Biomedical subjects
J E Davidson
Publications and source records attributed to J E Davidson.
Ulnar peripheral nerve stimulation by train-of-four technique in adult nonmedicated patients.
BACKGROUND: Peripheral nerve stimulation is necessary to quantify the level of neuromuscular blockade and prevent prolonged paralysis related to drug accumulation. Some nurses and physicians are hesitant to administer nerve stimulation because of concerns about inflicting pain on the patient. OBJECTIVE: To describe the feeling associated with train-of-four ulnar nerve stimulation, and to quantify discomfort, monitor heart rate response, and define the amount of current necessary to stimulate thumb adduction. METHODS: Healthy, nonmedicated volunteer subjects (N = 39) were asked to describe train-of-four ulnar nerve monitoring at 3 current strengths. Heart rate was monitored throughout the testing procedure. The milliamperes delivered at each current strength and the occurrence of thumb adduction were recorded. RESULTS: Subjects described nerve stimulation generally as an unusual prickly sensation. On a discomfort scale of 1 to 10, the mean discomfort score when stimulated with the current setting at 4 (15.5-23.6 mA) was 3.63. Level 4 stimulation produced thumb adduction in 54% of subjects. No heart rate change occurred in response to nerve stimulation. CONCLUSION: Nerve stimulation by train-of-four method was moderately uncomfortable but not painful. Heart rate response could not be relied on as a measurement of discomfort. Protocols for stimulation should include testing at level 4 and increasing as necessary to cause thumb adduction.
Neuromuscular blockade: indications, peripheral nerve stimulation, and other concurrent interventions.
Neuromuscular blocking agents (NMBAs) are used in critical illness to reduce metabolic demands and prevent ventilator asynchrony in patients refractory to sedation and anxiolysis. Concurrent interventions for patients receiving neuromuscular blockade include many factors related to prevention, maintenance, and monitoring during immobilization. Prevention interventions include skin care, turning regimes, physical therapy, eye care, and pulmonary toilet to prevent atelectasis, pneumonia, skin breakdown, and corneal ulceration. Maintenance interventions include provision of nutrition, sedation, anxiolysis, and psychosocial support. Monitoring interventions include trending oxygenation parameters and ventilatory care parameters, as well as assessment of the depth of paralysis by assessing clinical evidence of movement, airway pressure waveforms, and peripheral nerve stimulation results. Cost of therapy is influenced by preventing the side-effects of immobility, the choice of NMBA, and concurrent drug therapies, as well as by titration of the NMBA to the lowest drug dose possible to obtain clinical end-points. Clinical end-points are individualized by the prescribing physician and may range from "no movement" to "movement acceptable but no evidence of spontaneous respirations" to "movement acceptable but no ventilator asynchrony." Whenever "no movement"c is identified as the goal, a nerve stimulator is used to identify the depth of paralysis and prevent accidental surplus drug administration, which may result in prolonged paralysis. Methods for using the nerve stimulator and troubleshooting techniques are discussed.
Measurement of complement activation products in patients with chronic rheumatic diseases.
Measurement of the complement activation products C1s:C1-inh, C3bP and C5b-9 by ELISA in plasma samples from normals, rheumatoid arthritis (RA) and systemic lupus erythematosis (SLE) patients showed significantly elevated levels in the two patient groups (P less than 0.0001 for C1s:C1-inh, C3bP and C5b-9) compared to normals. In seropositive RA patients there were significant correlations between the levels of the three complement activation complexes and IgM-RF, IgG-RF and IgA-RF. However, IgM-RF did not interfere with any of the ELISA systems. Mean levels of C1s:C1-inh, C3bP and C5b-9 were the same in paired plasma and synovial fluids; however, C3bP levels in the paired samples did not correlate with one another by rank. Our conclusions are that: (a) elevated plasma levels of these complement activation products are detectable in rheumatic diseases; (b) plasma levels of these complement activation products are related to Rheumatoid factor (RF) levels in seropositive RA patients; and (c) IgM-RF does not influence these solid-phase ELISA procedures.
Program to deal effectively and safely with the nursing shortage.
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Porencephaly and optic hypoplasia in neonatal isoimmune thrombocytopenia.
Five children with prenatal intracerebral damage associated with neonatal isoimmune thrombocytopenic purpura are described, and characteristic neurological features listed. These include optic hypoplasia which has not been previously documented in this condition.
Psychiatric aspects of HIV infection.
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