Hepatic blood flow and oxygen extraction ratio during normothermic recirculation and total body cooling as viability predictors in non-heart-beating donor pigs

BACKGROUND

Our aim was to evaluate the hepatic blood flows and oxygen metabolism of non-heart-beating donor (NHBD) pigs, with the use of cardiopulmonary bypass (CPB) and normothermic recirculation (NR) before total body cooling, and its relationship with recipient survival.

METHODS

Thirty-five pigs were transplanted with an allograft from NHBDs. After warm ischemia (WI) time (20, 30, or 40 min), CPB and NR were run for 30 min. After this period, the animals were cooled to 15 degrees C. In the control group (20 min of WI), the period of NR was excluded. Liver procurement was then performed.

RESULTS

Survival rate was 100% in the 20WI, 70% in the 30WI, and 50% in the 40WI. Control group survival rate was 0%. Hepatic artery blood flow and portal blood flow recovered during NR. Pump blood flow during CPB increased rapidly during NR and was significantly higher in the 20WI. When donors of the livers transplanted in "surviving pigs" (DSP) were compared with donors of the livers transplanted in "nonsurviving pigs" (DNSP), hepatic artery blood flow, portal blood flow, and pump blood flow were higher in the DSP. Hepatic oxygen extraction ratio increased in the three groups with respect to baseline values. Hepatic oxygen extraction ratio was lower in the 20WI than in the other groups and was lower in the DSP than in the DNSP.

CONCLUSIONS

The use of a NR period before total body cooling improves survival of liver transplantation in NHBDs. Portal blood flow and pump blood flow measurements can predict the viability of the grafts.

[Outcome of patients who underwent surgical repair of aneurysm after subarachnoid hemorrhage]

BACKGROUND

Follow-up study of patients with surgical repair of aneurysmal subarachnoidal hemorrhage (SAH), looking for clinical outcome predictors.

PATIENTS AND METHODS

Sixty two patients consecutively admitted to a teaching hospital, from January 1992 to December 1995 were included in the study. We studied preoperative, intraoperative and postoperative features looking for their relationship with the outcome. The ultimate outcome was evaluated by means of Glasgow Outcome Scale on discharge and 6 months later.

RESULTS

Smoking (p = 0.0001) and arterial hypertension (AHT) (p = 0.0186) were more frequent in these patients than in general population, but without relationship to the outcome as with the age of the clinical status on admission. The greatest statistical relationship was found between the level of consciousness on postoperative awakening (measured by the Hunt and Hess scale), and the outcome (p = 2.53 x 10(-8). From our results we made an algorithm that correctly assigned 92% of studied patients to their outcome.

CONCLUSIONS

All patients admitted on with aneurysm SAH deserve intensive care treatment besides their clinical grade. The level of consciousness on postoperative awakening was a good outcome predictor.

[Analysis of the current status of neuroanesthesia in Spain using a national survey]

OBJECTIVES

Advances in complementary diagnostic explorations, surgical support technology and the complexity of neurophysiological monitoring require anesthesiologists to acquire specific knowledge for dealing with neurosurgery. We aimed to study the implantation of new anesthetic-surgical techniques in the field of neurosurgery, and the state of neuroanesthesia as a subspecialty in Spain.

MATERIAL AND METHODS

A 20-item postal questionnaire sent to anesthesiology department heads of Spanish hospitals with neurosurgery teams.

RESULTS

We received responses from 62% of the hospitals surveyed. Of these, 69% performed stereotaxic surgery, 30% functional cerebral surgery (for Parkinson's disease and epilepsy) and 21% offered neuroendoscopy. In 38% of the hospitals cerebral metabolism was monitored (hemoglobin oxygen saturation in the jugular or regional cerebral oxygen saturation) and/or cerebral electrophysiology (electroencephalogram, evoked potentials) and in 23.8% flows and pressures were measured (transcranial precordial and/or tracheoesophageal Doppler). Anesthesiologists specializing in neurosurgery are present in 62% of the hospitals. Interventionist neuroradiology is performed in 57%. It was noteworthy that 14.3% do not regularly have an anesthesiologist present during such high risk procedures.

CONCLUSIONS

Although most centers continue performing "classical" neurosurgery with standard monitoring, a substantial proportion of hospitals (38%) show evidence of advancing in anesthetic techniques for neurosurgery in Spain. Anesthesia for neurosurgery as a subspecialty is available in 62% of the responding hospitals.

