Transthoracic impedance accurately estimates pulmonary wedge pressure in patients with decompensated chronic heart failure

Routine cardiac catheterization to assess pulmonary capillary wedge pressure (PCWP) is not recommended in heart failure (HF), and various noninvasive tools have been proposed. The authors evaluated the reliability of echocardiography, brain natriuretic peptide (BNP), and thoracic electrical bioimpedance (TEB) in predicting PCWP in 29 patients (72±4?years, New York Heart Association class 3.5±0.9, ejection fraction 28%±6%) who underwent hemodynamic evaluation for worsening HF. Echocardiography was performed immediately before the hemodynamic study. During clinical stability, PCWP, plasma BNP, and TEB were simultaneously assessed. Among TEB variables, thoracic conductance (thoracic fluid content [TFC]=1/kΩ) was used. PCWP was related with E/E' obtained with mitral Doppler and mitral annulus tissue Doppler imaging echocardiography (?R=0.55, P<.005), with BNP levels (R=0.43, P<.01) and TFC values (R=0.69, P<.001). For detection of PCWP ≥15?mm?Hg, TFC ≥35/kΩ had high specificity (97%) and sensitivity (86%) and negative (92%) and positive (97%) predictive value, while E/E' and BNP levels had poorer specificity. After infusion of the inodilator levosimendan, changes in TFC and PCWP were of the same order of magnitude and mutually related. In worsening HF, TEB could help avoid right heart catheterization, since it may estimate PCWP better than BNP or echocardiography. Moreover, TFC could be used for noninvasive assessment of drugs' effect.     

Iatrogenic calcinosis cutis following nadroparin injection

Accumulation of calcium in the skin is usually classified as a group of disorders referred to as calcinosis cutis. We report the case of a patient who developed iatrogenic calcinosis at the site of subcutaneous administration of low-molecular-weight heparins (LMWH) as nadroparin. This is usually used for the prevention of deep venous thrombosis, especially following renal transplantation. The role of calcium content in nadroparin is discussed.     

Time dependence of chloroform-induced metabolic alterations in the liver and kidney of B6C3F1 mice

The time course of some biochemical changes in the liver and in the kidney was studied in B6C3F1 male mice dosed with a single i.p. injection of 150 mg/kg body weight (b.w.) CHCl₃. Hepatic and renal microsomal cytochrome P450 (P450) content and some related monooxygenase activities, CHCl₃ oxidative and reductive metabolism, cytosolic reduced glutathione (GSH) content and serum markers of nephrotoxicity were measured. In the liver no biochemical changes were produced up to a week after chloroform treatment. On the contrary, the drug-metabolizing enzyme system in the kidney was dramatically and rapidly inactivated by chloroform treatment. Maximum loss of GSH (50%), P450 (80%) and of different enzymatic activities, including CHCl₃ bioactivation, occurred during the first 5 h. These biochemical alterations are early effects, not secondary to morphological tissue changes. Kidney parameters, altered by chloroform treatment, returned to control values at different times: renal function markers became normal in 48 h; GSH levels were recovered at 96 h and the drug-metabolizing enzyme activities at longer times. The present results clearly show that repeated daily doses of chloroform, as those used in carcinogenicity tests, find renal tubular cells not at their physiological status, due to the changes produced by the first chloroform dose. Therefore the similarity in P450-dependent chloroform metabolism shown in vitro by hepatic and renal microsomes from untreated B6C3F1 male mice or in vivo in animals treated once, is lost during repeated treatments. These features should be considered in understanding the different susceptibility of the liver and the kidney to chloroform-induced tumours. Received: 18 May 1999 / Accepted: 19 July 1999     

Effects of baricity of 0.5% or 0.75% levobupivacaine on the onset time of spinal anesthesia: a randomized trial

PURPOSE: Levobupivacaine has been extensively evaluated for spinal anesthesia. Its pharmacologic properties are similar to those of bupivacaine, but differences in density between two commercially-available preparations of plain levobupivacaine might lead to different block profiles. We examined the characteristics of spinal anesthesia using the same dose of 0.5% and 0.75% plain levobupivacaine. METHODS: In this randomized, controlled, double-blind clinical trial, 60 ASA I-III patients, scheduled for hip fracture surgery, were randomly allocated to receive spinal anesthesia with 15 mg of either 0.5% (group Levo-0.5), or 0.75% (group Levo-0.75) plain levobupivacaine. Onset time (primary outcome), sensory block height level by pinprick, motor block using a modified Bromage scale, and hemodynamic variables were recorded. RESULTS: In group Levo-0.5 (n = 29), surgical anesthesia was obtained within 15 (10-20) min, compared to 12 (7-21) min in group Levo-0.75 (n = 31) (p = 0.409). The highest sensory block level was T11 (T6-T12) in group Levo-0.5, and T10 (T8 - T12) in group Levo-0.75 (p = 0.759). Mean duration of anesthesia was 285 (224-303) min in group Levo-0.5, and 318 (243-375) min in group Levo-0.75 (p = 0.117). The groups were similar in regards to the number of failed blocks requiring general anesthesia, and the number of patients requiring vasopressors. CONCLUSIONS: In this population of elderly patients, spinal anesthesia with 15 mg of either 0.5% or 0.75% plain levobupiva-caine resulted in similar onset of pharmacological actions, and outcomes. Potential differences in baricity did not appear to be clinically relevant in this setting.