Cerebral protection: pathophysiology and treatment of increased intracranial pressure

Change in the optic nerve sheath diameter after deflation of a pneumatic tourniquet: a prospective observational study

Applying a pneumatic tourniquet provides surgeons with a bloodless surgical field. However, application of the tourniquet induces various physiological changes. We evaluated the effect of tourniquet deflation on the intracranial pressure by using ultrasonography to measure the optic nerve sheath diameter (ONSD) in patients undergoing lower limb surgery. The ONSD was measured in 20 patients at five time points: after anesthetic induction (T0) and immediately before (T1), immediately after (T2), 5 min after (T3), and 10 min after tourniquet deflation (T4). Hemodynamic and respiratory variables were recorded. The ONSD showed significant differences at each point (P < 0.001). The ONSDs at T2 and T3 were significantly greater than that at T1 (P = 0.0007 and < 0.0001, respectively). The change in the end-tidal carbon dioxide partial pressure (EtCO2) was similar to the change in the ONSD. The change in the ONSD was significantly correlated with the change in the EtCO2 after tourniquet deflation (r = 0.484, P = 0.030). In conclusion, the ONSD, as an indicator of intracranial pressure, increased after tourniquet deflation in patients undergoing lower limb surgery. This was correlated with an increased EtCO2 and arterial carbon dioxide partial pressure.Trial registration: ClinicalTrials.gov (NCT03782077).

Angiotensin II for Near Drowning: A Case Series

Objective:

This case series describes the effect of angiotensin II administration on hemodynamics in patients with parenchymal lung injury due to submersion injury.

Case Summary:

A 33-year-old female and a 72-year-old female were both brought to the emergency department after incidents of near drowning. Upon arrival to the emergency department, both patients were hemodynamically unstable and were eventually intubated for airway protection. Imaging done by conventional chest radiograph for both patients revealed bilateral pulmonary edema. Due to their hemodynamic status, vasopressors were initiated for both patients and were quickly titrated, leading to the initiation of angiotensin II. In one patient, angiotensin II was initiated early in shock and resulted in rapid improvement of hemodynamics. In the other patient, angiotensin II was initiated later and a more muted response was observed.

Conclusions:

In patients with near drowning, angiotensin II appeared to improve hemodynamic status rapidly. This is the first case series to report the use of this new vasoactive agent in this population and poses noteworthy mechanistic considerations.

Evolving Challenges in Prehospital Trauma Services: Current Issues and Suggested Evaluation Tools

For the past two decades, prehospital trauma care has been addressed almost generically in terms of the related approaches to epidemiology, research, and management. However, evolving directions in research have helped emergency medical services (EMS) practitioners to delineate more focused treatment strategies according to the mechanism of injury, anatomic involvement, and the patient's clinical condition. Recent studies in the areas of trauma-associated circulatory arrest, severe blunt head injury, and post-traumatic hemorrhage following penetrating truncal injury suggest that current standard approaches to patient care should be reconsidered. In turn, this need for re-examination of trauma management strategies calls for the development of appropriate evaluation tools within EMS systems. Proper research design is dependent upon several key issues including: 1) the type of study (system study versus examination of a specific intervention); 2), the population under study; 3) physiological and anatomical scoring method; 4) prospective definitions of interventions and meaningful outcome variables (both morbidity and mortality; 5) relative outcome compared to known standards; and 6) prospective determination of statistical requirements.

Prehospital care of the patient with major trauma

Recent research efforts have demonstrated that many longstanding practices for the prehospital resuscitation of trauma patients may be inappropriate under certain circumstances. For example, traditional practices, such as application of anti-shock garments and i.v. fluid administration to raise blood pressure, may even be detrimental in certain patients with uncontrolled bleeding, particularly those with penetrating injuries. ETI, although potentially capable of transiently prolonging a patient's ability to tolerate circulatory arrest, may also be harmful if overzealous PPV further compromises cardiac output, particularly in those patients with severe hemodynamic instability. In addition, if these procedures delay patient transport, any benefit that they may offer could be outweighed by the delay in definitive care. Although traditionally taught to "hyperventilate" the patient with severe head injury, current recommendations are to avoid this tactic unless there is evidence of herniation. Even time-honored traditions, such as universal spinal precautions and CPR during circulatory arrest, are being scrutinized [2,134]. Further prospective randomized clinical trials are needed to better define the role of many overlapping therapies in prehospital trauma care. Such research must specifically address and stratify the different mechanisms of injury, anatomic areas involved, and the physiologic staging of the injury. Furthermore, the efficacy of a single intervention may be masked by a confounding variable [5]. For example, a trial of an effective new HBOC in moribund patients that indicates no advantage in the study results may have been confounded by overzealous PPV, which may have led to suboptimal outcomes. It is hoped that, in the future, EMS physicians will be able to not only better discriminate in their management of patients with major trauma but also improve outcomes as a result.

