Comparison of time course of neuromuscular blockade in young children following rocuronium and atracurium.

In order to compare the neuromuscular effects following rocuronium 0.6 mg kg-1 and atracurium 0.5 mg kg-1 30 children aged from 18 to 67 months were studied under the same anaesthetic conditions. After induction of anaesthesia with etomidate and fentanyl, neuromuscular blockade was monitored by recording the electromyographic response of the adductor pollicis muscle to a supramaximal train-of-four (TOF) stimulation of the ulnar nerve at 2 Hz for 2 s at 20-s intervals. Intubation was performed when more than 90% muscle relaxation was achieved, thereafter anaesthesia was maintained with 70% nitrous oxide in oxygen and isoflurane 0.5% end-tidal. Mean onset of action was significantly faster following rocuronium (86 +/- 44.9 s) (mean +/- SD) compared with atracurium (126.3 +/- 61.0 s). Clinical duration with rocuronium was 22.8 +/- 5.31 min and thus significantly shorter than that of atracurium, which was 31.5 +/- 6.01 min. A statistically significant difference between rocuronium and atracurium also had been found for recovery of T1 to 50%, 75% and 90% as well as for the time taken to a TOF ratio of 70%. The recovery index for rocuronium and atracurium was not significantly different with 9.2 +/- 3.43 min and 10.9 +/- 2.65 min, respectively. Thus, rocuronium may be more advantageous than atracurium for short-lasting surgical procedures in young children.

Intubating conditions and onset of action after rocuronium, vecuronium, and atracurium in young children.

To evaluate muscle relaxant onset times and tracheal intubating conditions, 60 children (ASA physical status I or II) aged 18 to 72 mo were randomly assigned to receive a bolus of either rocuronium 0.6 mg/kg, vecuronium 0.1 mg/kg, or atracurium 0.5 mg/kg. After induction of anesthesia with etomidate 0.2-0.4 mg/kg and fentanyl 1-3 mg/kg, lungs were ventilated with 50% nitrous oxide in oxygen via a face mask. The evoked electromyogram of the adductor pollicis to a train-of-four stimulation every 20 s was monitored. After administration of the muscle relaxant, endotracheal intubation was attempted every 30 s, beginning 30 s after drug administration, until intubation could be achieved with good or excellent conditions. Rocuronium produced acceptable intubating conditions significantly faster (all tracheas intubated within 60 s) compared with vecuronium (120 s) and atracurium (180 s). The quality of intubating conditions at the time of completed intubation was rated significantly better with rocuronium than with vecuronium or atracurium. However, onset to 95% block at the adductor pollicis muscle was not significantly different after rocuronium (92 +/- 46.9 s), vecuronium (112 +/- 33.3 s), or atracurium (134 +/- 57.1 s), and mean neuromuscular block achieved at the point of successful intubation was not complete in all groups. We conclude that clinically acceptable intubating conditions are produced more rapidly with rocuronium than with atracurium or vecuronium.

[The effect of different types of anesthetic respirators on oxygenation and ventilation in infants during short-term anesthesia. A study using transcutaneous PO2 and PCO2 monitoring]. / Der Einfluss verschiedener Narkosebeatmungsverfahren auf Oxygenierung und Ventilation von Säuglingen. Eine Untersuchung mittels transkutaner PO2- und PCO2-Messung.

