Michele Zasa

Intrathecal ropivacaine 5 mg/ml for outpatient knee arthroscopy: a comparison with lidocaine 10 mg/ml

Purpose: The aim of this prospective, randomised, blind study was to compare the evolution of spinal block produced with 50 mg lidocaine 10 mg/ml and 10 mg ropivacaine 5 mg/ml for outpatient knee arthroscopy.

Systemic hemodynamic effects of sequential pneumatic compression of the lower limbs: a prospective study in healthy volunteers

STUDY OBJECTIVE To evaluate the effects on systemic hemodynamics of sequential pneumatic compression of the lower limbs in healthy volunteers. DESIGN Prospective, self-controlled, volunteer study. SETTING University teaching hospital. PATIENTS 11 healthy volunteers, aged 25 +/- 1.3 years. INTERVENTIONS AND MEASUREMENTS After volunteers underwent a 6-hour period of fasting and 15 minutes of rest in the supine position, baseline systemic hemodynamics were assessed using transthoracic electrical bioimpedance. Peripheral venous pressure was measured using a 16-gauge intravenous cannula inserted in the forearm and connected to a pressure monitor. Then sequential pneumatic compression of the lower limbs was activated for a 30-minute period, and systemic hemodynamic measurements were repeated. In each volunteer, measurements were repeated twice in two consecutive days, and average values were calculated for each volunteer. MAIN RESULTS After activation of sequential pneumatic compression of the lower limbs, mean arterial blood pressure increased from 90 mmHg (79-107 mmHg) to 95 mmHg (79-129 mmHg) (P = 0.02), whereas heart rate decreased from 79 bpm (51-94 bpm) to 75 bpm (53-90 bpm) (P = 0.02). This was associated with a significant increase in peripheral vascular resistance index (from 545 [440-1066] to 613 [369-1280] dynes s cm(-5) m(-2) [P = 0.013]) and reduction in cardiac index (from 3.4 [2.7- 4.5] to 3.2 [2.5-4.0] L/min per m2 [P = 0.034]). CONCLUSIONS The application of sequential pneumatic compression to the lower limbs is associated with minor increases in mean arterial blood pressure, with moderate reduction of cardiac output and heart rate.

Continuous lumbar epidural infusion of levobupivacaine : effects of small-or large-volume regimen of infusion

Background: The question of whether the dose, concentration or volume of a local anesthetic solution is the relevant determinant of the spread and quality of post‐operative epidural analgesia is still open. In this prospective, randomized, double‐blind study, we compared the effects of a large volume–low concentration with a small‐volume–high‐concentration lumbar epidural infusion of levobupivacaine.

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 levobupivacaine resulted in similar onset of pharmacological actions, and outcomes. Potential differences in baricity did not appear to be clinically relevant in this setting.RésuméObjectif: La lévobupivacaïne en rachianesthésie a fait l’objet de nombreuses évaluations. Ses propriétés pharmacologiques sont semblables à celles de la bupivacaïne, mais les densités différentes de deux préparations de lévobupivacaïne simple disponibles sur le marché pourraient avoir pour conséquences des profils de blocs différents. Nous avons examiné les caractéristiques d’une rachianesthésie réalisée à l’aide d’une même dose de lévobupivacaïne simple à 0,5 % ou à 0,75 %.Méthode: Dans cette étude clinique randomisée, contrôlée et en double aveugle, 60 patients ASA I-III devant subir une chirurgie pour une fracture de la hanche ont été randomisés à recevoir une rachianesthésie avec 15 mg de lévobupivacaïne simple, soit à 0,5 % (groupe Levo-0.5), soit à 0,75 % (groupe Levo-0.75). Le délai d’installation (résultat principal), le niveau du bloc sensitif mesuré à la piqûre, le bloc moteur mesuré par une échelle de Bromage modifiée et les variables hémodynamiques ont été enregistrés.Résultats: Dans le groupe Levo-0.5 (n=29), l’anesthésie chirurgicale a été réalisée en 15 (10–20) min, par rapport à 12 (7–21) min dans le groupe Levo-0.75 (n=31) (P=0,409). Le niveau de bloc sensitif le plus élevé était T11 (T6–T12) dans le groupe Levo-0.5, et T10 (T8–T12) dans le groupe Levo-0.75 (P=0,759). La durée moyenne de l’anesthésie était de 285 (224–303) min dans le groupe Levo-0.5, et de 318 (243–375) min dans le groupe Levo-0.75 (P=0,117). Le nombre de blocs non réussis ayant nécessité une anesthésie générale et le nombre de patients nécessitant des vasopresseurs étaient semblables dans les deux groupes.Conclusion: La rachianesthésie réalisée avec 15 mg de lévobupivacaïne simple à 0,5 % ou 0,75 % chez une population de patients âgés provoque des réactions pharmacologiques semblables et donne des résultats similaires. Les différences possibles de baricité ne semblent pas avoir été pertinentes dans ce contexte.