Identification of a Drosophila presenilin homologue: evidence of alternatively spliced forms

Some cases of Alzheimer's disease are inherited as a dominant trait in humans. To date, mutations in three genes account for some of them: the amyloid precursor protein (APP) and presenilins 1 and 2 (PS-1 and PS-2, respectively). The function of the presenilins is still unclear, although they belong to a transmembrane protein-gene family, probably involved in some signaling pathway. We report here the isolation of the Drosophila presenilin homologue using the human PS-1 and PS-2 cDNAs as probes. Only one single gene has been detected in the Drosophila genome and evidence for alternatively spliced forms is presented and compared to the isoforms reported in humans. Temporal and spatial expression has been assessed by Northern blot and in situ hybridization on embryos of different developmental stages.

Pseudohypertriglyceridaemia

A mistake can be made in interpreting plasma triglyceride levels since in some cases pseudohypertriglyceridaemia may result from increased plasma glycerol due to a glycerol kinase deficit. Most automated triglyceride assays used in laboratories do not contain a negative control, i.e. a glycerol assay. We report two cases with pseudohypertriglyceridaemia due to hyperglycerolaemia and describe the clinical and biological features which suggested the diagnosis.

Evolution of beta-amylase: patterns of variation and conservation in subfamily sequences in relation to parsimony mechanisms

Soybean and sweet potato beta-amylases are structured as alpha/beta barrels and the same kind of folding may account for all known beta-amylases. We provide a comprehensive analysis of both protein and DNA (coding region) sequences of beta-amylases. The aim of the study is to contribute to the knowledge of the evolutionary molecular relationships among all known beta-amylases. Our approach combines the identification of the putative eightfold structural core formed by beta-strands with a complete multi-alignment analysis of all known sequences. Comparing putative beta-amylase (alpha/beta)8 cores from plants and microorganisms, two differentiated versions of residues at the packing sites, and a unique set of eight identical residues at the C-terminal catalytical site are observed, indicating early evolutionary divergence and absence of localized three-dimensional evolution, respectively. A new analytical approach has been developed in order to work out conserved motifs for beta-amylases, mostly related with the enzyme activity. This approach appears useful as a new routine to find sets of motifs (each set being known as a fingerprint) in protein families. We demonstrate that the evolutionary mechanism for beta-amylases is a combination of parsimonious divergence at three distinguishable rates in relation to the functional signatures, the barrel scaffold, and alpha-helix-containing loops.

[Postoperative analgesia in herniated disk surgery. Comparative study of diclofenac , lysine acetylsalicylate, and ketorolac]

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective in treating musculoskeletal pain and are theoretically ideal for treating postoperative pain of the lumbar column.

OBJECTIVES

To compare the analgesic efficacy and side effects of treatment with 3 NSAIDs (lysine acetylsalicylate, ketorolac and diclofenac) in the treatment of pain after surgery for lumbar disc hernia.

PATIENTS AND METHODS

We enrolled 75 ASA I-II patients undergoing discectomy because of lumbar disc hernia; balanced general anesthesia was used in all cases. The patients were randomly distributed in 3 groups based on type of analgesia given in the immediate postoperative period. Group A received lysine acetylsalicylate (1800 mg), group B received ketorolac (30 mg) and group C received diclofenac (75 mg). The analgesics were diluted in 100 mg of saline solution and administered through a peripheral vein over 10 min. We evaluated the analgesia attained on a visual analog scale (VAS) and the physiological response to pain was assessed by monitoring changes in arterial pressure, heart rate and breathing frequency. If analgesia was insufficient 30 min after administration of the drug, 200 mg of lysine cloximate was given as a top-up. The side effects of each drug were also recorded.

RESULTS

VAS evaluation showed significant reductions in pain 60 min after administration in groups A and B and after 120 min in group C. Nine patients in each group required lysine cloximate. There were no significant differences in physiological response among the 3 groups. No patient suffered major side effects. Mild side effects were reported most often in group B.

CONCLUSIONS

The NSAIDs studied were inadequately for treating pain after surgery for lumbar disc hernia. Ketorolac was no better than the other analgesics studied but was associated with a higher number of mild side effects.

[Intravenous anesthesia using propofol during lengthy neurosurgical interventions]

OBJECTIVE

To compare the hemodynamic stability and time to recovery of consciousness after long-duration (> 3 h) neurosurgery with 2 anesthetic protocols: total intravenous anesthesia with propofol as the single hypnotic agent and inhalational anesthesia with isoflurane.

