Morphological variability of black bullhead Ameiurus melas in four non-native European populations

External morphology in black bullhead Ameiurus melas, a fish species considered to have high invasive potential, was studied in its four non-native European populations (British, French, Italian and Slovak). The aim of this study was to examine this species' variability in external morphology, including ontogenetic context, and to evaluate its invasive potential. Specimens from all non-native populations reached smaller body size compared to individuals from native populations. Juvenile A. melas were found to have a relatively uniform body shape regardless of the population's origin, whereas adults developed different phenotypes depending upon location. Specimens from the U.K., Slovak and French populations appeared to be rather similar to each other, whereas the Italian population showed the most distant phenotype. This probably results from the different thermal regime in the Italian habitat. Ameiurus melas from non-native European populations examined in this study showed some potential to alter the body shape both within and between populations. The phenotypic plasticity of A. melas, however, was not found to be as significant as in other invasive fish species. The results suggest that morphological variability itself is not necessarily essential for invasive success. The invasiveness of A. melas is therefore probably favoured by variations in its life-history traits and reproduction variables, together with some behavioural traits (e.g. voracious feeding and parental care) rather than by phenotypic plasticity expressed in external morphology.

Empirical standard mass equation for Salmo marmoratus

Total length (L(T)) (range 24-1000 mm; mean ±S.E. = 170.21 ± 0.36 mm) and mass (W) (range 0.10-9590 g; mean ±S.E. = 76.03 ± 0.87 g) of 36,460 specimens of marble trout Salmo marmoratus were used to compute a standard mass (W(s)) equation for this species by means of the empirical percentile (EmP) method. The EmP W(s) equation calculated was: log(10) W(s) = -5.208 + 3.202 log(10) L(T) - 0.046 (log(10) L(T))(2) (L(T) range 90-570 mm) and it is valid throughout the species' area of distribution across Europe.

Neuromuscular block in Italy: a survey of current management

BACKGROUND

Little is known about current use of neuromuscular blocking agents by Italian anesthetists. This paper reports the results of a survey conducted to obtain information about current management of neuromuscular block in Italy.

METHODS

A questionnaire was given to Italian Anesthetists attending the 64nd National Congress of the Italian Society of Anesthesia, Intensive Care, Analgesia and Intensive Therapy S.I.A.A.R.T.I. (Parma, 13th-16th October 2010). Collected data were stratified by age, geographical location, and the total number of surgical procedures performed in the hospitals concerned.

RESULTS

One thousand four hundred forty patients correctly compiled questionnaires were collected. 50% of respondents used clinical tests to monitor the level of neuromuscular blockade. The main clinical tests cited for the evaluation were: keeping the head lifted up for 5 seconds, protruding the tongue and opening the eyes. Train-of-four was used by 50% of respondents on a routine basis. Only 33% of anesthetists reply that a train-of-four ratio of 90% or more is the safe level prior to extubation.

CONCLUSION

Clinical signs are used by most of the Italian anesthetists to assess the recovery from neuromuscular blockade. There is poor awareness about their inability to indicate even a significant degree of residual neuromuscular block. A more extensive use of quantitative instrumental monitoring is required for the more rational use of neuromuscular blocking agents.

Goal-directed therapy in anesthesia: any clinical impact or just a fashion?

Goal-directed therapy (GDT) describes the protocolized use of cardiac output and related parameters as end-points for fluid and/or inotropic therapy administration. Identifying the patient who will benefit from it has implications throughout perioperative management. The fundamental principle behind GDT is optimizing tissue perfusion by manipulating heart rate, stroke volume, hemoglobin and arterial oxygen saturation to improve oxygen delivery by using fluids, inotropes, red blood cells and supplementary oxygen. Although cardiac output and SvO2 were previously measured using the pulmonary artery catheter, a number of less invasive methods are now available. For intraoperative GDT, the esophageal Doppler-derived Flow Time correct (FTc) is the parameter used most frequently, although other parameters such as stroke volume obtained from Vigileo, PICCO and/or LiDCO, mixed and/or central venous oxygen saturation (SvO2/ScvO2), oxygen delivery and global end diastolic volume (PiCCO system) may be applied in daily clinical practice. The correct target to be followed during the intraoperative period must be clearly established. Most parameters depend primarily on O2 consumption and are not reliable or useful during anesthesia. To date, the quantity and the type of fluids to administer during major elective surgery remain an object of continuing debate. In conclusion, in terms of evidence-based medicine, GDT during anesthesia has a clinical impact when performed using an FTc-based fluids algorithm protocol. In contrast, GDT can be considered unreliable if confusing targets such as SvO2 or ScvO2 higher than 70% during anesthesia are followed.

