[Hepatic resection. A contribution and its analysis]

The authors outline their experience in the field of resective hepatic surgery, both with regard to benign and malignant pathologies, and analyse the results in relation to indications and techniques, but also focusing attention on the assessment of postoperative functional alterations, in order to evaluate the hepatic reserve and the organ's response to demolitive surgery. All operations were carried put in the First Division of Surgery at the Ospedale Civile, Asti, from January 1989 to September 1992. In all cases, even in major hepatectomies, a "trans-parenchymal" technique was adopted. Before surgery tests were carried out in relation to the topography of disease, its nature, associated pathologies and the functional hepatic reserve. Operative mortality was zero and morbidity was negligible, probably because rigorous selection criteria and indications for surgery were adopted. Morbidity was even restricted in the two patients suffering from HCC on cirrhosis (?) and this may probably be attributed to the limitation of resection to solely oncological purposes and their classification as Child-Pugh's stage A. The results regarding the liver response to demolitive surgery appear to be indicative and revealed a highly significant and discriminating difference between elective and emergency surgery.

Energy cost and efficiency of riding aerodynamic bicycles

Traction resistance (Rt) was determined by towing two cyclists in fully dropped posture on bicycles with an aerodynamic frame with lenticular wheels (AL), an aerodynamic frame with traditional wheels (AT), or a traditional frame with lenticular wheels (TL) in calm air on a flat wooden track at constant speed (8.6-14.6 m.s-1). Under all experimental conditions, Rt increased linearly with the square of air velocity (v2a); r2 equal to greater than 0.89. The constant k = delta Rt/delta v2a was about 15% lower for AL and AT (0.157 and 0.155 N.s2 x m-2) than for TL bicycles (0.184 N.s2 x m-2). These data show firstly, that in terms of mechanical energy savings, the role of lenticular wheels is negligible and, secondly, that for TL bicycles, the value of k was essentially equal to that found by others for bicycles with a traditional frame and traditional wheels (TT). The energy cost of cycling per unit distance (Cc, J.m-1) was also measured for AT and TT bicycles from the ratio of the O2 consumption above resting to speed, in the speed range from 4.7 to 11.1 m.s-1. The Cc also increased linearly with v2a, as described by: Cc = 30.8 + 0.558 v2a and Cc = 29.6 + 0.606 v2a for AT and TT bicycles. Thus from our study it would seem that AT bicycles are only about 5% more economical than TT at 12.5 m.s-1 the economy tending to increase slightly with the speed.(ABSTRACT TRUNCATED AT 250 WORDS)

Propofol induces bronchodilation in mechanically ventilated chronic obstructive pulmonary disease (COPD) patients

The aim of this study was to evaluate the effects of propofol administration (2 mg.kg-1 i.v.) on the airways resistances and respiratory mechanics of patients affected by COPD exacerbation, requiring mechanical ventilation. Twenty patients required anaesthesia for diagnostic or therapeutic procedures. Fourteen consecutive patients were divided at random into two groups: Group P received propofol and Group C (control) received only Intralipid 10%; an additional group of six patients received i.v. flunitrazepam (0.03 mg.kg-1). Lung mechanics (dynamic and static compliance, peak inspiratory pressure, intrinsic positive and expiratory pressure, minimal and maximal resistances of the respiratory system) were evaluated in basal conditions and 3 and 6 min after propofol, Intralipid or flunitrazepam administration. We did not observe significant variations of the evaluated variables after Intralipid or flunitrazepam (Groups C and F), while in patients who received propofol (Group P), we observed the following modifications: dynamic compliance increased from 2.3 +/- 0.3 to 2.8 +/- 0.4 ml.kPa-1 (P < 0.05), peak inspiratory pressure decreased from 3.3 +/- 0.7 to 2.8 +/- 0.4 kPa (P < 0.05), minimal resistances of the respiratory system (that mainly reflect airways resistances) decreased from 1 +/- 0.2 to 0.7 +/- 0.2 kPa.l-1 x s-1 (P < 0.01). Our results suggest that propofol induces bronchodilation in mechanically ventilated COPD patients, and that this effect is not related specifically to the induction of general anesthesia.

