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2.
Infection ; 38(5): 357-62, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20652354

RESUMO

BACKGROUND: Published guidelines for the treatment of healthcare-associated pneumonia (HCAP) recommend initial broad-spectrum antibiotics with appropriate de-escalation based on culture results. Guideline recommendations are based on data from intubated patients, in whom cultures are easily obtained. The approach to antibiotic de-escalation for culture-negative patients has not been addressed. Consequently, there are no published reports that describe the current standard of practice. PATIENTS AND METHODS: All patients admitted to a university hospital with a diagnosis of HCAP, as defined by use of a pneumonia orderset, were identified retrospectively over a 2-year period. Antibiotics prescribed on admission, during hospital stay, and on discharge were recorded. De-escalation was defined as a change in the initial antibiotic therapy from broad- to narrow-spectrum coverage within 14 days of the initial prescription. The Pneumonia Severity Index was used for risk-adjustment. RESULTS: A total of 102 patients were included in the analysis; of these, 72% (n = 73) were culture-negative. There were more males in the culture-negative than culture-positive group; otherwise, baseline characteristics were similar. Antibiotic therapy was de-escalated in 75% of the culture-negative group and 77% of the culture-positive group (p = 1.00). Culture-negative patients were de-escalated approximately 1 day earlier than culture-positive patients (3.93 vs. 5.04 days, p = 0.03). Culture-negative patients who were de-escalated had a shorter length of hospitalization, lower hospital costs, and lower mortality rates. In 70% of the culture-negative patients, a respiratory fluoroquinolone was chosen for de-escalation. CONCLUSION: In this single-center study, most of the patients with culture-negative HCAP were safely de-escalated to a respiratory fluoroquinolone.


Assuntos
Antibacterianos/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Pneumonia/tratamento farmacológico , Padrões de Prática Médica , Adulto , Idoso , Infecção Hospitalar/microbiologia , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia/microbiologia , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/isolamento & purificação , Estudos Retrospectivos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/isolamento & purificação , Adulto Jovem
3.
J Pediatr ; 135(1): 105-7, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10393614

RESUMO

We reviewed the incidence and morbidity of a 10-fold medication error among all premature infants treated with indomethacin. We detected 4 incidents among 1059 indomethacin doses given to infants weighing less than 1000 g. None of the infants had intracranial hemorrhage, necrotizing enterocolitis, or significant deterioration of renal function.


Assuntos
Anti-Inflamatórios não Esteroides/intoxicação , Permeabilidade do Canal Arterial/tratamento farmacológico , Indometacina/intoxicação , Doenças do Prematuro/tratamento farmacológico , Erros de Medicação/estatística & dados numéricos , Displasia Broncopulmonar/induzido quimicamente , Hemorragia Cerebral/induzido quimicamente , Enterocolite Necrosante/induzido quimicamente , Feminino , Humanos , Recém-Nascido , Masculino , Estudos Retrospectivos
4.
Obstet Gynecol ; 90(5): 809-14, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9351769

RESUMO

OBJECTIVE: To assess the neurodevelopmental outcome of infants born at 24-26 weeks' gestation. METHODS: One hundred thirty-eight nonanomalous infants were born at our hospital after pregnancies of 24-26 weeks' gestation between 1990 and 1994. Ninety-four infants survived to discharge and 86 were followed in a nursery follow-up program for outcome. Associations between gestational age and neurodevelopmental outcome and risk factors and outcome were analyzed. Mean age at follow-up was 32 months. RESULTS: The frequency of cerebral palsy did not differ significantly in the three groups (11, 20, and 11% at 24, 25, and 26 weeks, respectively). The incidence of normal cognitive outcome was associated significantly with gestational age at birth (28, 47, and 71% normal at 24, 25, and 26 weeks, respectively). Poor neurologic outcome was associated with the medical risk factor of intracranial hemorrhage grade 3 or 4 or periventricular leukomalacia. Poor cognitive outcome was correlated with both medical and social risk factors; however, there was an association between poor cognitive outcome and lower gestational age (P < .05), regardless of the relationships of any other risk factors to cognitive outcome. CONCLUSION: Although the incidence of cerebral palsy was low in these three groups, the high percentage of infants born at 24 and 25 weeks' gestation with cognitive deficits is concerning.


