Noninvasive capnometry for continuous monitoring of mental status: a tale of 2 patients.
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Adult↗
Biomedical subjects
Daniel P Davis
Publications and source records attributed to Daniel P Davis.
The ability of paramedics to predict aspiration in patients undergoing prehospital rapid sequence intubation.
One of the purported benefits to invasive prehospital airway management is the prevention of aspiration; however, aspiration events may occur before the arrival of prehospital personnel. We explore the timing of aspiration in patients with severe traumatic brain injury (TBI) undergoing paramedic rapid sequence intubation (RSI). Severely head-injured (Glasgow Coma Scale [GCS] score 3-8) adults were prospectively enrolled into the San Diego Paramedic RSI Trial. As part of the prehospital data collection tool, paramedics prospectively assessed for clinical evidence of aspiration before RSI (pre-intubation), aspiration events occurring during RSI (peri-RSI), and regurgitation of vomitus or blood after intubation (post-intubation). Data were abstracted from work sheets used during the RSI procedure, a telephone debriefing by one of the principal investigators immediately after delivery of the patient, and San Diego County prehospital and trauma databases. The incidence of pre-intubation aspiration, peri-RSI aspiration, and post-intubation regurgitation of vomitus or blood were determined. Patients with and without pre-intubation aspiration were compared with regard to pre- and post-intubation hypoxia and the rate of aspiration pneumonia. Logistic regression was used to explore the association between pre-intubation aspiration and various demographic and clinical factors. The results showed that pre-intubation aspiration was noted by paramedics in 72/269 patients in whom complete data were available. Peri-RSI aspiration was reported in one patient; there were no reported cases of post-intubation regurgitation of vomitus or blood. Patients in the pre-intubation aspiration group required more intubation attempts, had a higher incidence of desaturations and lower pre- and post-intubation SaO(2) values, and were more frequently diagnosed with aspiration pneumonia. Pre-intubation aspiration was associated with severe TBI, GCS score of 3, younger age, and the absence of alcohol intoxication despite controlling for age, gender, GCS, Head AIS (Abbreviated Injury Score), and serum ethanol. It is concluded that paramedics seem to be able to accurately assess for aspiration in patients undergoing prehospital RSI. The vast majority of aspiration events seem to occur before the arrival of prehospital personnel. Alteration in consciousness from TBI may carry a higher risk of aspiration than with other causes, such as alcohol intoxication.
Abbreviated Injury Scale↗
Diffusion-weighted magnetic resonance imaging versus computed tomography in the diagnosis of acute ischemic stroke.
Current treatment protocols using reperfusion therapy for acute ischemic stroke rely on non-contrast computed tomography (NCCT), with most indications including the absence of acute hemorrhage or large volume of infarction in the presence of clinical signs and symptoms. This predictably results in a significant incidence of the administration of reperfusion therapy to patients with "stroke mimics," such as migraine headache or Todd's paralysis after a seizure. Diffusion-weighted imaging (DWI) is a technique based on magnetic resonance imaging (MRI) that may be more sensitive and specific for acute cerebral ischemia than NCCT. In addition, data for techniques such as perfusion-weighted imaging can be acquired with minimal additional time required. This may allow better risk assessment of a clinical response to reperfusion therapy vs. the possibility of hemorrhagic complications. This article describes a methodical review of studies comparing the sensitivity, specificity, positive predictive value, and negative predictive value of DWI vs. NCCT in the evaluation of acute ischemic stroke. Data from studies meeting our screening criteria are combined to produce overall values for each.
Brain Ischemia↗
Traumatic brain injury outcomes in pre- and post- menopausal females versus age-matched males.