Repair of two unruptured intracranial aneurysms in the presence of coarctation of the aorta-anesthetic implications and management

A case of two incidental familial intracranial aneurysms associated with asymptomatic coarctation of the aorta is reported. Priority was assigned to aneurysm surgery, which was accomplished by means of two distinct procedures, both requiring moderate, deliberate hypotension. Invasive monitoring always included radial and femoral as well as pulmonary artery pressures, together with mixed venous oximetry and thermodilution cardiac outputs. Spinal somatosensory-evoked potentials were also continuously registered, to prevent spinal cord ischemia. In fact, even moderate hypotension may critically reduce perfusion in the lower, already hypotensive district, because of coarctation.

[Congenital duodenal stenosis. A case treated in adulthood]

The authors report their experience the diagnosis and management of congenital duodenal malformation in adults. They emphasize problems and difficulties in this disease of pediatric age and the physiopathological adaptation in these years. They point out that surgery can modify important metabolic functions and sub-clinical pathological conditions that the malformation made up.

[Myorelaxants and intracranial pressure (ICP) in neurosurgery. Preliminary clinical results of pipecurium bromide (Arduan) on ICP and on cerebral perfusion pressure (CPP)]

Pipecurium bromide, a new non-depolarizing myorelaxant, was administered intravenously, at a dose of 0.06 mg/kg, to 10 patients suffering from expansive endocranial lesions, who had been anesthetised to undergo neurosurgery. The following parameters were recorded simultaneously, before and after drug administration: intracranial pressure, mean arterial blood pressure, central venous pressure, heart rate and end tidal CO2. No statistically significant changes in the above parameters were observed following the administration of the myorelaxant; these observations, which were considered together with the long duration of action, confirm that pipecurium bromide is a valuable tool in anesthesia for neurosurgery.

Effects of low-dose propofol administration on central respiratory drive, gas exchanges and respiratory pattern

The effects of sedative-hypnotic doses of propofol on respiratory drive and pattern have not yet been extensively described. Repeated small boluses of propofol (0.6-0.3 mg.kg-1) were administered to ten ASA I patients undergoing carpal tunnel release using regional anaesthesia. Airway pressure, capnography and pneumotachography were continuously recorded. With respect to basal values, no significant variations of respiratory rate, minute volume, tidal volume, inspiratory and expiratory time, total expiratory cycle, Ti/Ttot, TV/Ti, P0.1, EtCO2 and blood gas analysis were observed. Low doses of propofol, to maintain conscious sedation of light sleep, have not been shown to cause respiratory depression.

Clinical evaluation of different doses of pipecuronium bromide during nitrous-oxide-fentanyl anaesthesia in adult surgical patients

The neuromuscular and cardiovascular effects of three different doses of pipecuronium were studied in 60 adult patients. Neuromuscular blockade was measured using electromyographic activity of the adductor pollicis muscle after supramaximal stimulation of the ulnar nerve at 0.1 Hz and 2 Hz. Three subgroups (A, B, C) of 20 patients received pipecuronium doses of 60, 80 and 100 micrograms kg-1, respectively, as an intubating dose and, when necessary, maintenance doses were administered at 25% single twitch recovery in a dose of one-quarter of the initial one. The onset time was 5.4 +/- 2.0 min for 60 micrograms kg-1 and similar for 80 and 100 micrograms kg-1 (3.9 +/- 1.1 and 3.6 +/- 1.1 min). The duration of action was 45 +/- 10 min for 60 micrograms kg-1, 74 +/- 25 and 94 +/- 21 for 80 and 100 micrograms kg-1, respectively. The recovery indices were measured in all patients after neostigmine administration (Groups B and C) and after neostigmine and edrophonium (Subgroup A, 10 patients each). TOF ratio was significant only 2 min after edrophonium administration in Group A patients. Variations of heart rate and blood pressure were not significant.