Knowledge of residual curarization: an Italian survey

BACKGROUND

The use of neuromuscular blocking agents (NMBAs) is widespread in anesthetic practice; little is known about the current use of these drugs in Italy. This survey was conducted to obtain information about the most commonly used clinical tests and the train-of-four (TOF) ratios that are considered as being reliable for assessing recovery from neuromuscular blockade at the end of anesthesia and the estimated occurrence rates of post-operative paralysis in Italian hospitals.

METHODS

The questionnaire was given to Italian anesthesiologists attending the 62nd National Congress of the Italian Society of Anesthesia, Analgesia and Intensive Therapy. Collected data were stratified by age and the total number of surgical procedures performed in the hospitals concerned.

RESULTS

Seven hundred and fifty-four correctly compiled questionnaires were collected (response rate 88.7%). Seventy three percent of the respondents only used clinical tests for monitoring the level of neuromuscular blockade. The main clinical tests cited for the evaluation of residual paralysis were keeping the head lifted up for 5 s, protruding the tongue and opening the eyes. TOF was used by 35% of the respondents on a routine basis. Only 24% of the interviewed anesthesiologists reported that before extubation, a TOF ratio of at least 0.9 should be reached.

CONCLUSIONS

Most Italian anesthetists assess the recovery from neuromuscular blockade only by clinical signs. There is poor awareness about the inability of such techniques to indicate even a significant amount of residual neuromuscular block. A more extensive use of quantitative instrumental monitoring is required for the more rational use of NMBAs.

Perioperative considerations in HIV-infected liver transplanted patients

The introduction of highly active antiretroviral therapy (HAART) has improved survival in HIV patients, allowing them to undergo liver transplantation (OLT) in cases of end-stage liver disease. HIV patients show a higher incidence of pulmonary hypertension. The aim of this study was to evaluate pulmonary and systemic hemodynamic changes in HIV-infected patients compared with a non-HIV-infected group of patients undergoing OLT.

METHODS

We analyzed 20 HIV-infected patients and 20 non-HIV-infected patients who underwent OLT. We analyzed preoperative cardiovascular status, as well as intra- and postoperative hemodynamic data. Hemodynamic data were recorded at 4 predefined phases during OLT and at 24, 48, and 72 hours after intensive care unit (ICU) admission. We also evaluated the following perioperative aspects: transfusion requirements, postoperative mechanical ventilation time, ventilation time, and length of ICU and of hospital stay.

RESULTS

HIV-positive patients were younger than controls with a greater incidence of coinfection with hepatotropic viruses. One HIV-infected patient died in the ICU. Hemodynamic data showed a higher cardiac index and higher pulmonary vascular resistance index among HIV-infected patients, but without any clinical impact. No significant difference in blood unit transfusions, postoperative time on mechanical ventilation, or length of ICU or hospital stay was observed between the groups.

CONCLUSIONS

Although the number of patients studied is limited, we concluded that HIV-infected patients undergoing OLT showed similar perioperative courses as non-HIV-infected patients.

A novel approach to reversal of neuromuscular blockade

Postoperative residual curarization is still a problem of the modern anesthesia. Neostigmine is not the safest drug that allows a safe decurarization, especially when neuromuscular transmission monitoring is not used. Sugammadex is a A-cyclodextrin designed to encapsulate rocuronium bromide, providing a rapid reversal of neuromuscular blockade. It has not cardiovascular, respiratory and cholinergic effects. It has been used in renally impaired patients with no neuromuscular blockade recurrence. Sugammadex reverses either a shallow or a deep neuromuscular block. Volatile agents such as sevoflurane seems not to influence the sugammadex ability to reverse the rocuronium neuromuscular blockade. There is no difference in the sugammadex pharmacokinetic in children and adults. Sugammadex would be able to have a role in the future in reversing a non depolarizing steroidal neuromuscular block.