Assuntos
Paralisia Cerebral/epidemiologia , Deficiências do Desenvolvimento/epidemiologia , Recém-Nascido Prematuro , Pré-Escolar , Estudos de Coortes , Feminino , Seguimentos , Idade Gestacional , Humanos , Incidência , Recém-Nascido , Masculino , Gravidez , Estudos Retrospectivos , Fatores de Risco
5.
Obstet Gynecol ; 90(5): 803-8, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9351768

RESUMO

OBJECTIVE: To determine neonatal survival, short-term morbidities, and cost per survivor in pregnancies delivered at 24-26 weeks' gestation in a center in which antenatal steroids and exogenous surfactant are standard care. METHODS: A retrospective cohort study compared survival, short-term outcome, and initial hospital charges for pregnancies delivered at 24-26 weeks during 1990-1994. We calculated hospital costs for each year by using the corresponding institutional cost-charge ratio. RESULTS: There were 138 infants after excluding those with severe anomalies. Survival was 43%, 74%, and 83% at 24, 25, and 26 weeks, respectively (P = .006). The majority of women received antenatal steroids, and the majority of surviving neonates received exogenous surfactant. Severe retinopathy of prematurity and chronic lung disease decreased significantly from 24 to 26 weeks (P < or = .026). The likelihood of having a surviving infant without chronic lung disease or severe retinopathy of prematurity was 35% at 24 weeks and 78% at 26 weeks. Hospital costs for the 29 nonsurvivors were $1.46 million and for the 94 surviving infants were $16.9 million. The cost per day was similar at each gestational age, whereas the cost to produce a survivor was $294,749, $181,062, and $166,215 at 24, 25, and 26 weeks, respectively. CONCLUSION: Survival at 24 weeks was only 43% despite treatment with antenatal steroids and exogenous surfactant. The cost per survivor for infants born at 24 weeks was higher than the cost for those born after 1 more week in utero. Outcome improved markedly between 24 and 26 weeks, and small differences in gestational age lead to large economic differences. All efforts should be attempted to prolong pregnancy, and if prolongation is unsuccessful, treatment options including nonintervention should be available to parents of 24-week gestations.


Assuntos
Doenças do Prematuro/economia , Doenças do Prematuro/mortalidade , Recém-Nascido Prematuro , Adulto , Estudos de Coortes , Feminino , Idade Gestacional , Preços Hospitalares , Custos Hospitalares , Humanos , Mortalidade Infantil , Recém-Nascido , Masculino , Morbidade , Gravidez , Estudos Retrospectivos
6.
Am J Respir Crit Care Med ; 154(2 Pt 1): 484-90, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8756826

RESUMO

We report the activity of recombinant human surfactant apoprotein-C (rSP-C[Cys]2) and various phospholipids in a preterm rabbit model of respiratory distress syndrome (RDS). Mixtures of rSP-C(Cys)2 and certain phospholipids had similar activity (lung compliance and lung pressure-volume behavior) to rabbit surfactant in this model. The activity of rSP-C(Cys)2 was maximal at 1 mol% protein and varied significantly with the phospholipid composition. Chemically synthesized SP-C had similar activity to rSP-C(Cys)2. Deletion of six amino-terminal residues did not affect function. Substitution of cysteines and cysteine6 with adjacent serines (rSP-C[Ser]2) by site-specific mutagenesis minimized aggregation of rSP-C but did not affect activity. Palmitoylation of cysteine5 and cysteine6 in rSP-C (rSP-C[C16]2) did not enhance the activity of rSP-C(Cys)2. We conclude that bacterial expression is a practical source of functional SP-C, and that nonacylated forms of SP-C may be useful adjuvants to phospholipids in the treatment of RDS and possibly other forms of acute lung injury.


