Blunt Abdominal Trauma

Accuracy of physical and ultrasonographic examinations by emergency physicians for the early diagnosis of intraabdominal haemorrhage in blunt abdominal trauma

OBJECTIVE

To determine the accuracy of physical examination and ultrasonographic evaluation performed by emergency physicians in cases of blunt abdominal trauma for the early diagnosis of intraabdominal haemorrhage.

METHODS

In this clinical prospective study, trauma patients were evaluated with four-quadrant ultrasonography by emergency physicians after initial stabilisation and physical examination. Diagnoses based on demographic data, physical examination and emergency physician's ultrasonography were compared with the subsequent clinical course.

RESULTS

A total of 442 patients participated in the study. The sensitivity and specificity of emergency physician's ultrasonographic examination to detect intraabdominal haemorrhage were 86 and 99%, respectively. Pre-test sensitivity and specificity of physical examination to detect intraabdominal haemorrhage were 39 and 90%, respectively.

CONCLUSIONS

Physical examination was not a reliable method to detect intraabdominal haemorrhage in cases of blunt abdominal trauma. In contrast, abdominal ultrasonography performed by emergency physicians was a reliable diagnostic tool. Emergency physicians should be familiar with abdominal ultrasonographic examination, which should be routine in cases of blunt abdominal trauma.

FAST (focused assessment with sonography in trauma) accurate for cardiac and intraperitoneal injury in penetrating anterior chest trauma

OBJECTIVE

To evaluate the FAST (focused assessment with sonography in trauma) examination for determining traumatic pericardial effusion and intraperitoneal fluid indicative of injury in patients with penetrating anterior chest trauma.

METHODS

An observational prospective study was conducted over a 30-month period at an urban level I trauma center. FAST was performed in the emergency department by emergency physicians and trauma surgeons. FAST results were recorded before review of patient outcome as determined by 1 or more of the following: thoracotomy, laparotomy, pericardial window, cardiologic echocardiography, diagnostic peritoneal lavage, computed tomography, and serial examinations.

RESULTS

FAST was undertaken in 32 patients with penetrating anterior chest trauma: 20 (65%) had stab wounds, and 12 (35%) had gunshot wounds. Sensitivity of FAST for cardiac injury (n = 8) in patients with pericardial effusion was 100% (95% confidence interval, 63.1%-100%); specificity was 100% (95% confidence interval, 85.8%-100%). The presence of pericardial effusion determined by FAST correlated with the need for thoracotomy in 7 (87.5%) of 8 patients (95% confidence interval, 47.3%-99.7%). One patient with a pericardial blood clot on cardiologic echocardiography was treated nonsurgically. FAST had 100% sensitivity for intraperitoneal injury (95% confidence interval, 63.1%-100%) in 8 patients with views indicating intraperitoneal fluid but without pericardial effusion, again with no false-positive results, giving a specificity of 100% (95% confidence interval, 85.8%-100%). This prompted necessary laparotomy in all 8.

CONCLUSIONS

In this series of patients with penetrating anterior chest trauma, the FAST examination was sensitive and specific in the determination of both traumatic pericardial effusion and intraperitoneal fluid indicative of injury, thus effectively guiding emergent surgical decision making.

How distracting is distracting pain?

The study was to determine the effect of preexisting pain on the perception of a painful stimulus. We conducted a cross-section study at an urban ED using convenience sampling. Adult patients who had a 20-g IV catheter placed as part of their ED care were eligible for the study. Patients were excluded for the following reasons: more than one IV attempt, altered mental status, visual impairment, intoxication, or a physical abnormality at the IV site. Patients were asked to indicate on a 10-cm visual analog scale (VAS) the amount of pain they had at baseline immediately before IV placement. They were then asked to indicate on a separate VAS the amount of pain caused by the IV placement. Correlation between baseline pain and pain of the IV was assessed using Pearson's rho. One hundred patients were enrolled in the study. The pain of IV placement did not differ significantly by gender, race, who placed the IV, or the location of the IV. The correlation between baseline pain and pain of the IV placement was poor (rho =.14, confidence interval:-.06-.33). The response to a standardized painful stimulus among ED patients does not correlate highly with the severity of preexisting pain.