Inhaled aerosolized prostaglandin E1, pulmonary hemodynamics, and oxygenation during lung transplantation

BACKGROUND

The use of inhaled aerosolized prostaglandin E(1) (aerPGE(1)), a pulmonary vasodilator, has not been widely analyzed. In contrast to prostacyclin, PGE(1) has a shorter lifetime and is metabolized in a greater amount from the lungs, lowering the risk of systemic effects. The aim of this study was to analyse the effects of aerPGE(1) administration on pulmonary hemodynamics and oxygenation during lung transplantation.

METHODS

Eighteen patients undergoing lung transplantation were enrolled in this study. During the first lung implantation, systemic and pulmonary hemodynamic and oxygenation data were evaluated in three phases: -- baseline in 100% O(2); during aerPGE(1) -- after 15 min of aerosolized prostaglandin E(1) administration in 100% O(2); after aerPGE(1) -- 15 min after the end of the prostaglandin E(1) administration in 100% O(2).

RESULTS

During aerPGE(1) a reduction in mPAP, PVRI, and Qs/Qt and an increase in PaO(2)/FiO(2) were observed. Soon after prostaglandin inhalation was ceased, the mPAP, the PVRI, and the Qs/Qt increased while PaO(2)/FiO(2) decreased. During the study, no significant difference in systemic pressure among the phases was noted. A high correlation between changes in mPAP, Qs/Qt and PaO(2)/FiO(2) after aerPGE(1) administration and baseline values was observed. ROC curve analysis showed that values of 40 mmHg of mPAP, 21.7% of the pulmonary shunt, and 364 mmHg for PaO(2)/FiO(2) predict a decrease in mean pulmonary arterial pressure and pulmonary shunt or an improvement in oxygenation of 10% with respect to baseline values.

CONCLUSION

A low dose of aerosolized prostaglandin E(1) decreases pulmonary arterial pressure and improves oxygenation without impairment on systemic hemodynamics, also during anesthesia for lung transplantation. The effect seems to depend on baseline values, which can be considered to be a predictor of the prostaglandin response.

The liver transplant recipient with cardiac disease

Liver transplantation is a stressful condition for the cardiovascular system of patients with advanced hepatic disease. The underlying hemodynamic and cardiac status of patients with cirrhosis is crucial to determine which patients should became recipients. Generally preoperative cardiovascular testing is performed on potential candidates who are more than 45 years old, or have diabetes mellitus, or peripheral vascular disease, or more than two standard cardiac risk factors. Recent data suggest that the prevalence of coronary artery disease among patients with cirrhosis is much greater than previously believed; it likely mirrors or exceeds the prevalence rate in the healthy population. The morbidity and mortality of patients with coronary artery disease who undergo orthotopic liver transplantation (OLT) without treatment are unacceptably high. In conclusion, accurate preoperative cardiac evaluation according to the new American Heart Association & American College of Cardiology should lead to detect and treat coronary artery disease before liver transplantation. In case of alcohol-related cardiomyopathy, portopulmonary hypertension, and hypertrophic cardiomyopathy, there should be a case-by-case discussion by the hepatologist and cardiologist to consider the patient for liver transplantation. No robust data are available on the impact of decompensated dilated heart failure in this setting. If a recipient with cardiac disease is scheduled for OLT, we strongly suggest advanced intra- and postoperative hemodynamic monitoring plus transesophageal echocardiography.

Fenoldopam mesylate and renal function in patients undergoing liver transplantation: a randomized, controlled pilot trial

To test the relative effects on serum creatinine (CRE), blood urea nitrogen (BUN), and urine output of small-dose dopamine and fenoldopam in patients undergoing liver transplantation, we randomized 43 patients to 1 of 2 continuous infusions over 48 h, starting with anesthesia induction: fenoldopam, 0.1 microg . kg(-1) . min(-1) or dopamine, 2 microg . kg(-1) . min(-1). We used predetermined hemodynamic and intravascular volume goals (intrathoracic blood volume index 800-1000 mL/m(2), extravascular lung water index <7 mL/kg) to manage patients with an algorithm for use of mannitol and furosemide to maintain urine output >1 mL . kg(-1) . h(-1). At postoperative day 3, the median CRE increase was 0.2 mg/dL (interquartile range [IQR] -0.2-0.5) with fenoldopam and 0.5 mg/dL (IQR 0.3-0.9, P = 0.004) in the dopamine group. The BUN increase was median 2 mg/dL (IQR -2-8) versus 8.5 mg/dL (IQR 5-12, P = 0.01), respectively, with fenoldopam versus dopamine. Urine output was similar; however, significantly fewer fenoldopam patients required furosemide compared with dopamine patients (median 1 [IQR 0-3] versus 3 [IQR 2-4], respectively, P = 0.003). The hemodynamic effects of dopamine and fenoldopam were similar. Compared with dopamine, in the setting of liver transplantation, fenoldopam is associated with better CRE and BUN values.