Assuntos
Pulmão/fisiopatologia , Proteolipídeos/uso terapêutico , Surfactantes Pulmonares/uso terapêutico , Síndrome do Desconforto Respiratório do Recém-Nascido/tratamento farmacológico , Animais , Humanos , Recém-Nascido , Fosfolipídeos/química , Fosfolipídeos/uso terapêutico , Proteolipídeos/química , Surfactantes Pulmonares/química , Coelhos , Proteínas Recombinantes/química , Proteínas Recombinantes/uso terapêutico , Síndrome do Desconforto Respiratório do Recém-Nascido/fisiopatologia
7.
J Pediatr ; 127(3): 466-71, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7658282

RESUMO

OBJECTIVE: To examine the role of ductus arteriosus (DA) constriction and loss of luminal blood flow in producing permanent closure of the DA in human infants. METHODS: We studied 77 newborn infants (gestational age, 23 to 33 weeks) with asymptomatic patent ductus arteriosus (PDA), who had "complete clinical closure" (defined as the disappearance of all PDA signs) after treatment with indomethacin (three doses within 36 hours). All infants had an echocardiogram 24 to 36 hours after the last dose of indomethacin. They were then followed for the development of ductus reopening. RESULTS: Despite the absence of clinical signs, 18 (23%) of 77 infants still had some residual luminal blood flow according to their echocardiograms. The failure to obliterate luminal blood flow completely was directly related to the infant's postnatal age when treatment was begun and to the amount of fluid administered before treatment. Subsequently the DA reopened in 16 (21%) of 77 infants. As predicted, infants with residual luminal blood flow after indomethacin treatment had a higher rate of subsequent clinical reopening than did those with no luminal flow. In addition, immature infants had a significantly higher reopening rate than did more mature infants. The increased risk of reopening in immature infants was seen even when indomethacin caused complete obliteration of ductus luminal blood flow. CONCLUSION: The DA of immature infants is resistant to the constriction-induced ischemic damage that is necessary for subsequent permanent closure of the vessel.


Assuntos
Permeabilidade do Canal Arterial/tratamento farmacológico , Indometacina/uso terapêutico , Canal Arterial/diagnóstico por imagem , Canal Arterial/efeitos dos fármacos , Permeabilidade do Canal Arterial/diagnóstico por imagem , Permeabilidade do Canal Arterial/etiologia , Ecocardiografia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Recidiva , Estatística como Assunto , Fatores de Tempo
8.
Pediatr Res ; 37(1): 21-5, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7700729

RESUMO

Surfactant apoprotein A (SP-A) reduces the inhibitory effects of plasma proteins on the surface tension lowering properties of pulmonary surfactant in vitro. To test the effects of SP-A in vivo we administered a complete natural dog lung surfactant (DLS) containing apoproteins SP-A, SP-B, and SP-C, a butanol extract of DLS (DLSE) containing only apoproteins SP-B and SP-C, and DLSE supplemented with SP-A intratracheally to prematurely delivered rabbit pups in the presence of increasing amounts of human plasma. In the absence of plasma DLS and DLSE (100 mg/kg phospholipid) had comparable effects on lung mechanics (compliance during ventilation with a tidal volume of 6-7 mL/kg and quasi-static pressure-volume behavior) in this surfactant deficiency model. Plasma proteins in increasing amounts to a maximum protein concentration of 62.5 mg/mL had no effect on the response of the pups to DLS. In contrast, plasma added to DLSE in concentrations above 20 mg/mL significantly increased the peak inspiratory pressure (PIP) required to ventilate the pups with a tidal volume of 6-7 mL/kg, reduced the calculated total lung compliance, and decreased the deflation lung volumes. The inhibitory effects of plasma on DLSE were significantly less when SP-A was added to DLSE (5:1, phospholipid:SP-A, wt:wt). The addition of SP-A to DLSE in plasma restored the activity of the extract to levels comparable to complete DLS. These results suggest that plasma can interfere with surfactant function and that SP-A has a significant protective effect for surfactant against the inhibitory effects of plasma in vivo.


