High risk and low prevalence diseases: Blast injuries

INTRODUCTION

Blast injury is a unique condition that carries a high rate of morbidity and mortality, often with mixed penetrating and blunt injuries.

OBJECTIVE

This review highlights the pearls and pitfalls of blast injuries, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Explosions may impact multiple organ systems through several mechanisms. Patients with suspected blast injury and multisystem trauma require a systematic evaluation and resuscitation, as well as investigation for injuries specific to blast injuries. Blast injuries most commonly affect air-filled organs but can also result in severe cardiac and brain injury. Understanding blast injury patterns and presentations is essential to avoid misdiagnosis and balance treatment of competing interests of patients with polytrauma. Management of blast victims can also be further complicated by burns, crush injury, resource limitation, and wound infection. Given the significant morbidity and mortality associated with blast injury, identification of various injury patterns and appropriate management are essential.

CONCLUSIONS

An understanding of blast injuries can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Acute Water Intoxication With Resultant Hypo-Osmolar Hyponatremia Complicated by Hypotension Secondary to Diffuse Third-Spacing

Hypotonic hyponatremia secondary to acute water intoxication is most commonly associated with primary polydipsia in the setting of psychiatric illness. However, in certain circumstances, otherwise healthy individuals can be compelled to consume large enough volumes of water to overwhelm the kidney’s dilutional capacity of urine and cause a potentially life-threatening rapid decline in serum sodium. We present such a case of a 20-year-old basic military trainee with acute symptomatic hypotonic hyponatremia after drinking five to six liters of water prior to urine drug testing. The clinical manifestations of this disorder are non-specific and can be seen with many different pathologic processes, presenting a diagnostic challenge to the emergency clinician. This challenge can be further complicated by unclear or unobtainable history depending on clinical presentation. The authors will discuss key diagnostic and treatment elements of this potentially life-threatening disease to encourage clinicians to utilize social history when evaluating cases of acute water intoxication and resultant symptomatic hypotonic hyponatremia. 

Evaluation of levonorgestrel intrauterine system upon presumed nonintact removal

A 51 year old woman presented for removal of her expired levonorgestrel intrauterine device (IUD). The IUD arms appeared absent upon IUD removal. Further examination of the device revealed that the arms were concealed inside the hormonal cylinder. Recognizing abnormal presentations of the levonorgestrel IUD upon removal can avoid unnecessary procedures.

Agricultural contamination of groundwater as a possible risk factor for growth restriction or prematurity

Agricultural activity on Prince Edward Island poses a potential hazard to groundwater, which is the sole source of drinking water on the island. This study investigates the potential impact of groundwater nitrate exposure on prematurity and intrauterine growth restriction on Prince Edward Island. A total of 210 intrauterine growth restriction cases, 336 premature births, and 4098 controls were abstracted from a database of all Island births. An ecological measure of groundwater nitrate level was used to gauge potential exposure to agriculturally contaminated drinking water. The higher nitrate exposure categories were positively associated with intrauterine growth restriction and prematurity, and significant dose-response trends were seen, even after adjustment for several important covariates. Nevertheless, these risks must be interpreted cautiously because of the ecological nature of this exposure metric. An investigation using nitrate levels for individual study subjects is needed to confirm this association.

[Renoscintigraphy applied with etylenedicysteine labeled with technetium 99m and SPECT technique as a method of examining kidneys in children with vesicoureteric reflux]

Vesicoureteric reflux (VUR) can lead to renal parenchymal damage. Renal scarring is an important cause of chronic renal failure and hypertension in children. The significance of possible effects determines the necessity of early diagnosis of urinary tract pathology. The aim of the paper was to evaluate the morphology and function of kidneys with VUR using selected radioisotope techniques, and to compare the sensitivity of planar technique and single-photon emission computed tomography (SPECT) technique in detection of renal scarring. In 45 children with VUR the following test were performed: ultrasonography, renoscintigraphy with technetium-99m-ethylenedicysteine (EC-Tc-99m) and technetium-99m-dimercaptosuccinic acid (DMSA-Tc-99m) scintigraphy with planar and SPECT mode. Stage of VUR correlates with stage of cortical lesions estimated as a value of effective renal plasma flow (ERPF) in kidney, as well as scarring intensity in static scintigraphy. The use of SPECT increases sensitivity of examination for detection small, single scars. It seems that SPECT should be used more frequently in children in the group of scarring risk. That would allow for earlier diagnosis of renal scarring, enabling efficient treatment. Due to the correlation between ERPF and parameters obtained in DMSA scintigraphy, renoscintigraphy with EC-Tc-99m may be applied to monitor the progress of renal scarring.