La Crosse encephalitis in children

BACKGROUND

La Crosse encephalitis is a mosquito-borne disease that can be mistaken for herpes simplex encephalitis. It has been reported in 28 states but may be underrecognized.

METHODS

We investigated the manifestations and clinical course of La Crosse encephalitis in 127 patients hospitalized from 1987 through 1996. The diagnosis was established by serologic testing for IgM and IgG antibodies to La Crosse virus. Data were collected by chart review.

RESULTS

Most of the patients were school-aged children (mean [+/-SD] age, 7.8+/-3.5 years; range, 0.5 to 15.0). Symptoms included headache, fever, and vomiting (each in 70 percent or more of the patients), seizures (in 46 percent), and disorientation (in 42 percent). Thirteen percent had aseptic meningitis. Hyponatremia developed in 21 percent, and there were signs of increased intracranial pressure in 13 percent. Six patients, including three with cerebral herniation, underwent intracranial-pressure monitoring. The 13 patients (11 percent) whose condition deteriorated in the hospital had decreases in serum sodium levels (P=0.007), and increases in body temperature (P=0.003) at the time of deterioration. At admission, these patients more often had a history of vomiting (P=0.047) and a score of 12 or lower on the Glasgow Coma Scale (P=0.02) than the others; a trend toward a greater prevalence of seizures at admission was also evident in this group (P=0.07). All the patients survived, but 15 of them (12 percent) had neurologic deficits at discharge. Follow-up assessments, performed in 28 children, suggested an increase in cognitive and behavioral deficits 10 to 18 months after the episode of encephalitis.

CONCLUSIONS

La Crosse virus infection should be considered in children who present with aseptic meningitis or encephalitis. Hyponatremia and increasing body temperature may be related to clinical deterioration.

The efficacy of esmolol versus lidocaine to attenuate the hemodynamic response to intubation in isolated head trauma patients

OBJECTIVE

To assess the effect of esmolol vs lidocaine to attenuate the detrimental rise in heart rate and blood pressure during intubation of patients with isolated head trauma.

METHODS

This was a prospective, double-blind, randomized study, performed at an urban, county teaching emergency department. Participants were 30 patients with isolated head trauma. Each underwent a standardized intubation protocol including esmolol or lidocaine, both at 2 mg/kg.

RESULTS

Esmolol was used in 16 patients and lidocaine in 14. Mechanisms of injury included 12 assaults, 6 motor vehicle collisions, 6 falls, 4 auto-vs-pedestrian crashes, and 2 bicycle incidents. Mean ethanol level was 0.116+/-0.133 SD (range 0-0.482). Mean Glasgow Coma Scale (GCS) score was 7.9+/-4.0 SD. Cranial computed tomography (CT) hemorrhagic findings included 9 subdural/epidural hematomas, 6 cortex hemorrhages, and 2 multi-hemorrhages. Eleven patients received surgical intervention: 9 patients received a craniotomy, and 2 a ventricular catheter. The 2-minute time interval around intubation was used to assess each drug's efficacy. The mean difference change between groups for heart rate was 4.0 beats/min (95% CI = -17.7 to 9.7 beats/min), for systolic blood pressure was 1.3 mm Hg (95% CI = -27.8 to 30.4 mm Hg), and for diastolic blood pressure was 2.6 mm Hg (95% CI = -27.1 to 21.9 mm Hg). The power of this study was 90% to detect a 20-beat/min difference in heart rate, a 35-mm Hg difference in systolic blood pressure, and a 20-mm Hg difference in diastolic blood pressure.

