Successful weaning from cardiopulmonary bypass with central venous prostaglandin E1 and left atrial norepinephrine infusion in patients with acute pulmonary hypertension.

OBJECTIVE: Postoperative pulmonary hypertension increases the mortality risk in cardiac surgery. We have used central venous prostaglandin E1 (PGE1) and left atrial norepinephrine (NE) infusion to wean from cardiopulmonary bypass (CPB) patients with refractory postoperative pulmonary hypertension. DESIGN: Observational, nonrandomized study. SETTING: Department of Cardiac Surgery in a university hospital. PATIENTS: We studied 10 nonconsecutive American Society of Anesthesiologists III and New York Heart Association class III-IV patients with postoperative pulmonary hypertension and low cardiac output syndrome preventing separation from CPB. INTERVENTIONS: Patients received right atrial PGE1 (31.5 +/- 6.26 ng/kg/min) and left atrial NE (0.11 +/- 0.02 microg/kg/min) infusion. Hemodynamic data were obtained before CPB (T0), after CPB under maximal inotropes and vasodilator infusion (T1), 10 mins (T2) and 12 hrs (T3) after PGE1 and NE infusion, and 48 hrs after withdrawal of PGE1 and NE (T4). MEASUREMENTS AND MAIN RESULTS: All patients were successfully weaned from CPB and survived. The biatrial infusion of PGE1 and NE caused a dramatic reduction in mean pulmonary artery pressure (from 42.8 +/- 5.1 mm Hg at T1 to 28.5 +/- 2.6 mm Hg at T2 and 20.5 +/- 2.0 mm Hg at T4), pulmonary vascular resistance index (from 1158 +/- 269 dyne x sec/cm5 x m2 at T1 to 501 +/- 99 dyne x sec/cm5 x m2 at T2 and 246 +/- 50 dyne x sec/cm5 x m2 at T4), and pulmonary-to-systemic vascular resistance index ratio (from 0.61 +/- 0.17 at T1 to 0.20 +/- 0.04 at T2 and 0.11 +/- 0.03 at T4). Cardiac index increased from 1.7 +/- 0.2 L/min/m2 at T1 to 2.3 +/- 0.2 L/min/m2 at T2 and 2.9 +/- 0.1 L/min/m2 at T4. CONCLUSIONS: In patients with refractory postoperative pulmonary hypertension, the combined administration of low-dose PGE1 in the right atrium and NE in the left atrium is an effective means to wean patients from cardiopulmonary bypass.

Calcium chloride minimizes the hemodynamic effects of propofol in patients undergoing coronary artery bypass grafting.

OBJECTIVE: To assess the hemodynamic effects of propofol and the counteracting effect of calcium chloride (CaCl2) in patients undergoing coronary artery bypass grafting (CABG). DESIGN: Prospective, randomized study. SETTING: University hospital, department of cardiac surgery. PARTICIPANTS: Fifty-eight patients undergoing elective CABG, divided into group A (n = 29) and group B (n = 29). INTERVENTIONS: Anesthesia was induced with a combination of fentanyl, 7 microg/kg; pancuronium, 0.1 mg/kg; and propofol, 1.5 mg/kg, administered over 60 seconds. A blinded investigator administered saline in group A patients and 10 mg/kg of CaCl2 in group B patients at the same speed and same time as propofol administration through another lumen of the central venous catheter. MEASUREMENTS AND MAIN RESULTS: Hemodynamic data were obtained at baseline (T0), 2 minutes after anesthesia induction (T1), and 2 minutes after tracheal intubation (T2). Heart rate decreased significantly in group A patients (86.2+/-11.3 beats/min at T0 and 72.8+/-7.5 beats/min at T2; p < 0.001). Mean arterial pressure decreased significantly in patients in both groups (group A, 108.0+/-12.0 mmHg at T0; 74.6+/-14.6mmHg at T2;p < 0.001 and group B, 106.0+/-10.2 mmHg at T0; 90.4+/-10.0 mmHg at T2; p < 0.05). Stroke volume index, cardiac index, and cardiac output decreased in group A patients (39.4+/-4.1 mL/beat/m2 at T0 and 28.8+/-5.2 mL/beat/m2 at T2; p < 0.05; 3.4+/-0.6 L/min/m2 at T0 and 1.9+/-0.3 L/min/m2 at T2; p < 0.001; 5.9+/-0.9 L/min at T0 and 3.4+/-0.4 L/min at T2; p < 0.001, respectively), whereas in group B patients, changes were negligible (38.1+/-7.0 mL/beat/m2 at T0 v 35.7+/-6.6 mL/beat/m2 at T2; (NS) 3.3+/-0.5 L/min/m2 at T0 v 2.7+/-0.3 L/min/m2 at T2; (NS) 5.7+/-0.9 L/min at T0 v 4.7+/-0.5 L/min at T2; (NS), respectively). CONCLUSION: Simultaneous administration of CaCl2 during the induction of anesthesia minimizes the potential negative effect of propofol on cardiac function in cardiac patients.

