No excess risk of adverse birth outcomes in populations living near special waste landfill sites in Scotland

A recent study showed small excess risks of low birth weight, very low birth weight and certain congenital anomalies in populations living near landfill sites in Great Britain. The objective of the current study was to investigate the risk of adverse birth outcomes associated with residence near special waste landfill sites in Scotland. We studied risks of adverse birth outcomes in populations living within 2 km of 61 Scottish special waste landfill sites operational at some time between 1982 and 1997 compared with those living further away. 324,167 live births, 1,849 stillbirths, and 11,138 congenital anomalies (including terminations) were included in the study. Relative risks were computed for all congenital anomalies combined, some specific anomalies and prevalence of stillbirth and low and very low birth weight (< 2500 g and < 1500 g). For all anomalies combined, relative risk of residence near special waste landfill sites was 0.96 (99% confidence interval 0.89 to 1.02) adjusted for confounders. Adjusted risks were 0.71 (0.36 to 1.42) for neural tube defects, 1.03 (0.85 to 1.26) for cardiovascular defects, 0.84 (0.58 to 1.22) for hypospadias and epispadias (with no excess of surgical corrections), 0.78 (0.27 to 2.23) for abdominal wall defects (1.32 (0.42-4.17) for hospital admissions), 1.22 (0.28 to 5.38) for surgical correction of gastroschisis and exomphalos and 1.01 (0.96 to 1.07) and 1.01 (0.90 to 1.15) for low and very low birth weight respectively. There was no excess risk of stillbirth. In conclusion, we found no statistically significant excess risks of congenital anomalies or low birth weight in populations living near special waste landfill sites in Scotland.

Glycosaminoglycan Hydrogels as Supplemental Wound Dressings for Donor Sites

Chemically crosslinked glycosaminoglycan (GAG) hydrogel films were evaluated as biointeractive dressings in a porcine model for donor-site autograft wounds. Multiple 5 x 5 x 0.03 cm wounds were created on the dorsum of pigs. Half of the wounds were treated with a GAG film plus an occlusive dressing (Tegaderm), whereas the other half were treated with Tegaderm alone. At 3, 5, or 7 days after surgery, the partially healed wounds were excised and evaluated histologically for three animals at each time point. By day 3, epithelial cells had proliferated and migrated from wound edges and from epithelial islands associated with residual hair follicles to begin to cover the wound bed. A statistically significant increase in coverage was observed for GAG + Tegaderm-dressed wounds than for those with Tegaderm alone at day 3 and day 5 post-surgery. By day 7, all treatment groups were completely healed. Thus, GAG hydrogels accelerated wound healing by enhancing re-epithelialization.

Burn center management of necrotizing soft-tissue surgical infections in unburned patients

BACKGROUND

Patients with necrotizing soft-tissue infections present great challenges in management from initial presentation through definitive care. Because burn centers concentrate expertise in critical care, wound management, and rehabilitation, we examined the effectiveness of burn center care for patients with necrotizing infections.

METHODS

We reviewed our burn center's experience with all patients admitted from 1990 through 1999 with a primary diagnosis of necrotizing fasciitis (NF) or Fournier's gangrene (FG).

RESULTS

Fifty-seven patients were identified, 18 with FG and 39 with NF. Patients had a high incidence of preexisting medical problems, including diabetes (37%), obesity defined as greater than 20% above ideal body weight (33%), and hypertension (33%). Seven of 57 (12%) patients died. Patients required a mean of 4.1 operative procedures (range 1 to 15) for definitive wound closure. The mean length of stay (survivors only) was 28.5 days, (range 3 to 70). Although costs increased throughout this period, a formal program of cost-containment resulted in no increase in actual charges per day, from a mean of $4,735 in 1991 to $5,202 in 1999.

CONCLUSIONS

Burn centers can provide successful and cost-effective acute care, definitive wound closure, and rehabilitation for patients with NF and FG.

Mutational analysis of branching in pea. Evidence that Rms1 and Rms5 regulate the same novel signal

The fifth increased branching ramosus (rms) mutant, rms5, from pea (Pisum sativum), is described here for phenotype and grafting responses with four other rms mutants. Xylem sap zeatin riboside concentration and shoot auxin levels in rms5 plants have also been compared with rms1 and wild type (WT). Rms1 and Rms5 appear to act closely at the biochemical or cellular level to control branching, because branching was inhibited in reciprocal epicotyl grafts between rms5 or rms1 and WT plants, but not inhibited in reciprocal grafts between rms5 and rms1 seedlings. The weakly transgressive or slightly additive phenotype of the rms1 rms5 double mutant provides further evidence for this interaction. Like rms1, rms5 rootstocks have reduced xylem sap cytokinin concentrations, and rms5 shoots do not appear deficient in indole-3-acetic acid or 4-chloroindole-3-acetic acid. Rms1 and Rms5 are similar in their interaction with other Rms genes. Reciprocal grafting studies with rms1, rms2, and rms5, together with the fact that root xylem sap cytokinin concentrations are reduced in rms1 and rms5 and elevated in rms2 plants, indicates that Rms1 and Rms5 may control a different pathway than that controlled by Rms2. Our studies indicate that Rms1 and Rms5 may regulate a novel graft-transmissible signal involved in the control of branching.