PATIENTS AND METHOD

We studied 58 middle-aged patients (range 40-50 years) scheduled for intracranial surgery. The patients, who all scored over 13 on the Glasgow coma scale before surgery, were randomly divided into two groups: 27 in group I received isoflurane and 31 in group II received propofol. Anesthetic induction was with sodium thiopental 4 mg/kg i.v. in group I and with propofol 2.5 mg/kg i.v. in group II. Both groups then received fentanyl 2 micrograms/kg i.v., lidocaine 1.5 mg/kg i.v. and vecuronium 0.2 mg/kg i.v. Before placement of the Mayfield head grip, with clamps, or before start of surgery in those cases in which the head grip was not used, all patients were given a 3 micrograms/kg i.v. dose of fentanyl. Hypnosis was maintained in group I with concentrations of isoflurane that were adequate for keeping minimum alveolar concentration (MAC) between 0.6 and 1. In group II maintenance was by continuous i.v. perfusion of propofol 10 mg/kg/h for 30 min., followed by 8 mg/kg/h for 30 min. and 6 mg/kg/h until the end of surgery. N2O was never used.

RESULTS

After induction systolic and mean arterial pressures (SAP and MAP) decreased significantly in both groups in comparison with baseline values (SAP: 113.1 +/- 30.0 vs. 140.9 +/- 27.08 mmHg in group I and 109.6 +/- 22.1 vs. 135.0 +/- 19.7 mmHg in group II; MAP: 76.8 +/- 18.7 vs. 95.6 +/- 17.0 mmHg in group I and 74.9 +/- 13.2 vs. 93.4 +/- 13.7 mmHg in group II). The patients in group II showed less tendency to develop arterial hypertension in response to orotracheal intubation (SAP and MAP at the moment of intubation: 156.4 +/- 33.7 and 104.6 +/- 18.1 mmHg, respectively, in group I as compared to 135.1 +/- 31.2 and 93.5 +/- 22.4 mmHg in group II; p < 0.05 between the 2 groups and p < 0.05 for the baseline and intubation pressures in group I). Time to recovery of effective, spontaneous breathing was shorter in group I (5.9 +/- 4.9 and 8.9 +/- 5.7 min.) than in group II (10.9 +/- 9.6 and 13.0 +/- 7.4 min.) and tubes could be extracted earlier from patients in the isoflurane group (10.4 +/- 6.1 min. vs. 17.6 +/- 12.8 min.; p < 0.01). We found no differences between the 2 groups for time until eye opening, response to verbal orders or time until start of spontaneous movement.

CONCLUSIONS

Propofol can be considered an alternative to the traditional thiopental-isoflurane sequence in neurosurgery lasting more than 3 h. In our study the hypertensive response to the stimulus of orotracheal intubation was lower in the propofol group than in the thiopental-isoflurane group.

Right ventricular systolic time intervals determined by means of a pulmonary artery catheter

OBJECTIVES

To evaluate the right ventricular systolic time interval as an index of right ventricular function and also to ascertain whether the right ventricular ejection fraction may be determined by means of a conventional pulmonary artery catheter.

DESIGN

Prospective study.

SETTING

Intensive care unit.

PATIENTS

Eight, consecutive critically ill adult patients.

METHODS

Simultaneous blind measurements, performed by two investigators, of the right ventricular systolic time interval and right ventricular ejection fraction, determined by means of a pulmonary artery catheter. Two studies, separated by an interval of 24 hrs, per patient. Linear regression analysis. Multiple regression test.

RESULTS

Of the 16 studies performed, two determinations of right ventricular systolic time intervals were technically inadequate. In the remaining 14 valid studies, we found one close linear correlation between the right ventricular ejection fraction and the preejection period/ejection time quotient measured using the simultaneous display of the electrocardiogram (EKG) and pulmonary arterial pressure curve (r2 = .90, p < .001, right ventricular ejection fraction = 68.96-60.59 x [right ventricular preejection period/right ventricular ejection time]). The method proved to be simple, very accurate, with little interobserver variation (8.09 +/- 10.6% interobserver variation for right ventricular preejection period/right ventricular ejection time) and provided adequate information regarding situations in which the performance of the right ventricle is modified in a given patient. The right ventricular preejection period/right ventricular ejection time quotient was the only variable that displayed a significant relationship with the right ventricular ejection fraction in the multivariate analysis (p < .001).