CONCLUSIONS

Esmolol and lidocaine have similar efficacies to attenuate moderate hemodynamic response to intubation of patients with isolated head trauma.

Comparison between hypertonic saline and mannitol in the reduction of elevated intracranial pressure in a rodent model of acute cerebral injury

Clinically both mannitol and hypertonic saline (HTS) have been used successfully to treat elevated intracranial pressure (ICP), although which therapy is superior is yet unclear. Most experimental data have been derived from animal models of brain injury using general anesthesia, which may not be applicable under other conditions. Our laboratory compared the efficacy of single, equi-osmolar bolus doses of HTS and mannitol in reducing elevated ICP in a lightly sedated, unrestrained rodent model of acute brain injury. Sprague-Dawley rats were mask anesthetized for craniectomy and placement of invasive monitors. Following emergence from anesthesia, continuous sedation was provided (0.25% halothane in oxygen). A focal, liquid nitrogen cold lesion was introduced to the right parietal cortex. Animals were continuously monitored and then treated with a single bolus of 0.9% saline (control group) or 11.0 mOsm/kg equivalents of either mannitol or HTS (experimental groups) at time of maximal ICP increase (60 minutes). Both mannitol and HTS reduced ICP, but HTS was more effective-53.9% reduction versus 35.0% (P < .01). The therapeutic action of HTS was also more durable, lasting up to 500 minutes whereas the mannitol treated animals were observed to return to, and overshoot the baseline elevated ICP by 10% to 25% by 120 minutes following dosing (P < .01). Despite these differences, brain water content was similar between groups. We conclude that HTS was more effective in reducing elevated ICP in this awake model of traumatic brain injury.

Effect of prehospital advanced life support on outcomes of major trauma patients

OBJECTIVE

Determine whether prehospital advanced life support (ALS) improves the survival of major trauma patients and whether it is associated with longer on-scene times.

METHODS

A 36-month retrospective study of all major trauma patients who received either prehospital bag-valve-mask (BVM) or endotracheal intubation (ETI) and were transported by paramedics to our Level I trauma center. Logistic regression analysis determined the association of prehospital ALS with patient survival.

RESULTS

Of 9,451 major trauma patients, 496 (5.3%) had either BVM or ETI. Eighty-one percent received BVM, with a mean Injury Severity Score of 29 and a mortality rate of 67%; 93 patients (19%) underwent successful ETI, with a mean Injury Severity Score of 35 and a mortality rate of 93%. Adjusted survival for patients who had BVM was 5.3 times more likely than for patients who had ETI (95% confidence interval, 2.3-14.2, p = 0.00). Survival among patients who received intravenous fluids was 3.9 times more likely than those who did not (p = not significant). Average on-scene times for patients who had ETI or intravenous fluids were not significantly longer than those who had BVM or no intravenous fluids.

CONCLUSION

ALS procedures can be performed by paramedics on major trauma patients without prolonging on-scene time, but they do not seem to improve survival.

The Ontario Prehospital Advanced Life Support (OPALS) study Part II: Rationale and methodology for trauma and respiratory distress patients. OPALS Study Group

The Ontario Prehospital Advanced Life Support (OPALS) Study represents the largest prehospital study yet conducted, worldwide. This study will involve more than 25,000 cardiac arrest, trauma, and critically ill patients over an 8-year period (1994-2002). The current article, Part II, describes in detail the rationale and methodology for major trauma and respiratory distress patients and for an economic evaluation of Advanced Life Support (ALS) programs in the OPALS Study. The OPALS Study, using a rigorous controlled methodology and a large sample size, should clearly indicate the benefit in trauma and respiratory distress patient survival and morbidity that results from the widespread introduction of prehospital ALS programs to communities of many different sizes. [Stiell IG, Wells GA, Spaite DW, Nichol G, O'Brien B, Munkley DP, Field BJ, Lyver MB, Luinstra LG, Dagnone E, Campeau T, Ward R, Anderson S, for the OPALS Study Group: The Ontario Prehospital Advanced Life Support (OPALS) Study Part II: Rationale and methodology for trauma and respiratory distress patients.

