Biomedical subjects

John R Richards

Publications and source records attributed to John R Richards.

14 recordsLinked to original sources

PubMed2006

Combined head and abdominal computed tomography for blunt trauma: which patients with minor head trauma benefit most?

The widespread availability of computed tomography (CT) in the diagnosis and management of blunt trauma has created the possibility of overuse without clear indications. Some clinicians believe that patients with head injury, intoxication, and/or distracting injury have an unreliable abdominal examination and should undergo combined head and abdomen CT. The objective of this study was to evaluate which patients with minor head trauma benefit most from combined head and abdomen CT. Consecutive blunt trauma patients, with a Glasgow coma scale (GCS) of 14 or 15, who underwent concomitant head and abdomen CT upon admission to a level I trauma center over a 2-year period were retrospectively reviewed. Patient demographics, mechanism of injury, physical exam, hospital course, and radiological and laboratory findings were recorded. Patients were divided into four subgroups based upon the presence or absence of intracranial and/or intraabdominal injury detected by CT. Among the 1,478 blunt head trauma patients, only 18 (1%) patients had both head and abdominal injuries detected by combined CT. One-hundred twelve (8%) patients had only head injuries, and 131 (9%) had only intraabdominal injuries detected. Patients with a GCS of 14 were more likely to have isolated head injury [odds ratio (OR) 3.1, P=0.001], while those with loss of consciousness were more likely to have combined head and intraabdominal injury (OR 6.8, P=0.03) or isolated head injury (OR 1.7, P=0.02). Abdominal tenderness was associated with increased risk of isolated intraabdominal injury (OR 1.8, P=0.0015). Hematuria was associated with increased risk of combined head and intraabdominal injury (OR 8.3, P=0.0004) or isolated intraabdominal injury (OR 7.9, P=0.0001). Patients with loss of consciousness and/or GCS of 14 frequently undergo head CT. The addition of an abdomen CT scan in this patient population should be based on objective clinical criteria such as presence of abdominal tenderness and/or hematuria.

Abdominal Injuries↗

PubMed2006

Utility of supine oblique radiographs in detecting cervical spine injury.

A retrospective case-control study was performed to determine if the addition of supine oblique radiographs to the routine cervical spine series results in the detection of patients with cervical spine injuries not identified with standard views alone. The cervical spine radiographs of 82 patients with known cervical spine injuries and 180 hospitalized patients without cervical spine injuries were collected. Radiographs of the two patient groups were randomly combined to form the study sample. The radiographs were reviewed independently by a board-certified radiologist and a board-certified emergency physician. During the first phase, each reviewer was provided with standard views of the cervical spine (lateral, anterior-posterior, open-mouth odontoid, and submental views). During the second phase, each reviewer was provided with the standard views and supine obliques. The reviewers were masked to all clinical information and previous radiologic interpretations. The results showed that in the first phase (standard views only), the two physicians had a sensitivity of 81% (95% confidence interval [CI] 74-87%) and a specificity of 93% (95% CI 90-96%). In the second phase (obliques included), the two physicians had a sensitivity of 76% (95% CI 69-83) and specificity of 90% (95% CI 87-93%). In a subset analysis of patients with posterior element (lamina, facet, and pedicle) fractures, the two physicians had a sensitivity of 88% (95% CI 78-95%) with standard radiographs and 86% (95% CI 76-94%) with the addition of oblique radiographs. In conclusion the addition of supine oblique radiographs to the standard trauma cervical spine series did not increase the readers' sensitivity for detecting patients with cervical spine injuries. Routinely including oblique radiographs in patients undergoing radiographic screening of the cervical spine is not warranted.

Case-Control Studies↗

PubMed2006

Appearance of solid organ injury with contrast-enhanced sonography in blunt abdominal trauma: preliminary experience.

