Respiratory quotient estimations as additional prognostic tools in early septic shock

Central venous-to-arterial carbon dioxide difference (P_cvaCO₂), and its correction by the arterial-to-venous oxygen content difference (P_cvaCO₂/C_avO₂) have been proposed as additional tools to evaluate tissue hypoxia. Since the relationship between pressure and content of CO₂ (CCO₂) might be affected by several factors, some authors advocate for the use of C_cvaCO₂/C_avO₂. The aim of the present study was to explore the factors that might intervene in the difference between P_cvaCO₂/C_avO₂ and C_cvaCO₂/C_avO₂, and to analyze their association with mortality. Observational study in a 30-bed mixed ICU. Fifty-two septic shock patients within the first 24 h of ICU admission were studied. After restoration of mean arterial pressure, hemodynamic and metabolic parameters were evaluated. A total of 110 sets of measurements were performed. Simultaneous P_cvaCO₂/C_avO₂ and C_cvaCO₂/C_avO₂ values were correlated, but agreement analysis showed a significant proportional bias. The difference between P_cvaCO₂/C_avO₂ and C_cvaCO₂/C_avO₂ was independently associated with pH, S_cvO₂, baseline C_cvaCO₂/C_avO₂ and hemoglobin. A stepwise regression analysis showed that pH was the single best predictor for the magnitude of such difference, with very limited effect of other variables. At inclusion, variables associated with ICU-mortality were lactate, pH, P_cvaCO₂/C_avO₂, and the difference between P_cvaCO₂/C_avO₂ and C_cvaCO₂/C_avO₂. Initial S_cvO₂, P_cvaCO₂, C_cvaCO₂/C_avO₂, and cardiac index were not different in survivors and non-survivors. In a population of early septic shock patients, simultaneous values of P_cvaCO₂/C_avO₂ and C_cvaCO₂/C_avO₂ were not equivalent, and the main determinant of the magnitude of the difference between these two parameters was pH. The P_cvaCO₂/C_avO₂ ratio was associated with ICU mortality, whereas C_cvaCO₂/C_avO₂ was not.

Eosinophilic leukemia in three African pygmy hedgehogs (Atelerix albiventris) and validation of Luna stain

Neoplasia is usually encountered in the African pygmy hedgehog at a mean age of 3.5 y, and malignancy is common. Myelogenous leukemias are rarely reported in hedgehogs. We describe 3 cases of eosinophilic leukemia in adult, middle-aged (mean age: 2.3 y) hedgehogs, for which prognosis appears grave. In 1 case, attempted treatment was unsuccessful, and in all 3 cases, the disease course was rapid and all died soon after diagnosis. Blood smear evaluation, along with complete blood count, was critical in making the diagnosis in all cases. Luna stain was validated and used to better visualize eosinophils in cytologic and histologic sections. Electron microscopy confirmed the presence of specific granules in hedgehog eosinophils.

Central venous-to-arterial carbon dioxide difference and the effect of venous hyperoxia: A limiting factor, or an additional marker of severity in shock?

Central venous-to-arterial carbon dioxide difference (P_cvaCO₂) has demonstrated its prognostic value in critically ill patients suffering from shock, and current expert recommendations advocate for further resuscitation interventions when P_cvaCO₂ is elevated. P_cvaCO₂ combination with arterial-venous oxygen content difference (P_cvaCO₂/C_avO₂) seems to enhance its performance when assessing anaerobic metabolism. However, the fact that PCO₂ values might be altered by changes in blood O₂ content (the Haldane effect), has been presented as a limitation of PCO₂-derived variables. The present study aimed at exploring the impact of hyperoxia on P_cvaCO₂ and P_cvaCO₂/C_avO₂ during the early phase of shock. Prospective interventional study. Ventilated patients suffering from shock within the first 24 h of ICU admission. Patients requiring FiO₂ ≥ 0.5 were excluded. At inclusion, simultaneous arterial and central venous blood samples were collected. Patients underwent a hyperoxygenation test (5 min of FiO₂ 100%), and arterial and central venous blood samples were repeated. Oxygenation and CO₂ variables were calculated at both time points. Twenty patients were studied. The main cause of shock was septic shock (70%). The hyperoxygenation trial increased oxygenation parameters in arterial and venous blood, whereas PCO₂ only changed at the venous site. Resulting P_cvaCO₂ and P_cvaCO₂/C_avO₂ significantly increased [6.8 (4.9, 8.1) vs. 7.6 (6.7, 8.5) mmHg, p 0.001; and 1.9 (1.4, 2.2) vs. 2.3 (1.8, 3), p < 0.001, respectively]. Baseline P_cvaCO₂, P_cvaCO₂/C_avO₂ and S_cvO₂ correlated with the magnitude of PO₂ augmentation at the venous site within the trial (ρ -0.46, p 0.04; ρ 0.6, p < 0.01; and ρ 0.7, p < 0.001, respectively). Increased P_cvaCO₂/C_avO₂ values were associated with higher mortality in our sample [1.46 (1.21, 1.89) survivors vs. 2.23 (1.86, 2.8) non-survivors, p < 0.01]. P_cvaCO₂ and P_cvaCO₂/C_avO₂ are influenced by oxygenation changes not related to flow. Elevated P_cvaCO₂ and P_cvaCO₂/C_avO₂ values might not only derive from cardiac output inadequacy, but also from venous hyperoxia. Elevated P_cvaCO₂/C_avO₂ values were associated with higher PO₂ transmission to the venous compartment, suggesting higher shunting phenomena.

