摘要:

Our previous studies suggested that the greater diminution in burn-induced cardiac contractile function which occurs in young and elderly subjects compared with adult subjects is related to differences in intracellular calcium availability to the myofilaments. We recently showed that improved cardiac function after hypertonic saline dextran (HSD) resuscitation from burn injury in adults was related to enhanced intracellular calcium content. In the study presented here, 126 hearts isolated from neonatal, adult, and senescent guinea pigs were used to evaluate age-related differences in cardiac contractile response to HSD resuscitation from burn injury. Scald burn was induced in 30 adult, 18 neonatal, and 30 senescdent guinea pigs; within each age group, half of the burned animals were resuscitated with lactated Ringer's (Parkland formula, 4 mL/kg/% burn for 24 hours); half received an initial bolus of HSD (4 mL/kg, IV) plus lactated Ringer's (1 mL/kg/% burn for 24 hours). An additional 16 animals from each group served as sham burn controls. Burn injury impaired cardiac function more in neonatal and senescent animals compared with adult animals as indicated by the fall in left ventricular pressure (from 74 ± 3 to 56 ± 4, from 63 ± 2 to 53 ± 2, and from 88 ± 2 to 67 ± 3 mm Hg,p= 0.01, respectively) and +dP/dt max (from 1,139 ± 50 to 1,150 ± 50 mm Hg/sec,p= 0.01, respectively) and -dP/dt max (from 1,110 ± 56 to 917 ± 40, from 836 ± 40 to 673 ± 30, and from 1,159 ± 30 to 915 ± 5 mm Hg/sec,p= 0.01, respectively). Lactated Ringer's resuscitation failed to correct burn-induced cardiac contractile defects in any age groups. Postburn cardiac dysfunction persisted after HSD plus lactated Ringer's resuscitation in neonatal and senescent hearts but returned to baseline values in adults as indicated by higher left ventricular pressure (61 ± 3,53 ± 3, and 86 ± 2 mm Hg) +dP/dt max (1,021 ± 56, 988 ± 57, and 1349 ± 60 mm Hg/sec,p= 0.01). Our data indicate that HSD effectively resuscitates burn injury in adults while significant cardiac dysfunction persists after HSD resuscitation from burns in neonatal and senescent guinea pigs.

ISSN:0022-5282    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The acute metabolic effects of epinephrine and cortisol, as well as the influence of substrate background on the effects of these two hormones were investigated in normal subjects. While receiving a hypocaloric dextrose feeding (50 mg/kg/h) (DEX), the subjects received a 6-hour continuous intravenous infusion of epinephrine (30 ng/kg-min) (EPI), followed by a 6-hour infusion of a combination of epinephrine (30 ng/kg-min) and cortisol (3.0 ml/kg-min) (EC). The hormone infusion was repeated 1 week after a continuous intravenous feeding regimen (TPN) was begun with a caloric content of 1.5 times the measured metabolic rate. Under both DEX and TPN, EPI produced increased energy expenditure, hyperglycemia, hyperlactic acidemia, and hypoaminoacidemia. Except for a further increase in circulating glucose levels during the DEX condition, these variables were not altered by the addition of cortisol. Epinephrine under both feeding conditions increased lactate efflux from the extremity without changes in peripheral oxygen or glucose uptake. The hypoaminoacidemic response to EPI in the DEX condition was associated with a decrease in extremity efflux of amino acids (-654 ± 89 nmol/min/100 cm3tissue at baseline vs −330 ± 86 nmol/min/100 cm3for EPI,p< 0.05). No change in extremity amino acid flux was noted in response to EPI during total parenteral nutrition. Even with addition of cortisol no significant efflux of amino acids above baseline levels was noted in either feeding condition. We therefore conclude that (1) total parental nutrition cannot abolish the hypermetabolic or hyperglycemic response to epinephrine and cortisol; (2) increased extremity lactate efflux and lactic acidosis can occur in response to epinephrine without evidence of diminished oxygen delivery to the extremity; and (3) these two hormones are not primary mediators of acute extremity nitrogen loss.

ISSN:0022-5282    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Pulmonary injury resulting from inhalation of chemical and particulate products of incomplete combustion is one of the principal determinants of mortality following burn injury. In this study, the histopathology of inhalation injury was examined in sheep. Mild, moderate, or severe smoke injury was produced in anesthetized sheep by insufflation with various doses of ambient temperature smoke, generated by burning polyethylene, wood pulp, and nonwoven cellulose pads. A total of 64 sheep were exposed and evaluated at times ranging from 15 minutes to 4 weeks after exposure. Morphologic changes in the lungs were studied using light microscopy and both transmission and scanning electron microscopy. The primary, dose-responsive injury observed was acute cell membrane damage in the trachea and bronchi leading to edema, progressive necrotic tracheobronchitis with pseudomembrane formation, and airway obstruction. These inflammatory and occlusive effects were followed by congestion, alveolar space edema, atelectasis, and bronchopneumonia. Morphologic changes occuring in the alveolar epithelium following high smoke dosage included intracellular edema in type-I cells, changes in the membrane-bound vacuoles of type-II cells, and septal thickening caused by interstitial edema. No capillary endothelial changes were observed.