OBJECTIVE: The purpose of this study was to compare the detection rate of injury and characterize imaging findings of contrast-enhanced sonography and non-contrast-enhanced sonography in the setting of confirmed solid organ injury. SUBJECTS AND METHODS: This prospective study involved identifying hepatic, splenic, and renal injuries on contrast-enhanced CT. After injury identification, both non-contrast-enhanced sonography and contrast-enhanced sonography were performed to identify the possible injury and to analyze the appearance of the injury. The sonographic appearance of hepatic, splenic, and renal injuries was then analyzed, and the conspicuity of the injuries was graded on a scale from 0 (nonvisualization) to 3 (high visualization). RESULTS: Non-contrast-enhanced sonography revealed 11 (50%) of 22 injuries, whereas contrast-enhanced sonography depicted 20 (91%) of 22 injuries. The average grade for conspicuity of injuries was increased from 0.67 to 2.33 for spleen injuries and from 1.0 to 2.2 for liver injuries comparing non-contrast-enhanced with contrast-enhanced sonography, respectively, on a scale from 0, being nonvisualization, to 3, being high visualization. The splenic injuries appeared hypoechoic with occasional areas of normal enhancing splenic tissue within the laceration with contrast-enhanced sonography. Different patterns were observed in liver injuries including a central hypoechoic region. In some liver injuries there was a surrounding hyperechoic region. CONCLUSION: Contrast-enhanced sonography greatly enhances visualization of liver and spleen injuries compared with non-contrast-enhanced sonography. Solid organ injuries usually appeared hypoechoic on contrast-enhanced sonography, but often a hyperechoic region surrounding the injury also was identified with liver injuries.

Abdominal Injuries↗

PubMed2005

Ultrasound detection of blunt urological trauma: a 6-year study.

The objective of this study was to assess the utility of emergency ultrasonography in the detection of blunt urological injury. A retrospective review was conducted of all consecutive emergency blunt trauma ultrasonograms (US) obtained at a level I trauma centre from January 1995 to January 2001. Among the 4320 emergency ultrasonograms performed, 596 patients (14%) had intraabdominal injury and, of these, 99 patients (17%) had urological injuries. The sensitivity of ultrasound for all urological injuries was 67%, and specificity was 99.8%. For isolated urological injuries, sensitivity and specificity were 55.6 and 99.8%, respectively. Ultrasound was most accurate in the detection of grade III renal injuries, identifying 14/15 (93%), and 13 underwent laparotomy. For isolated urological injuries, 15 of 25 (60%) patients with a true-positive US underwent laparotomy compared to 3 of 20 (15%) with a false-negative US. Isolated urological injury was significantly associated with an ultrasonographic pattern of free fluid in the left upper quadrant and the left pericolic gutter (odds ratio=55.1; P<0.001), followed by isolated fluid in the left pericolic gutter (odds ratio=8.6; P=0.04). Although emergency ultrasonography is useful in the triage of patients with blunt urological trauma, it may miss significant urological injury requiring further intervention. As most renal injuries may be managed non-operatively, further studies such as contrast-enhanced CT or angiography should be obtained in the stable patient with suspected blunt urological injury.

Abdominal Injuries↗

PubMed2005

The fast is positive, now what? Derivation of a clinical decision rule to determine the need for therapeutic laparotomy in adults with blunt torso trauma and a positive trauma ultrasound.

INTRODUCTION: The object of this study was to derive a clinical decision rule for therapeutic laparotomy among adult blunt trauma patients with a positive abdominal ultrasound for trauma (FAST) examination. METHODS: We retrospectively reviewed the trauma registry and medical records of all critical trauma patients who underwent a FAST examination in the emergency department (ED) in a university Level I trauma center over a 3-year period. Blunt trauma patients aged >16 years who had a positive FAST examination (defined as the presence of intraperitoneal fluid) were eligible. We selected seven clinical and ultrasound variables available during ED resuscitation for analysis: age, presence of an episode of hypotension (systolic blood pressure <90 torr in the ED), presence of abdominal tenderness, chest injury, pelvic fracture, femur fracture, and FAST fluid location (right upper quadrant [RUQ] only; RUQ plus other location; other location only). The primary outcome variable was whether a laparotomy was performed and whether this laparotomy was needed to provide the definitive surgical intervention ("therapeutic laparotomy"). We analyzed the variables using binary recursive partitioning analysis to create a decision rule. RESULTS: There were 2336 FAST examinations performed during the study period, resulting in 230 (9.8%) positive examinations in patients meeting inclusion criteria. There were 135 patients who had therapeutic laparotomies and 95 who did not need laparotomy. The groups were similar in baseline characteristics. In the recursive partitioning analysis, the first node in the decision tree was the presence of fluid in the RUQ. Of the 144 patients with RUQ fluid, 105 (73%, 95% confidence interval [CI] 64%-80%) required therapeutic laparotomy. Of the 86 patients without RUQ fluid, 30 (35%, 95% CI 25%-46%) nevertheless required therapeutic laparotomies, and the variables blood pressure, femur fracture, abdominal tenderness, and age further divided these patient into high- and low-risk groups. Of the 12 patients without RUQ fluid who had normal blood pressures, no femur fractures, no abdominal tenderness, and were aged 60 years and younger, none (95% CI 0%-22%) required therapeutic laparotomy. In conclusion, given a positive FAST examination, the presence of fluid in the RUQ is an important predictor of the need for therapeutic laparotomy. CONCLUSION: In the absence of fluid in the RUQ, there are other clinical variables that may allow for the development of a clinical decision rule regarding the need for therapeutic laparotomy.