Atracurium, cisatracurium, vecuronium and rocuronium in patients with renal failure

AIM

The cumulative index, the recovery, the onset and the duration of action, of atracurium, cisatracurium, vecuronium and rocuronium in uremic patients undergoing kidney transplantation compared to healthy patients undergoing general surgery were studied.

METHODS

In all patients (64 uremic vs 62 "healthy" patients) after anesthesia induction, atracurium 0.5 mgxkg(-1) or cisatracurium 0.15 mgxkg(-1) or vecuronium 0.1 mgxkg(-1) or rocuronium 0.6 mgxkg(-1) were administered, and at the end of surgery when T1 reached 25% neostigmine 0.05 mgxkg(-1) was given. Neuro-muscu-lar transmission was monitored by accelerometry (TOF-GUARD, Organon).

RESULTS

Cumulative index of vecuronium (1.3+/-0.1 vs 1.06+/-0.11, p<0.001) and rocuronium (1.45+/-0.18 vs 1.04+/-0.16, p<0.001), recovery index (time of T1 25-75) of atracurium (14.2+/-5 vs 9+/-4, p<0.005), cisatracurium (18.7+/-3 vs 9.1, p<0.001), vecuronium (18.5+/-3 vs 12.5+/-3, p<0.001) and rocuronium (18+/-6 vs 11+/-4, p<0.001) and interval T1 25% to TOF 0.8 of cisatracurium (20.5+/-1.2 vs 16+/-2.1, p<0.001) and vecuronium (27+/-6.3 vs 20+/-3.3, p<0.001) were longer in uremic patients. The onset time and the duration of action of atracurium, cisatracurium, vecuronium and rocuronium were similar in all groups compared to controls one.

CONCLUSION

In patients with renal failure the use of atracurium, cisatracurium, vecuronium and rocuronium is suitable and predictable in terms of onset, and duration of action. Care has to be taken to vecuronium and rocuronium cumulative index. Neuromuscular trasmission has to be always monitored.

Preload and haemodynamic assessment during liver transplantation: a comparison between the pulmonary artery catheter and transpulmonary indicator dilution techniques

BACKGROUND AND OBJECTIVE

Liver transplantation is characterized by several changes in intravascular blood volume due to vasodilatation based on neurohumoral mediators, intraoperative bleeding and anaesthesia technique effects. Today, with the transpulmonary indicator dilution technique, cardiac index (CIart) can be evaluated and preload assessed in terms of the intrathoracic blood volume index (ITBVI). The aim was to analyse in patients undergoing liver transplantation two preload variables, pulmonary artery occlusion pressure (PAOP) and ITBVI with respect to cardiac index (CIpa) and stroke volume index (SVIpa), the correlation between ITBVI and PAOP, and secondary the relationship between the changes (delta) of ITBVI and PAOP and the changes of CIpa and SVIpa, and the relationships between deltaITBVI and deltaPAOP. The reproducibility and precision of all CIart and CIpa measurements were also evaluated.

METHODS

A prospective study was performed in 60 patients monitored with a pulmonary artery catheter and with the PiCCO system. The variables were evaluated with a linear regression model.

RESULTS

Linear regression analysis between ITBVI-CIpa and ITBVI-SVIpa were r2 = 0.47 (P < 0.0001) and r2 = 0.55 (P < 0.0001) respectively, while PAOP poorly correlated to CIpa (r2 = 0.02), SVIpa (r2 = 0.015) and ITBVI (r2 = 0.002). Only changes in ITBVI were correlated with changes in CIpa (delta1, r2 = 0.37; delta2, r2 = 0.32), and SVIpa (delta1, r2 = 0.60; delta2, r2 = 0.47). The mean bias between CIart and CIpa was 0.13 L min(-1) m(-2) (2 SD = 1.04L min(-1) m(-2)) (r2 = 0.86, P < 0.0001).

CONCLUSIONS

In comparison with PAOP, ITBVI seems a more reliable indicator of cardiac preload in patients undergoing liver transplantation.