Gender differences in outcomes from major trauma have been described previously, and exogenous female hormone administration appears to be neuroprotective following traumatic brain injury (TBI). This analysis explored outcomes in pre- and post-menopausal females versus age-matched males. A total of 13,437 patients (n = 3,178 females, n = 10,259 males) with moderate-to-severe TBI (head AIS > or = 3) were identified from our county trauma registry. Overall mortality was similar between males and females (22% for both). Logistic regression was used to compare gender outcome differences, with a separate analysis performed for premenopausal (< 50 years) versus postmenopausal (> or = 50 years) patients, and after stratification by decade of life. No statistically significant difference in outcomes was observed for pre-menopausal females versus males (odds ratio [OR] 1.06; 95% confidence interval [CI] 0.83, 1.35; p = 0.633), but outcomes were significantly better in postmenopausal females versus males (OR 0.63, 95% CI 0.48-0.81, p < 0.001) after adjusting for age, mechanism of injury, Glasgow Coma Scale (GCS), hypotension (SBP < or = 90 mm Hg), head Abbreviated Injury Score (AIS), and Injury Severity Score (ISS). Stratification by decade of life revealed the gender survival differential inflection point to occur between ages 40-49 (OR 1.06, 95% CI 0.66-1.71, p = 0.798) and ages 50-59 (OR 0.38, 95% CI 0.20-0.74, p = 0.005). In addition, Revised Trauma Score and Injury Severity Score (TRISS) was used to calculate probability of survival (PS); all patients were then stratified by decade of life, and males and females were compared with regard to mean survival differential (outcome - PS). The identical pattern of improved outcomes in post-menopausal but not pre-menopausal females versus age-matched males was observed. These data suggest that endogenous female sex hormone production is not neuroprotective.
Adolescent↗
Early ventilation and outcome in patients with moderate to severe traumatic brain injury.
OBJECTIVES: An increase in mortality has been reported with early intubation in severe traumatic brain injury, possibly due to suboptimal ventilation. This analysis explores the impact of early ventilation on outcome in moderate to severe traumatic brain injury. DESIGN: Retrospective, registry-based analysis. SETTING: This study was conducted in a large county trauma system that includes urban, suburban, and rural jurisdictions. PATIENTS: Nonarrest trauma victims with a Head Abbreviated Injury Score of > or =3 were identified from our county trauma registry. INTERVENTIONS: Intubated patients were stratified into 5 mm Hg arrival PCO(2) increments. Logistic regression was used to calculate odds ratios for each increment, adjusting for age, gender, mechanism of injury, year of injury, preadmission Glasgow Coma Scale score, hypotension, Head Abbreviated Injury Score, Injury Severity Score, PO(2), and base deficit. Increments with the highest relative survival were used to define the optimal PCO(2) range. Outcomes for patients with arrival PCO(2) values inside and outside this optimal range were then explored for both intubated and nonintubated patients, adjusting for the same factors as defined previously. In addition, the independent outcome effect of hyperventilation and hypoventilation was assessed. MEASUREMENTS AND MAIN RESULTS: A total of 890 intubated and 2,914 nonintubated patients were included. Improved survival was observed for the arrival PCO(2) range 30-49 mm Hg. Patients with arrival PCO(2) values inside this optimal range had improved survival and a higher incidence of good outcomes. Conversely, there was no improvement in outcomes for patients within this optimal PCO(2) range for nonintubated patients after adjusting for all of the factors defined previously. Both hyperventilation and hypoventilation were associated with worse outcomes in intubated but not nonintubated patients. The proportion of arrival PCO(2) values within the optimal range was lower for intubated vs. nonintubated patients. CONCLUSIONS: Arrival hypercapnia and hypocapnia are common and associated with worse outcomes in intubated but not spontaneously breathing patients with traumatic brain injury.
Adult↗
The predictive value of field versus arrival Glasgow Coma Scale score and TRISS calculations in moderate-to-severe traumatic brain injury.