Abdominal Injuries↗

PubMed2004

Electron tunneling in rhenium-modified Pseudomonas aeruginosa azurins.

Laser flash-quench methods have been used to generate tyrosine and tryptophan radicals in structurally characterized rhenium-modified Pseudomonas aeruginosa azurins. Cu(I) to "Re(II)" electron tunneling in Re(H107) azurin occurs in the microsecond range. This reaction is much faster than that studied previously for Cu(I) to Ru(III) tunneling in Ru(H107) azurin, suggesting that a multistep ("hopping") mechanism might be involved. Although a Y108 radical can be generated by flash-quenching a Re(H107)M(II) (M=Cu, Zn) protein, the evidence suggests that it is not an active intermediate in the enhanced Cu(I) oxidation. Rather, the likely explanation is rapid conversion of Re(II)(H107) to deprotonated Re(I)(H107 radical), followed by electron tunneling from Cu(I) to the hole in the imidazole ligand.

Azurin↗

PubMed2004

Blunt abdominal injury in the pregnant patient: detection with US.

PURPOSE: To determine the accuracy of ultrasonography (US) for the detection of blunt intraabdominal injury in pregnant patients and to compare differences between pregnant and nonpregnant patients of childbearing age. MATERIALS AND METHODS: A retrospective review of results of all consecutive emergency blunt trauma US examinations performed at a level I trauma center from January 1995 to June 2002 was conducted. Data on demographics, free fluid location, and patient outcome were collected. Injuries were determined on the basis of results of computed tomography and/or laparotomy. The Student t test was used to detect differences between continuous variables, and chi(2) analysis was used to evaluate differences between proportions. RESULTS: A total of 2319 US examinations for blunt trauma were performed in girls and women between the ages of 10 and 50 years. There were 328 pregnant patients, 23 of whom had intraabdominal injury. The mean age of the pregnant patients was 24.7 years +/- 6.1 (standard deviation) (age range, 14-42 years). In pregnant patients, the sensitivity of US was 61% (14 of 23 patients), the specificity was 94.4% (288 of 305 patients), and the accuracy was 92.1% (302 of 328 patients). Pregnant patients were significantly more likely to have sustained injuries from assault (odds ratio: 2.6, P < .001). The most common pattern of free fluid accumulation detected at US in pregnant patients was that of fluid in the left and right upper quadrants and pelvis (n = 4, 29%); the second most common pattern was one of isolated pelvic fluid (n = 3, 21%). CONCLUSION: For detection of intraabdominal injury, US was less sensitive in pregnant patients than in nonpregnant patients but was highly specific in both subgroups. The sensitivity of US was highest in pregnant patients during the first trimester.

Abdominal Injuries↗

PubMed2004

Sonographic patterns of intraperitoneal hemorrhage associated with blunt splenic injury.

OBJECTIVE: To determine the correlation between sonographic detection of free fluid in the left upper quadrant and blunt splenic injury. METHODS: A retrospective review was conducted of all consecutive emergency blunt trauma sonograms obtained at a level I trauma center from January 1995 to January 2001. Data were collected on demographics, free fluid location, and patient outcome. Injuries were determined from computed tomography, diagnostic peritoneal lavage, laparotomy, or a combination thereof. RESULTS: A total of 4320 blunt trauma sonograms were obtained, and 596 patients (14%) had intra-abdominal injuries. The mean age was 33.7 +/- 19.1 years (range, 1-95 years), with 294 (49%) male and 302 (51%) female. There was no statistical difference between age, sex, or mechanism for all subgroups. There were 409 true-positive, 187 false-negative, 88 false-positive, and 3636 true-negative findings. Sensitivity of sonography for detecting all intra-abdominal injuries was 68%, and specificity was 97.6%; sensitivity for detecting isolated splenic injuries was 73.8%. Locations of free fluid in patients with nonsplenic injuries were compared with those in patients with splenic injuries. Isolated left upper quadrant free fluid was significantly associated with splenic injury (odds ratio = 3.0; P = .002), followed by diffuse free fluid (odds ratio = 2.1; P = .005). A subanalysis of isolated splenic injuries also revealed a significant association with left upper quadrant free fluid (odds ratio = 3.1; P = .007) and diffuse free fluid (odds ratio = 2.7; P = .0007). CONCLUSIONS: Free fluid in the left upper quadrant is significantly associated with splenic injury. This finding should triage patients more rapidly to computed tomography, angiography, embolization, and laparotomy.