Abdominal trauma in infants and children: prompt identification and early management of serious and life-threatening injuries. Part II: Specific injuries and ED management

Evaluation of children with suspected abdominal trauma could be a difficult task. Unique anatomic and physiologic features render vital sign assessment and the physical examination less useful than in the adult population. Awareness of injury patterns and associations will improve the early diagnosis of abdominal trauma. Clinicians must have a complete understanding of common and atypical presentations of children with significant abdominal injuries. Knowledge of the utility and limitations of available laboratory and radiologic adjuncts will assist in accurately identifying abdominal injury. While other obvious injuries (eg, facial, cranial, and extremity trauma) can distract physicians from less obvious abdominal trauma, an algorithmic approach to evaluating and managing children with multisystem trauma will improve overall care and help to identify and treat abdominal injuries in a timely fashion. Finally, physicians must be aware of the capabilities of their own facility to handle pediatric trauma. Protocols must be in place for expediting the transfer of children who require a higher level of care. Knowledge of each of these areas will help to improve the overall care and outcome of children with abdominal trauma.

Ultrasound of blunt abdominal trauma

Widely accepted in Europe and Asia as a screening tool for blunt abdominal trauma, sonography is gradually gaining popularity among trauma and emergency physicians in the United States. Sonography has been shown to be comparable with DPL and CT for the detection of hemoperitoneum and superior to both modalities because of its rapidity, noninvasiveness, portability, and low cost. With its ability to demonstrate the amount of intraperitoneal hemorrhage within minutes of a patient's arrival, sonography may be considered the screening modality of choice for blunt abdominal trauma.

Computed tomography for blunt abdominal trauma in the ED: a prospective study

A study was undertaken to determine the criteria for ordering abdominal computed tomography (CT) in the emergency department (ED) for stable patients who sustained blunt trauma and to identify a patient population at high risk for having intra-abdominal injury (IAI) utilizing physical examination, decrease in hematocrit, and hematuria. Patients in a university ED who had abdominal CT from April 1995 to October 1995 were evaluated prospectively. Before the scan, the examining physician completed an entry form that included physical findings, hematocrit, hematuria, Glasgow Coma Scale score, intoxication, distracting injuries, reasons for obtaining the scan, and planned disposition. Patients were followed until discharge. A total of 196 patients were evaluated. Abdominal tenderness was present in 120 patients. Twenty-two patients had IAI. Eight required surgical intervention, and all 8 had abdominal tenderness. A total of 40 potential trauma admissions were averted by obtaining CT within the ED. The combined abnormal abdomen examination and presence of hematuria had a sensitivity of 64%, specificity of 94%, positive predictive value of 56%, and negative predictive value of 95%. Decrease of > or = 5 in hematocrit was not statistically significant for detection of IAI. CT had no false negatives in this cohort. These results show that early CT scanning of stable patients who have sustained blunt trauma is an effective screen for IAI and may result in fewer total admissions, but has potential for overuse. Patients with abdominal pain and hematuria should be scanned. The benefit of a CT scan for patients without tenderness or with an isolated decrease in hematocrit is questionable.

Injuries distracting from intraabdominal injuries after blunt trauma

While most conscious patients with severe intraabdominal injuries (IAI) will usually present with either abdominal pain or tenderness, there is a small group of awake and alert patients in whom the physical examination will be falsely negative because of the presence of associated extraabdominal ("distracting") injuries. We sought to define the types of extraabdominal injuries that could lead to a false negative physical examination for potentially severe IAI in adult victims of blunt trauma. This study was prospectively performed on consecutive blunt trauma patients over a 14-month period in our level I trauma center. Inclusion criteria were as follows: (1) Glasgow Coma Scale score of 15; (2) age 18 years or older; and (3) computed tomography (CT) of the abdomen or diagnostic peritoneal lavage (DPL) performed regardless of initial physical examination findings. Patients were questioned specifically about the presence of abdominal pain and the initial abdominal examination was documented in addition to other extraabdominal injuries. Abdominal injuries were considered to be present based upon either abdominal CT findings or a positive DPL. Patients with and without abdominal pain or tenderness were compared for the presence of IAI. A total of 350 patients were enrolled. There were 142 patients with neither abdominal pain nor tenderness (group 1) and 208 patients with either or both (group 2). Ten of the 142 patients (7.0%) in group 1 had IAI compared with 44 of the 208 patients (21.2%) in group 2 (P = .0003). Presence of pain and/or tenderness had a sensitivity of 82%, a specificity of 45%, a positive predictive value of 21%, and negative predictive value of 93%. All 10 patients in group 1, and 36 of the 44 group 2 patients, had associated extraabdominal injuries. Although the presence of abdominal pain or tenderness was associated with a significantly higher incidence of IAI, the lack of these findings did not preclude IAI.

