An elevated C-reactive protein level in an inpatient rehabilitation setting after joint replacement: To act or not to act? – that is the question

C-reactive protein (CRP) is part of a battery of “routine bloods” performed by residents on patients when they are admitted into a rehabilitation unit. Generally, an elevated CRP is considered to be an indicator of an acute infective process. Numerous studies have indicated that the CRP peaks on the 2nd or 3rd day post total hip arthroplasty (THR) and total knee arthroplasty (TKR) and returns to normal by day 7. When the CRP level remains elevated, it is generally felt that infection should be excluded.We performed a prospective study on 45 consecutive patients admitted into a rehabilitation unit post hip and knee arthroplasty over a 6 months period, to evaluate the incidence of an elevated CRP on admission, to determine whether an isolated elevated CRP on admission to a rehabilitation setting should not be considered as an indicator of an infective process.We found all patients (100%) had elevated CRP''s on admission, ranging from 8.6 mg/L to 139.2 mg/L, between days 5–7 post-operatively. By day 14, CRP''s reduced, but 91% of patients still had elevated CRP''s, ranging from 2.1 mg/L to 47.3 mg/L after THR and 4.8 mg/L to 40 mg/L after TKR at day 14.These results suggest that even in uncomplicated elective joint arthroplasty, CRP''s can remain elevated up to 14 days post-procedure, in the absence of an infective process.An isolated elevated CRP on admission to a rehabilitation setting should not be considered as an indicator of an infective process, but rather part of the normal post-operative inflammatory response. The elevated CRP should be monitored and only an upward trend requires further investigation and management.     

Amidolytic assay of human factor XI in plasma: comparison with a coagulant assay and a new rapid radioimmunoassay

The traditional coagulant assay for plasma factor XI suffers from a relatively high coefficient of variation, the need for rare congenitally deficient plasma, and a poor correlation between precision and sensitivity. We have developed a simple functional amidolytic assay for factor XI in plasma using the chromogenic substrate PyrGlu-Pro-Arg- p-nitroanilide (S-2366). After inactivation of alpha 1-antitrypsin, CI inhibitor, and other plasma protease inhibitors with CHCI3, plasma was incubated with kaolin, in the absence of added calcium, which limited the enzymes formed to those dependent on contact activation. Soybean trypsin inhibitor was used to minimize the action of kallikrein on the substrate. Once the reaction was complete, corn trypsin inhibitor was used to inactive factor XIIa, the enzyme generated by exposure of plasma to negatively charged surfaces, which had activated the factor XI. The assay is highly specific for factor XI, since plasma totally deficient in that zymogen yielded only 1%-3% of the enzymatic activity in normal plasma under identical conditions. The requirements for complete conversion of factor XI to XIa in plasma within 60 min were, respectively, factor XII, 0.6 U/ml, and high molecular weight kininogen, 0.2 U/ml. Prekallikrein was not an absolute requirement for complete activation but did accelerate the reaction. The intraassay coefficient of variation was 3.4%, and the mean of 35 normal plasmas was 1.00 U +/- 0.24 SD. In addition, a new rapid radioimmunoassay was devised using staphylococcal protein A as the precipitating agent for a complex of factor XI antigen with monospecific rabbit antibody. The mean was 1.01 U +/- 0.30 SD. The correlation coefficients for amidolytic versus coagulant and amidolytic versus radioimmunoassay were r = 0.95 for the former and 0.96 for the latter. Thus, a simple, accurate amidolytic assay and a radioimmunoassay have been devised for measuring factor XI in plasma that correlate well with the coagulant activity of factor XI, as determined in our laboratory.     

Impact of timing of presentation of acute pancreatitis to a tertiary care centre on the outcome

Background and objectives

Despite improvement in outcomes of acute pancreatitis (AP), some subgroups remain at increased risk. We studied the impact of onset-to-admission interval to a tertiary care centre on outcomes in AP.

Strategies for Insect Management in Cauliflower (Brassica oleraceae var. botrytis) Through Habitat Intervention

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Intercropping is one of the important components of habitat management based on the principle of reducing...