Reappraising the prehospital care of the patient with major trauma

Recent research efforts have demonstrated that many long-standing practices for the prehospital resuscitation of trauma patients may be inappropriate, particularly in certain circumstances. Traditional practices, such as application of antishock garments and IV fluid administration, may even be detrimental in certain patients with uncontrolled bleeding. Endotracheal intubation, although potentially capable of prolonging a patient's ability to tolerate circulatory arrest, may be harmful if overzealous ventilation further compromises cardiac output in such severe hemodynamic instability. If these procedures delay patient transport, any benefit they may offer could be outweighed by delaying definitive care. To improve current systems of trauma care, future trauma research must address the different mechanisms of injury, the anatomic areas involved, and the physiologic staging in a given patient.

Near-drowning: epidemiology, pathophysiology, and initial treatment

Drowning is a major cause of accidental deaths, especially in children. The most serious pathophysiologic consequence of near-drowning is hypoxemia, which usually is due to aspiration-induced noncardiogenic edema. Therefore, initial resuscitative efforts need to be directed at establishing adequate oxygenation and ventilation, followed by rewarming and fluid administration. Although completely asymptomatic patients with normal vital signs, oxygenation and chest radiographs require only 4 to 6 hours of observation, many near-drowning victims will require at least 24 hours of observation. Despite these measures, approximately 25% of victims presenting to the Emergency Department will die and another 6% will develop neurological sequelae. Therefore, it is vital that better efforts be made by the community in promoting and instituting water safety programs.

Head trauma

No definitive, clinically proven drug therapy currently exists for reversal or amelioration of the injurious cellular events initiated by head trauma. The patient's physiologic status should therefore be monitored and managed as best as possible bearing in mind all the factors that can aggravate intracranial abnormalities. All treatment options have positive and negative aspects that should be considered and balanced on an individual patient basis. A major concern in the management of head-injured patients is the avoidance or treatment of intracranial hypertension. This may be achieved largely through medical means and accurate efforts can only be made if intracranial pressure and the variables that influence it are monitored directly. A definite place exists for surgery in the management of head-injured patients, though such a decision is best guided by objective evaluation of the intracranial vault.

Highlighting intracranial pressure monitoring in patients with severe acute brain trauma

Intracranial pressure (ICP) monitoring was carried out in 100 patients with severe acute brain trauma, primarily by means of a subarachnoid catheter. Statistical associations were evaluated between maximum ICP values and: 1) Glasgow Coma Scale (GCS) scores; 2) findings on computed tomography (CT) scans of the head; and 3) mortality. A significant association was found between low GCS scores (3 to 5) and high ICP levels, as well as between focal lesions on CT scans and elevated ICP. Mortality was significantly higher in patients with ICP > 40 mm Hg than in those with ICP < or = 20 mm Hg.

Cerebral edema and intracranial pressure monitoring

With the wide acceptance of liver transplantation as a therapeutic alternative in fulminant hepatic failure (FHF), the successful management of patients with this syndrome has acquired a new urgency. Topping the list of medical problems is the development of brain swelling. Two decades after the recognition of its importance, brain edema and intracranial hypertension still constitute a major cause of death in these patients. In a more recent classification of FHF, brain edema was especially prominent in those subjects with "hyperacute failure," in whom a period of 7 days or less elapsed between the development of jaundice and encephalopathy. The goal of this review is to discuss two aspects of this clinical problem. On one hand, elucidation of its pathogenesis should lead to a more rational therapeutic approach; such an information would also be valuable to understand the relationship between hepatic encephalopathy and brain edema, a source of controversy. Studies of pathogenic mechanisms are difficult to perform in humans and animal models of FHF have proven valuable, as brain swelling can be detected with some regularity. On the other hand, an increasing array of techniques is now available in the intensive care setting to monitor patients with FHF. Of these, intracranial pressure monitoring has received the most critical attention. However, concerns with the risks of craniotomy and the need to acquire more dynamic information has led several groups to explore non-invasive methods that evaluate the consequences of intracranial hypertension. Their role, though potentially exciting, is still uncertain.