Ultrasound detection of foreign bodies and procedure guidance

As emergency physicians become familiar with the use of ultrasonography, this safe procedure will likely become a standard technique having multiple uses in the emergency department. Ultrasonography assists in foreign body localization and retrieval and is potentially important in applications, such as reliable endotracheal tube placement, visualization of ingested medication, vascular access, and drainage of collected fluids.

Computed tomography and blunt abdominal injury: patient selection based on examination, haematocrit and haematuria

The criteria for ordering abdominal CT scans in the secondary survey of stable bluntly injured patients was examined. A patient population at high risk for having intra-abdominal injury (IAI) was identified by physical examination, a fall in haematocrit, and haematuria. A total of 444 patients receiving abdominal CT scans at a large urban trauma centre were reviewed. IAI was diagnosed in 49 (11 per cent), by radiographic and/or intra-operative findings. Abdominal tenderness was present in all 17 patients who underwent surgery. The sensitivity and specificity of abdominal CT scanning was 90 per cent and 99 per cent, respectively. The abdominal exam had a sensitivity of 63 per cent and a specificity of 65 per cent. A fall in haematocrit > or = 5 was not statistically significant. The combined abdominal exam and haematuria yielded a specificity of 93 per cent with a negative predictive value (NPV) of 93 per cent. Early CT scanning of stable patients who had sustained blunt injuries is an effective screen for IAI. The benefit of a CT scan for patients without abdominal tenderness or with an isolated fall in haematocrit is questionable. Serial abdominal examinations should remain the most timely and cost-effective method for identifying IAI in stable patients. The specificity and NPV of abdominal tenderness combined with haematuria approaches that of CT.

Prospective crossover study of the effect of phlebotomy and intravenous crystalloid on hematocrit

OBJECTIVE

To compare the changes in hematocrit (Hct) between phlebotomized and nonphlebotomized individuals given IV crystalloid.

METHODS

A prospective, crossover volunteer study was performed comparing Hct changes immediately and 30 minutes after IV crystalloid bolus in 20 healthy adults with and without prebolus phlebotomy. In the control portion, volunteers were given a 15-mL/kg bolus of normal saline over 30 minutes with Hct determination before (H1), immediately after (H2), and 30 minutes after (H3) crystalloid infusion. At least 7 days later, the same subjects were phlebotomized 1 unit of blood and then administered a 15-mL/kg IV bolus of normal saline 30 minutes later. Hcts were obtained before (H4) and 30 minutes after (H5) phlebotomy (immediately prior to crystalloid infusion). Hcts were also obtained immediately after (H6) and 30 minutes after (H7) crystalloid infusion. A post-hoc test performance analysis was then performed to determine the Hct drop thresholds that would yield the maximal sensitivity and specificity for 500 mL of blood loss (via phlebotomy) in this population.

RESULTS

The Hct (%) drops in the nonphlebotomized individuals receiving IV fluids averaged 4.5 +/- 1.3 immediately and 3.2 +/- 1.3 30 minutes after infusion. These drops were different (p < 0.05) from the Hct drop in individuals receiving IV fluids after phlebotomy, which averaged 6.6 +/- 1.5 and 5.7 +/- 1.1, respectively. Post-hoc analysis revealed that Hct drops of 5.4 immediately, or 4.3 at 30 minutes after infusion, had a sensitivity of > 90% and a specificity of 75% for identification of patients in the phlebotomy group.

CONCLUSIONS

The practice of measuring serial Hcts may be helpful to identify trauma patients with occult blood loss. A prospective clinical trial is needed to validate these Hct drop thresholds (immediate and 30 minutes postinfusion) in crystalloid-resuscitated trauma patients.

Ultrasound in the evaluation and management of blunt abdominal trauma

Failure to detect intraabdominal injury in the patient with blunt trauma may result in significant morbidity and mortality. The diagnosis of abdominal injury remains a clinical challenge. Presented here is a review of recent literature comparing ultrasound with diagnostic peritoneal lavage and computed tomography in the evaluation of blunt abdominal trauma.