Assuntos
Apoproteínas/farmacologia , Proteínas Sanguíneas/farmacologia , Proteínas Associadas a Surfactantes Pulmonares , Surfactantes Pulmonares/metabolismo , Surfactantes Pulmonares/farmacologia , Animais , Animais Recém-Nascidos , Apoproteínas/isolamento & purificação , Cães , Feminino , Humanos , Complacência Pulmonar/efeitos dos fármacos , Complacência Pulmonar/fisiologia , Medidas de Volume Pulmonar , Gravidez , Surfactantes Pulmonares/isolamento & purificação , Coelhos , Mecânica Respiratória/efeitos dos fármacos , Mecânica Respiratória/fisiologia
9.
J Appl Physiol (1985) ; 77(4): 1840-9, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7836208

RESUMO

To study the in vivo activity of the surfactant apoproteins (SP-A, SP-B, SP-C), we administered surfactants with defined apoprotein compositions to prematurely delivered rabbit pups. Rabbits given simple phospholipid mixtures containing dipalmitoylphosphatidylcholine and phosphatidylglycerol supplemented with both SP-B and SP-C or either protein alone had significantly greater lung compliance during ventilation and lung expansion during a quasi-static pressure-volume maneuver than did saline-or lipid-treated controls. The response to the surfactants containing SP-B/C was markedly dependent on the level of end-expiratory pressure used during ventilation. When the rabbits were ventilated with a positive end-expiratory pressure (PEEP) of 4 cmH2O, lung function in the pups treated with SP-B/C was not significantly different from rabbit surfactant-treated controls. Addition of SP-A to the surfactants containing SP-B/C did not significantly further improve lung function if the pups were ventilated with a PEEP of 4 cmH2O. With a lower PEEP of 1 cmH2O, lung function in the pups given surfactants containing SP-B/C was no longer equivalent to the lung function of the rabbit surfactant-treated controls. At the lower PEEP, SP-A significantly improved lung function when it was added to surfactants containing SP-B and SP-C. No beneficial effect of SP-A was seen when the surfactant contained either SP-B or SP-C alone. We conclude that with assisted ventilation that includes a moderate level of PEEP, SP-B and SP-C significantly enhance the effect of a simple phospholipid mixture on the lung function of prematurely delivered rabbits. At lower levels of PEEP the effects of SP-B and SP-C on lung function are markedly reduced but can be restored by the addition of SP-A. Our results are consistent with the existence of cooperative protein-protein interactions in surfactant function in vivo and suggest that the response to a surfactant will be determined by both the ventilation strategy and the surfactant composition. composition.


Assuntos
Pulmão/fisiologia , Respiração com Pressão Positiva , Surfactantes Pulmonares/farmacologia , Respiração/fisiologia , Animais , Animais Recém-Nascidos , Humanos , Pulmão/anatomia & histologia , Pulmão/efeitos dos fármacos , Proteolipídeos/farmacologia , Proteína A Associada a Surfactante Pulmonar , Proteínas Associadas a Surfactantes Pulmonares , Surfactantes Pulmonares/química , Coelhos , Respiração/efeitos dos fármacos
10.
J Pediatr ; 123(6): 953-62, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8229530

RESUMO

OBJECTIVE: To examine the cost effects of a single dose (5 ml/kg) of a protein-free synthetic surfactant (Exosurf) as therapy for neonatal respiratory distress syndrome, for both rescue and prophylactic therapy. RESEARCH DESIGN: Nonblinded, randomized clinical trials of both rescue and prophylactic therapy. Regression analyses were used to control for the independent effects of sex, multiple birth, delivery method, birth weight, and surfactant therapy. SETTING: The prophylactic trial was conducted at a university medical center only; the rescue trial also included a tertiary community hospital. PATIENTS: Prophylaxis was administered immediately after birth to 36 infants (38 control subjects) with birth weights between 700 and 1350 gm. Rescue therapy was administered at 4 to 24 hours of age to 53 infants (51 control subjects) with established respiratory distress syndrome and birth weights > or = 650 gm (no upper limit). Infants in the prophylactic trial were not eligible for the rescue trial. RESULTS: For the rescue trial, there was a $16,600 reduction in average hospital costs (p = 0.18), which was larger than the cost of the surfactant ($450 to $900), yielding a probable net savings. For the prophylactic trial, hospital costs were larger for treated infants versus control subjects who weighed less than about 1100 gm at birth and lower for treated infants versus control subjects who weighed more than 1100 gm at birth (p < 0.05). For the prophylactic sample, the result was an average cost per life saved of $71,500. CONCLUSIONS: Single-dose rescue surfactant therapy is probably a cost-effective therapy because it produced a lower mortality rate for the same (and probably lower) expenditure. Single-dose prophylactic therapy for smaller infants (< or = 1350 gm) appeared to yield a reduction in mortality rate for a small additional cost. The use of multiple-dose therapy in infants who do not respond to initial therapy may alter the effects described above to either increase or decrease the observed cost-effectiveness of surfactant therapy. Regardless, surfactant therapy will remain a cost-effective method of reducing mortality rates, relative to other commonly used health care interventions.


