Radiation from CT scans in paediatric trauma patients: Indications,effective dose,and impact on surgical decisions

Objectives

The purpose of this study was to determine the effective dose of radiation due to computed tomography (CT) scans in paediatric trauma patients at a level 1 Canadian paediatric trauma centre. We also explored the indications and actions taken as a result of these scans.

Patients and methods

We performed a retrospective review of paediatric trauma patients presenting to our centre from January 1, 2007 to December 31, 2008. All CT scans performed during the initial trauma resuscitation, hospital stay, and 6 months afterwards were included. Effective dose was calculated using the reported dose length product for each scan and conversion factors specific for body region and age of the patient.

Results

157 paediatric trauma patients were identified during the 2-year study period. Mean Injury Severity Score was 22.5 (range 12–75). 133 patients received at least one CT scan. The mean number of scans per patient was 2.6 (range 0–16). Most scans resulted in no further action (56%) or additional imaging (32%). A decision to perform a procedure (2%), surgery (8%), or withdrawal of life support (2%) was less common. The average dose per patient was 13.5 mSv, which is 4.5 times the background radiation compared to the general population. CT head was the most commonly performed type of scan and was most likely to be repeated. CT body, defined as a scan of the chest, abdomen, and/or pelvis, was associated with the highest effective dose.

Conclusions

CT is a significant source of radiation in paediatric trauma patients. Clinicians should carefully consider the indications for each scan, especially when performing non-resuscitation scans. There is a need for evidence-based treatment algorithms to assist clinicians in selecting appropriate imaging for patients with severe multisystem trauma.     

Massive transfusion in paediatric and adolescent trauma patients: Incidence,patient profile,and outcomes prior to a massive transfusion protocol

Objectives

The purpose of this study was to quantify the incidence, patient profile, and outcomes associated with massive transfusion in paediatric trauma patients prior to establishing a massive transfusion protocol.

Methods

We performed a retrospective review of paediatric trauma patients treated at London Heath Sciences Centre between January 1, 2006, and December 31, 2011. Inclusion criteria were Injury Severity Score (ISS) greater than 12 and age less than 18 years.

Results

435 patients met the inclusion criteria. Three hundred and fifty-six (82%) did not receive packed red blood cells in the first 24 h, 66 (15%) received a non-massive transfusion (<40 mL/kg), and 13 (3%) received a massive transfusion (>40 mL/kg). Coagulopathy of any kind was more common in massive transfusion (11/13; 85%) than non-massive (32/66; 49%) (p = 0.037). Hyperkalemia (18% versus 23%; p = 0.98) and hypocalcemia (41% versus 46%; p = 1.00) were similar in both groups. Of the 13 massively transfused patients, 9 had multisystem injuries due to a motor vehicle collision, 3 had non-accidental head injuries requiring surgical evacuation, and 1 had multiple stab wounds. In the absence of a massive transfusion protocol, only 8 of the 13 patients received both fresh frozen plasma and platelets in the first 24 h. Massive transfusion occurred in patients from across the age spectrum and was associated with severe injuries (mean ISS = 33), a higher incidence of severe head injuries (92%), longer hospital stay (mean = 36 days), and increased mortality (38%).

Conclusions

This study is the first to describe the incidence, complications, and outcomes associated with massive transfusion in paediatric trauma patients prior to a massive transfusion protocol. Massive transfusion occurred in 3% of patients and was associated with coagulopathy and poor outcomes. Protocols are needed to ensure that resuscitation occurs in a coordinated fashion and that patients are given appropriate amounts of fresh frozen plasma, platelets, and cryoprecipitate.     

Outcomes in patients requiring repeat extracorporeal membrane oxygenation

Background

As the number of patients requiring extracorporeal membrane oxygenation (ECMO) increases nationwide, many patients may require ECMO more than once. We review our experience and outcomes in patients requiring repeat ECMO support.

Methods

The Nebraska ECMO Research Database was utilized for data analysis, and repeat ECMO patients (REPs) were compared to the overall ECMO population.

Results

Of 246 patients, 2.4% (6/246) were REPs. There was no statistical difference between the median days of initial support run (P = 0.670) and second support run (P = 0.813) for REPs when comparing to the non‐REP population. Median hospital length of stay for REPs was 53 days (16‐124) compared to the non‐REPs, who had a median hospital length of stay of 22 days (1‐270); P = 0.043. In‐hospital mortality rate for REPs was 50% (3/6) and 50% for non‐REPs (120/240). Survival 30 days postdischarge for REPs was 50% (3/6) compared to non‐REPs at 48.3% (116/240); P = NS.

Conclusions

Outcomes for repeat ECMO patients compare favorably to the overall ECMO population and suggest a need to explore and broaden the clinical indications for repeat ECMO.     