BACKGROUND: Glasgow Coma Scale (GCS) scores are widely used to quantify level of consciousness in the prehospital environment. The predictive value of field versus arrival GCS is not well defined but has tremendous implications with regard to triage and therapeutic decisions as well as the use of various predictive scoring systems, such as Trauma Score and Injury Severity Score (TRISS). This study explores the predictive value of field GCS (fGCS) and arrival GCS (aGCS) as well as TRISS calculations using field (fTRISS) and arrival (aTRISS) data in patients with moderate-to-severe traumatic brain injury (TBI). METHODS: Major trauma victims with head Abbreviated Injury Scores of 3 or greater were identified from our county trauma registry over a 16-year period. The predictive ability of fGCS with regard to aGCS was explored using univariate statistics and linear regression modeling. The difference between aGCS and fGCS was also modeled against mortality and the composite endpoint using logistic regression, adjusting for fGCS. The predictive value of preadmission GCS (pGCS), defined as either fGCS or aGCS in nonintubated patients without a documented fGCS, with regard to mortality and a composite endpoint representing the need for neurosurgical care (death, craniotomy, invasive intracranial pressure monitoring, or intensive care unit care >48 hours) was determined using receiver-operator curve (ROC) analysis. Finally, fTRISS and aTRISS predicted survival values were compared with each other and to observed survival. RESULTS: A total of 12,882 patients were included. Mean values for fGCS and aGCS were similar (11.4 and 11.5, respectively, p = 0.336), and a strong correlation (r = 0.67, 95% CI 0.66-0.69, p < 0.0001) was observed between them. The difference between fGCS and aGCS was also predictive of outcome after adjusting for fGCS. Good predictive ability was observed for pGCS with regard to both mortality and neurosurgical intervention. Both fTRISS and aTRISS predicted survival values were nearly identical to observed survival. Observed and fTRISS predicted survival were nearly identical in patients undergoing prehospital intubation CONCLUSIONS: Values for fGCS are highly predictive of aGCS, and both are associated with outcome from TBI. A change in GCS from the field to arrival is highly predictive of outcome. The use of field data for TRISS calculations appears to be a valid methodological approach, even in severely injured TBI patients undergoing prehospital intubation.
Brain Injuries↗
The combination of isoflurane and caspase 8 inhibition results in sustained neuroprotection in rats subject to focal cerebral ischemia.
Although isoflurane can reduce ischemic neuronal injury after short postischemic recovery intervals, data from our laboratory have demonstrated that this neuroprotection is not sustained and that delayed apoptotic neuronal death, mediated in part by activation of caspases, contributes to the gradual increase in the size of the infarction. We tested the hypothesis that the neuroprotective efficacy of isoflurane can be prolonged with the administration of z-IETD-fmk, a specific inhibitor of caspase 8. Fasted Wister rats were anesthetized with isoflurane and randomly allocated to awake-vehicle, isoflurane-vehicle, awake-IETD, or isoflurane-IETD groups (n = 25 per group). Animals were subjected to 60 min focal ischemia by filament occlusion of the middle cerebral artery (MCAO). Daily intracerebroventricular injections of z-IETD-fmk or vehicle were administered via an implanted cannula starting before ischemia and continuing until 14 days post-MCAO. Neurological assessment was performed 14 days after ischemia after which the volume of cerebral infarction and number of intact neurons in the peri-infarct cortex were determined. Total infarction volume was less in the isoflurane-IETD group than in awake-vehicle, isoflurane-vehicle, and awake-IETD groups. Infarction volume was also less in the awake-IETD group versus the awake-vehicle group. The number of intact neurons within the peri-infarct cortex was significantly less in the awake-vehicle group in comparison with the other three experimental groups. The isoflurane-IETD group had better neurologic outcomes than both vehicle-treated groups at 14 days post-MCAO. These results suggest that a combination of isoflurane and a caspase 8 inhibitor can produce neuroprotection that is evident even after a recovery period of 14 days. This combination demonstrated greater efficacy than the administration of either isoflurane or z-IETD-fmk alone. These results are consistent with the premise that continuing apoptosis contributes to the enlargement of cerebral infarction during the recovery period and that its inhibition can provide sustained neuroprotection.
Animals↗
Access to trauma centers.
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Health Services Accessibility↗
The inadvertent administration of anticoagulants to ED patients ultimately diagnosed with thoracic aortic dissection.
OBJECTIVES: Aortic dissection (AD) may present similarly to acute coronary syndrome or pulmonary embolus; however, anticoagulation may be detrimental to patients with AD. METHODS: Clinical data were abstracted from medical records of emergency department (ED) patients with nontraumatic AD. Patients administered with anticoagulants were compared with non-anticoagulated patients with regard to presenting symptoms, chest radiograph and electrocardiogram (ECG) findings, and outcome. RESULTS: A total of 44 ED patients with nontraumatic AD was identified over a 4-year period; anticoagulants were administered to 9 (21%). Anticoagulated patients had a higher incidence of chest pain without back pain (78% vs 23%; P = .002) and ST elevations or depressions on ECG (89% vs 6%; P < .001) and were less likely to have a widened mediastinum on chest radiograph (0% vs 67%; P < .001). Two ED anticoagulated patients died, one required a second surgery for bleeding complications, and another suffered a stroke after reversal of anticoagulation. CONCLUSIONS: There is a clinically significant incidence of anticoagulation administration to ED patients ultimately diagnosed with AD, especially in the presence of ambiguous ECG and radiographic findings.