Assuntos
Álcoois Graxos/economia , Fosforilcolina , Polietilenoglicóis/economia , Surfactantes Pulmonares/economia , Síndrome do Desconforto Respiratório do Recém-Nascido/tratamento farmacológico , Custos e Análise de Custo , Combinação de Medicamentos , Álcoois Graxos/uso terapêutico , Feminino , Custos Hospitalares , Mortalidade Hospitalar , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Polietilenoglicóis/uso terapêutico , Surfactantes Pulmonares/uso terapêutico , Análise de Regressão , Síndrome do Desconforto Respiratório do Recém-Nascido/economia , Síndrome do Desconforto Respiratório do Recém-Nascido/mortalidade , Síndrome do Desconforto Respiratório do Recém-Nascido/prevenção & controle
11.
Pediatrics ; 88(1): 1-9, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2057244

RESUMO

EXOSURF is a protein-free surfactant composed of 85% dipalmitoylphosphatidylcholine, 9% hexadecanol, and 6% tyloxapol by weight. A single dose of 5 mL of EXOSURF per kilogram body weight, which gave 67 mg of dipalmitoylphosphatidylcholine per kilogram body weight, or 5 mL/kg air was given intratracheally in each of two controlled trials: at birth to neonates 700 through 1350 g (the prophylactic trial, n = 74) or at 4 to 24 hours after birth to neonates greater than 650 g who had hyaline membrane disease severe enough to require mechanical ventilation (the rescue trial, n = 104). In both studies, time-averaged inspired oxygen concentrations and mean airway pressures during the 72 hours after entry decreased significantly (P less than .05) in the treated neonates when compared with control neonates. Thirty-six percent of the treated neonates in the rescue study had an incomplete response to treatment or relapsed within 24 hours, suggesting the need for retreatment in some neonates. In the rescue trial, risk-adjusted survival increased significantly in the treated group. There were no significant differences in intracranial hemorrhages, chronic lung disease, or symptomatic patent ductus arteriosus between control and treated infants in either trial.


Assuntos
Álcoois Graxos/uso terapêutico , Doença da Membrana Hialina/prevenção & controle , Fosforilcolina , Polietilenoglicóis/uso terapêutico , Surfactantes Pulmonares/uso terapêutico , Administração por Inalação , Peso ao Nascer , Combinação de Medicamentos , Avaliação de Medicamentos , Álcoois Graxos/administração & dosagem , Seguimentos , Humanos , Doença da Membrana Hialina/tratamento farmacológico , Doença da Membrana Hialina/epidemiologia , Doença da Membrana Hialina/mortalidade , Recém-Nascido , Polietilenoglicóis/administração & dosagem , Surfactantes Pulmonares/administração & dosagem , Recidiva , Análise de Regressão , Respiração Artificial , Fatores de Tempo
12.
Am Rev Respir Dis ; 136(3): 651-6, 1987 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3307569