Assessment of tissue viability in complex extremity injuries: utility of the pyrophosphate nuclear scan

BACKGROUND

Extensive extremity injuries often require difficult decisions regarding the necessity for amputation or radical debridement. During the past decade, we have used technetium-99 pyrophosphate (PyP) scanning as an adjunct in this setting. This study was performed to assess the accuracy of PyP scan in predicting the need for amputation in relation to clinical, operative, and pathologic findings.

METHODS

Review of our computerized registry identified 11 patients (10 men, age 36.1 +/- 14.9 years) admitted from 1990 to 1999 who underwent PyP scan. Using operative and pathologic findings, accuracy of the PyP scan was graded as supporting or refuting the clinical assessment of the need for amputation.

RESULTS

Eight patients suffered high-voltage electrical injuries, one had severe frostbite, and two suffered soft-tissue infections. In most cases, PyP scan showed clear demarcation of viable and nonviable tissue, verifying the need for amputation (positive); those that demonstrated viable distal tissues confirmed at operation were considered negative. PyP scan had a sensitivity of 94%, a specificity of 100%, and an accuracy of 96% in this setting.

CONCLUSION

Technetium-99 PyP scanning is a useful adjunct in predicting the need for amputation in extremities damaged by electrical injury, frostbite, or invasive infection. In addition, by providing an objective "picture" of extremity perfusion, PyP scans can be helpful in convincing patients of the need for amputation.

Is immediate chest radiograph necessary after central venous catheter placement in a surgical intensive care unit?

BACKGROUND

Current standard of care dictates that central venous catheter (CVC) insertion should be followed by an immediate chest radiograph to confirm appropriate position and rule out complications. We hypothesized that a subset of monitored intensive care unit patients exists that is at low risk for complications and might safely have radiographic evaluation of line placement deferred until the next scheduled radiograph.

METHODS

Data regarding patient and procedural characteristics were obtained prospectively for 184 CVC placed between March 1, 1998, and June 30, 1999. Retrospective data regarding complications were obtained by chart review for an additional 174 CVC placed during the study period but for which data sheets were not completed. All procedures were followed by chest radiography.

RESULTS

We documented a complication rate of 9% with the vast majority (25 of 31, 81%) of complications consisting of incorrect positioning. The number of needle passes was greater in the group suffering pneumothorax and arterial puncture than the uncomplicated group (5.6 versus 1.9, P = 0.008). "Straightforward" operator gestalt (P = 0.04) and number of needle passes <3 (P = 0.03) were factors correlating with the absence of complications. These factors had negative predictive values of 94% and 96%, respectively.

CONCLUSION

Placement of CVC is safe in experienced hands. In monitored intensive care unit patients who undergo a "straightforward" procedure with <3 needle passes, chest radiograph can be safely deferred until the next scheduled examination.

The demand and supply of nutritional advice and guidance in Scottish family planning services

Recent changes to the health services have led to an increased provision of clinical care in family planning clinics. While some women may only require contraceptive services, others may demand advice on a breadth of lifestyle issues, including diet and nutrition. Obesity affects 17% of women of childbearing age in Scotland and being overweight during pregnancy has significant health risks. A postal survey of 227 nurses identified as working in family planning clinics in Scotland was conducted in 1998. After a mail shot and one reminder, a net response rate of 64% (n = 145) was achieved. Overall, it was found that obesity was perceived as the most extensive problem in women of childbearing age. Seventy nurses (48%) reported that, in addition to offering family planning services, they gave dietary advice 'frequently' or 'always' to their clients without being asked. There were differences in nutrition-related activities in consultations between nurses offering family planning services only and those who routinely offered nutritional advice. Over half (61%) of the nurses reported that they would give advice regarding weight management even if the patients were not seeking help, although there was no significant difference between the two comparison groups. In some cases, the nutritional advice offered to clients highlighted a deficit in training. Most nutrition education came from diploma and/or training courses and scientific literature, followed by 'experience'. Those nurses already embracing a nutritional advice and guidance role were more interested in further nutrition training (p = 0.018) than the other nurses. However, overall, 67% of the nurses wished to train further in nutrition and weight management. The findings suggest that family planning nurses should be supported to develop nutritional advice and guidance skills, and that there is a pressing need for training in public health nutrition and weight management for nurses working in family planning services.

Point-source modelling using matched case-control data

We describe an extension to matched case-control studies of the parametric modelling framework developed by Diggle (1990) and Diggle and Rowlingson (1994) to investigate raised risk around putative sources of environmental pollution. We use a conditional likelihood approach for the family of risk functions considered in Diggle and Rowlingson (1994). We show that the likelihood surface that results from these models may be highly irregular, and provide a Bayesian analysis in which we investigate the posterior distribution using Markov chain Monte Carlo. An analysis of one-one matched data that were collected to investigate the relationship between respiratory disease and distance to roads in East London is presented.

