Frequency of bacteremia associated with transesophageal echocardiography in intensive care unit patients: a prospective study of 139 patients.

OBJECTIVE: To determine the occurrence rate of bacteremia associated with transesophageal echocardiography in intensive care unit (ICU) patients. DESIGN: A prospective study of 139 patients undergoing transesophageal echocardiography. SETTING: The medical ICU of a tertiary referral teaching hospital. PATIENTS: One hundred thirty-nine ICU patients (mean age 58 yrs) who underwent transesophageal echocardiography. INTERVENTIONS: Blood samples were systematically drawn for aerobic and anaerobic culture at the following times: before (blood culture 1), at the end of (blood culture 2), and 30 mins after (blood culture 3) transesophageal echocardiography examinations. MEASUREMENTS AND MAIN RESULTS: The mean duration of transesophageal echocardiography was 35 mins (range 7 to 120). One hundred thirty-four patients received mechanical ventilation; 125 patients had a nasogastric tube. Fifty-one patients had one or more underlying conditions that usually justify antimicrobial prophylaxis of bacterial endocarditis before high-risk procedures. Fifty-six patients did not receive any antibiotic treatment at the time of transesophageal echocardiography. In 114 patients, the three blood cultures were negative. In six patients, transesophageal echocardiography was performed during a preexisting bacteremia. A contamination (only one positive blood culture of the three sampling times) with coagulase-negative staphylococci occurred in four patients at blood culture 1, five patients at blood culture 2, and six patients at blood culture 3. Contamination with Corynebacterium species occurred in two patients at blood culture 2. In one patient receiving cefotaxime and netilmicin, blood culture 1 was sterile and blood cultures 2 and 3 yielded coagulase-negative staphylococci. In one patient receiving no antibiotic treatment, blood culture 1 was sterile and blood cultures 2 and 3 yielded Enterococcus faecalis. None of these two patients received a specific antibiotic treatment or developed any secondary septic focus. CONCLUSIONS: The overall frequency of bacteremia induced by transesophageal echocardiography in ICU patients was 1.4% (two of 139 patients) (95% confidence interval 0.2% to 5.1%). The frequency did not differ whether patients received antibiotics before transesophageal echocardiography (one [1.2%] of 83 patients) or not (one [1.8%] of 56 patients) (p = .96). Therefore, routine antimicrobial prophylaxis does not appear justified before transesophageal echocardiography in ICU patients.

Diagnostic accuracy and therapeutic impact of transthoracic and transesophageal echocardiography in mechanically ventilated patients in the ICU.

STUDY OBJECTIVES: To assess the respective diagnostic accuracy of transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) and their therapeutic implications in mechanically ventilated patients, in the intensive care unit (ICU). DESIGN: A prospective study. SETTINGS: Intensive care units of two tertiary referral teaching hospitals. PATIENTS: One hundred eleven ICU patients (81 men and 30 women; mean age 57 +/- 16 years). Fifty-seven percent were hospitalized for medical illnesses, 16.5 percent after thoracic surgery, 10.5 percent after other surgery, and 16.0 percent for multiple trauma. Their Simplified Acute Physiologic Score was 16 +/- 5. INTERVENTIONS: The echocardiograms were performed in order to solve well-defined clinical problems. TTE was the first step of the procedure and TEE was performed only when (1) TTE did not solve the clinical problems, and (2) TTE yielded unsuspected findings requiring TEE. During each echocardiographic study, the following were noted: ventilatory mode, clinical problems, imaging quality, results, consequence on acute care, duration of the procedure, and potential complications of TEE. Diagnostic accuracy was defined as the proportion of solved problems, and therapeutic impact was defined as changes on acute care that resulted directly from the procedure. MEASUREMENTS AND RESULTS: One hundred twenty-eight consecutive TTE and 96 TEE were performed. TTE solved 60 of 158 clinical problems (38 percent), whether positive end-expiratory pressure (> 4 cm H2O) was present or not (28 of 74 vs 32 of 84: p > 0.50). TTE allowed evaluation of left ventricular function in 77 percent of cases and pericardial effusion in every case, but it did not solve most of the other clinical problems. Indeed, the diagnostic accuracy of TEE was markedly superior (95/98 vs 60/158: p < 0.001), but TEE required a physician's presence longer (43 +/- 17 min vs 27 +/- 12 min: p < 0.001). When TTE and TEE were scheduled (n = 96), TEE yielded an additional diagnosis or excluded with more certitude a suspected diagnosis, except in two cases. TEE had a therapeutic impact more frequently than TTE (35/96 vs 20/128: p < 0.001). Cardiovascular surgery was prompted by echocardiographic findings in ten patients. TEE was well tolerated in all patients; there were no complications. CONCLUSIONS: TEE is a valuable well-tolerated imaging technique in mechanically ventilated patients. For the assessment of left ventricular systolic function and pericardial effusion; however, TTE continues to be an excellent diagnostic tool, even when positive end-expiratory pressure is present. Both TTE and TEE have a therapeutic impact in approximately 25 percent of cases.