Neuromuscular relaxants in non-cardiac surgery after cardiomyoplasty.

PURPOSE: Dynamic cardiomyoplasty is a therapeutic alternative to heart transplantation in irreversible cardiac insufficiency. Little information exists about the use of muscle relaxants in patients with cardiomyoplasty. In particular, it is not clear if the muscle flap is responsive to neuromuscular blockers. The purpose of this report is to describe the safe use of vecuronium in a patient with cardiomyoplasty. CLINICAL FEATURES: A 59-yr-old man, after cardiomyoplasty for dilated cardiomyopathy two years earlier, underwent general anaesthesia with fentanyl, propofol and vecuronium during surgery for intestinal ischaemia. Intraoperative transthoracic echocardiography showed that vecuronium did not affect muscle flap motion. Two days after surgery he died in septic shock. Post-mortem histological and immunohistochemical examination showed nervous degeneration of the flap probably as a result of the chronic low frequency pacing. There was also an increase in extrajunctional receptors and an alteration in junctional receptors, as demonstrated by the negative reaction to anti-synaptophysin antibodies, used to identify the neuromuscular plate. CONCLUSION: In patients undergoing non-cardiac surgery after previous cardiomyoplasty, muscle relaxants, such as vecuronium, may be used safely. Depolarising agents, such as succinylcholine, should probably be avoided because of the possible exaggerated actions on extrajunctional receptors.

Do we know the costs of what we prescribe? A study on awareness of the cost of drugs and devices among ICU staff.

OBJECTIVE: To evaluate the level of cost awareness of drugs and devices among intensive care unit (ICU) doctors with variable levels of experience (senior intensivists, junior intensivists, residents). DESIGN: Interview-questionnaire. SETTING: ICU of the University of Rome "La Sapienza". PARTICIPANTS: 60 ICU doctors (40 specialists in anaesthesia and intensive care, 20 residents). MEASUREMENTS AND RESULTS: The estimated prices of drugs and devices were compared with the correct prices; responses within a range +/- 20% of the true price were arbitrarily considered correct; all the subgroups of doctors made inaccurate estimates of the prices, showing an absence of any impact of professional experience of cost awareness. CONCLUSION: The doctors in the study showed a high level of inaccurate cost awareness of drugs and devices.

Noninvasive ventilation for the treatment of acute respiratory failure in patients with hematologic malignancies: a pilot study.

OBJECTIVE: To evaluate treatment with noninvasive ventilation (NIV) by nasal mask as an alternative to endotracheal intubation and conventional mechanical ventilation in patients with hematologic malignancies complicated by acute respiratory failure to decrease the risk of hemorrhagic complications and increase clinical tolerance. DESIGN: Prospective clinical study. SETTING: Hematologic and general intensive care unit (ICU), University of Rome "La Sapienza". PATIENTS: 16 consecutive patients with acute respiratory failure complicating hematologic malignancies. INTERVENTIONS: NIV was delivered via nasal mask by means of a BiPAP ventilator (Respironics, USA); we evaluated the effects on blood gases, respiratory rate, and hemodynamics along with tolerance, complications, and outcome. MEASUREMENTS AND RESULTS: 15 of the 16 patients showed a significant improvement in blood gases and respiratory rate within the first 24 h of treatment. Arterial oxygen tension (PaO2), PaO2/FIO2 (fractional inspired oxygen) ratio, and arterial oxygen saturation significantly improved after 1 h of treatment (43+/-10 vs 88+/-37 mmHg; 87+/-22 vs 175+/-64; 81+/-9 vs 95+/-4%, respectively) and continued to improve in the following 24 h (p < 0.01). Five patients died in the ICU following complications independent of the respiratory failure, while 11 were discharged from the ICU in stable condition after a mean stay of 4.3+/-2.4 days and were discharged in good condition from the hospital. CONCLUSIONS: NIV by nasal mask proved to be feasible and appropriate for the treatment of respiratory failure in hematologic patients who were at high risk of intubation-related complications.

Treatment of acute respiratory failure by prolonged non-invasive ventilation in a child.