High throughput purification of combinatorial libraries

This article summarizes recent advances at MDS Panlabs which provide for the high-throughput preparative HPLC purification of our Optiverse screening library. Topics covered include unique methods for the preparation, purification, characterization, and plating of purified screening compounds. Also discussed are procedures for data tracking as samples proceed through the purification process.

Accumulation of chlorpyrifos on residential surfaces and toys accessible to children

Quantitative examination of major pathways and routes of exposure to pesticides is essential for determining human risk. The current study was conducted in two apartments and examines the accumulation of the pesticide chlorpyrifos in childrens' toys after the time suggested for reentry after application. It has been established for the first time that a semivolatile pesticide will accumulate on and in toys and other sorbant surfaces in a home via a two-phase physical process that continues for at least 2 weeks postapplication. A summation of the above for a 3-6-year-old child yielded an estimated nondietary total dose of 208 microg/kg/day. Potential exposure from the inhalation pathway was negligible, while dermal and nondietary oral doses from playing with toys contributed to 39 and 61% of the total dose, respectively. If children with high frequency mouthing behavior are considered as candidates for acute exposure to chlorpyrifos residues, the estimated acute dose could be as high as 356 microg/kg/day. Routine reapplication of pesticides could lead to continued accumulation in toys and other sorbant surfaces, e.g., pillows, with large sorbant reservoirs, which can become a long-term source of exposure to a child. Estimates of a child's nondietary exposure to chlorpyrifos associated with toys and other sorbant surfaces for a period of 1 week following application appear to be of public health concern, and studies of actual childhood exposure from this pathway are warranted in the home environment. The above information should be used to determine if current procedures for postapplication reentry are sufficient and to evaluate the need for procedures to store frequently used household toys, pillows, and other sorbant objects during insecticidal application.

Accumulation of chlorpyrifos on residential surfaces and toys accessible to children

Quantitative examination of major pathways and routes of exposure to pesticides is essential for determining human risk. The current study was conducted in two apartments and examines the accumulation of the pesticide chlorpyrifos in childrens' toys after the time suggested for reentry after application. It has been established for the first time that a semivolatile pesticide will accumulate on and in toys and other sorbant surfaces in a home via a two-phase physical process that continues for at least 2 weeks postapplication. A summation of the above for a 3-6-year-old child yielded an estimated nondietary total dose of 208 microg/kg/day. Potential exposure from the inhalation pathway was negligible, while dermal and nondietary oral doses from playing with toys contributed to 39 and 61% of the total dose, respectively. If children with high frequency mouthing behavior are considered as candidates for acute exposure to chlorpyrifos residues, the estimated acute dose could be as high as 356 microg/kg/day. Routine reapplication of pesticides could lead to continued accumulation in toys and other sorbant surfaces, e.g., pillows, with large sorbant reservoirs, which can become a long-term source of exposure to a child. Estimates of a child's nondietary exposure to chlorpyrifos associated with toys and other sorbant surfaces for a period of 1 week following application appear to be of public health concern, and studies of actual childhood exposure from this pathway are warranted in the home environment. The above information should be used to determine if current procedures for postapplication reentry are sufficient and to evaluate the need for procedures to store frequently used household toys, pillows, and other sorbant objects during insecticidal application.

