On-line medical direction: a prospective study

OBJECTIVES: To determine the frequency with which physician, on-line medical direction (OLMD) [direct medical control] of prehospital care results in orders, to describe the nature of these orders, and to measure OLMD time intervals. METHODS: Blinded, prospective study. SETTING: A university hospital base-station resource center. PARTICIPANTS: Ten emergency physicians, 50 advanced life support providers. INTERVENTIONS: Prehospital treatment was directed by both standing orders and OLMD physician orders. Independent observers recorded event times and the characteristics of OLMD. RESULTS: Physician orders were given in 47 (19%) of the 245 study cases, and covered a variety of interventions, including many already authorized by standing orders. Mean OLMD radio time was four minutes (245 +/- 216 seconds [sec]), and time from beginning of OLMD to hospital arrival averaged 12 minutes (718 +/- 439 sec). Mean transport time in this system was 13 minutes. CONCLUSION: Despite detailed standing orders, OLMD results in orders for clinical interventions in 19% of cases. On-line medical direction requires about four minutes of physician time per call. This constituted about one-third of the potential field treatment time interval in this system. Thus, OLMD appears to play an important role in providing quality prehospital care.     

Assessment of primary health care access status: an analytic technique for decision making

Access to health care is an issue that has caught the attention of health care providers, policy formulators, and policy analysts, with particular emphasis on access to primary care, which affords all people a viable portal into the health care system.This paper proposes an analytical approach to the assessment of relative primary care access status, measured as the capability to deliver basic primary care services within specific geographic civil areas, or parishes, within the state of Louisiana. An additive multiattribute utility method is employed to develop a scoring system to rank parishes according to a primary care access, or health system capability, numerical score. Routinely collected parameters are used to measure each parish's current capability to provide primary care services. These parameters include demographic, mortality, morbidity, and resource data.A group of experts was used to give weight to each parish's parameter values, resulting in a relative score for each. Thus, parishes (or other geographic areas) can be ranked according to their primary care access status. This information can then be used to allocate resources, to distribute funds for health care services, and to guide policy formulation and implementation.     

Immunophenotypic and DNA content characteristics of plasma cells in multiple myeloma and monoclonal gammopathy of undetermined significance

In the present paper we review the immunophenotypic characteristics of plasma cells (PC) and the PC DNA contents from multiple myeloma (MM) and monoclonal gammopathy of undetermined significance (MGUS), and its value for the differential diagnosis between both entities. The strong reactivity for CD38 and the positivity for CD138 are the two best markers for identifying PC. Myelomatous PC display an heterogeneous phenotype consistent with the fact that the neoplastic clone is able to undergo a certain degree of differentiation. In addition, PC from MM patients usually lack surface expression of B-cell associated antigens and frequently display reactivity for markers which are not restricted to the B-cell lineage. In MGUS patients, two clearly defined and distinct PC subpopulations can be identified. One of these PC subpopulations shows phenotypic characteristics identical to those of normal PC, including a very strong reactivity for the CD38 antigen, intermediate/low light scatter characteristics and positivity for CD19, in the absence of CD56, and corresponds to the residual normal bone marrow PC. The second PC subpopulation shows an immunophenotype similar to that of myelomatous PC, characterized by a slightly lower reactivity for CD38 and strong CD56 expression, on the absence of positivity for CD19, these PC corresponding to the clonal counterpart. Using a simultaneous staining for PC and DNA, around 60% of MM and 73% of MGUS patients display DNA aneuploidy, the majority of them being hyperdiploid. However, in contrast to MM patients, in MGUS patients two clearly different PC subsets can be discriminated in most cases (73%): a diploid and an aneuploid (hyperdiploid) subset, corresponding to normal and clonal PC, respectively. Upon comparing hyperdiploid with diploid patients in MM, the former display a better prognosis, in line with the higher incidence of DNA hyperdiploidy in MGUS. A clear correlation between the percentage of S-phase PC and several prognosis features of MM has been found. In spite of these findings, no significant differences in the percentage of pathological S-phase PC are detected between MM and MGUS patients. Regarding the differential diagnosis between MGUS and MM, multivariate analysis shows that the ratio between the number of clonal and normal residual PC is the best single parameter.     

Distribution of p75 and trk-neurotrophin receptor proteins in adult human sympathetic ganglia

We investigated the expression of immunoreactivity (IR) for low- (p75) and high-affinity (trk proteins) neurotrophin-receptor proteins in adult human paravertebral-sympathetic ganglion neurons. Mouse monoclonal antibodies against the pan-neurotrophin-receptor p75, and rabbit polyclonal antibodies against specific epitopes of the intracytoplasmic domain on trk neurotrophin-receptor proteins were used in fresh unfixed and formaldehyde-fixed paraffin-embedded sympathetic ganglia. All adult human paravertebral-sympathetic neurons displayed trkA neurotrophin-receptor-like protein IR, 10% express trkC neurotrophin-receptor-like protein IR, 37–44% show p75 IR, and no IR was obtained for trkB neurotrophin-receptor-like protein. The intensity of immunostaining was independent of the neuron size. Labelling of non-neuronal tissues, especially blood-vessel walls, was observed for p75, trkA and trkC neurotrophin-receptor proteins. These results indicate that overlapping exists in the expression of p75 and trk neurotrophin-receptor proteins in adult human paravertebral-sympathetic neurons, and suggest that neurotrophins might act on these neurons.     