PURPOSE: To evaluate the feasibility and the efficacy of non-invasive ventilation (NIV) by nasal mask in a paediatric patient. CLINICAL FEATURES: A four-year-old girl with acute lymphocytic leukaemia (ALL L1, pre-pre B) complicated by acute respiratory failure was treated with NIV. ON admission she exhibited hyperpyrexia (40C), pancytopaenia and severe hypoxia with hypocapnia (PaO2 = 45 mmHg; PaCO2 = 28.2 mmHG; pH = 7.30; SpO2 = 76%; ABE = -7.3 mmol.L-1. With NIV, PaO2 improved (PaO2 = 78 +/- 8 mmHG; SpO2 = 86 +/- 2; PaCO2 = 39 +/- 2) throughout the first day. Treatment was continued for six days until the patient was discharged. No complications were recorded. CONCLUSION: Non-invasive ventilation by nasal mask may represent a choice in the treatment of acute respiratory failure of parenchymal origin in paediatric haematological patients.

Efficacy of nefopam for the prevention and treatment of amphotericin B-induced shivering.

BACKGROUND: Shivering is experienced by up to 70% of patients undergoing amphotericin B therapy. Treatment with meperidine hydrochloride, currently the most widely used medication for controlling amphotericin B-induced shivering, was compared with nefopam hydrochloride, which has been successfully used to treat post-operative shivering. METHODS: Forty-five patients with cancer and systemic fungal infections randomly received nefopam hydrochloride, 0.3 mg/kg, meperidine hydrochloride, 0.7 mg/kg, or saline solution intravenously 15 minutes before the cessation of amphotericin B infusion (1 mg/kg for 45 minutes). If shivering persisted, patients in the control (saline solution) group received either nefopam hydrochloride, 0.3 mg/kg, or meperidine hydrochloride, 0.7 mg/kg. RESULTS: Occurrence of shivering 15 minutes after the cessation of amphotericin B infusion was significantly less frequent in the nefopam (6.6%) and meperidine (40%) groups compared with the control group (66.6%). The incidence of shivering in the nefopam group with respect to the meperidine group was also significantly reduced. Moreover, nefopam administration to 5 persistently shivering patients in the control group definitively stopped the shivering in all of them (100%) in a mean (+/- SD) time of 29.1 +/- 4.8 seconds, while meperidine terminated shivering in 4 (80%) of 5 patients in a mean (+/- SD) time of 200.0 +/- 30.2 seconds. The adverse reactions that can be ascribed to nefopam or meperidine use were nausea and sedation, respectively, and may be considered negligible. CONCLUSION: Nefopam seems to be more effective than meperidine in preventing and quickly suppressing amphotericin B-induced shivering.

[Weaning in cardiopulmonary bypass patients with compromised cardiac function. Comparison of enoximone and dopamine]. / Weaning dal bypass cardiopolmonare di pazienti coronaropatici a funzionalità cardiaca compromessa. Confronto tra enoximone e dopamina.

OBJECTIVE: Evaluate the effects of enoximone and dopamine in patients with impaired left ventricular function after cardiopulmonary bypass (CPB). DESIGN: Prospective study on a consecutive series of patients subdivided into two groups: enoximone (Group E) and dopamine (Group D). SETTING: Policlinico Umberto I, University La Sapienza of Rome. PATIENTS AND METHODS: Thirty patients undergoing elective myocardial revascularization. Before weaning from CPB the patients received inotropic drugs as follows: Group E: enoximone: bolus: 1 mg/kg in 10 min, and continuous infusion of 5 mcg/kg/min; Gruppo D: dopamine: continuous infusion of 5 mcg/kg/min. Hemodynamic measurements were made using a Swan-Ganz catheter inserted before the induction of anaesthesia. RESULTS: Enoximone has proved to be effective in decreasing pre-load and after-load of both right and left ventricle by a positive lusitropic effect and a reduction of systolic stress, thereby increasing the cardiac index. In group D patients maintenance of cardiac output has been demonstrated to be dependent on a chronotropic effect. As a consequence in group D the increase in rate-pressure product has reached potentially dangerous values, reflecting a marked increase in myocardial oxygen consumption. On the contrary in Group E the increase in rate-pressure product has been much more limited. Finally both drugs have proven effective, since all patients have been easily weaned from CPB. CONCLUSIONS: Enoximone is a useful and easily-handled drug to facilitate weaning from CPB of patients with preoperative impaired ventricular function.

Changes in coagulation patterns, blood loss and blood use after cardiopulmonary bypass: aprotinin vs tranexamic acid vs epsilon aminocaproic acid.