The corrosion resistance of Wiron(®)88 in the presence of S. mutans and S. sobrinus bacteria

The corrosion resistance of Wiron(®)88, a Ni-Cr-Mo alloy, was evaluated in liquid growth media in the absence and presence of the Streptococcus sobrinus and Streptococcus mutans strains. Open circuit potential measurements, cyclic voltammetry, linear sweep voltammetry, as well as electronic microscopy coupled to electron diffraction spectroscopy (SEM/EDS), were the main techniques used in this study. It was concluded that the presence of S. sobrinus and S. mutans have only a slight effect on the corrosion resistance of the Wiron(®)88 alloy, with the S. mutans being slightly more aggressive. For both strains the corrosion resistance R p is of the same order (kΩ cm(2)). After 24 h immersion the S. sobrinus lead to and R p of 11.02, while the S. mutans lead to of 5.59 kΩ cm(2). SEM/EDS studies on the Wiron(®)88 samples, with 24 days of immersion, at 37 °C, have confirmed bio-corrosion of the alloy occurring through the dissolution of Ni as Ni(2+) and formation of chromium and molybdenum oxides. The bacterial adhesion to the surface is not uniform.

Solitary hemangioma of the small bowel disclosed by wireless capsule endoscopy

A nine-year-old child presented with melena and anemia. She had similar symptoms five months earlier and had undergone an extensive workup with upper gastrointestinal endoscopy and colonoscopy, both normal and 99m-Tc-RBC-scintigraphy which was positive in the right lower quadrant. This time, capsule endoscopy was performed and disclosed an hemangioma with a dark spot suggesting recent bleeding in the ileum. The lesion was resected. Pathological examination revealed a transmural cavernous hemangioma. Small bowel hemangioma is a rare disease. Its diagnosis is extremely difficult and is usually obtained during surgery. Capsule endoscopy is an endoscopic technique that can improve preoperative diagnosis, as reported in the present case.

Boophilus microplus: the pattern of bovine immunoglobulin isotype responses to high and low tick infestations

Cattle present variable levels of resistance to ticks and the immune correlates of these heritable phenotypes must be known in order to develop effective vaccines. The antibody responses to tick salivary antigens were examined in cattle of tick-susceptible (Holstein) and tick-resistant (Nelore) breeds. After heavy infestations, levels of IgG1 and IgG2 antibodies decreased in Holsteins and remained the same in Nelores. Conversely, levels of IgE antibodies increased in Holsteins. Different sizes of tick burdens modulated the IgG1 antibody response in a susceptible breed (Aberdeen): levels were higher than in controls in heavily infested animals, but not in those undergoing intermediary or minimal infestations. The three experimental groups presented similar levels of IgG2 antibodies. Levels of IgE antibodies were higher only in animals undergoing intermediate infestations. These results indicate that tick infestations suppress the IgG antibody response in susceptible breeds, that IgE antibodies are not protective, and that the dose of tick saliva modulates the isotype of host antibody responses.

[Diagnostic value of transesophageal echocardiography in the diagnosis of infectious endocarditis. A comparative analysis comparing it with transthoracic echocardiography]

The aim of this study is to compare the performance of Transesophageal Echocardiography (TEE) and the Transthoracic approach (TTE) in the diagnosis of Infectious Endocarditis (IE). Between October/90, the data we started transesophageal ultrasound, till April/92, we performed 33 TTE in inpatients with clinical suspicion of IE. Twenty pts (61%) had one or two prosthesis. All the pts had a previous TTE. The diagnosis of IE determined by non-echocardiographic data was established on 18 pts. The other 15 pts, without clinical criteria of IE, were used as the control group. The Echocardiographic criteria for the diagnosis of IE were for both diagnostic tools the presence of masses suggesting vegetation of abscess. The diagnosis was correctly made by TTE in 8 of the 18 pts (S-44%) and by TEE in 16 of the 18 pts (S-89%) with clinical criteria for IE. Of the 15 patients without clinical criteria for IE 14 were correctly identified by TTE (Sp-93%) and 13 by TEE (Sp-89%). With a similar VPP (89%) for both tools has TEE a significative higher value for NPV than TTE (87% vs 58%). This study suggests that TEE, at a same level of specificity as TTE, is highly more sensitive in the diagnosis of IE (S-89 14 for TEE and S-44 23 for TTE) a figure that recommends that all patients with clinical suspicion of IE and a negative TTE should perform a TEE.

[AIDS and the heart]

The authors present an historical introduction, a geographic description and an epidemiologic review of AIDS in Portugal and in the world. After HIV presentation, a laboratory and clinic approach to this syndrome is done, discussing its systemic manifestations. A special interest is given to the different aspects of cardiac lesions particularly its myocardial involvement. Analysing therapeutic results, despite of dismal present of clinic investigation, some hope is being invested in future achievements.