Continuous infusion of rocuronium in a paediatric intensive care unit

Purpose  

To evaluate prospectively the efficacy and dose requirements of rocuronium administered by continuous infusion for neuromuscular blockade in a paediatric ICU population.     

The Effectiveness of the Gene Which Slows the Rate of Wallerian Degeneration in C57BL/Ola Mice Declines With Age

The rate of Wallerian degeneration is unusually slow in severed axons of mice of the C57BL/Ola strain. Within mice of that strain we have now found that the rate of degeneration increases with the age of the animal. In 4-week-old mice nerve stimulation evokes muscle contractions even 5 days after sciatic nerve section and compound action potentials can be recorded in the distal nerve stump up to 3 weeks after section. In 1-year-old animals no action potentials can be excited 5 days after nerve section. Heterozygous mice carrying only one copy of the dominant gene show the same age-related decline in viability of the distal nerve stump after axotomy, and the rate of decline is no greater than for homozygous mice. The more rapid rate of degeneration of severed axons of mice of the C57BL/6J strain was affected in the opposite way by age, degeneration occurring more slowly in older animals.     

Local anesthesia in reduction mastoplasty for out-patient surgery

To perform a breast reduction under local anesthesia we need a large amount of anesthetic with lasting effects. For this I use a solution of 25 cc of lidocaine, 25 cc of bupivacaine, and 1 cc of epinephrine in 350 cc of saline solution. The bupivacaine allows a 4–6-hour operation. Once the breast is infiltrated, a great amount of anesthetic is lost in the incision, in the dissection, and in the resected tissue. Thus, a low dose remains subcutaneously to be metabolized by the liver. The serum lidocaine levels are low during these operations, as demonstrated by fluorescence polarization immunoassay. Under analgesic sedation the submammary sulcus and the retroglandular space are infiltrated, blocking the perforants of the intercostal nerves, under the areola, beneath the skin where the incision is made and where the aerola is placed. This procedure has been applied to many techniques of breast reduction by modifying the infiltration under the incision lines. For hypertrophy up to 1000 g, 200–300 cc of anesthetic solution is used for both breasts at one stage, while for gigantomastia, about 400 cc of anesthetic is used, infiltrating and reducing one after the other. As the blood loss is minimal and the recovery very fast, with an appropriate adhesive bandage and a soutien, the patient could be discharged in the afternoon. Our experience includes 94 reduction mastoplasties with local anesthesia, and also 74 other mastoplasties with equally good results. There were no patient complaints and, in general, they felt very comfortable, awakening without pain or side effects.     

Effects of intravenously administered lidocaine on pulmonary vagal afferents and phrenic nerve activity in cats

The ability of lidocaine to suppress activity of single vagal afferent fiber and that of phrenic nerve was studied in 20 cats anesthetized with pentobarbital. Slowly adapting stretch receptors (SAR, n = 16) and rapidly adapting stretch receptors (RAR, n = 7) were identified by their discharge pattern to pulmonary inflation. Intravenous lidocaine (1mg·kg^–1 or 2mg·kg^–1) produced a suppression of SAR activity but not of RAR activity. Suppression of phrenic nerve activity lasted much longer than that of SAR. These findings indicate that iv lidocaine acts more dominantly on CNS than on peripherals. We conclude that iv lidocaine prevents cough and hemodynamic changes caused by airway manipulation mainly through its action on CNS and not on peripherals (peripheral nerves or their receptor).(Aoki M, Harada Y, Namiki A, et al.: Effects of intravenously administered lidocaine of pulmonary vagal afferents and phrenic nerve activity in cats. J Anesth 6: 395–400, 1992)     

Central course of digital axons within the median nerve of Macaca mulatta.

The traditional view that axons are not functionally grouped within proximal human nerve is based on the interfascicular dissections of Sunderland ('45). However, microstimulation and microneurography (Schady et al., '83a; Hallin, '90) reveal proximal grouping of cutaneous sensory axons from small areas of skin. In the present studies, conjugates of horseradish peroxidase with wheat germ agglutinin (HRP-WGA) were used to trace the course of digital nerve axons within the median nerve of Macaca mulatta. The electrophysiologic findings were confirmed, suggesting the potential for precise surgical realignment of functionally related axons even after proximal nerve transection. Radial digital nerves were labeled in the thumb (bilateral, 1 animal), the index finger (unilateral, 2 animals), and the middle finger (bilateral, 1 animal). Median nerve cross sections were cut at 1-cm intervals, treated with tetramethyl benzidine to demonstrate HRP-WGA within axons, and compiled to form maps of each digital nerve "territory" within the median nerve. These territories were limited to a single, densely labeled fascicle at the wrist level. They expanded somewhat in the forearm to encompass clusters of labeled axons within a matrix of unlabeled axon profiles. The clusters were more loosely packed in the arm, occupying 1/3 to 1/6 of the nerve cross section at the entrance to the brachial plexus. The three digital nerve territories studied were widely separated at the wrist level. In the proximal arm, there was moderate intermingling of axons from adjacent digits, but those to the middle finger and thumb remained segregated. Territory configuration differed widely overall, but was moderately constant for each digit. The location of territories within the nerve was often strikingly similar from right to left and from animal to animal, with occasional prominent variations reflecting isolated rotation of one nerve.     