The Effects of Pipecuronium Bromide on Intracranial Pressure and Cerebral Perfusion Pressure

Twenty patients with expansive pathologic intracranial lesions, who were anesthetized with thiopental, nitrous oxide in oxygen, and fentanyl and mechanically ventilated to ensure normocarbia, received pipecuronium bromide 70 microg/kg i.v. Intracranial pressure (ICP), heart rate, arterial pressure, central venous pressure (CVP), EKG, and end-tidal CO2 were simultaneously recorded for 5 min before and for 15 min after administration of the muscle relaxant. No statistically significant changes in ICP and cerebral perfusion pressure were observed after administration of pipecuronium bromide. Cardiovascular stability was maintained during the study period except for a small, although significant, decrease of the CVP from 5.7 +/- 2.5 (SEM) to 5.0 +/- 2.5 mm Hg. These results, together with the long-lasting muscular effect of pipecuronium bromide, suggest that this new neuromuscular blocking agent may be used for muscle relaxation during neurosurgical operations in patients who have normal intracranial pressure at the time of administration of the drug.

[Pulmonary endometriosis. Clinical case]

Pulmonary endometriosis is a rare entity and there is little information regarding its treatment. We report a young female who developed hemoptysis in coincidence with menstruation. Pelvic endometriosis was confirmed histologically and pulmonary endometriosis was inferred. Treatment with Danazol led to suppression of both menstruation and hemoptysis, thus confirming the clinical diagnosis.

[Major and minor complications in carotid surgery]

The Authors report their experience of major and minor complications in carotid surgery. They analyse the causes and emphasize that a thorough preoperative study and a quick surgical technique are very important in reducing the rate of complications in this essentially preventive form of surgery.

[Surgical treatment of liver metastases of colorectal carcinoma. Our experience and review of the literature]

The authors describe their personal experience of the surgical treatment of hepatic MTS caused by colon-rectum ca. Following a review of the literature, including therapeutic protocols which do not always agreed, the problems inherent to the number, site, size and appearance of MTS themselves are discussed. Different approaches are compared in an attempt to clarify this pathology about which still very little is known. There is often uncertainty regarding the cases which should be treated surgically, and there is certainly a need for a greater number of case studies so as to avoid relying on the sensitivity and experience of the individual surgeon.

Energy cost and efficiency of sculling a Venetian gondola

Oxygen uptake was measured on four male subjects during sculling gondolas at constant speeds from approximately 1 to approximately 3 m.s-1. The number of scullers on board in the different trials was one, two or four. Tractional water resistance (drag, D, N) was also measured in the same range of speeds. Energy cost of locomotion per unit of distance (C, J.m-1), as calculated from the ratio of O2 uptake above resting to, increased with v according to a power function (C = 155.2.v1.67; r = 0.88). Also D could be described as a power function of the speed: D = 12.3.v2.21; r = 0.94). The overall efficiency of motion, as obtained from the ratio of D to C, increased with speed from 9.2% at 1.41 m.s-1 to 14.5% at 3.08 m.s-1. It is concluded that, in spite of this relatively low efficiency of motion, the gondola is a very economic means. Indeed, at low speeds (approximately 1 m.s-1), the absolute amount of energy for propelling a gondola is the same as that for waking on the level at the same speed for a subject of 70 kg body mass.

[Parietal damage in intestinal infarction. Clinical and anatomo-pathological considerations]

The physiopathology of parietal damage due to acute ischaemia is reviewed on the basis of a personal series of more than 70 cases. The reported data (not particularly abundant) is examined and an attempt made to draw conclusions that, free from mere theoretical and abstract value, may materially help the surgeon in his by no means easy decision to revascularize or resect an intestinal segment.