Aged↗
The impact of aeromedical response to patients with moderate to severe traumatic brain injury.
STUDY OBJECTIVE: Aeromedical crews offer an advanced level of practice and rapid transport to definitive care; however, their efficacy remains unproven. Previous studies have used relatively small sample sizes or have been unable to adequately control for the effect of other potentially influential variables. Here we explore the impact of aeromedical response in patients with moderate to severe traumatic brain injury. METHODS: This was a retrospective analysis using our county trauma registry. All patients with head Abbreviated Injury Score of 3 or greater were included; interfacility transfers were excluded. The impact of aeromedical response was determined using logistic regression, adjusting for age, sex, mechanism, preadmission Glasgow Coma Scale score, head Abbreviated Injury Score, Injury Severity Score, and the presence of preadmission hypotension. Propensity scores were used to account for variability in selection of patients to undergo air versus ground transport. Patients with moderate and severe traumatic brain injury, as defined by head Abbreviated Injury Score and Glasgow Coma Scale score, were compared. Finally, aeromedical patients undergoing field intubation were compared with ground patients undergoing emergency department (ED) intubation. RESULTS: A total of 10,314 patients meeting all inclusion and exclusion criteria and with complete data sets were identified and included 3,017 transported by aeromedical crews. Overall mortality was 25% in the air- and ground-transported cohorts, but outcomes were significantly better for the aeromedical patients when adjusted for age, sex, mechanism of injury, hypotension, Glasgow Coma Scale score, head Abbreviated Injury Score, and Injury Severity Score (adjusted odds ratio [OR] 1.90; 95% confidence interval [CI] 1.60 to 2.25; P<.0001). Good outcomes (discharge to home, jail, psychiatric facility, rehabilitation, or leaving against medical advice) were also higher in aeromedical patients (adjusted OR 1.36; 95% CI 1.18 to 1.58; P<.0001). The primary benefit appeared to be in more severely injured patients, as reflected by head Abbreviated Injury Score and Glasgow Coma Scale score. Improved survival was also observed for air-transported patients intubated in the field versus ground-transported patients given emergency intubation in the ED (adjusted OR 1.42; 95% CI 1.13 to 1.78; P<.001). CONCLUSION: Here we analyze a large database of patients with moderate to severe traumatic brain injury. Aeromedical response appears to result in improved outcomes after adjustment for multiple influential factors in patients with moderate to severe traumatic brain injury. In addition, out-of-hospital intubation among air-transported patients resulted in better outcomes than ED intubation among ground-transported patients. Patients with more severe injuries appeared to derive the greatest benefit from aeromedical transport.
Abbreviated Injury Scale↗
The UCSD Research Associate Program: a recipe for successfully integrating undergraduates with emergency medicine research.
Previous reports have documented the successful integration of undergraduates into the Emergency Department (ED) to assist in data collection for various research projects, with resultant improvements in departmental academic productivity. These reports have not detailed the exact procedures required to institute such a program. Over 100 undergraduates from three institutions currently participate in the UCSD Research Associate Program. Here we document our experience with the inception of such a program and define the various components required to successfully conduct an ED undergraduate research associate program, defining the roles of key personnel, detailing the administrative component, discussing the selection of appropriate research projects and the design of data and instruction sheets, addressing issues related to training and didactics, and suggesting strategies for recruitment and upkeep of interest.
California↗
The association between operator confidence and accuracy of ultrasonography performed by novice emergency physicians.