Rapid-sequence intubation in head trauma

Elevated intracranial pressure commonly is associated with severe head injury. Emergency airway management technique in the patient who has sustained severe head injury must optimize conditions for intubation, minimize the adverse effects of intubation, and permit rapid and effective management of the elevated intracranial pressure. Disturbances in autoregulation make the injured brain particularly susceptible to the adverse effects of alterations of systemic blood pressure. Airway manipulation without adequate pharmacologic support can cause precipitous changes in systemic hemodynamic parameters. This article reviews the physiologic and pathologic relationship among airway management, systemic hemodynamic parameters, and intracranial pressure. Specific recommendations for the use of neuromuscular blocking agents, anesthetic induction agents, and adjunctive medications are provided.

Management of closed head injury in the patient with maxillofacial trauma

Closed head injury (CHI) affects approximately one in five patients who sustain facial fractures. The effects can range from simple loss of consciousness to coma and death. The high incidence of CHI in the facial trauma population and the potential for mortality and neurologic morbidity make it a distinct concern of the practicing oral and maxillofacial surgeon. This article discusses the evaluation, monitoring, and management of CHI and includes special consideration of the treatment of maxillofacial injuries in these patients.

Transport considerations for the head-injured patient: are we contributing to secondary injury?

The association between an improved prognosis and early treatment, including surgical intervention, makes air transport for the head-injured patient an important component of care. Patient positioning and the use of hyperventilation have been modes of treatment used for decreasing cerebral edema and ICP for many years. This standard of care should be emphasized during air medical transport as well.

Intracranial pressure monitoring and treatment: a contemporary view

ICP monitoring and recording provide another important parameter in the intensive care management of many critically ill patients and have been shown to augment the clinical neurologic examination, particularly in comatose patients suffering from severe head trauma, toxic and metabolic encephalopathies, massive cerebral infarctions, and many other central nervous system insults. Once considered an experimental tool restricted exclusively to sophisticated specialty neurosurgical and neuroanesthesia intensive care units, this straightforward and rapidly evolving technology is readily available and relatively easy to apply as a bedside intensive care procedure for selected patients. Many indications of particular interest to emergency physicians are indicated. The precise role of ICP monitoring in the prehospital management of patients has not been established. At this time, the conventional treatments for presumed ICP elevations, as outlined, are the mainstays of prehospital care. ICP monitoring may have a role in more extended or lengthy interinstitutional transfers of some critically ill patients.

Thiopental infusion in the treatment of intracranial hypertension complicating fulminant hepatic failure

Intracranial hypertension complicating fulminant hepatic failure has a mortality in excess of 90% in the presence of renal failure if not rapidly responsive to mannitol and ultrafiltration. Based on data which suggest that barbiturates can be of value in controlling the intracranial hypertension of head injury, intravenous thiopental was assessed in 13 patients with fulminant hepatic failure. All had developed acute renal failure complicated by intracranial hypertension unresponsive to other modes of therapy and were likely by all published criteria to have little chance of survival. The dosage of thiopental was adjusted incrementally until intracranial pressure, measured by extradural transducers, fell to within normal limits or adverse hemodynamic changes occurred. The intracranial pressure was reduced, in each case, by 185 to 500 mg (median: 250 mg) thiopental given over 15 min, and in eight cases continuing infusion achieved stable normal intracranial pressure and cerebral perfusion pressure. Five of the patients made a complete recovery and there were only three deaths from intracranial hypertension. Side effects were few and included minor hypotension controlled by dose reduction. The response of otherwise intractable intracranial hypertension and the 38% survival rate was remarkable for a group of patients with such a poor prognosis.

Acute post-traumatic respiratory physiology and insufficiency

This article reviews the physiologic mechanisms by which acute injury results in respiratory insufficiency. It delineates the need for oxygenation versus ventilatory support and provides a pragmatic approach to dealing with the proper early respiratory support of the victim of chest trauma as well as the rationale for various immediate treatment modalities. In addition, it discusses various assessment techniques and clinical clues that predict the onset of late respiratory complications in the patient with serious injuries.

Syndrome of idiopathic hyperammonemia after high-dose chemotherapy: review of nine cases

PURPOSE

The syndrome of idiopathic hyperammonemia occurs in patients who have received high-dose cytoreductive therapy for the treatment of hematologic malignancy. It is characterized by abrupt alteration in mental status and respiratory alkalosis associated with markedly elevated plasma ammonium levels in the absence of any identifiable cause, and frequently results in intractable coma and death. Our goal was to survey clinical and pathologic manifestations of the disorder and discuss treatment options.

