lidocaine has a rapid effect and is effective for treating a sudden manifestation of vasospasm. In contrast, continuous topical application may be more effective for maintaining the blood flow and preventing vasospasm. Therefore we believe that persistent vasospasm should first be treated with several topical applications of lidocaine; if this helps improve the condition, continuous topical application can be subsequently used as a preventive measure.

Basic ideas and concepts for multiple comparison procedures.

Around 1970, the author proposed a general theoretical approach to multiple decision problems (MDPs) of which multiple comparison problems (MCPs) are special cases. Suppose that a sample space Χ is given together with a set of probability distributions P = {P(θ), θ ∈ Ω} defined over Χ. Let a finite partition of the parameter space Ω = cupω(a), a ∈ A be given. Based on the observation X ∈ X, an MDP is to decide, which ω(a) the true parameter θ belongs to. An MD confidence procedure is a mapping ψ from X to the class of subsets of A, such that the probability that cupω(a), ω(a) C ψ(X) includes the true parameter θ is not smaller than 1-α(θ) . Here, 1-α(θ) is called the level of the confidence procedures and may vary depending on θ∈ω(a) . The MP confidence procedures are derived from the following proposition. When the ω(a) 's are mutually disjoint, there is a one-to-one correspondence between an MD confidence procedure ψ and a collection of (non-randomized) tests for the hypotheses H(a) : θ∈ω(a) with level α(a) by rejecting the hypothesis H(a) if ω(a) ∉ ψ(X). In this paper we discuss in detail the problems of determining the signs or the orderings of normal means. The resulting confidence procedures from the LR tests are seen to be too complicated and difficult to understand. We therefore propose simplified, less powerful methods. We define an overlapping partition of Ω into simple sets, such that the original ω(a) 's can be expressed as an intersection of such simple sets. For each such set we define rejection regions corresponding to the levels α, α/2,...,α/k. Then we obtain the acceptance regions for H(a) : θ∈ω(a) given as the intersection of all acceptance regions for the simple sets containing ω(a) at the level α/k, if there are k such simple sets. This method can be extended to obtain sequential confidence procedures.

[Implementation of the immunological method for improvement on accurate platelet counts].

Rapid and accurate platelet counting is clinically required in severe thrombocytopenia. Prophylactic platelet transfusions are usually indicated in thrombocytopenia with platelet counts less than 20,000/microliter. It was recently reported that the confidence lower limit of platelet counts by automated blood cell counter is about 14,000/microliter. Clinical blood samples occasionally contain red-cell fragments or large platelets. In these cases, platelets should be counted by the phase-contrast microscopy. However, this manual operation is accurate but not precise and needs complicated technique. Abbott has developed an immunological platelet counting method by CELL-DYN 4000. We measured platelet counts in 137 blood samples from thrombocytopenic patients. These samples included red-cell fragmentation and large platelets on blood smears. We compared platelet counts with the immunological method(PLTimm) to those with Brecher-Cronkite, the optical(PLTo) and the impedance method(PLTi). PLTimm correlated more closely with the phase-contrast microscopy counts than PLTo or PLTi. In patients with microangiopathic hemolytic anemia, PLTo or PLTi could not exclude red-cell fragments, but PLTimm absolutely excluded red-cell fragments. In patients with giant platelets, PLTo or PLTi could not include large platelets but PLTimm included them and coincided well with platelet counts by the phase-contrast microscopy. These results indicate that the immunological method by CELL-DYN 4000 appears to be accurate and a very useful method for accurate platelet counts in severe thrombotybopenia.