The variable accuracy of emergency department (ED) ultrasound described in the literature has limited its utility as the sole imaging modality in critical decision making. Although ultrasound accuracy is highly dependent upon the technical abilities of the operator and conditions unique to each patient, no previous study of ED ultrasound has included estimates of operator confidence. This prospective observational study explores the association between operator confidence and the accuracy of ED ultrasound. Ultrasound was not performed in our ED until a formal training module was instituted. Patients were enrolled prospectively for the first year following the training module if they underwent one of the following ultrasound studies: abdominal examination for intraperitoneal fluid, right upper quadrant examination for gallstones, renal examination for hydronephrosis, pelvic examination for intrauterine pregnancy, abdominal examination for aorta diameter > 3 cm, or cardiac examination for pericardial fluid. In addition, formal ultrasound, computed tomography, magnetic resonance imaging, or an invasive procedure was required as a "gold standard" for each patient. Operators recorded their interpretation of the ED ultrasound and rated their confidence with the analysis before the formal imaging study or procedure. Test performance characteristics for each examination type and for all studies together were determined. The association between operator confidence and accuracy was explored using logistic regression and by determining test performance characteristics with patients stratified by confidence value. A total of 276 ED ultrasound studies were included. There were no significant differences in accuracy between ED attendings and residents. Overall accuracy, sensitivity, specificity, LR+, and LR- were 90%, 92%, 86%, 6.8, and 0.09, respectively. With confidence scores of 9 or 10 (n = 113), these values improved to 96%, 99%, 90%, 9.6, and 0.01, respectively. Logistic regression revealed an association between confidence and ED ultrasound accuracy (p < 0.001). It is concluded that a significant association exists between operator confidence and the accuracy of ED ultrasound. High confidence values are associated with clinically useful test performance characteristics.
Abdomen↗
The association between field Glasgow Coma Scale score and outcome in patients undergoing paramedic rapid sequence intubation.
Early intubation is standard for treating severe traumatic brain injury (TBI). Aeromedical crews and select paramedic agencies use rapid sequence intubation (RSI) to facilitate intubation after TBI, with Glasgow Coma Scale (GCS) score commonly used as a screening tool. To explore the association between paramedic GCS and outcome in patients with TBI undergoing prehospital RSI, paramedics prospectively enrolled adult major trauma victims with GCS 3-8 and clinical suspicion for head trauma to undergo succinylcholine-assisted intubation as part of the San Diego Paramedic RSI Trial. The following data were abstracted from paramedic debriefing interviews and the county trauma registry: demographics, mechanism, vital signs including GCS score, clinical evidence of aspiration before RSI, arrival laboratory values, hospital course, and outcome. Paramedic GCS calculations were confirmed during debriefing interviews. Patients were stratified by GCS score, with chi-square and receiver-operator-curve (ROC) analysis used to explore the relationship between GCS and hypoxia, head injury severity, aspiration, intensive care unit (ICU) length of stay, and outcome. Cohort analysis was used to explore potential reasons for early extubation and discharge from the ICU in some patients. A total of 412 patients were included in this analysis. A total of 81 patients (20%) were extubated and discharged from the ICU in 48 h or less; these patients had higher pre-RSI oxygen saturation (SaO(2)) values and higher arrival serum ethanol levels. Paramedic and physician GCS calculations had high agreement (kappa=0.995). A statistically significant relationship was observed between GCS score and Head Abbreviated Injury Score (AIS), survival, and pre-RSI SaO(2) values. However, ROC analysis revealed a limited ability of GCS to predict the presence of severe TBI, injury severity, desaturation, aspiration, ICU length of stay, or ultimate survival. In conclusion, paramedics seem to accurately calculate GCS values before prehospital RSI. Although a relationship between paramedic GCS and outcome exists, the ability to predict the severity of injury, airway-related complications, ICU length of stay, and overall survival is limited using this single variable. Other factors should be considered to screen TBI patients for prehospital RSI.
Adult↗
The three-phase model of cardiac arrest as applied to ventricular fibrillation in a large, urban emergency medical services system.
BACKGROUND: Cardiac arrest is responsible for significant morbidity and mortality, with consistently poor outcomes despite the rapid availability of prehospital personnel for defibrillation attempts in patients with ventricular fibrillation (VF). Recent evidence suggests a period of cardiopulmonary resuscitation (CPR) prior to defibrillation attempts may improve outcomes in patients with moderate time since collapse (4-10 min). OBJECTIVES: To determine cardiac arrest outcomes in our community and explore the relationship between time since collapse, performance of bystander CPR, and survival. METHODS: Non-traumatic cardiac arrest data were collected prospectively over an 18-month period. Patients were excluded for: age <18 years, a "Do Not Attempt Resuscitation" (DNAR) directive, determination of a non-cardiac etiology for arrest, and an initially recorded rhythm other than VF. Patients were stratified by time since collapse (<4, 4-10, > 10 min, and unknown) and compared with regard to survival and neurological outcome. In addition, patients with and without bystander CPR were compared with regard to survival. RESULTS: : A total of 1141 adult non-traumatic cardiac arrest victims were identified over the 18-month study period. This included 272 patients with VF as the initially recorded rhythm. Of these, 185 had a suspected cardiac etiology for the arrest; survival to hospital discharge was 15% in this group, with 82% of these having a good outcome or only moderate disability. Survival was highest among patients with time since collapse of less than 4 min and decreased with increasing time since collapse. There were no survivors among patients with time since collapse greater than 10 min. Among patients with time since collapse of 4 min or longer, survival was significantly higher with the performance of bystander CPR; there was no survival advantage to bystander CPR among patients with time since collapse less than 4 min. CONCLUSIONS: The performance of bystander CPR prior to defibrillation by EMS personnel is associated with improved survival among patients with time since collapse longer than 4 min but not less than 4 min. These data are consistent with the three-phase model of cardiac arrest.