Still hungry in hospital: identifying malnutrition in acute hospital admissions

We assessed the prevalence, methods for recognition and clinical management of malnutrition in acute admissions in a large academic inner-city hospital. Of a total of 337 patients, it was possible to measure both height and weight in 219 patients (65% of admissions). As an alternative for bed-bound patients, mid-upper arm circumference was not very reliable in predicting BMI (sensitivity 98%; specificity 65%), and waist circumference even less so. Of these, 13% were malnourished (body mass index BMI <18.5 kg/m(2) or BMI 18.5-20 kg/m(2) with reported weight loss >3 kg in the last 3 months). Six patients (31% of those with BMI <18.5 kg/m(2)) and one with BMI 18.5-20 kg/m(2) were recognized as suffering from malnutrition and referred to the dietitian. Review of case records could not establish if the diagnosis was missed in the remainder, or if a conscious decision was taken not to manage malnutrition actively. Malnutrition in acute hospital admissions goes apparently unrecognized and unmanaged in 70% of cases. Since there are serious consequences, and effective simple treatment is readily available, increased awareness is required, with routine assessment of nutritional status in all patients.

Situational trust and co-operative partnerships between physicians and their patients: a theoretical explanation transferable from business practice

A model to explain interpersonal trust development, and its consequences for co-operative behaviour in doctor/patient partnerships derived from the context of business relationships is applied to patient/physician relationships. Threshold barriers exist against all human behaviours or actions and trust is the process by which barriers to co-operation and compliance are overcome. Dispositional trust (a psychological trait to be trusting) is dominant in the early stages of a relationship and contributes to the weight of subsequent trust development. Co-operative behaviour or compliance ultimately requires a secure situational trust emerging from consultations, which is carried forward as learnt trust and modified in each subsequent consultation. The model comprises three types of situational trust (calculus-based, knowledge-based, and identification trust) and five co-operation criteria from which to determine an individual's tendency for co- operative behaviour. These model components can be identified and mapped from a range of qualitative data, with the aim of enhancing co-operative behaviour and efficiently achieving optimal patient compliance.

Intestinal obstruction secondary to enteral feedings in burn trauma patients

BACKGROUND

Enteral feeding is preferred for maintaining gut integrity and providing nutrition in trauma patients. Recent reports suggest that use of early enteral feeds is successful and that complications are rare. A recent burn patient, who suffered apparent bowel obstruction and perforation secondary to enteral feedings, led us to review our experience with mechanical complications of tube feedings.

METHODS

We searched our registry of patients treated for acute burn trauma injury and identified patients treated for acute bowel obstruction in the past 3 years.

RESULTS

Four patients were identified, ages 22 to 44, with burns of 6 to 92% total body surface area. Each required intubation and ventilatory support during initial treatment, complicated by adult respiratory distress syndrome and sepsis. We began enteral feeds 1 to 3 days after admission. At approximately 14 days after admission, each patient deteriorated clinically, which led to emergent abdominal exploration; the tube feedings caused bowel obstruction and associated complications. Each patient improved with laparotomy.

CONCLUSION

Bowel obstruction, ischemic necrosis, or both, secondary to early and aggressive nutrition with a fiber supplemented enteral feeding is an uncommon, life-threatening complication. Understanding and early recognition of this potential complication are essential to prevention or successful treatment.

Who gets what treatment for obesity? A survey of GPs in Scotland

OBJECTIVE

To describe the types and delivery of obesity treatment currently favoured by General Practitioners (GPs) working in Scotland.

DESIGN

Representative cross-sectional survey using a postal questionnaire which included case stories as stimuli for questions about the GPs' nutrition guidance to overweight female patients.

SUBJECTS

A systematic sample of 1400 general practitioners (GPs) from a total of 3593 GPs working in Scotland in 1997.

RESULTS

From 1363 eligible GPs, 609 returned the full questionnaire and a further 132 took part in a telephone mini-interview. Net response was 54.4% (741/1363). Almost half of the GPs (45.6%) reported that they had read the recent national clinical guideline for integrating obesity prevention with weight management (SIGN 1996). The majority of GPs (89.6%) agreed that nutrition has an important role to play in the management of disease and 82.4% agreed that they can offer healthy eating advice to patients. However, only 34.8% of GPs believed that they had been successful in treating overweight patients. Routinely used treatments involve either a dietitian, practice nurse and/or a commercial slimming group and realistic weight loss was considered one criteria of successful treatment by some GPs. Age, year qualified and location of practice were found to have little influence over variations in GP treatment while weak associations between gender of GP and treatment were found.

CONCLUSIONS

The readership of the clinical guidelines in Scotland has been moderate so far although a multidisciplinary approach to obesity treatment is recognised. Further investigations of any relationships between nutrition education-obesity treatment are needed.

Plasmapheresis as an adjunct treatment in toxic epidermal necrolysis

BACKGROUND

Toxic epidermal necrolysis (TEN) is a severe, progressive disease characterized by the sudden onset of skin necrosis. It is frequently associated with systemic involvement and has a high rate of morbidity and mortality. Standard therapy includes meticulous wound care, fluid replacement, and nutritional support in an intensive care setting.

OBJECTIVE

We evaluated the outcomes of patients treated in a burn unit for TEN over a 9-year period and compared the outcomes of a subset of patients treated with plasmapheresis with those managed by conventional means.