Effects of selective phosphodiesterase inhibitors on platelet-activating factor- and antigen-induced airway hyperreactivity, eosinophil accumulation, and microvascular leakage in guinea pigs

There is currently interest in the potential use of selective inhibitors of cyclic nucleotide phosphodiesterases (PDE) in the treatment of asthma. In this study we examined the effects of three selective PDE inhibitors, milrinone (PDE III), rolipram (PDE IV) and zaprinast (PDE V), on the broncoconstriction produced by antigen and histamine, the airway hyperreactivity and microvascular leakage after aerosol exposure to platelet-activating factor (PAF) and antigen, and the antigen-induced eosinophil infiltration in guinea-pig lung. Inhaled rolipram (0.01–10 mg ml^–1) inhibited dose dependently the bronchospasm produced by aerosol antigen (5 mg ml^–1) an anaesthetised, ventilated guinea-pigs. Rolipram (10 mg ml^–1) produced maximal inhibition of antigen-induced bronchoconstriction but only partial inhibition of the response to aerosol histamine (1 mg ml^–1). Milrinone and zaprinast (each 10 mg ml^–1) showed weak, or no, inhibitory effects against bronchoconstriction produced by aerosol antigen or histamine. Pretreatment with rolipram (10 mg kg^–1, i.p.) prevented airway hyperreactivity to histamine which develops 24 h after exposure of conscious guinea-pigs to aerosol PAF (500 g ml^–1) or antigen (5 mg ml^–1). The pulmonary eosinophil infiltration obtained with 24 h of antigen-exposure was inhibited by rolipram. In contrast, milrinone and zaprinast (each 10 mg kg^–1, i.p.) failed to reduce either the airway hyperreactivity of the eosinophil accumulation in these animals. Rolipram (1–10 mg ml^–1) reduced the extravasation of Evans blue after aerosol PAF (500 g ml^–1) at all airway levels while a lower dose (0.1 mg ml^–1) was only effective at intrapulmonary airways. Rolipram (0.01–1 mg ml^–1) markedly reduced airway extravasation produced by inhaled antigen (5 mg ml^–1). Zaprinast (1–10 mg ml^–1) was also effective against airway microvascular leakage produced by aerosol PAF or antigen while milrinone (10 mg ml^–1) had no antiexudative effect. These data support previous suggestions that pharmacological inhibition of PDE IV results in anti-spasmogenic and anti-inflammatory effects in the airways and may be useful in the treatment of asthma.     

Hypotension induced by sodium nitroprusside administered via an automatic-adaptive dose regulating system. Experimental development

Sodium nitroprusside (NPS) is a potent vasodilator which is frequently administered for the control of arterial blood pressure and peripheral resistances. Manual regulation of the dose is difficult and requires a permanent surveillance of patients under treatment. Several attempts have been made to develop an automatized system able to safely control the dose of the drug in clinical practice. However, since now the results have not been completely satisfactory. The aim of our study was to develop of a new automatic-adaptative system able to continuously control the dose of NPS. The system consists of a high precision infusion pump controlled by a microprocessor. Arterial blood pressure is continuously monitorized and according to its values NPS is automatically regulated to maintain blood pressure within a preselected range. A control "fuzzy logic" algorithm was used. We have assessed the efficacy, adaptability, and safeness of the system. The system was tested in 15 mongrel dogs. The protocol was divided into two parts. During the first part a 25% to 30% reduction in blood pressure from baseline values lasting for a period of 4 hours was attempted. The second part was devoted to test the adaptability of the control unit during induced unstable hemodynamic situations. Group I dogs were subjected to volume overload. Group II were treated with noradrenaline to increase blood pressure, and group III underwent a venous bleeding to produce arterial hypotension. Control of arterial blood pressure was achieved after a minimum of 5 min and a maximum of 19 min (mean values = 13.3 min).(ABSTRACT TRUNCATED AT 250 WORDS)     

Biomechanics and Classification of the Cartilaginous Structures to Project the Nasal Tip

The present paper is the long-term conclusion of our preliminary presentation at the 1992 ISAPS Congress (Guadalajara, Mexico). This is the result of 29 cadaver dissections of different ages and both sexes. We have observed that length, thickness, and resistance correlate with the possibility to project the nasal tip with the mere structure of the alar cartilage and its medial crurae. We also demonstrated the existence and antagonistic action of Pitanguy's ligament as well as the depressing ligament to project the nasal tip. In this study, besides focusing on classifying the medial crus according to its thickness, length, and resistance, which is already different from any previous classification, we also focused on its surgical utility, and its interaction with other anatomic elements, to achieve the desired projection. Clinically, we present a 12-year experience with 1653 cases operated under this premise.