Monitoring of ventilation in infants is difficult and often not very reliable. In this study, transcutaneous measurement of blood gas tensions was used to investigate the influence of four different modes of ventilation on oxygenation and ventilation in anaesthetized infants. METHODS. In a randomised study, transcutaneously measured PO2 (tc-PO2) and PCO2 (tcPCO2) tensions were continuously registered in 42 ASA class I and II infants between 3 and 24 weeks of age undergoing minor surgical procedures (inguinal hernia repair). Two breathing systems combined with different modes of ventilation were evaluated: manual ventilation with Kuhn's T-piece system and face mask (group A; n = 11) or endotracheal tube (group B; n = 10); manual ventilation with paediatric circuit system and face mask (group C; n = 11); and mechanical ventilation with paediatric circle system, endotracheal tube, and positive end-expiratory pressure (PEEP) 3 cm H2O (group D; n = 10). Transcutaneous values were measured by a combined tcPO2/PCO2 electrode (E 5277, Radiometer). Anaesthesia was maintained by controlled ventilation with N2O/O2 (67%/33%) and halothane 0.5-1.5 vol.%. Surgical and anaesthetic techniques were standardized and the anaesthetist was blinded to the measured values. RESULTS. Preoperative mean tcPO2 values while spontaneously breathing air ranged between 69 and 75 mmHg in all patients. During anaesthesia and controlled ventilation (FiO2 = 0.33), there was a significant increase in tcPO2 (P < 0.01) in 3 groups: in groups A and D mean tcPO2 increased to 90-100 mmHg and in group C to 110-120 mmHg. In contrast, tcPO2 in group B reached only 75-80 mmHg, which was not considered significant. Postoperatively, tcPO2 immediately reached baseline values in all patients (Fig. 2). Compared to preoperative values, the alveolar-tcPO2 difference (AtcDO2) significantly increased during anaesthesia in all groups (Fig. 3). The tcPCO2 measurements revealed marked alveolar dysventilation, with hyperventilation supervening in groups A, B, and D; in group C, however, most (7 of 11) infants were normoventilated (Fig. 4). CONCLUSIONS. Adverse effects of anaesthesia on pulmonary function in infants are caused by loss of the PEEP effect induced by the physiological subglottic stenosis. Endotracheal intubation and the increase in chest wall compliance during anaesthesia lead to a decrease in functional residual capacity (FRC) associated with premature airway closure and ventilation/perfusion mismatch. These pathophysiological disturbances result in a marked increase in AaDO2 and low arterial PO2 values despite high FiO2, as could be observed when intubated infants had been ventilated with a high-flow T-piece system (group B). Mechanical ventilation with a paediatric circuit system and endotracheal tube allows the use of low PEEP levels (group D), which may replace the lost subglottic function and partially restore the FRC. Ventilation by mask does not disturb the functional subglottic stenosis, and the impairment of pulmonary function will depend solely on the decrease in FRC caused by increased chest wall compliance (group A). If mask ventilation is combined with a paediatric circuit system (group C), the pressure relief valve produces a low PEEP of 2 to 3 cm H2O, which may partially counteract the decrease in FRC. With regard to oxygenation, the paediatric circle system proved to be superior to the high-flow T-piece system independent of whether children were ventilated via a face mask or an endotracheal tube. The group-specific differences in degree of dysventilation with manual ventilation show that the type of breathing system is important with regard to the size of the tidal volume delivered. Thus, tidal volumes will be unintentionally increased by the high fresh gas flow needed when a T-piece system is used. The lower flow and preadjusted pressure limit may prevent the delivery of excessive tidal volumes with the paediatric circuit system...

[Hemodynamics of coronary surgery patients following magnesium aspartate infusion]. / Hämodynamik koronarchirurgischer Patienten nach Magnesium-Aspartat-Infusion.

Hypertension is a common phenomenon in patients undergoing aortocoronary bypass grafting. This hypertension increases myocardial oxygen consumption and can be prevented by application of vasodilators. A possible cause is activation of the renin angiotensin system. Magnesium is a potent vasodilator and has a beneficial effect after myocardial ischaemia. The study was performed to analyse the influence of magnesium infusion on the haemodynamic status and plasma renin activity in patients undergoing aortocoronary bypass grafting. METHODS. Eighteen patients (NYHA classification II-III) undergoing bypass surgery were divided into two groups, a magnesium and a control group. The magnesium group (n = 9) received 0.8 mEq/kg per h magnesium aspartate as an infusion for 15 min while still awake. After induction of anaesthesia, the magnesium infusion was reduced to 0.2 mEq/kg per h and stopped after aortic cannulation was completed. Plasma magnesium levels and concentrations within erythrocytes were measured. Anaesthesia was induced by flunitrazepam (0.01 mg/kg), fentanyl (0.005 mg/kg) and pancuronium (0.1 mg/kg). After intubation, patients were normoventilated with N2O/O2 = 1:1 and isoflurane (0.5-1.0 vol%). Additional doses of fentanyl (0.0025 mg/kg) were injected before the incision and before sternotomy. Mean arterial pressure, heart rate, cardiac index, total peripheral resistance, pulmonary vascular resistance, mean pulmonary arterial pressure, pulmonary capillary wedge pressure, left ventricular stroke work index, right ventricular stroke work index, intrapulmonary shunt and plasma renin activity were evaluated at five predefined points: (1) prior to magnesium infusion; (2) after magnesium infusion; (3) 10 min following induction of anaesthesia under steady-state conditions; (4) after sternotomy; (5) after aortic cannulation. RESULTS. Concerning the haemodynamic parameters (MAP, RAP, PAP, PCWP) no significant difference between the two groups could be demonstrated. In the control group peripheral resistance (TPR) was higher following sternotomy and aortic cannulation than in the magnesium group. Magnesium prevented decrease of the cardiac index (CI) under steady-state conditions, during sternotomy and following aortic cannulation. Left and right ventricular stroke work indexes (LVSWI and RVSWI) were higher in the magnesium group. Plasma renin levels were not significantly different between the two groups. CONCLUSION. Patients undergoing cardiac surgery benefit from magnesium administration in the pre-bypass phase. Due to its vasodilating effect, magnesium lowers the output impedance of the left ventricle and improves cardiac pumping function. It opposes detrimental cardiovascular responses to sternotomy and following aortic cannulation. Also of importance is the advantageous effect of magnesium on cardiac arrest elicited by cardioplegia and for reactivation of the ischaemic myocardium.