Prevalence of and potential risk factors for symptoms associated with insecticide use among animal groomers

Pet groomers make numerous insecticide applications during the flea season, but few studies have examined their health complaints. The Pesticide Control Program of the New Jersey Department of Environmental Protection conducted a health and safety survey of this population. All licensed pet applicators in New Jersey were contacted, as were New Jersey veterinarians listed as pet-animal practitioners by the American Veterinary Medical Association. Approximately 36% of the respondents indicated that during the 1994 flea season, they had experience at least one of the 17 symptoms associated with insecticide application. Central nervous system symptoms (headache, dizziness, or confusion) and skin symptoms (skin rash or numbness/tingling) were reported most frequently. Logistic regression results suggest that applications per season, years as an applicator, certain hygiene variables, certain classes of products, and status of applicator (veterinary vs veterinary) are potentially important risk factors.

Growth factors in mouse mammary cell interactions in vitro

Paracrine interactions may be important in homeostasis of mammary gland. We have previously reported that normal mammary epithelial cells and stromal cells stimulate the growth of mammary tumor cells in 3-dimensional cultures in collagen gels. We now describe the ability of EGF, TGF beta, bFGF, aFGF, and PDGF to directly affect growth of tumor cells in 3-dimensional cultures in collagen gels. In addition, we assessed the ability of neutralizing antibodies against each growth factor to disrupt interactions between normal mammary cells and mammary tumor cells. Only bFGF and PDGF directly stimulated growth of the mouse mammary tumor cells. However, neither anti-bFGF nor anti-PDGF abrogated the stimulation of tumor cells by normal mammary epithelial cells or normal mammary stromal cell.

[CA 19-9 and CA 125 antigens in the sera of patients with cancer of the large intestine in relation to its clinical progress]

By radioimmunoassay the concentration of the CA 19-9 antigen was determined in the serum of 68 patients with large bowel cancer, while the CA 125 antigen was determined in 26 patients with this disease. Both markers were determined with CIS kits. In all, 127 determinations were done. The results were as follows: 1) CA 19-9 concentration increased with disease progression from 21% (in grade I of local-regional progression, A, B, C according to Dukes), through 41% above-normal results in group II (with metastases--Dukes' grade D), to 67% in case of recurrence of the tumor, and to 0% in group IV--with absent recurrence sign after radical surgical intervention. 2) CA 125 is without clinical value in large bowel cancer.

Pretreatment concentrations of breast carcinoma antigen (CA 15.3) and mucin-like carcinoma-associated antigen in patients with carcinoma of the breast

Pretreatment serum concentrations of breast carcinoma antigen (CA 15.3) and mucin-like carcinoma-associated antigen (MCA) were determined in 129 patients with breast carcinoma. Concentrations of both markers were within the normal range in patients with Stage I disease. Concentrations of CA 15.3 were elevated (greater than 40 U/ml) in 3, 11 and 48%, those of MCA (greater than 17 U/ml) in 11, 18 and 52%, and those of one or the other marker in 11, 18 and 58% of the patients with Stage II, III and IV disease, respectively. The elevation of either marker roughly paralleled the size of the tumor being normal in the patients with localized cancer, slightly elevated in a small proportion of the patients with locoregional cancer, and moderately to markedly elevated in half of the patients with distant metastases. Correlation between serum concentrations of CA 15.3 and MCA was highly significant (p less than 0.0001). It is concluded that the markers were equally sensitive and that an elevated serum level was a useful adjunct for staging, implying systemic disease.

[Neoplastic encephalopathy in the light of 2 observed cases]

The authors report two cases of neoplastic encephalopathy. In one patient with oviduct carcinoma it had the form of cerebellopathy. In the other case of renal carcinoma it appeared as encephalopathy with a nearly exclusive involvement of cerebral hemispheres. The reaction of microglia, lymphocytes and diffuse demyelination found in these cases are regarded by the authors as a result of autoimmunization in the course of malignant neoplasm. Attention is called to the importance of axial computer tomography in the intravital diagnosis of this encephalopathy.

[Case of spontaneous intracerebral hematoma with subsequent development of post-hemorrhagic cyst]

The authors describe a case of spontaneous intracerebral haematoma treated conservatively. After three months a large posthaemorrhagic cyst of the brain was found in the sensorimotor area. The authors suppose that in case of surgical treatment the course of the disease and its sequelae would have been much milder. The interest shown by neurologists in the problem of spontaneous intracerebral haematoma seems to be too low and the possibility of surgical treatment is not mentioned in the neurological literature.