METHODS

The records of 16 patients with a diagnosis of TEN obtained from a computerized database were reviewed. Parameters recorded included extent of body surface area involvement and number of mucous membranes involved at admission, complications such as sepsis or need for mechanical ventilation, length of stay, and disposition.

RESULTS

Sixteen patients were included in this study. Ten were treated with conventional support measures alone. Six were treated with plasmapheresis. The average age was 42.4 years; the male/female ratio was 1:2.2. Sulfamethoxazole/trimethoprim was implicated in causation in 6 patients. The average extent of involvement on admission in all patients was 51.5% total body surface area. The average length of stay in all patients was 14.8 days. Eight patients (50%) were discharged home, 4 (25%) were discharged to a rehabilitation facility, and 4 (25%) died (2 of sepsis, 2 of cardiopulmonary arrest). None of the plasmapheresis-treated patients died.

CONCLUSION

Plasmapheresis is a safe intervention in extremely ill TEN patients and may reduce the mortality in this severe disease. Prospective studies are needed to further define its usefulness.

P50 suppression in recent-onset schizophrenia: clinical correlates and risperidone effects

Chronic schizophrenic patients often do not suppress the auditory P50 component of the event-related potential to the second of 2 clicks, presented 500 ms apart, suggesting a loss of normal inhibition. This study attempted to replicate the P50 suppression deficit in patients with recent-onset schizophrenia and to examine whether P50 is related to clinical symptoms or is affected by an atypical antipsychotic medication. Data from 22 recent-onset schizophrenia patients and 11 normal controls revealed that disruption in P50 suppression is present during the early stages of illness. In addition, impaired P50 suppression covaried with clinical ratings of anxiety, depression, and anergia; results also suggested that the P50 inhibitory deficit may be related to the degree of patients' attentional impairment. Finally, risperidone, compared with a typical antipsychotic medication, improved inhibition of P50 to the second click. These results support P50 suppression as a measure of disordered neurocognition in schizophrenia.

P50 suppression in recent-onset schizophrenia: clinical correlates and risperidone effects

Chronic schizophrenic patients often do not suppress the auditory P50 component of the event-related potential to the second of 2 clicks, presented 500 ms apart, suggesting a loss of normal inhibition. This study attempted to replicate the P50 suppression deficit in patients with recent-onset schizophrenia and to examine whether P50 is related to clinical symptoms or is affected by an atypical antipsychotic medication. Data from 22 recent-onset schizophrenia patients and 11 normal controls revealed that disruption in P50 suppression is present during the early stages of illness. In addition, impaired P50 suppression covaried with clinical ratings of anxiety, depression, and anergia; results also suggested that the P50 inhibitory deficit may be related to the degree of patients' attentional impairment. Finally, risperidone, compared with a typical antipsychotic medication, improved inhibition of P50 to the second click. These results support P50 suppression as a measure of disordered neurocognition in schizophrenia.

Inhaled nitric oxide versus conventional therapy: effect on oxygenation in ARDS

A randomized, controlled clinical trial was performed with patients with acute respiratory distress syndrome (ARDS) to compare the effect of conventional therapy or inhaled nitric oxide (iNO) on oxygenation. Patients were randomized to either conventional therapy or conventional therapy plus iNO for 72 h. We tested the following hypotheses: (1) that iNO would improve oxygenation during the 72 h after randomization, as compared with conventional therapy; and (2) that iNO would increase the likelihood that patients would improve to the extent that the FI(O2) could be decreased by > or = 0.15 within 72 h after randomization. There were two major findings. First, That iNO as compared with conventional therapy increased Pa(O2)/FI(O2) at 1 h, 12 h, and possibly 24 h. Beyond 24 h, the two groups had an equivalent improvement in Pa(O2)/FI(O2). Second, that patients treated with iNO therapy were no more likely to improve so that they could be managed with a persistent decrease in FI(O2) > or = 0.15 during the 72 h following randomization (11 of 20 patients with iNO versus 9 of 20 patients with conventional therapy, p = 0.55). In patients with severe ARDS, our results indicate that iNO does not lead to a sustained improvement in oxygenation as compared with conventional therapy.

Early prediction of prolonged ventilator dependence in thermally injured patients

BACKGROUND

Recent studies suggest that when prolonged ventilator dependence (PVD) can be predicted in trauma or intensive care unit patients, early tracheostomy may reduce hospital stay and improve utilization of resources. This study was performed to develop criteria predictive of PVD (> 14 days) in burn patients.

METHODS

We reviewed burn patients aged > or =16 years admitted between 1990 and 1994 who required ventilator support for > or =3 days. Using the variables full-thickness burn size, age, inhalation injury, and worst PaO2/FiO2 on ventilator day 3, an equation predicting PVD was created using logistic regression. The equation was tested by applying it to 1995 patients.

RESULTS

When a probability of >0.5 was considered predictive of PVD, the equation correctly predicted PVD in 82% of 1990 to 1994 patients (n = 110) and 90% of 1995 patients (n = 29).

CONCLUSION

PVD in burn patients can be predicted using objective variables in the early postburn period. Predictions can be used to select patients for prospective studies of early tracheostomy.