Abdominal Injuries↗

PubMed2003

Frequency of acute coronary syndrome in patients presenting to the emergency department with chest pain after methamphetamine use.

We reviewed the frequency of acute coronary syndrome (ACS) in patients presenting to our emergency department (ED) with chest pain after methamphetamine (MAP) use during a 2-year interval. Thirty-three patients (25 males, 8 females; average age 40.4 +/- 8.0 years) with a total of 36 visits met study inclusion criteria: 1) non-traumatic chest pain, 2) positive MAP urine toxicology screen, 3) admission to "rule-out" myocardial infarction, 4) chest radiograph demonstrating no infiltrates. An ACS was diagnosed in 9 patients (25%). Three patients (8%) (2 ACS and 1 non-ACS) suffered cardiac complications (ventricular fibrillation, ventricular tachycardia, supraventricular tachycardia, respectively). Age, gender, cardiac risk factors, prior coronary artery disease, initial systolic blood pressure and heart rate did not differ significantly in the ACS and non-ACS groups. The initial and subsequent electrocardiograms (EKG) were normal in 1/9 (11%) patients with ACS and 16/27 (59%) without ACS (p < 0.05). Our findings suggest that: 1) ACS is common in patients hospitalized for chest pain after MAP use, and 2) the frequency of other potentially life-threatening cardiac complications is not negligible. A normal EKG lowers the likelihood of ACS, but an abnormal EKG is not helpful in distinguishing patients with or without ACS.

Academic Medical Centers↗

PubMed2003

Droperidol in the emergency department: is it safe?

Droperidol is an antipsychotic and antiemetic drug that has been used extensively by emergency physicians, psychiatrists, and anesthesiologists worldwide since 1967. It also has been used effectively for other diverse conditions, such as treatment of headache and vertigo. As of January 2001, Droperidol was no longer available in Europe after its founder, Janssen-Cilag Pharmaceuticals, discontinued its distribution. In December 2001, the United States Food and Drug Administration (FDA) placed a black box warning on the use of Droperidol in response to an association between Droperidol and fatal cardiac dysrhythmias, such as torsade de pointes, resulting from prolongation of the QT interval. In this review we closely examine the pharmacology, indications, use, and complications associated with Droperidol, and speculate on its future use in the Emergency Department.

Antiemetics↗

PubMed2003

Cricoid ring integrity: implications for cricothyrotomy.

STUDY OBJECTIVES: The rapid 4-step technique for cricothyrotomy was originally described as making use of a single traction hook on the cricoid ring. However, it is possible that such hook placement could lead to damage of the cricoid ring. As an alternative, a double-hook device was developed to augment the rapid 4-step technique by dispersing forces applied to the cricoid ring. The objectives of this study were to compare the requisite forces for intubation and the structural tolerances of the cricoid ring between the single- and double-hook techniques. METHODS: We randomized 56 human cadaver specimens to undergo either cricothyrotomy with intubation followed by cricoid ring breakage or cricoid ring breakage alone. We randomized those cadaver specimens undergoing cricothyrotomy with intubation with respect to the initial hook technique used and then crossed over to the alternate technique for repeat intubation and subsequent cricoid ring breakage. We performed all cricothyrotomies in a similar manner with a consistent technique. We measured the intubation and breakage forces for the single- and double-hook techniques and calculated 95% confidence intervals (CIs). RESULTS: The mean force to intubate with the single-hook technique was 18 N (95% CI 14 to 22 N), and the mean force to intubate with the double-hook technique was 23 N (95% CI 17 to 29 N). There was a significant difference between the mean forces required to break the cricoid ring with the single-hook technique (54 N; 95% CI 47 to 62 N) versus with the double-hook technique (101 N; 95% CI 89 to 113 N; difference in means 47 [95% CI 34 to 60 N]). CONCLUSION: When applying the rapid 4-step technique for cricothyrotomy, the force required to intubate with either the single- or double-hook technique is small. The cricoid ring, however, tolerates significantly more force without breakage when the double-hook technique is used.