[A fatal bleeding complication following central venous catheterization in end-stage pancytopenia. Medical and legal consequences]. / Tödliche Blutungskomplikation nach zentralem Venenkatheterismus bei behandelter Panzytopenie im Finalstadium. Medizinische und strafrechtliche Konsequenzen.

An attempt to insert a central venous catheter into the internal jugular vein of a patient suffering from pancytopenia failed and due to massive bleeding into the cervical tissue the patient developed severe dyspnoea and died during unsuccessful endotracheal intubation. A five-year judicial inquiry finally discharged the anaesthesiologist revealing that forensic aspects like a valid patient's consent, exact documentation of operations and therapies, clear arrangement with patient's relatives as well as an early detailed written epicrisis play a major role. This may be the only way to early counteract medically inane causal relationship being presented by the relative's advocate. Especially in the patient at high risk central venous catheterisation requires strict checking the indication, the corresponding choice of the correct technique during venipuncture, and a sufficient haemostatic pretreatment and care after catheterisation.

[Porto-femoro-subclavian bypass and the rapid infusion technique in orthotopic liver transplantation]. / Portofemoro-Subclavia Bypass und "Rapid Infusion"-Technik bei orthotoper Lebertransplantation.

Veno-venous bypass during orthotopic liver transplantation is commonly performed as a porto-femoro-axillary bypass. Right-angle positioning of one patient's arm and surgical preparation of the femoral and axillary veins are necessary. In 17 patients and 20 consecutive orthotopic liver transplant procedures the common porto-femoro-axillary veno-venous bypass was substituted by porto-femoro-subclavian bypass with a percutaneous 20 F cannulation set (LAUB catheter, Cook). The 20 F catheter was introduced into the left subclavian vein by Seldinger's technique before the operation and was connected intraoperatively to the outflow tube of the biopump. Surgical preparation of the axillary vein was not performed. In 10 patients a Y-connector was used to connect up the Rapid Infusion System in addition. Postoperatively the catheter was left in place for 2-4 days. Introduction and removal of the catheter were uneventful in all cases. High blood flow through the catheter could be maintained by a low driving pressure of the pump (4000 ml/min; 100 mmHg). No intraoperative complications were observed. Shunt flows remained stable throughout the surgical procedure during the anhepatic stage. There was no bleeding from the puncture site, especially after removal of the catheter, though several patients had a poor coagulatory status in the early postoperative period. Two postoperative complications were observed: air embolism due to disconnection and formation of a thrombus at the catheter tip, which it was possible to remove together with the catheter itself. Installation of an irrigation infusion in the postoperative period and well-tightened connections help avoid such complications as thrombus formation, bleeding or air embolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Cáncer de la vejiga urinaria y hábito de fumar / Cancer of the urinary bladder and smoking habit

Se informa que los derivados orthohidroxilados de las aminas aromáticas son metabolitos que se liberan en la vejiga donde originan carcinomas. Se producen en el metabolismo del triptófano cuerpos con estructura similar, entre ellos la 3-hidrociquinurenina y el ácido carcinogenético. Se encuentran estos cuerpos en cantidades excesivas en la orina de los fumadores, quienes son incapaces de transformarlos en nicotenamida. Los fumadores en un grupo de 90 enfermos con carcinoma transicional de vejiga, alcanzaron el 90 porciento, en tanto que en el grupo control, constituido por 90 enfermos con carcinoma del colon, sólo alcanzaron el 40 porciento: 5 porciento>2 (AU)

Hemangioendoteliosarcoma y cirrosis hepática 25 años después de una angiografía con dióxido de torio (Thorotrast) / Hemangioendotheliosarcoma and cirrohosis of liver twenty five years following an angiography using thorium dioxide (Thorotrast)

Se presenta el caso de un paciente que presentó hemangioendoteliosarcoma hepático con metástasis en el miocardio y suprarrenal derecha asociado a cirrosis hepática, ambas lesiones secundarias a la administración de dióxido de torio (Thorotrast), 25 años de la muerte de dicho paciente. Se comprueba una vez más que el dióxido de torio provoca cirrosis y tumores hepáticos. La asociación de lesiones en nuestro enfermo apoya la hipótesis de que la inducción tumoral se relaciona con dos factores: la radiación mantenida y la cirrosis con su prolongada regeneración(AU)

Nuestra experiencia en el tratamiento quirúrgico de las vesículas aéreas del pulmón

Se hace una revisión de la literatura referentes a los quistes y vesículas aéreas del pulmón y se propone la nomenclatura y clasificación de estas lesiones que creemos más correctas y comprensibles. Se exponen brevemente los problemas de diagnóstico que plantean estas lesiones. Se precisan las indicaciones del tratamiento quirúrgico en los quistes y vesículas aéreas del pulmón, las técnicas que deben seleccionarse frente a cada caso particular y los resultados obtenidos con este tratamiento. Se expone la frecuencia absoluta y relativa de esta patología en 1000 autopsias del Hospital Docente "General Calixto García". Se presenta la revisión de 23 pacientes operados en este Hospital (AU)