A review of computerized tomography in blunt abdominal trauma at Christchurch Hospital

A review was undertaken of computerized tomography (CT) of the abdomen, performed between March 1993 and December 1994 for blunt abdominal trauma at Christchurch Hospital. CT findings were correlated with the clinical outcome. The outcome was either recovery from an abdominal point of view with or without laparotomy, or postmortem. A total of 116 CTs were reviewed, of which 76 were abnormal. CT was highly sensitive and specific for a variety of abdominal traumatic lesions. There were 1 false positive and 4 false negatives (only 2 of these significant). There was 1 non-therapeutic laparotomy based on CT findings. There was only 1 case of delayed treatment based on CT results. Three patients had unexplained findings of pneumoperitoneum. Care should be taken when interpreting the presence of free intraperitoneal air on CT scan. The possibility of missed bowel perforation should be considered, especially in the presence of free intra-abdominal fluid and no solid organ injury to account for it. CT scans are useful in the conservative management of solid organ injuries.

Laparoscopic surgery and its potential for medical complications

Laparoscopic surgery is very popular among physicians and patients because this technique is associated with safety, shorter hospital stay, early return to normal activity, and cosmetic acceptance of the operative scar. Although the procedure involves minimal invasion and tissue damage, it has potentially serious complications, including cardiopulmonary effects that result mainly from hypercarbia and raised intraabdominal pressure caused by pneumoperitoneum. Absorbed carbon dioxide from the peritoneal cavity tends to cause acidosis. Leakage of the gas into tissue spaces may induce subcutaneous emphysema, pneumothorax, pneumomediastinum and pneumopericardium. Cardiac effects include arrhythmias, hypotension, cardiac arrest, gas embolism, pulmonary edema, and myocardial ischemia or infarction. Some of these effects, though rare, are serious and potentially fatal. Physicians should anticipate these problems in their patients undergoing laparoscopic procedures. This review discusses the technique of and physiologic considerations in laparoscopic surgery as well as its potential complications.

Ultrasound in the diagnosis of injury

Ultrasound is one of several modalities useful in the work-up of an injured patient. It is a bedside technique which is quick, economical and highly reliable in filtering out the patients who are in urgent need of laparotomy. For the moment, this is the prime and only function of this modality. The US examination can and should be repeated with a very low threshold. Apart from the complication rate, which is zero for US, it shares many virtues with DPL. Ultrasonography in a badly injured victim is a challenging investigation which should be done by an expert. In most situations, this will be a radiologist whose presence in the emergency room could further be used for expert film reading and development as well as the unhampered implementation of a rational follow-up imaging strategy. Follow-up modalities, however impressive, should not be compared with first-line investigations. In expert hands, accuracy figures between DPL and US do not differ decisively but one must bear in mind that DPL spans only one compartment while US gives information about much more vital areas. DPL is complementary to US; it is of paramount importance to understand that DPL spoils the US examination (and CT as well) but is not hindered by repeated US. DPL can and should be used to investigate the nature of free intra-peritoneal fluid when the amount does not warrant laparotomy. Neither US nor DPl are substitutes for sound clinical judgement.

Blunt abdominal trauma

Assessment and management of patients with blunt abdominal trauma remains a challenge for emergency physicians. The spectrum of injury ranges from the trivial to the catastrophic and the initial assessment, resuscitation, and investigation of patients with abdominal trauma must be individualized. This article covers the important aspects of patient history and physical examination and addresses the relevant investigative tools available. An approach to the assessment of patients with abdominal trauma is provided; the goal is to diagnose significant injuries as soon as possible and avoid the pitfall of a delayed or missed diagnosis.

Objectives to direct the training of emergency medicine residents on off-service rotations: traumatology, Part 2

This is the 31st article in a continuing series of objectives to direct emergency medicine resident experiences on off-service rotations. Neck and torso trauma accounts for a large portion of injuries, and its management is an essential part of training in emergency medicine. Due to the often life-threatening presentations of trauma victims, resident instruction may be conducted at the bedside in difficult and demanding situations. Therefore, it is essential for residents to have specific goals and objectives to guide their acquisition of knowledge required to make critical decisions for patients with major trauma.