[Double liver-kidney transplantation in the presence of a positive T cross-match]. / Double transplantation hépatique et rénale en présence d'un cross-match T positif.

Kidney transplantation, when performed across a positive T lymphocyte cross-match, is always followed by the occurrence of a hyperacute rejection. On the other hand, successful hepatic allografts have been reported under these same conditions. Furthermore, clinically and experimentally hepatic allograft has been reported to induce tolerance of other organs from the same donor. Thus, combined liver-kidney transplantation constitutes an ideal application of these immunological events. We report here the case of a sequential liver-kidney transplantation in which liver transplantation performed prior to kidney transplantation with an organ from the same donor induced kidney tolerance despite an initial positive T lymphocyte cross-match.

Defective hepatitis B virus particles are generated by packaging and reverse transcription of spliced viral RNAs in vivo.

Generation of replicative defective viruses is frequently observed during viral infections. We now report that encapsidation and reverse transcription of spliced viral RNA is an additional mechanism for synthesis of defective viral particles. We have investigated the in vivo synthesis of a spliced hepatitis B virus (HBV) RNA. By using the polymerase chain reaction with different sets of primers on DNA purified from infected livers and the HepG2 HBV cell line, we detected a subgenomic HBV DNA complementary to the spliced viral RNA. Its nucleotide sequence was found to be identical to that previously described for the spliced RNA. This HBV RNA is packaged and reverse transcribed in vivo, the cDNA being incorporated into circulating particles. This finding establishes the synthesis of spliced HBV RNA in vivo and indicates that its reverse transcription can give rise to defective viruses.

Assay of hepatitis B virus DNA by polymerase chain reaction and its relationship to pre-S- and S-encoded viral surface antigens.

The polymerase chain reaction was evaluated as a diagnostic tool in 72 chronic hepatitis B virus carriers. Hepatitis B virus DNA was detectable in the serum of HBsAg-positive virus carriers using aliquots as small as 100 al. The detection limit for cloned hepatitis B virus DNA was 100 ag. Primer pairs for different regions of the HBV genome resulted in different sensitivity. Detection of the amplified hepatitis B virus DNA by Southern blotting and subsequent scintillation counting or densitometry allowed a semiquantitative assay. Using several primer pairs in parallel for optimal detection, all HBeAg-positive HBsAg carriers, 80% of HBe antibody-positive symptomatic HBsAg carriers and 57% of asymptomatic HBe antibody-positive HBsAg carriers were found to have hepatitis B virus DNA in the serum. During antiviral therapy hepatitis B virus DNA disappeared by the polymerase chain reaction assay in patients who became HBeAg negative, but polymerase chain reaction detected a relapse earlier than did the conventional dot blot. Pre-S antigens were assayed in serum and liver samples from most chronic carriers by enzyme-linked immunosorbent assay and/or immunoblot. Although most viremic carriers were strongly positive for pre-S1 and pre-S2 antigens, some hepatitis B virus DNA-positive HBsAg carriers did not have detectable pre-S antigens, and vice versa. Our data show that assay of hepatitis B virus DNA in the serum by polymerase chain reaction is by far more proficient than by dot blot and that it cannot be replaced by serological assays of HBeAg or pre-S antigen.

Polymerase chain reaction to detect hepatitis B virus DNA and RNA sequences in primary liver cancers from patients negative for hepatitis B surface antigen.

BACKGROUND AND METHODS: The role of hepatitis B virus (HBV) in the course of patients with primary liver cancer who are negative for hepatitis B surface antigen has been debated. We used the polymerase chain reaction to evaluate 28 such patients for the presence of DNA and RNA sequences of the virus; 22 of these patients had associated cirrhosis. The patients were from areas with different prevalences of HBV infection (South Africa, Italy, France, and Japan). RESULTS: Antibodies to the surface and core antigens of HBV were detected in 10 of the 23 patients tested. HBV DNA sequences were detected in 17 of the 28 patients, including 8 of the 10 with HBV antibodies and 6 of 13 without HBV serologic markers. HBV RNA molecules were found in four of five tumors tested. CONCLUSIONS: Our investigation indicates that transcriptionally active HBV genomes are present in various geographic areas among patients with liver cancer who are negative for hepatitis B surface antigen. This observation is consistent with an etiologic role for the virus in the development of these tumors.

Polymerase chain reaction for studies of mother to child transmission of HIV1 in Africa.

The feasibility and implications of the use of the polymerase chain reaction (PCR) assay in studies of HIV1 mother to child transmission in Africa were investigated. Uncultured leukocyte blood cells (PBL) obtained in Brazzaville (Congo) from newborns and infants (mean age = 27 weeks) of infected mothers were tested. HIV1 DNA sequences were identified in the PBL of six of eight newborns and 14 of 23 babies born to HIV1-positive mothers. In addition two of four babies, who at birth had been seropositive and subsequently were seronegative, were HIV1 DNA positive by PCR. This study demonstrates directly, therefore, a high rate of HIV1 transmission in Africa; it also indicates that PCR should be used for such epidemiological studies.