Effect of surfactant substitution on lung effluent phospholipids in respiratory distress syndrome: evaluation of surfactant phospholipid turnover, pool size, and the relationship to severity of respiratory failure

The turnover and pool size of surfactant has been studied in animals, but there is little similar information in humans. In the present investigation lung effluent phospholipids were studied in 29 small preterm infants with severe RDS. Thirteen were treated with mechanical ventilation, and 16 additionally received natural human surfactant. The first dose (60 mg surfactant/kg body wt) was given between 2 and 10 h of age, and the surfactant was given again if there was an insufficient response. Together 260 aspirates, recovered during routine suctioning of the airways, were analyzed for phospholipids. Phosphatidylglycerol, present only in exogenous surfactant, was used as a specific marker to estimate the apparent pool size and the half-life of surfactant phospholipid. In addition, the saturated phosphatidylcholine/sphingomyelin ratios were correlated with the ventilatory index (mean airway pressure X fractional inspiratory oxygen/arterial oxygen tension). There was a linear correlation between the ventilatory index and the saturated phosphatidylcholine/sphingomyelin (r approximately -0.70) but no consistent correlation between the ventilatory index and the amount of phospholipids in the aspirate. The saturated phosphatidylcholine/sphingomyelin ratio increased during the surfactant-induced remission of respiratory failure, decreased during the recovery. The control infants tended to have lower saturated phosphatidylcholine/sphingomyelin ratios during the first week than the surfactant-treated infants.(ABSTRACT TRUNCATED AT 250 WORDS)     

Combating infectious diseases through multivalent design

Many biological interactions are multivalent, linking two particles via many copies of the same ligand-receptor binding pair. Examples of multivalent binding range from cell-cell adhesion to the assembly of large protein complexes from constituent multimers to the binding of AB5 bacterial toxins at the cell surface. Multivalent interactions can be effectively mimicked, inhibited, or disrupted through the design of suitable multivalent ligands. We review here recent work on multivalent ligand design based on a number of different chemical scaffolds, with a specific emphasis on the use of structure-based ligand design to target multimeric bacterial toxins.     

Advantages of real-time spatial compound sonography of the musculoskeletal system versus conventional sonography

OBJECTIVE: Spatial compound sonography is a method that obtains sonographic information from several different angles of insonation and combines them to produce a single image. By reducing speckle and improving definition of tissue planes, this method can potentially improve image quality in musculoskeletal sonography. The purpose of our study was to compare real-time spatial compound sonography with conventional high-resolution musculoskeletal sonography. MATERIALS AND METHODS: Thirty-four patients underwent sonography of the musculoskeletal system for a variety of indications. All patients were evaluated using conventional high-resolution sonography and real-time spatial compound sonography performed with a 12-5-MHz multifrequency linear array transducer. Conventional images and compound images depicting the same musculoskeletal structure were obtained in pairs. A total of 118 images (59 image pairs) were randomly assorted and reviewed on a computer monitor by three experienced sonologists working independently. The reviewers were unaware of the type of images they were evaluating. Image quality was rated using a 5-point scale. The image parameters evaluated were definition of tissue planes, speckle, other noise, and image detail. RESULTS: Analysis of variance revealed that real-time spatial compound sonography significantly improved definition of soft-tissue planes, reduced speckle and other noise, and improved image detail when compared with conventional high-resolution sonography (p < 0.0001 for all evaluated parameters). CONCLUSION: Real-time spatial compound sonography significantly improved sonographic image quality in the musculoskeletal system when compared with conventional high-resolution sonography. Because musculoskeletal sonography is highly dependent on image quality and tissue-plane definition, spatial compound sonography represents an important development.     

Impact of a medically supervised safer injecting facility on drug dealing and other drug-related crime

North America's first medically supervised safer injecting facility (SIF) recently opened in Vancouver, Canada. One of the concerns prior to the SIF's opening was that the facility might lead to a migration of drug activity and an increase in drug-related crime. Therefore, we examined crime rates in the neighborhood where the SIF is located in the year before versus the year after the SIF opened. No increases were seen with respect to drug trafficking (124 vs. 116) or assaults/robbery (174 vs. 180), although a decline in vehicle break-ins/vehicle theft was observed (302 vs. 227). The SIF was not associated with increased drug trafficking or crimes commonly linked to drug use.     

Inactive free : total prostate specific antigen ratios in ejaculate from men with suspected and known prostate cancer, compared with young control men

OBJECTIVE: To measure free : total prostate specific antigen (PSA) ratios in ejaculate from men with suspected and known prostate cancer, and in young control men, to determine if this ratio might be useful in discriminating benign from malignant prostatic conditions. Patients, subjects and methods Forty-seven men with prostate cancer (positive biopsies), 52 men with suspected prostate cancer but who had negative biopsies and 28 young men (< 30 years old) and with no family history of cancer, provided either a single ejaculate specimen (total 59) or multiple specimens (total 193) on subsequent occasions. Free and total PSA were measured using appropriate assays. All specimens were diluted in a PSA-negative female serum pool. RESULTS: The median free : total PSA ratios were 0.76-0.81 among the patient groups and control men, and there was no statistical difference between the groups. These data presumably only reflect the inactive component of free PSA, given that any alpha2-macroglobulin or alpha1-antichymotrypsin in the assay serum diluent was likely to have bound the active free PSA component in these samples. Similar results were obtained from those providing single and multiple samples, suggesting that a single specimen is sufficient to reflect the seminal plasma free : total PSA ratio over that period. There was no relationship between seminal plasma free : total PSA ratio and age for the controls or the positive biopsy group, although there was a negative relationship (i.e. a decline with age) that almost reached significance in those with negative biopsies (P = 0.058, R2 = 0.07). CONCLUSIONS: This is the first report of free : total PSA ratios in the ejaculate of men with suspected and known prostate cancer compared with young control men. Although no significant changes were detected in the free : total PSA ratios in ejaculate, these results may be confounded by differences in ratios with age, as is the case for serum PSA or different molecular forms of PSA. Indeed, these data suggest that a large proportion of free PSA in seminal plasma may be inactive. Further studies are needed to determine the potential utility of measuring free : total PSA, or other candidate markers, in ejaculate to better discriminate benign from malignant prostate disease.