ISSN:0022-5282    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Peripheral venous access can often be difficult to obtain in infants and young children. Landmark articles in the 1940s showed that the intraosseous (IO) route was a viable one for resuscitation. While anecdotal reports and clinical experience suggest that blood products can be transfused via the IO route, it has not been specifically studied nor documented. We performed a prospective study to document the feasibility of red blood cell transfusion via the IO space. We studied the rapid infusion of51Cr-labeled red blood cells via the IO space through an 18-gauge IO needle in three normovolemic immature swine. Serial central venous samples were removed at 30 seconds and at 1, 5, 15, 30, and 60 minutes and analyzed for evidence of radiolabeling. Our results revealed rapid delivery of radiolabeled red blood cells into the central circulation with no evidence of early heomolysis. Highest counts were seen in samples taken at 30 seconds to 1 minute. We conclude that the IO route is a viable means for blood transfusion in a nonhemorrhagic model.

ISSN:0022-5282    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

A prospective study was undertaken to evaluate the use of ceftriaxone in patients with abdominal trauma admitted to our hospital over a period of 6 months. Because of the large trauma load and an unacceptable waiting period before surgery combined with the fact that many patients on 6-hourly antibiotic regimes often did not receive their second and third doses, it was decided to use ceftriaxone because of its long half-life with maintenance of fluid and tissue concentrations for 24–48 hours. Because ceftriaxone is not reliably effective against anerobic organisms such asBacteroides fragilis, it was decided to add metronidazole as a combined initial dose. Two hundred ninety patients were entered in this trial, of which there were 259 stab wounds (89.3%), 20 missile injuries (6.9%), and 11 blunt injuries (3.8%). It was found that the mean delay between injury and initial dosage of ceftriaxone was 9.1 hours, with a range of 1–126 hours, and the mean delay between antibiotic therapy and operation 6.3 hours, with a range of 0–39 hours. The organs most frequently injured were the small bowel, the large bowel, the stomach, and the liver. Wound infection developed in only 4 patients (1.4%); intra-abdominal sepsis did not occur; and 35 patients (12%) developed respiratory infections. There were no deaths. We concluded that ceftriaxone, because of its 24-hour dosage was not only convenient but also adequate to prevent intra-abdominal sepsis and there was no difference in cost between this product and our previous protocol of 6-hourly antibiotic regime.

ISSN:0022-5282    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The ventilatory effects of medical antishock trousers (MAST) were investigated using 10 healthy volunteers. Use of the MAST (60–80 mm Hg) decreased forced expiratory volume (-8% ± 4%,p< 0.01), vital capacity (-8% ± 5%,p< 0.01), and functional residual capacity (-12% ± 6%,p< 0.01) and induced a significant decrease in tidal volume (-30% ± 17%,p0.05), but minute ventilation was unmodified because of a concomitant increase in respiratory rate (+17% ± 8%,p< 0.001). The MAST modified the breathing pattern: the abdominal contribution to ventilation was markedly decreased (-57% ± 22%,p< 0.001), suggesting a decrease in the diaphragmatic contribution to ventilation. The MAST increased both the end-expiratory (+131% ± 115%,p< 0.01) and inspiratory variation (ΔPgas: +42% ± 40%,p< variation of esophageal pressure remained unchanged. Because of a higher ΔPgas, the dynamic compliance of the abdominal compartment markedly fell (77% ± 10%,p< 0.001). Transdiaphragmatic pressure (Pdi: +28% ± 30%,pp< 0.05) after inflation of the MAST, suggesting an increase in the diaphragmatic cost of breathing. Inspiratory activity of the parasternal intercostal muscles significantly increased after the MAST was inflated. Computerized tomography showed that the MAST induced a cephaled shift of the diaphragm, which reduced pulmonary height. In contrast, the transverse and sagittal diameters of the thorax increased. The thoracic transverse area significantly increased, but this increase was associated with an increase in the mediastinal area but not the lung area. In conclusion, the ventilatory effects of MAST in healthy volunteers are moderate but might be deletrious or enhanced in shocked trauma patients.

