Contamination of Blood Cultures From Arterial Catheters and Peripheral Venipuncture in Critically Ill Patients: A Prospective Multicenter Diagnostic Study.

BACKGROUND: Collecting blood cultures from indwelling arterial catheters is an attractive option in critically ill adult patients when peripheral venipuncture is difficult. However, whether the contamination proportion of blood cultures from arterial catheters is acceptable compared with that from venipuncture is inconclusive. RESEARCH QUESTION: Is contamination of blood cultures from arterial catheters noninferior to that from venipuncture in critically ill adult patients with suspected bloodstream infection? STUDY DESIGN AND METHODS: In this multicenter prospective diagnostic study conducted at five hospitals, we enrolled episodes of paired blood culture collection, each set consisting of blood drawn from an arterial catheter and another by venipuncture, were obtained from critically ill adult patients with cilinical indication. The primary measure was the proportion of contamination, defined as the number of false-positive results relative to the total number of procedures done. The reference standard for true bloodstream infection was blinded assessment by infectious disease specialists. We examined the noninferiority hypothesis that the contamination proportion of blood cultures from arterial catheters did not exceed that from venipuncture by 2.0%. RESULTS: Of 1,655 episodes of blood culture from December 2018 to July 2021, 590 paired blood culture episodes were enrolled, and 41 of the 590 episodes (6.9%) produced a true bloodstream infection. In blood cultures from arterial catheters, 33 of 590 (6.0%) were positive, and two of 590 (0.3%) were contaminated; in venipuncture, 36 of 590 (6.1%) were positive, and four of 590 (0.7%) were contaminated. The estimated difference in contamination proportion (arterial catheter - venipuncture) was -0.3% (upper limit of one-sided 95% CI, +0.3%). The upper limit of the 95% CI did not exceed the predefined margin of +2.0%, establishing noninferiority (P for noninferiority < .001). INTERPRETATION: Obtaining blood cultures from arterial catheters is an acceptable alternative to venipuncture in critically ill patients. CLINICAL TRIAL REGISTRATION: University Hospital Medical Information Network Center (UMIN-CTR); No.: UMIN000035392; URL: https://center6.umin.ac.jp/.

[An autopsy of a case of pulmonary hypertension secondary to pulmonary embolization of intrahepatic cholangiocarcinoma].

A 70-year-old woman was admitted to our hospital for one month because of progressive dyspnea. Her medical history included an operation for hepatolithiasis at age 47. She was a current smoker. Chest CT revealed emphysematous change and honeycombing in the lung and bilateral subpleural opacifications. Cardiac ultrasound examination showed pulmonary hypertension. Treatments with antibiotics, corticosteroids and heparin were unsuccessful. Despite mechanical ventilation, she died of respiratory failure. Autopsy revealed that intrahepatic cholangiocarcinoma had spread via the hematogeneous route, formed multiple emboli into the pulmonary small arteries, and led to severe pulmonary hypertension and lung infarction.

[A case of sensory ataxic neuropathy associated with asymptomatic primary biliary cirrhosis].

A 65-year-old woman showed progressive asymmetric sensory ataxic neuropathy (SAN) in upper limbs over 12 years, beginning with the onset of primary biliary cirrhosis (PBC). Nerve conduction study showed that sensory action potential was not evoked in upper limbs. Right superficial radial nerve biopsy showed the density of myelinated fibers was severely decreased with large-fiber predominance. Since Sjögren's syndrome (SjS) and paraneoplastic syndrome were denied, this type of neuropathy seems accompanied with asymptomatic PBC. Corticosteroid administration and intravenous immunoglobulin therapy failed to obtain any beneficial effect. The pathological mechanism is considered ganglionitis, which resembles that found in association with SjS. We should also consider PBC as the cause of SAN.