Aged↗
A follow-up analysis of factors associated with head-injury mortality after paramedic rapid sequence intubation.
BACKGROUND: The San Diego Paramedic Rapid Sequence Intubation (RSI) Trial documented an increase in mortality after paramedic RSI, with hyperventilation identified as a contributing factor in a small subgroup analysis. Here we explore factors affecting outcome in the entire cohort of patients undergoing paramedic RSI to confirm previous findings. This also represents a synthesis of findings from previous analyses METHODS: Adult trauma patients with severe head injury (Glasgow Coma Scale score, 3-8) who could not be intubated without RSI were prospectively enrolled in the trial. This analysis excluded patients without traumatic brain injury (head/neck abbreviated injury score <2 or failure to meet Major Trauma Outcome Study criteria) or death in the field or within 30 minutes of arrival. Each remaining trial patient was matched to two nonintubated historical controls from the county trauma registry based on: age, sex, mechanism, abbreviated injury scores for each body system, and Injury Severity Score. Logistic regression, cohort analysis, mean least squares regression, and discordant group analysis were used to explore the impact of various factors on outcome. RESULTS: Of the 426 trial patients, 352 met inclusion criteria for this analysis and were hand-matched to 704 controls. Trial patients and controls were identical with regard to all matching variables. Mortality was increased in RSI patients versus matched controls (31.8 versus 23.7%; odds ration, 1.5; 95% confidence interval, 1.1-2.0; p < 0.01). Hyperventilation was associated with an increase in mortality, whereas transport by aeromedical crews after paramedic RSI was associated with improved outcomes. The reported incidence of aspiration pneumonia was higher for the RSI patients. CONCLUSION: Paramedic RSI was associated with an increase in mortality compared with matched historical controls. The association between hyperventilation and mortality was confirmed. In addition, patients transported by helicopter after paramedic RSI had improved outcomes. Paramedic RSI did not seem to prevent aspiration pneumonia.
Abbreviated Injury Scale↗
The impact of prehospital endotracheal intubation on outcome in moderate to severe traumatic brain injury.
BACKGROUND: Although early intubation to prevent the mortality that accompanies hypoxia is considered the standard of care for severe traumatic brain injury (TBI), the efficacy of this approach remains unproven. METHODS: Patients with moderate to severe TBI (Head/Neck Abbreviated Injury Scale [AIS] score 3+) were identified from our county trauma registry. Logistic regression was used to explore the impact of prehospital intubation on outcome, controlling for age, gender, mechanism, Glasgow Coma Scale score, Head/Neck AIS score, Injury Severity Score, and hypotension. Neural network analysis was performed to identify patients predicted to benefit from prehospital intubation. RESULTS: A total of 13,625 patients from five trauma centers were included; overall mortality was 22.9%, and 19.3% underwent prehospital intubation. Logistic regression revealed an increase in mortality with prehospital intubation (odds ratio, 0.36; 95% confidence interval, 0.32-0.42; p < 0.001). This was true for all patients, for those with severe TBI (Head/Neck AIS score 4+ and/or Glasgow Coma Scale score of 3-8), and with exclusion of patients transported by aeromedical crews. Patients intubated in the field versus the emergency department had worse outcomes. Neural network analysis identified a subgroup of patients with more significant injuries as potentially benefiting from prehospital intubation. CONCLUSION: Prehospital intubation is associated with a decrease in survival among patients with moderate-to-severe TBI. More critically injured patients may benefit from prehospital intubation but may be difficult to identify prospectively.