RESUMO

We treated prematurely delivered rabbit pups with the synthetic surfactant that has been named Exosurf. By weight, Exosurf is 61.8% dipalmitoylphosphatidylcholine, 6.8% hexadecanol, 4.6% tyloxapol, and 26.7% NaCl. This simple mixture, suspended at 15 mg lipid X ml-1 water, has appropriate in vitro characteristics for a lung surfactant substitute. As determined by static pressure volume relationships performed after 30 min ventilation, lungs treated with Exosurf accepted significantly more gas at maximal inflation (36 versus 15 ml X kg-1 body weight) and had significantly greater volumes during deflation that did saline-treated control lungs; lungs treated with natural rabbit surfactant (SAM) had significantly larger volumes at maximal inflation (65 versus 35 ml X kg-1) and during deflation than did the Exosurf-treated lungs. After 30 min of ventilation with oxygen and fixation at 10 cm H2O pressure, the ratio of air space to tissue space was determined by a point-counting technique, and mean linear intercepts were measured for air spaces. Exosurf-treated lungs were intermediate between SAM and saline-treated lungs in both measurements. With positive pressure ventilation to maintain a tidal volume of 6.5 to 7.5 ml X kg-1, total compliance was significantly greater and inspiratory pressure significantly lower in both SAM- and Exosurf-treated animals than in saline-treated control animals, although the lungs of the SAM-treated animals were more compliant than the lungs of animals treated with Exosurf. During the first minute of positive pressure ventilation, lungs treated with SAM or Exosurf expanded equally rapidly, both expanding more rapidly than the saline-treated lungs.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Álcoois Graxos/uso terapêutico , Pulmão/fisiopatologia , Fosforilcolina , Polietilenoglicóis/uso terapêutico , Surfactantes Pulmonares/uso terapêutico , Síndrome do Desconforto Respiratório do Recém-Nascido/tratamento farmacológico , Animais , Combinação de Medicamentos/uso terapêutico , Recém-Nascido , Complacência Pulmonar , Medidas de Volume Pulmonar , Respiração com Pressão Positiva , Troca Gasosa Pulmonar/efeitos dos fármacos , Coelhos
14.
Radiology ; 145(2): 357-60, 1982 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7134435

RESUMO

Flashing tomosynthesis, a procedure that consists of a recording step and a reconstruction step, facilitates the tomographic imaging of coronary arteries. In a comparative study 10 postmortem coronary arteriograms were examined with 35-mm cine technique and with flashing tomosynthesis. The degrees of stenosis found with both of these techniques were compared with morphometrically obtained values. A higher correlation coefficient existed for the degrees of stenosis obtained with tomosynthesis and morphometry (r = 0.92, p less than 0.001, SEE = 9%) than for those obtained with cine technique and morphometry (r = 0.82, p less than 0.001, SEE = 16%). The technique has also been successfully carried out in 5 patients with coronary artery disease.


Assuntos
Angiografia/métodos , Angiografia Coronária , Tomografia por Raios X/métodos , Cineangiografia , Doença das Coronárias/diagnóstico por imagem , Humanos
15.
Artigo em Inglês | MEDLINE | ID: mdl-7263404

RESUMO

The mechanism of ventilatory depression during hypoxia in the neonate is unknown. Since endorphins depress ventilation and their actions are antagonized by naloxone, we tested the effect of naloxone on respiration during acute hypoxia in newborn rabbits. In 27 tracheotomized unanesthetized pups, ranging in age from 1 to 15 days, ventilation (VE) was measured in a body plethysmograph. At all ages, inhalation of 5% O2 initially increased VE; thereafter VE became depressed in association with a decrease in CO2 elimination (VCO2). The time constant of VE depression increased with age. During ventilatory and VCO2 depression, saline infusion had no effect. Infusion of naloxone (4 micrograms/g body wt), however, abruptly stimulated both VE and VCO2. Since naloxone acts by competitive blockade of opiate (endorphin) receptors, these data provide evidence that 1) depression in respiration and metabolism during hypoxia is related to the action of endorphins, 2) the degree of endorphin influence decreases with age, and 3) naloxone is effective in reversing hypoxic respiratory depression provided apnea is not established.


Assuntos
Animais Recém-Nascidos/fisiologia , Endorfinas/fisiologia , Hipóxia/fisiopatologia , Respiração , Envelhecimento , Animais , Hipóxia/metabolismo , Naloxona/farmacologia , Coelhos , Fatores de Tempo
16.
Artigo em Inglês | MEDLINE | ID: mdl-6266991