Cardiopulmonary bypass (CPB) increases risk of postoperative bleeding and need for transfusion. The aim of this study was to evaluate the effects of aprotinin, epsilon aminocaproic acid and tranexamic acid on coagulation patterns and need for banked blood transfusion. Ninety-six consecutive patients who underwent coronary artery bypass surgery were randomly assigned to 4 groups (24 patients each). The following parameters were monitored before, during and after CPB: activated lotting time, hemoglobin, prothrombin time, activated prothromboplastin time, fibrinogen, antithrombin III, xDP, Factor VIII, Thrombin-Antithrombin Complex and plasminogen. Analysis of postoperative bleeding and need for transfusion showed that the aprotinin group had significantly lower mediastinal bleeding. Transfused patients were 2, 4, 12 and 18 respectively in the aprotinin, epsilon aminocaproic acid, tranexamic acid and placebo treated group. In conclusion the use of protease inhibitors significantly reduces postoperative bleeding and transfusion. The aprotinin-treated group had the lower need for transfusion.

Effects of three techniques of lung management on pulmonary function during cardiopulmonary bypass.

In this study, 30 patients undergoing elective myocardial revascularization were divided randomly in three groups (10 patients each) with different management of the lungs during CPB: Group 1, lungs deflated; Group 2, static inflation with PEEP = 5 cmH2O and FIO2 = 1.0; Group 3, static inflation with PEEP = 5 cmH2O and FIO2 = 0.21. Measurements (Qs/Qt, P(A-a)O2, PaO2, Cstat, Cdyn, PIP, AUTO-PEEP, Rrs,max, Rrs,min and DRrs) were performed after the induction of anesthesia (T0), 20 minutes (T1) and 2 hours (T2) after the end of CPB. Respiratory mechanics data were obtained only at T0 and T2 because the sternal retraction. The Group 1 presented a statistically significant increase in Qs/Qt, P(A-a)O2 and Peak Inspiratory Pressure (PIP); in this group we noticed also a decrease in PaO2 values, static compliance (Cstat) and dynamic compliance (Cdyn) values comparing basal versus T1 and T2 values. The Group 2 showed a statistically significant increase in Qs/Qt and P(A-a)O2 values; also in this group we observed a statistically significant decrease in PaO2 and Cdyn values comparing basal versus T1 and T2 values. The Group 3 presented a statistically significant decrease in PaO2 values (basal versus T1 and T2); this group also presented an increase in Qs/Qt values, in the immediate postbypass period (T1), and P(A-a)O2 values significantly increase comparing basal versus T1 and T2 values. In all the three groups the respiratory system resistance and AUTO-PEEP values were unchanged after the end of CPB. The comparison between the groups showed a significant minor impairment of gas exchange (PaO2 and P(A-a)O2), Qs/Qt and Cstat in the third group of patients. These results show that lungs inflation with air during CPB, effectively preserve respiratory system mechanics: this might be due to a preservation of bronchial perfusion simply due to the mechanic expansion of the lung otherwise compromized when the lungs are completely collapsed. However it is necessary to emphasize that CPB has negative effects on gas-exchange whatever technique of lung management is used.

Central venous catheterization in pediatric patients affected by hematological malignancies.

The objective of this retrospective study was to evaluate the significance and complications of percutaneous central venous catheterization in pediatric patients affected by hematologic malignancies. One hundred and fifty-eight central venous catheters were inserted in 125 pediatric patients (male/female 67/58; median age: 4 years; range 10 m - 6 y.) affected by hematological malignancies. Venous access was obtained by means of a tunnelled silicone rubber Groshong catheter inserted percutaneously in the subclavian vein (91.1%), the internal jugular vein or in the femoral vein. The medial duration of catheterization was 231.8 days (range 8-1014 days). The total number of catheter days was 33,792 (92.6 years). There were no complications related to catheter insertion. Only one patient developed significant post-operative bleeding. One hundred and nine catheters (68.9%) were removed when they were no longer needed and 49 (31.1%) were removed due to complications: 6 catheter occlusions (12.2%), 7 were accidentally withdrawn (14.3%), 3 for local infections (6.1%) and 33 for catheter-related infection (67.3%). A Groshong catheter seems to provide good access to the blood stream for a long period of time with a low incidence of complications in children with acute hematological malignancies.

[Intramuscular and oral clonidine in premedication of the heart surgery patient: hemodynamic effects and interaction with high-dose fentanyl induction]. / Clonidina i.m. e per os nella premedicazione del paziente cardiochirurgico: effetti emodinamici ed interazioni con alti dosaggi induttivi di fentanyl.