Abbreviated Injury Scale↗
Ventilation patterns in patients with severe traumatic brain injury following paramedic rapid sequence intubation.
INTRODUCTION: Inadvertent hyperventilation has been documented during aeromedical transports but has not been studied following paramedic rapid sequence intubation (RSI). The San Diego Paramedic RSI Trial was designed to study the impact of paramedic RSI on outcome in patients with severe head injury. This analysis explores ventilation patterns in a cohort of trial patients undergoing end-tidal CO2 (ETCO2) monitoring. METHODS: Adult patients with severe head injury (Glasgow Coma Score: 3-8) unable to be intubated without RSI were prospectively enrolled in the trial. Midazolam and succinylcholine were used for RSI; rocuronium was administered following tube confirmation. Standardized ventilation protocols were used by most paramedics; however, one agency instituted ETCO2 monitoring during the second trial year, with paramedics instructed to target ETCO2 values of 30 to 35 mmHg. The incidence and duration of inadvertent hyperventilation (ETCO2: <30 mmHg) and severe hyperventilation (ETCO2: <25 mmHg) were explored for patients undergoing ETCO2 monitoring. The initial, final, minimum, and maximum values for ETCO2 and the maximum and minimum ventilatory rate values were also calculated using descriptive statistics (95% confidence interval). The pattern of ETCO2 values over time and distribution of recorded ventilatory rate values were explored graphically. RESULTS: A total of 76 trial patients had adequate ETCO2 data for this analysis. The mean values for initial, final, maximum, and minimum ETCO2 were 40.8 (range: 37.5-44.2), 28.4 (range: 25.4-31.4), 45.1 (range: 41.4-48.8), and 23.5 mmHg (range: 21.4-25.5), respectively. The mean maximum and minimum ventilatory rate values were 36.0/minute (range: 33.5-38.5) and 12.8/minute (range: 11.9-13.7), respectively. ETCO2 values less than 30 and 25 mmHg were documented in 79% and 59% of patients, respectively, with mean durations of 485 (range: 378-592) and 390 seconds (range: 285-494). CONCLUSION: Inadvertent hyperventilation is common following paramedic RSI, despite ETCO2 monitoring and target parameters.
Adult↗
The clinical presentation and impact of diagnostic delays on emergency department patients with spinal epidural abscess.
Previous reports have recommended the use of a "classic triad" of fever, spine pain, and neurologic deficits to diagnose spinal epidural abscess (SEA); however, the prognosis for complete recovery is poor once these deficits are present. This retrospective case-control study investigates the impact of diagnostic delays on outcome and explores the use of risk factor screening for early identification of SEA in a population of ED patients. Inpatients with a discharge diagnosis of SEA and a related ED visit before the admission were identified over a 10-year time period. In addition, a pool of ED patients presenting with a chief complaint of spine pain was generated; controls were hand-matched 2:1 to each SEA patient based on age and gender. Data regarding demographics, presence of risk factors, physical examination findings, laboratory and radiographic results, and clinical outcome were abstracted from medical records and entered into a database for further analysis. Patients with SEA were compared to matched controls with regard to the prevalence of risk factors and the "classic triad." We also explored the impact on outcome of diagnostic delays, defined as either: 1) multiple ED visits before diagnosis, or 2) admission without a diagnosis of SEA and >24 h to a definitive study. A total of 63 SEA patients were hand-matched to 126 controls with spine pain. Diagnostic delays were present in 75% of SEA patients. Residual motor weakness was present in 45% of these patients vs. only 13% of patients without diagnostic delays (odds ratio 5.65, 95% C.I. 1.15-27.71, p < 0.05). The "classic triad" of spine pain, fever, and neurologic abnormalities was present in 13% of SEA patients and 1% of controls during the initial visit (p < 0.01); one or more risk factors were present in 98% of SEA patients and 21% of controls (p < 0.01). The erythrocyte sedimentation rate (ESR) was more sensitive and specific than total white blood cell (WBC) count as a screen for SEA. In conclusion, diagnostic delays are common in patients with SEA, often leading to irreversible neurologic deficits. The use of risk factor assessment is more sensitive than the use of the classic diagnostic triad to screen ED patients with spine pain for SEA. The ESR may be a useful screening test before magnetic resonance imaging in selected patients.
Adult↗