The 1997 Lindberg Award. Effects of burn injury on bone and growth in a mouse model

Bone growth and remodeling are inhibited by severe burns in adult and pediatric patients, resulting in alterations in linear growth, bone mass, osteoporosis, and increased risk for pathologic fractures. This study of a mouse model of burn injury showed skeletal changes similar to those reported in patients with burn injuries. Baseline, control, sham, and burned mice were injected with fluorescent markers calcein and tetracycline for histomorphometric analysis. Total femur dry and ash weights and total calcium content were significantly lower 10 days after burn injury compared with sham and control animals. There also were decreases in the percentage of fluorochrome-labeled bone surfaces and bone formation rates in the burn-injured mice compared with control and sham mice; however, there were no differences in the mineral apposition rates. This model now provides an opportunity to examine cellular and molecular mechanisms contributing to skeletal pathology in a well-defined burn injury model.

Randomized trial of immune-enhancing enteral nutrition in burn patients

BACKGROUND

"Immune-enhancing" diets (IEDs) are aimed at improving outcomes in patients suffering trauma and infection. This study was conducted to evaluate a popular IED in patients suffering burn injury.

METHODS

Fifty burned patients were randomized to receive either Impact (Sandoz Nutrition, Minneapolis, Minn), an IED enhanced with omega-3 fatty acids, arginine, and RNA, or Replete (Clintec, Deerfield, Ill), our standard high-protein diet. Feedings were begun within 48 hours of injury, and continued until patients supported themselves with oral intake.

RESULTS

Forty-nine patients completed the study. The two feeding groups did not differ with respect to age, burn size, incidence of inhalation injury, or the quantity of calories and protein received. There were no differences between groups in mortality, length of hospitalization, hospital charges, days of ventilator support, or incidence of complications. Patients with inhalation injuries required more ventilatory support, and had longer lengths of hospitalization and higher costs.

CONCLUSIONS

Administration of an IED has no clear advantages over the use of less expensive high-protein enteral nutrition in burn patients.

Resuscitation of thermally injured patients with oxygen transport criteria as goals of therapy

Resuscitation from shock based on oxygen transport criteria has been widely used in trauma and surgical patients, but has not been examined in thermally injured patients. To study the possible efficacy of this type of resuscitation, the oxygen transport characteristics of burn resuscitation were studied in nine adults, of whom six had inhalation injuries, with a mean burn size of 45% total body surface area and a mean age of 33.4 years, who were resuscitated based on oxygen transport criteria. Pulmonary artery balloon flotation catheters were placed and hemodynamic and oxygen transport parameters (Fick method) were measured hourly for 6 hours. Patients received fluid boluses in addition to resuscitation calculated by the Parkland formula, until the pulmonary artery wedge pressure reached 15 mm Hg, after which dobutamine infusions (5 micrograms/kg/min) were initiated. Cardiac index increased from 2.51 to 6.57 L/min/m2 (p < 0.05), whereas systemic vascular resistance fell from 1534 to 584 dyne sec/cm5 (p < 0.05). Oxygen delivery (DO2I) and oxygen consumption (VO2I) indexes increased significantly during the study period (573 +/- 47 to 1028 +/- 57, and 132 +/- 8 to 172 +/- 16 ml/min/m2, respectively; p < 0.05). VO2I appeared dependent on DO2I at levels of DO2I less than 800 ml/min/m2. In this study, depressed cardiovascular function in patients with burn injuries responded to volume loading and inotropic support much as it does in patients with shock of other etiologies. Whether oxygen transport-based resuscitation is effective in improving survival or the incidence of multiple organ failure is unknown and will need to be evaluated in randomized trials.

Necrotizing group A streptococcal infections associated with streptococcal toxic shock syndrome

BACKGROUND

Group A streptococci (GAS) cause a variety of life-threatening infectious complications, including necrotizing fasciitis (NF), purpura fulminans (PF), and streptococcal toxic shock syndrome (strepTSS), in which bacteremia is associated with shock and organ failure.

METHODS

We reviewed our experience in the management of patients with necrotizing GAS infections from 1991 to 1995.

RESULTS

Eight adult patients (6 NF, 2 PF) were identified. Patients presented with fever, leukocytosis, and severe pain, and rapidly developed shock and organ dysfunction. The diagnosis of strepTSS was confirmed in 6 cases. A total of 54 surgical procedures were required, including widespread debridements and amputations. Two patients died (25%).

CONCLUSIONS

Recognition of the need for aggressive diagnosis and surgical treatment of this most rapidly progressive surgical infection is necessary for successful management.

Return to work as a measure of outcome in adults hospitalized for acute burn treatment

Rehabilitation of patients with burn injuries is receiving renewed interest because survival has improved, and health reform has mandated outcomes assessment. To determine factors affecting return to work, a survey was conducted among 234 employed patients treated from 1986 through 1993. The mean burn size was 13.3% total body surface area. Patients returned to work in a mean of 14.3 weeks; a number initially returned to light-duty or part-time jobs as a "bridge" to full-time employment. Length of hospitalization, number of surgeries, total and full-thickness burn size, and subjective assessments by patients of their functional ability correlated with time off work. Patients with health insurance were more likely to resume work than was expected, whereas those covered by Medicaid and those involved in injury-related lawsuits were less likely to return to work. It is hoped that this information can be used to design interventions aimed at improving this outcome of burn treatment.