OBJECTIVE: The aim of the study was to evaluate the efficacy of oral and i.m. clonidine as premedication in reducing the requirements of fentanyl for induction and to analyze its effects on the hemodynamics of patients with ischemic heart disease. SETTING: University Hospital. MATERIALS AND METHODS: The authors considered 30 patients (27 male and 3 female) undergoing CABG. Patients were premedicated 60-90 min before induction of anesthesia and were randomly distributed in three groups: Group A: oral diazepam 0.1 mg x kg -1; Group B: oral diazepam 0.1 mg x k-1 + oral clonidine 5 micrograms x kg-1; Group C: oral oral diazepam 0.1 mg kg-1 + i.m. clonidine 4 micrograms x kg-1. Induction of anesthesia was realized with fentanyl at speed of 500 mcg x min-1 until loss of consciousness was reached (no answer to three consecutive questions). MEASUREMENT: Hemodynamic data were recorded at TO(baseline), T1(induction of anesthesia), T2(3 min after intubation), T3(3 min. after skin incision). Results were analyzed by utilizing the average comparison Student "t" test and paired "t" test. A value of p < 0.05 was regarded as statistically significant. MAIN RESULTS: In groups B and C the inductive dose of fentanyl was much lower (p < 0.001) compared to control group (B = 19.23 +/- 3.57 micrograms x kg-1; C = 19.92 +/- 4.15 micrograms x kg-1; A = 28.39 +/- 6.4 micrograms x kg-1). This difference remained statistically significant (p < 0.001) also at T2 and T3 (T1: A = 42.79 +/- 3.21 mcg x kg-1; B = 29.07 +/- 6.18 micrograms x kg-1; C = 29.84 +/- 5.46 micrograms x kg-1; T2: A = 57.28 +/- 5.32 micrograms x kg-1; B = 43.22 +/- 3.87 micrograms x kg-1; C = 43.48 +/- 4.25 micrograms x kg-1). Considering the hemodynamic data, we report the heart rate in group B increased at T2 (p < 0.01), and systolic artery pressure raised in groups A (p < 0.05) and C (p < 0.01) at T2. Compared to baseline cardiac index showed a decrement at T3 in all groups of patients (p < 0.05). Systemic vascular resistance increased in all groups at T3 compared to baseline (p < 0.05). CONCLUSIONS: Clonidine proved to be useful to reduce narcotic requirements and to provide hemodynamic stability.

Metabolic aspects of cardiac and skeletal muscle tissues in the condition of hypoxia, ischaemia and reperfusion induced by extracorporeal circulation.

Extracorporeal circulation (ECC) during aortopulmonary bypass surgery allows the investigation of the metabolic and biochemical effects of hypoxia (skeletal muscle), ischaemia (cardiac muscle) and reperfusion (skeletal and cardiac muscle) in homogeneous groups of patients. In this study we examined the mitochondrial enzymic response to oxidative stress in 40 subjects, and analysis was carried out on heart and skeletal-muscle biopsies taken before, during and after aortic clamping and 115 min of ECC. The results obtained constitute a clinical and biochemical picture characterized by some peculiar adaptive changes of enzymic activities which thus antagonize the oxidative damage due to acute hypoxia, ischaemia and reperfusion. Consequently it seems that this cellular protective mechanism plays a crucial role in the reversibility of oxidative damage in hypoxic and ischaemic tissues.

Chronobiology of blood pressure in childhood: implications for tracking.

Chronobiology, in its methodological evolution, developed data series analyses paying particular attention to blood pressure (BP), because of the importance of this biorhythmic variable for assessing the risk of developing hypertension. An example of the potentiality of the chronobiologic procedures is given in the present report which deals with the inferential analysis of the BP 24-h patterns in 3-12 year-old children. By using the chronobiologic methodology, time-qualified standards for BP are calculated. Rhythmometric parameters for circadian rhythm of systolic and diastolic components of BP are also computed. Data presented are a tangible outcome for emphasizing the introduction of chronobiology in epidemiology and pediatrics in order to optimize the primary prevention and care of hypertension taking as reference the chronobiologic standards of BP.

Blood pressure monitoring from a biostatistical and clinical viewpoint for predicting fetal distress in preeclamptic pregnancy.

With technological progress, blood pressure monitoring has become a procedure largely applied in medical practice but not adequately systematized under a biostatistical viewpoint. This paper shows the complexity and importance of the biomathematical approach and its clinical implications in preeclamptic pregnancy. Data series were analyzed by means of noninferential and inferential procedures of biostatistics. A progressive gain of information is obtained, the inferential procedures showing an analytical resolution able to discriminate fetal distress in preeclamptic pregnancy.