CONCLUSIONS

Right ventricular systolic time intervals, measured using the simultaneous display of the pulmonary artery catheter curve and EKG, provide adequate information regarding right ventricle performance in critically ill patients. The close linear correlation between the right ventricular preejection period/right ventricular ejection time quotient and the right ventricular ejection fraction enables the investigator to estimate, with a high degree of accuracy, the right ventricular ejection fraction and the values derived from the preload of the right ventricle, without the need for a modified pulmonary artery catheter.

[Thrombosis of intrathoracic veins. A complication of venous catheterization for temporary hemodialysis]

Venous thrombosis of large vessels is a common complication, generally asymptomatic, that may occur during central venous catheterization for temporal hemodialysis. We report 2 cases of intrathoracic venous thrombosis which were suspected because of the difficulties occurring during catheterization of a new venous approach during dialysis. Both cases were diagnosed by angiography.

Adverse reactions to vancomycin prophylaxis in cardiac surgery

Several adverse effects of vancomycin have been reported. The aim of this study was to assess the incidence of adverse responses to antibiotic prophylaxis with vancomycin in cardiac surgical patients. Prospectively, 116 consecutive patients (106 adults and 10 children) undergoing cardiac surgical procedures in this institution from January to June 1990 were studied. After the anesthetic induction, vancomycin, 1 g in adults and 10 mg/kg in children, was intravenously administered over 30 minutes. The infusion rate was slowed if any adverse effect was observed. As a control group, 10 similar patients were evaluated during the same period of 30 minutes after anesthetic induction but prior to vancomycin administration and surgical stimulation. Thirty-one patients (26.72%) developed an adverse effect, mainly hypotension (29 patients, 25%), which was considered severe in 15 patients (12.93%). Seven patients (6.03%) developed a maculopapular erythema that was associated with hypotension (Red-Man's syndrome) in 5 patients and with bronchospasm in 1 patient. The incidence of adverse reactions in children (20%) was similar to the overall incidence. Only 1 patient in the control group (10%) developed hypotension during the period studied. The incidence of adverse reactions was not related to age, body weight, vancomycin dose administered per kilogram body weight, type of surgical procedure, or associated disease. Mean duration of the infusion was similar in patients with and without adverse responses (34.60 +/- 12.41 minutes and 37.38 +/- 14.55 minutes, respectively). It is concluded that perioperative prophylaxis with vancomycin in cardiac surgery produces a high and unpredictable risk of significant hypotension.

[Comparative study of propofol and sodium thiopental in short-duration anesthesia]

We have compared propofol and sodium thiopental in two groups of 20 women undergoing curettage. Patients received premedication with diazepam and were randomly allotted to propofol group (2 mg/kg, intravenously) or sodium thiopental group (5 mg/kg, intravenously). Anesthesia maintenance was carried out with spontaneous ventilation with 0(2)-N2O. When complementary doses were required, 20% of the initial dose was administered. There were no significant differences with respect to base arterial blood pressure and heart rate on induction, 2 minutes after induction and at the end of the operation. The time from the end of the operation to the patient began to respond to the order of open eyes and to the patient was aware enough to establish a coherent talk and to seat without help was similar in both groups. Adverse effects were minor in bith groups and significantly more frequent in propofol group. We conclude that propofol is a particularly interesting new anesthetic agent for short duration anesthesia.

[Use of a new inotropic agent, enoximone, in heart surgery]

We report our experience with the use of enoximone in 5 patients with severely depressed preoperative myocardial function who underwent cardiac surgery. In patients 1 and 2, enoximone was administered as the inotropic of choice before cardiopulmonary bypass (CPB) and a substantial improvement of cardiac index was achieved; in these patients, enoximone administration after CPB permitted to overcome low cardiac output which persisted after high dose dobutamine in patient 1, and in patient 2 right ventricular contractility improved. In patient 3 the use of enoximone permitted the discontinuation of CPB, which had not been previously possible with the association of dopamine and dobutamine. In this patient, adrenaline perfusion improved the low cardiac output syndrome but resulted in poorly tolerated side effects. However, in patient 4 the administration of enoximone during pre-CPB did not improve in a reduction in filling pressures without an increase in the cardiac index because the patient was hypovolemic. In patient 5, the administration of enoximone permitted to interrupt the infusion of dobutamine and to reduce the dose of sodium nitroprusside, which had resulted in significant tachycardia, with increased myocardial contractility and a reduction of vascular peripheral and pulmonary resistances. We conclude that enoximone, single or in association with other inotropics, should be considered a drug of choice in patients undergoing cardiac surgery who develop a low cardiac output syndrome.