Airway Obstruction↗

PubMed2002

Sonographic assessment of blunt abdominal trauma: a 4-year prospective study.

PURPOSE: Emergency abdominal sonography has become a common modality worldwide in the evaluation of injuries caused by blunt trauma. The sensitivity of sonography in the detection of hemoperitoneum varies, and little is known about the accuracy of sonography in the detection of injuries to specific organs. The purpose of this study was to determine the overall accuracy of sonography in the detection of hemoperitoneum and solid-organ injury caused by blunt trauma. METHODS: From January 1995 to October 1998, 3,264 patients underwent emergency sonography at our institution to evaluate for free fluid and parenchymal abnormalities of specific organs caused by blunt trauma. All patients with intra-abdominal injuries (IAIs) were identified, and their sonographic findings were compared with their CT and operative findings, as well as their clinical outcomes. RESULTS: Three hundred ninety-six (12%) of the 3,264 patients had IAIs. Sonography detected free fluid presumed to represent hemoperitoneum in 288 patients (9%). The sonographic detection of free fluid alone had a 60% sensitivity, 98% specificity, 82% positive predictive value, and 95% negative predictive value for diagnosing IAI. The accuracy was 94%. Seventy patients (2%) had parenchymal abnormalities identified with sonography that corresponded to actual organ injuries. The sensitivity of the sonographic detection of free fluid and/or parenchymal abnormalities in diagnosing IAI was 67%. CONCLUSIONS: Emergency sonography to evaluate patients for injury caused by blunt trauma is highly accurate and specific. The sonographic detection of free fluid is only moderately sensitive for diagnosing IAI, but the combination of free fluid and/or a parenchymal abnormality is more sensitive.

Abdominal Injuries↗

PubMed2002

Blunt abdominal trauma in children: evaluation with emergency US.

PURPOSE: To assess the accuracy of emergency abdominal ultrasonography (US) in the detection of both hemoperitoneum and parenchymal organ injury in children. MATERIALS AND METHODS: Imaging findings were recorded prospectively in 744 consecutive children who underwent emergency US from January 1995 to October 1998; free fluid and parenchymal abnormalities of specific organs were also noted. Patients with intraabdominal injuries were identified retrospectively. Computed tomographic (CT) findings, intraoperative findings, and clinical outcome were compared with the initial US findings. Sensitivity, specificity, and positive and negative predictive values were calculated for patients who underwent CT, laparotomy, or both after US. RESULTS: Seventy-five (10%) of 744 patients had intraabdominal injuries, and US depicted free fluid in 42 of them. US had 56% sensitivity, 97% specificity, 82% positive predictive value, and 91% negative predictive value for detection of hemoperitoneum alone. US helped identify parenchymal abnormalities that corresponded to actual organ injury without accompanying free fluid in nine patients (12%). Inclusion of identification of parenchymal organ injury at US increased the sensitivity of US to 68%, with an accuracy of 92%. CONCLUSION: US for blunt abdominal trauma in children is highly accurate and specific, but moderately sensitive, for detection of intraabdominal injury.

Abdomen↗

PubMed2002

Emergency department overcrowding in Florida, New York, and Texas.

BACKGROUND: This study was done to determine the incidence, causes, and effects of overcrowding in emergency departments (EDs) in Florida, New York, and Texas. METHODS: Surveys were mailed to a random sample of EDs in Florida, New York, and Texas. Questions included census, area population, frequency and causes of overcrowding, and impact. Causes of overcrowding were ranked on a 5-point scale. RESULTS: A total of 300 surveys were sent, and 210 (70%) were returned. Overcrowding was reported in 194 EDs (92%): New York (90%), Florida, (92%), and Texas (95%). Causes of ED overcrowding included hospital bed shortage, high medical acuity of patients, increasing patient volume, too few examination spaces, and shortage of RN staff. Overcrowding resulted in death, permanent disability, additional procedures, and increased length of hospitalization. CONCLUSION: In this survey of EDs, overcrowding was pervasive. Many factors contribute to ED overcrowding. Poor medical outcomes may occur because of overcrowding.

Crowding↗