Second-order analysis of space-time clustering

We consider the problem of detecting and describing space-time interaction in point process data. We extend existing second-order methods for purely spatial point process data to the spatial-temporal setting. This extension allows us to estimate space-time interaction as a function of spatial and temporal separation, and provides a useful reinterpretation of a popular test, due to Knox, for space-time interaction. Applications to simulated and real data indicate the method's potential.

Etiology and consequences of respiratory failure in thermally injured patients

Inhalation injury predisposes burn patients to pneumonia, respiratory failure, and death, but the incidence and consequences of respiratory failure in the absence of inhalation injury are not well known. In a review of 529 burn patients admitted over a 4-year period, patients with inhalation injury had a 73% incidence of respiratory failure (hypoxemia, multiple pulmonary infections, or prolonged ventilator support) and a 20% incidence of adult respiratory distress syndrome (ARDS). In patients without inhalation injury, respiratory failure developed in 5% of patients and ARDS in 2% (both p < 0.001). Patients with respiratory failure display a high incidence of multiple organ failure and mortality (27% to 50%), regardless of the presence of inhalation injury. All patients who died had multiple organ failure. This review demonstrates that respiratory failure, regardless of its cause, frequently leads to multiple organ failure and death. Inhalation injury, in the absence of respiratory failure, does not appear to contribute to mortality.

When and how to seek professional advice from the UKCC

You are a staff nurse beginning a new position on a busy medical ward with a high dependency unit attached and are about to start your first set of night shifts. You are aware that it is common practice for nursing staff on the ward to call a junior doctor and to receive verbal messages to administer certain drugs. You feel unsure and unhappy about this procedure. What should you do?

Aminoglycoside dosing in burn patients using first-dose pharmacokinetics

Burn patients have altered aminoglycoside pharmacokinetics, which often result in subtherapeutic serum concentrations when these drugs are administered by conventional dosing (CD) methods. First-dose (FD) pharmacokinetic calculations can be used in these patients to determine an appropriate dosing regimen. We reviewed our experience with FD methods (12 patients) and CD methods (14 patients). Therapeutic levels were achieved more promptly in the FD group than in the CD group (44.4 +/- 8.1 vs. 97.1 +/- 12.5 hours; p < 0.005). Therapeutic serum concentrations were achieved with the first set of steady-state levels in 11% of CD patients and in 67% of FD patients (p < 0.005). The FD group required significantly fewer dosing changes (2.1 +/- 0.3) than did the CD group (3.7 +/- 0.7, p < 0.005). These data demonstrate that aminoglycoside dosing using first-dose pharmacokinetics results in improved maintenance of therapeutic serum concentrations compared with conventional methods in burn patients.

Systemic fluoride toxicity in a child with hydrofluoric acid burns: case report

We report the case of a 14-month-old child with hydrofluoric acid burns who suffered cardiac arrest in association with profound hypocalcemia and hyperfluoridemia. Successful treatment included topical, subeschar, and intravenous calcium gluconate administration.

Bacterial translocation is prolonged in burned mice infected with cytomegalovirus

Cytomegalovirus is seen frequently in patients with burns and may enhance morbidity and mortality rates. Burned BALB/c mice that were given murine cytomegalovirus by intraperitoneal injection demonstrate increased bacterial translocation, as evidenced by positive mesenteric lymph node culture at 5 days after burn injury. The present experiment was conducted to investigate the time course and mechanism of this effect. A significant delay in the resolution of positive mesenteric lymph node cultures was observed with thermal injury alone. This was further reduced by the addition of murine cytomegalovirus infection to thermal injury. No such delay was seen with murine cytomegalovirus infection alone or in controls.

Tracheal venous blood and lymph collection: a model to study airway injury in sheep

Airway injury is a frequent result of the inhalation or aspiration of toxic material. Although upper airway damage can be identified endoscopically, pathophysiological changes are difficult to evaluate. This paper describes an animal model in which changes in tracheal blood and lymph flow rates, wet-to-dry weight ratios, and lymph-to-plasma protein ratios can be evaluated after injury. In this model, 12 cm of the cervical trachea were isolated using a double-cuffed endotracheal tube and injured with cotton smoke at near room temperature. Injury to the trachea was evaluated in twenty-five anesthetized sheep 4 (n = 3), 8 (n = 3), 24 (n = 3), 48 (n = 3), 96 (n = 3), and 192 (n = 2) h after smoke exposure and compared with sham control animals (n = 8). A significant increase in tracheal venous blood flow from 1.3 +/- 0.4 (SD) ml.min-1.cm-1 for the noninjured trachea to 2.8 +/- 1.2 was noted 24 h after injury (P less than 0.01). Lymph flow significantly increased from 1.3 +/- 0.4 microliters.min-1.cm-1 for the noninjured trachea to 9.8 +/- 3.3 24 h after injury while wet-to-dry weight ratios were elevated from 3.0 +/- 0.2 for noninjured trachea to 4.6 +/- 0.9 from 4 to 24 h after injury (P less than 0.01) and decreased to 3.7 +/- 0.5 by 96 h. Cast material consisting of airway exudate, cellular debris, and intact ciliated epithelial cells was both expectorated and found in the trachea when the animals were killed.(ABSTRACT TRUNCATED AT 250 WORDS)