RESUMO

Endorphins have been isolated from amniotic fluid and cord blood of mammals. To determine if these agents influence ventilation after birth, we measured ventilation (VE), tidal volume, inspiratory time, and respiratory frequency (f) in 19 rabbit pups before and after administration of naloxone (NLX), an endorphin antagonist. Tracheostomy and carotid artery cannulation were performed under light ether anesthesia. After 30-90 min for recovery the pups were placed in a body plethysmograph. Rectal temperature was kept at 37 +/- 0.5 degrees C. After 15 min of control measurements we infused saline, which had no respiratory effect. NLX (4 microgram/g) was then infused and measurements continued for 30 min. In 6 of 7 pups less than or equal to 4 days old, VE increased to 140-180% of control values and remained elevated for the remainder of the study period. Increased VE was due solely to increased f. By contrast, only 1 of 12 pups greater than or equal to 5 days old responded in this fashion. This difference was significant (P less than 0.005). Arterial blood gases were measured before and after NLX in 10 pups. In those pups who increased their ventilation after NLX, arterial CO2 tension fell and pH rose above pre-NLX values (P less than 0.05) for both variables). Blood gases of the group whose ventilation was uneffected remained unchanged. These results indicate that early in postnatal life endorphins probably modulate central respiratory drive in rabbits but that these agents become less important with maturation.


Assuntos
Animais Recém-Nascidos/fisiologia , Naloxona/farmacologia , Respiração/efeitos dos fármacos , Fatores Etários , Animais , Gasometria , Temperatura Corporal/efeitos dos fármacos , Corpo Carotídeo/efeitos dos fármacos , Coelhos , Receptores Opioides/fisiologia , Fatores de Tempo
17.
Am J Obstet Gynecol ; 134(7): 761-7, 1979 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-582356

RESUMO

We measured amniotic fluid surfactant by the semiquantitative foam stability test within 24 hours before delivery of 410 infants, 64 of whom developed HMD diagnosed by standard criteria. When surfactant titers were ranked in eight categories, they predicted graded risks of HMD. On this basis we defined five "risk groups" with significantly different incidences of HMD (I = 0.5%; II = 10%; III = 25%; IV = 41%; V = 79%). Infants in Groups I and II were heavier and more mature than those in Groups III to V. However, among infants of equivalent GA or birth weight, the incidence of HMD still correlated significantly with the foam test results. Within each risk group the incidence of HMD was equal among infants delivered by vagina and by cesarean section, slightly greater among males than females, and inversely proportional to GA. In Group V the incidence of HMD was 100% among infants at less than 33 weeks' GA. We used this relationship to devise a system that improved prediction of HMD by combining the foam test results with GA.


Assuntos
Líquido Amniótico/análise , Doença da Membrana Hialina/diagnóstico , Diagnóstico Pré-Natal/métodos , Surfactantes Pulmonares/análise , Amniocentese , Peso ao Nascer , Parto Obstétrico , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Métodos , Gravidez , Risco , Fatores Sexuais
20.
Pediatrics ; 58(4): 484-93, 1976 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-987574

RESUMO

We measured aortic and central venous pressures beginning soon after birth in 40 prematurely born infants with moderate or severe erythroblastosis fetalis, including 13 with severe and 10 with mild hydrops fetalis. All but four were asphyxiated at birth and this affected intravascular pressures. Before resuscitation, aortic or central venous pressure or both were elevated in more than one third. All but two of the remaining infants had normal initial pressures. Following resuscitation which relieved acidosis, hypoxia, and anemia, but did not reduce blood acidosis, hypoxia, and anemia, but did not reduce blood volume, the high pressures usually fell to normal and occasionally to subnormal levels, normal pressures fell to subnormal in almost one half, and those with initial subnormal pressures remained hypotensive. In all, 40% were hypotensive after resuscitation; treatment with blood volume expanders consistently returned these pressures to normal. Only two of the 13 severely hydropic infants and none of the mildly hydropic had findings indicative of hypervolemia and myocardial failure which persisted after treatment of asphyxia.


Assuntos
Pressão Sanguínea , Eritroblastose Fetal/fisiopatologia , Doenças do Prematuro/fisiopatologia , Animais , Asfixia Neonatal/complicações , Asfixia Neonatal/diagnóstico , Volume Sanguíneo , Pressão Venosa Central , Feminino , Humanos , Hipotensão/etiologia , Hipotensão/terapia , Recém-Nascido , Gravidez , Respiração Artificial
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