Gender Differences in Case Mix and Outcome of Critically Ill Patients

INTRODUCTION The potential for gender-related bias in the provision of medical treatments has gained increased interest in recent years. The aim of this retrospective, observational study was to evaluate the association between gender and clinical outcome in an Italian mixed medical-surgical ICU population. METHODS Data on 1978 patients admitted to the ICU during a 3-year period were analyzed. Demographics, diagnosis, and hospital stay details were recorded. RESULTS Male ICU admissions were predominant over female ones (64% vs 36%). Neither ICU survival rate (80% in group male, 79% in group female; P = 0.602) nor hospital survival rate (72% in group male, 72% in group female; P = 0.820) showed gender-related differences. A statistically significant difference was found in terms of mean (SD) age (57 [19] years in group male, 62 [18] years in group female; P < 0.001), ICU length of stay (7.0 [9.1] days in group male, 5.7 [7.7] days in group female; P < 0.001) and length of mechanical ventilation (6.3 [8.4] days in group male, 5.3 [7.5] days in group female; P = 0.001). Severity of illness, measured through the simplified acute physiology score II, was not statistically different between gender groups; nor was the incidence of infective complications. After stratifying for diagnostic subgroups a few gender differences were pointed out, but none of them affecting ICU and hospital survival rates. A Kaplan-Meier 30-day ICU survival analysis revealed no differences between the male and female groups of the study population. CONCLUSIONS According to our results, mortality among critically ill patients was not influenced by gender. Despite a higher frequency of men admitted, women were older than men. Moreover, men were treated for a longer period of time than women. Limitations of the study were the inability to establish causal relations and to account for variables with important effects on the reported associations. Moreover, the sample size was small if compared to similar multicenter studies.

An unusual case of high central venous pressure

158 Annals of Cardiac Anaesthesia  Vol. 16:2  Apr-Jun-2013 of the humerus, aplasia of the radius (as in this case) and phocomelia.[3] In a clinical and genetic study (n = 55), all cases of HOS had upper limb involvement, the left side was more severely affected, the females had more severe defects, and cardiac defects were seen in 95% of familial cases.[4] Cardiac defects included ASD (34%), ventricular septal defect (25%), ECG changes (35%), and asymptomatic conduction disturbance with variable degree of AV block. Even patients with minimal upper limb defects should receive a thorough cardiac examination and possibly an echocardiogram, because the severity of the limb defects does not correlate with the severity of the cardiac defect. An ASD is sometimes associated with abnormalities of venous return such as anomalous pulmonary venous drainage, inferior vena caval interruption, and persistent left superior vena cava. Correct preoperative diagnosis of systemic and pulmonary venous anomalies is essential for appropriate cannulation and management during CPB.[5] The peripheral venous access and arterial cannulation may be difficult in patients with significant limb abnormalities. Upper limb defects may make fixation of an appropriate size BP cuff difficult, and inaccurate pressures may be displayed by non‐invasive monitors. Two of the Holt and Oram’s original family had hypoplastic peripheral vessels which prevented cardiac catheterization.[2] The use of ultrasound‐guided cannulation may improve success rate in such patients. [6] In our case, we did not find any cardiac or skeletal abnormality in any of the parents which suggests a spontaneous genetic mutation in the baby. To summarize, in patients of HOS, the potential for difficult arterial and venous cannulation, difficult intubation, and problem with non‐invasive BP monitoring must be kept in mind.