Endotoxin (LPS) increases mesenteric vascular resistance (MVR) and bacterial translocation (BT)

Endotoxemia is responsible for many of the pathophysiologic alterations that occur with Gram-negative sepsis. We utilized a chronic ovine model to determine the hemodynamic disturbances in the gastrointestinal tract during endotoxemia. Sheep with indwelling arterial, venous, and pulmonary arterial catheters were used. An ultrasonic flow probe was placed on the cephalic mesenteric artery. The animals were subjected to: 1) Ringer's lactate infusion (sham n = 6); or 2) 1.5 mcg/kg E. coli endotoxin (n = 6) over over a period of one half hour and were monitored for 48 hours. They were then sacrificed and specimens of mesenteric lymph node, liver, spleen, kidney, and lung obtained for bacteriologic cultures and histologic analysis. Sheep receiving endotoxin showed more than 50% reduction in the mesenteric blood flow. Mesenteric vascular resistance increased while non-mesenteric systemic vascular resistance decreased. The increase in the total systemic vascular resistance, noted during endotoxemia, was thus likely due to the increase in the mesenteric vascular resistance. At autopsy there were positive cultures for microorganism in the mesenteric lymph nodes in six out of six sheep with endotoxemia as compared to one out of six of control. Thus the vasoconstriction in the mesenteric areas may have resulted in bacterial translocation from the GI tract.

Cytomegalovirus infection promotes bacterial translocation in thermally injured mice

Thermally injured mice that were given intraperitoneal injections of murine cytomegalovirus (MCMV) appeared to be clinically septic and to have increased mortality rates. To evaluate the possible role of MCMV infection in promoting bacterial translocation in burned mice, mesenteric lymph nodes were cultured from two strains of mice (BALB/c and CBA) that were given thermal injuries alone, MCMV alone, or both. BALB/c mice injected with 5 X 10(5) plaque-forming units MCMV following a 15% to 16% total body surface area scald injury had increased incidence of positive mesenteric lymph node cultures compared with other groups. No intestinal mucosal histologies, mucosal dry weights, or wet-to-dry weight ratios in any animals were abnormal. Differences in cecal bacterial concentrations were not observed. Murine cytomegalovirus infection appears to enhance bacterial translocation in this model.

A comparison of effects of thermal injury and smoke inhalation on bacterial translocation

Thermal injury as well as smoke inhalation injury results in serious morbidity and high mortality. In a chronic ovine model, we studied the development of bacterial translocation to the mesenteric lymph node, liver, spleen, kidney, and lung following: 1) sham injury (N = 6), 2) cutaneous thermal injury (N = 5), 3) cotton smoke inhalation injury (N = 4), 4) combined thermal injury and smoke inhalation injury (N = 7). Cardiac output, mean arterial pressure, and plasma protein concentration were maintained within 10% of preinjury values. Urine output was maintained above 1 ml/kg/hour with fluid and plasma resuscitation. A wide-beam ultrasonic flow probe was chronically implanted to allow serial measurement of cephalic mesenteric arterial blood flow throughout the 48-hour experimental period. Sheep were sacrificed 48 hours following injury for quantitative organ culture of mesenteric lymph node, liver, spleen, kidney, and lung. Measurements of mesenteric blood flow demonstrated a decrease to 48 +/- 8%, 80 +/- 5%, and 64 +/- 9% of preinjury levels in sheep receiving thermal injury, smoke inhalation injury, and combination injury, respectively. The sham animals maintained mesenteric blood flow at 102 +/- 7% of control levels. Thermal injury, as well as combination thermal and smoke inhalation injury, resulted in higher levels of translocation than smoke inhalation injury alone.

Selective permeability changes in the lungs and airways of sheep after toxic smoke inhalation

The effect of toxic smoke inhalation on selective microvascular sieving of macro-molecules and lymph protein flux was assessed in adult sheep to determine whether the time course of microvascular dysfunction differs between the lung and trachea. Protein flux across the lung increased sixfold 48 h after inhalation of the products of incomplete cotton combustion, whereas tracheal protein flux increased fivefold 8 h after exposure and returned to near base line 48 h after exposure. The lung and trachea selectively retained some sieving to three different protein macromolecules with molecular radii of 36, 54, and 123 A. In the lungs the sieving selectivity for these macromolecules was least 48 h after injury, and in the trachea molecular selectivity was least 8 h after injury. These data suggest that the time course of microvascular injury differs for the trachea and the lung; microvascular changes are detected earlier in the trachea than in the lung. The inhalation injury described thus permits the characterization of the time course of airway and lung microvascular changes.

Development of oral-motor skills in the neurologically impaired child receiving non-oral feedings

Treatment of children with swallowing dysfunction requires a holistic approach based on a global view of their problems and needs. The connection of the swallowing mechanism with the sensorimotor organization of postural tone and movement throughout the body is a critical factor in the evaluation and treatment of children whose dysphagia is rooted in a neurologic disorder. An appropriate program includes work with the development of movement skills, sensory processing, learning, social skills, and communication. The initial focus is placed on oral-motor treatment, rather than direct work on oral feeding. The primary goal of the program is to develop the appropriate use of the mouth, respiratory, and phonatory systems in exploration, sound play, and as much oral feeding as possible. Oral feeding is the by-product of a total program, not its major goal.