ISSN:0022-5282    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Agriculture is widely recognized as one of the most dangerous occupations in the United States. The risk of agricultural trauma extends beyond the adult work force to include farm children. During a 2-year study of agricultural trauma conducted at the Marshfield Clinic/St. Joseph's Hospital, 246 (26.9%) of all agricultural injury victims were children (age less than 19 years). Teenagers were at greatest risk, but there were also many injuries among preschool children under the age of 6 years. Injuries occurred most often during the summer months, on weekends, and during the evening hours from 6:00 PM to 10:00 PM. There were relationships between the body part injured and the age of the child as well as between the agent associated with the injury and the age and gender of the child. Preschool farm children are particularly liable to experience head and neck trauma and injuries resulting from falls. Any succcessful effort to address either the prevention or treatment of agricultural trauma will need to consider that children have a unique pattern of injuries that differs from that of adults.

ISSN:0022-5282    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

To evaluate the impact of helmet use on injury severity, patient information was prospectively obtained for all bicyclists involved in collisions with motor vehicles seen at a level-I trauma center from January 1986 to January 1989. Two hundred ninety-eight patients were evaluated; in 284 (95.3%, study group) cases there was documentation of helmet use or nonuse. One hundred sixteen patients (40.9%) wore helmets and 168 (59.1%) did not. One hundred ninety-nine patients (70.1%) had an ISS > 15, while 85 (29.9%) were severly injured (ISS < 15). Only 5.2% of helmet users (6/116) had an ISS < 15 compared with 47.0% (79/168) of nonusers (p< 0.0001). The mean ISS for helmet users was 3.8 compared with 18.0 for nonusers (p< 0.0001). Mortality was higher for nonusers (10/168, 6.0%) than for helmet users (1/116, 0.9%%;p< 0.025). A striking finding was noted when the group of patients without major head injuries (246) was analyzed separately. Helmet users in this group still had a much lower mean ISS (3.6 vs. 12.9,p< 0.001) and were much less likely to have an ISS > 15 (4.4% vs. 32.1%,p< 0.0001) than were nonusers. In this group, 42 of 47 patients with an ISS > 15 (89.4%) were not wearing helmets. We conclude that helmet nonuse is strongly associated with severe injuries in this study population. This is true even when the patients without major head injuries are analyzed as a group; a finding to our knowledge not previously described. This implies that nonusers of helmets tend to be in higher impact crashes than helmet users, since the injuries suffered in body areas other than the head also tend to be much more severe. It is possible that at least some of the “protection” afforded helmet wearers in previous studies may be explained by safer riding habits rather than solely a direct effect of the helmets themselves.

ISSN:0022-5282    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Alcohol-impaired driving is a major issue confronting today's society. New legislation is emerging to help curtail this ongoing problem. To evaluate the legislative effects in terms of outcome pertaining to injured drivers, we analyzed the records of 116 consecutive motor vehicle drivers who were admitted to our trauma center over a 16-month period. Medical reports, police reports, and drivers' abstracts were reviewed. Of the 116 drivers, 61 (53%) had blood alcohol concentrations that exceeded the legal limit (blood alcohol level ≧ 100 mg/dL) on arrival at the emergency department. Only four of these patients were ticketed for driving under the influence and received the mandatory suspension of their driver's license. None was convincted of this offense, which carries criminal charges and a revocation of the driver's license. Mechanisms for efficient collection of blood specimens and mandatory occurrence reporting are two recommendations that merit investigation to obviate further escape of injured, intoxicated drivers from the legal net. In addition, alcohol rehabilitation and education cannot be overlooked and should warrant strong societal support.

ISSN:0022-5282    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Developmental changes in the anatomy and physiology of growing children are thought to improve the survivability of older children to significant injury. The effect of age upon survival, however, is poorly defined. Data for 4,615 patients less than 15 years old from a statewide trauma center registry were analyzed. Injury and survival were characterized by Abbreviated Injury Scale (AIS, 1985 revision), Injury Severity Score (ISS), Revised Trauma Score (RTS), and probability of survival [P(s)] andZby TRISS. Patients were separated into age groups of 0 through 4, 5 through 9, and 10 through 14 years. The survival rate for patients with a maximum AIS 3 for any region was significantly higher in the 10–14-year age group. There were no significant differences in survival rates from head, thoracic, and abdominal injuries stratified by AIS among the three age groups. Survival rates for ISS cohorts were consistently lowest in the 0–4-year age group, but differences failed to reach significance. Survival for RTS and P(s) intervals were similar for all ages. TheZstatistic reached significance for all children (Z= 4.717,W= 1.049), and for each group (Z= 2.203–3.029). Corresponding values of theWstatistic suggest approximately one additional unexpected survivor per 100 admitted children when compared with the Major Trauma Outcome Study. Logistic regression for patients with all data required for TRISS showed no significant effect for any of the three age groups. We conclude that for this patient set, survival after childhood injury is independent of the age groups used in this study, after controlling for injury severity.

ISSN:0022-5282    

出版商:OVID    

年代:1991

数据来源: OVID