[Comparison of intramuscular and intranasal premedication with midazolam in children]

The study involved 40 children ASA I to II type who were randomly divided into two groups of 20 patients with comparable age and sex profile. Premedication consisting of 0.2 mg/kg of midazolam (Dormicum, Roche) and 0.015 mg/kg of atropine was administered 30 to 40 min before surgical intervention by intramuscular way in one group and by intranasal in the other one. In the operating room a peripheral vein was cannulated and general anesthesia was induced with thiopental sodium and succinylcholine. Arterial blood oxygen saturation, heart rate, arterial blood pressure and respiratory rate were measured at baseline, beginning of sedation (closing eyes), and arrival at the operating room. The time at the onset of sedation, the degree of sedation at the operating room, and the reaction to the venopuncture were also measured. In both groups of patients heart rate and systolic arterial blood pressure measured at the arrival to the operating room were significantly higher than those recorded at baseline and at the onset of sedation. Diastolic blood pressure in patients with intranasal premedication increased on arrival to the operating room with respect to the sedation values. Arterial oxygen saturation significantly decreased from the baseline values in both groups at the onset of sedation and on arrival at the operating room. There were no significant changes in respiratory rate. None of the alterations had clinical consequences. There were no significant differences in the onset of sedation (12.42 +/- 4.07 min in the intramuscular group and 15.26 +/- 7.99 min in the intranasal administration), degree of sedation and response to venopunction in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparison of anesthesia with thiopental or etomidate in short duration operations]

Forty ASA I-II women who were scheduled for uterine curettage were randomly allotted to two groups of 20 patients each. Both groups were age- and weight- matched. They were pre-treated with atropine (0.01 mg/kg) and diazepam (0.1 mg/kg). Anesthesia was induced with 2.5% thiopental (5 mg/kg) or 0.1% etomidate (0.3 mg/kg) and was maintained with N2/O2 at 50% and isoflurane at 1% adding supplementation doses of inducer (20% of initial dose) when required. Quality of induction and maintenance of anesthesia, cardiovascular effects, secondary effects and quality and rapidity of awakening were evaluated. Etomidate patients presented a higher number of secondary effects and pain on injection of the drug (p less than 0.05) and occurrence of excitatory motions (p less than 0.01) attained statistical significance. Evaluation of anesthesia quality was significantly higher with thiopental (p less than 0.05). There were no differences with respect to the remaining studied variables. We conclude that etomidate when used as unique agent in anesthesia induction has no advantages over thiopental in healthy patients undergoing short duration operations.

[Effect of intravenous anesthetic premedication using diazepam and fentanyl on the arterial oxygen saturation. A pulse-oximetric study]

The effects of anesthetic premedication with diazepam and phentanyl on the arterial oxyhemoglobin saturation (SpO2) were monitored with a pulsioximeter (BIOX 3700, Ohmeda) in 83 patients scheduled for traumatologic and orthopedic surgery who had baseline SpO2 higher than 95%. Premedication was carried out with phentanyl (0.1 mg) and diazepam (2.5 mg increments) until a somnolence state (eye closure), reversible with verbal stimuli, was achieved. The patients were breathing room air during the study. Premedication induced a significant reduction of SpO2 (p less than 0.001) from baseline values of 96.6 +/- 1.2% to 92.7 +/- 2.9% after sedation and to minimal values of 85.9 +/- 6.1%. In 60 patients (72.3%), minimal SpO2 was lower than 90%, and it was lower than 85% in 32 (38.8%). However, 34 of them (73.3%) recovered a SpO2 higher than 90% with verbal respiratory stimuli, but 16 (26.7%) only did so with oxygen administration. Cyanosis was not detected in any case. Minimal saturation was significantly correlated with baseline SpO2, age and smoking habit. Pulsioximetric monitoring or, if not available, routine oxygen administration, are recommended in patients undergoing pharmacological sedation.

[Epidemiologic aspects of accidental poisoning in children in Aragón (author's transl)]

Authors have studied epidemiologic aspects of 1,363 cases of accidental poisonings in children on a total of 25,136 cases of accidents that have been observed in Aragon hospitals. The following parameters were included in the protocol: sex (males: 57.6%), age (between 1-3 years: 57.9%), day time (12.00-16.00 hours: 30.8%), year season (spring-summer: 56.5%), week day (monday: 18.0%), poisoning (drugs and domestic products: 65.9%), house place (kitchen: 38.1%) and treatment (ambulatory: 81.7%).