Morphological studies on the venous drainage of the trachea in the neck of sheep

Systemic venous drainage of the cervical portion of the trachea from the cricoid cartilage to the sternal notch was observed in 50 adult sheep. In all animals, the first five to six tracheal rings starting at the cricoid cartilage were drained by the thyroid veins (v. thyroideae) bilaterally to the external jugular veins (v. jugularis externa). A venous complex draining the remaining cervical portion of the trachea was observed only on the left side of the trachea. This complex drained to the cranial vena cava (vena cava cranialis). India ink or Evans blue dye were infused into small vessels draining this area for verification. Variations in this venous complex were classified into three types based upon length of trachea drained. Type I was found in 26%, type II found in 58%, and type III found in 16% of the sheep studied and drained 23 +/- 5%, 58 +/- 11% and 78 +/- 10% of the cervical portion of the trachea, respectively. Blood flow from this area of the trachea was 85 +/- 28 mL/min/100 g wet issue. This study identified and classified the venous drainage of the cervical portion of the trachea in sheep.

The role of complement and IgG on zymosan opsonization

Zymosan particles require opsonization for optimal interaction with granulocytes and activation of their respiratory burst. In the present study we evaluated the serum factors necessary for zymosan opsonization. First, zymosan was treated with either normal serum or hypogammaglobulinemic serum (HGS), which is deficient in immunoglobulins (Ig) but has a normal concentration of complement components. Using granulocyte chemiluminescence to assay opsonization, the activity of particles treated with HGS was 66 +/- 1.9% (mean +/- SEM) of that with normal serum (p less than 0.001), suggesting a role of Ig. HGS opsonic activity was restored to normal when the particles were also treated with IgG; however, neither heat-inactivated normal serum (56 degrees C, 30 min) nor pure human IgG alone had opsonic activity. The roles of the classical (CCP) and alternative (ACP) pathways of the complement system were also investigated. ACP activity seemed essential, since inactivation of the ACP (50 degrees C, 30 min) eliminated the activity of normal serum. However, when the ACP was intact, CCP action appeared to participate in opsonization, since selective CCP inactivation with EGTA and MgCl2 reduced the opsonic activity of normal serum by 26 +/- 3.3% (p less than 0.005). Thus, it is concluded that the ACP, CCP, and IgG all participate in zymosan opsonization.

Comparison of plasma hormone changes using a "conventional" and a "paper" pill formulation of a low-dose oral contraceptive

Two formulations of a low-dose oral contraceptive (Microgynon: 150 microgram of levonorgestrel [NG] +30 micrograms of ethynylestradiol [EE2]) were studied. The first was the "conventional" pill; the second was a "paper" pill prepared by evaporation of aliquots of a solution of the component steroids onto squares of edible cellulose separated by perforations, similar to a sheet of postage stamps. The effects of the two formulations on plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17beta-estradiol (E2), and progesterone were compared. Samples of blood were obtained from five women during a treatment period on the "conventional" pill and from five on the "paper" pill. When possible, blood samples were also obtained from a "control" cycle of each of these female subjects. Plasma LH, FSH, E2, and progesterone levels were determined by specific radioimmunoassay methods during control and treatment periods and NG and EE2 levels during treatment periods. Eight-hour plasma profiles for NG and EE2 at the beginning and in the later stage of the treatment periods were obtained and these samples were also analyzed for LH, FSH, E2, and progesterone. Results showed that with one exceptcrogynon were equally effective in suppressing ovulation. As in a previous study, FSH levels appeared to be one of the most sensitive indices of suppression.

Studies on low-dose oral contraceptives: cervical mucus and plasma hormone changes in relation to circulating D-norgestrel and 17alpha ethynyl-estradiol concentrations

A study was undertaken to determine the effects of a low-dose oral contraceptive comprising 150 mug of D-norgestrel and 30 mug of 17alpha-ethynyl estradiol (Microgynon) on the plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17BETA-ESTRADIOL, AND PROGESTERONE AND ON THE PHYSICAl properties of cervical mucus. Samples of blood and cervical mucus were obtained from three women during a treated cycle and the immediately-following "withdrawal" cycle. Specific radioimmunoassay methods were used to determine LH, FSH, 17beta-estradiol, and progesterone levels in treated and withdrawal cycles, and D-norgestrel and 17alpha-ethynyl estradiol in samples obtained during treated cycles. The concentration of synthetic steroids was also measured in blood samples obtained before and 1 hour after ingestion of the contraceptive to determine the maximal daily variation. The results indicated that the contraceptive action of this combined low-dose oral contraceptive is mediated through suppression of ovulation and by rendering the cervical mucus impenetrable to sperm. Plasma FSH levels appeared to be one of the most sensitive indices of suppression. Determination of D-norgestrel and 17alpha-ethynyl estradiol showed that 3 to 4 days were required to reach maximal plasma levels and that daily fluctuations were considerable. Withdrawal of the pill resulted in an immediate return to ovulatory cycles in all three subjects studied.