Antibodies in sera from patients with inflammatory demyelinating polyradiculoneuropathy react with ganglioside LM1 and sulphatide of peripheral nerve myelin

Summary Sera from 23 patients with acute Guillain Barré syndrome (GBS), 15 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and from 40 age-matched blood donors were analysed for antibodies to acidic glycosphingolipids from human brain and peripheral nerve. Antibodies to ganglioside LM1, the major ganglioside of peripheral nerve myelin, were found in 43% of GBS and in 67% of CIDP patients' sera, and in 20% of the blood donors. However, anti-sulphatide antibodies were detected in 65% and 87% of the sera from GBS and CIDP patients, respectively, but only in 15% of the control sera. Sulphatide is the major acidic glycosphingolipid in myelin and its concentration in peripheral nerve myelin is 100 times higher than that of LM1. The high frequency of LM1 and, in particular of sulphatide antibodies, might thus be relevant to the pathogenesis of the GBS and CIDP. Abbreviations: The ganglioside nomenclature used according to Svennerholm [24]. LM1, IV³NeuAc-nLcOse₄Cer, GM1, II³NeuAcGgOse₄Cer; GD1a, IV³NeAc,II³NeuAc-GgOse₄Cer; GD1b, II³(NeuAc)₂-GgOse₄Cer; GT1b, IV³NeuAc,II³(NeuAc)₂-GgOs₄Cer; LU1, sulphate-3-glucuronyl paragloboside; sulphatide, 3-sulphogalacto-sylceramide     

The natural history of somatosensory and autonomic nerve dysfunction in relation to glycaemic control during the first 5 years after diagnosis of Type 1 (insulin-dependent) diabetes mellitus

Summary The natural evolution of neural dysfunction was studied prospectively over 5 years following diagnosis of Type 1 (insulin-dependent) diabetes in 32 patients aged 12–36 years. Motor and sensory nerve conduction velocities, heart rate variation at rest and during deep breathing, and pupillary function were measured at diagnosis and after 3,12, 24,48, and 60 months. Thermal and vibration sensation thresholds were determined after 24, 48, and 60 months of diabetes. Mean HbA₁ levels of months 3–60 within the normal range of <8.3% (7.3±0.2%) were observed in 13 patients (Group 1), while a mean HbA₁ of months 3–608.3% (10.0±0.3%) was found in 19 patients (Group 2). Mean nerve conduction was significantly diminished in Group 2 as compared with Group 1 in at least 4 out of 6 nerves tested during months 12–60 (p<0.05). Both tests of heart rate variation were significantly impaired in Group 2 as compared with Group 1 after 24 and 60 months (p<0.05), but no differences in pupillary function were observed between the groups. Thermal discrimination but not vibration perception thresholds on the foot were significantly higher in Group 2 than in Group 1 at 40 and 60 months (p<0.05). Abnormalities in nerve conduction, thermal discrimination, and heart rate variation, but not vibration perception threshold and the pupillary function tests were significantly more frequent in Group 2 than in Group 1 at 60 months (p<0.05). After 60 months, none of the patients of Group 1, but 6 and 4 patients of Group 2 developed subclinical or symptomatic neuropathy, respectively (p<0.05). These findings suggest that the evolution of subclinical and symptomatic neuropathy during the first 5 years after diagnosis of Type 1 diabetes may be predicted by poor glycaemic control and prevented by near-normoglycaemia.     

Characterization of rat hyperplastic bile ductular epithelial cells in culture andin vivo

A novel intrahepatic biliary cell culture/in vivo transplantation system has been developed with an essentially pure population of bile ductular epithelial cells isolated from rat liver 6–12 weeks after bile duct ligation. In primary culture, these cells retain staining strongly for -glutamyltranspeptidase and glutathione S-transferase P. The cytoplasm of cultured bile ductular cells reacts with an anti-laminin antibody, but loses immunoreactivity with a monoclonal anti-cytokeratin 19 antibody. Semiconservative DNA synthesis in the cultured cells was dependent upon the continued presence of 10% fetal calf serum in the medium. Replicating bile ductular cells could be subcultured for a finite number of passages. In addition, freshly isolated bile ductular epithelial cells gave rise to well differentiated bile ductular structures when transplanted into the interscapular fat pads of syngeneic recipient rats.Presented at the Proceedings of the International Meeting on Normal and Neoplastic Growth in Hepatology, Bari, Italy, June 1989.This work was supported by USPHS Grant RO1 CA39225 to Dr. Sirica by the National Cancer Institute, Department of Health and Human Services.     

Sensory nerve pathology in amyotrophic lateral sclerosis

Summary A detailed morphometric study was performed on sural nerve biopsies to determine the consistency of sensory nerve pathology in amyotrophic lateral slcerosis (ALS) and to seek a correlation between the severity of peripheral nerve pathology and disease duration. Nerve biopsies from patients with ALS consistently showed evidence of early axonal atrophy, increased remylination and a shift in the diameter distributions curve towards smaller fiber diameters. Importantly, the severity of sensory nerve pathlogy in ALS patients correlated with disease duration. The peripheral nerve sodium pump concentration of patients was not reduced. It is concluded that an ingravescent dorsal root ganglion neuronopathy is seen in the incipient stages of ALS, preferentially affecting the largest neurons and resulting in turn in progressive axonal atrophy, secondary demyelination-remyelination and finally in nerve fiber degeneration. Etiologically, a parallel involvement of motor and sensory neurons suggests a more widespread metabolic disturbance in ALS than simply sick motor neurons.Supported by a grant from the New Zealand Neurological Foundation