PATIENTS AND METHODS

Plasma ammonium levels were measured in patients on the acute leukemia service or on the bone marrow transplant service at The Johns Hopkins Hospital, and a level more than twice normal was considered diagnostic of hyperammonemia. The syndrome was identified in nine patients; in eight, hyperammonemia occurred after administration of intensive cytoreductive therapy that resulted in profound leukopenia. The disorder occurred in the ninth patient two months after allogeneic bone marrow transplantation.

RESULTS

Three of the nine patients survived an episode of idiopathic hyperammonemia; one patient subsequently died of leukemia and one of recurrent idiopathic hyperammonemia. The one long-term survivor is currently alive and well without neurologic sequelae 250 days after autologous bone marrow transplantation.

CONCLUSION

Because neurologic function can deteriorate rapidly, early recognition of this disorder and close monitoring of the patient's neurologic status are critical.

Treatment of resistant intracranial hypertension with hypertonic saline. Report of two cases

The authors describe two patients with traumatic cerebral edema and intracranial hypertension in whom the continued use of mannitol and furosemide resulted in a progressive lessening of the effect of these agents on the intracranial pressure (ICP) and caused prerenal failure. Intravenous administration of hypertonic saline (50 ml and 20 ml of a 5-mmol/ml saline solution over 10 minutes in Cases 1 and 2, respectively) produced a prolonged reduction in the ICP and improved renal function in both cases. It is suggested that if a reduction in ICP without diuresis is required in patients with traumatic cerebral edema, treatment with intravenous hypertonic saline should be considered.

Clinical pharmacokinetic considerations in the treatment of increased intracranial pressure

Life-threatening increased intracranial pressure can be reversed by a variety of drugs. These compounds all have some disadvantages, producing rebound effects, severe coma or cardiovascular depression and electrolyte imbalance. However, reduction of intracranial pressure is a prerequisite for recovery and the benefits of treatment outweigh the risks. Dexamethasone is rapidly eliminated, the short half-life (about 3 hours) indicating that dosage intervals should be kept small. As yet, however, its therapeutic efficacy has not been clearly demonstrated. Therefore, an association between pharmacokinetics and pharmacodynamics cannot be established. Osmotic diuretics are the most widely used agents for reduction of intracranial pressure. Pharmacokinetics show a very close relationship to changes in serum osmolality, but there are large variations in the clearance. For the use of osmotics, the blood-brain barrier must be intact. Osmotic diuretics may lead to intracerebral oedema or to acute renal failure as serum osmolality increases. Considering the pharmacokinetics of each drug, and the dynamics of intracerebral pressure and osmolality, an intermittent, individually titrated dosage should be administered, with simultaneous monitoring of intracranial pressure. Frusemide (furosemide) can be used as an adjunct, to enhance the effect of osmotic diuretics. Its pharmacokinetics are limited by renal function, depending on age as well as on the extent of renal impairment. Altered renal elimination of concomitantly administered drugs, and electrolyte imbalances should be anticipated when diuretics are used. Barbiturates are certain to decrease intracranial pressure in humans by an as yet unknown mechanism. Their administration is recommended for patients that do not respond to conventional therapy. As barbiturates can result in deep coma, knowledge of their pharmacokinetics is of great importance for recovery. Following single doses, pentobarbitone has a relatively long elimination half-life (about 22 hours). However, after repeated administration for several days, its elimination may be enhanced due to autoinduction. Thiopentone kinetics are characterised by distribution and redistribution into deep peripheral compartments. Administration of high and frequent doses leads to considerably delayed recovery. This is not true for methohexitone, which shows comparable pharmacokinetics after single and multiple dose administration. Elimination depends on liver blood flow. Thus, recovery from methohexitone-coma is rapid. Rapid elimination is also an important characteristic of etomidate and alphaxalone/alphadolone, two non-barbiturate hypnotics.(ABSTRACT TRUNCATED AT 400 WORDS)

Prehospital management of trauma: a tale of three cities

The controversies that have surrounded the prehospital management of trauma stem not only from a lack of appropriate evaluation data, but also from a lack of medical accountability and "street-wise," academic physician involvement within emergency medical services (EMS) systems. As a result, the approach to EMS trauma care has often been over-generalized and debated in terms of simplistic, unidimensional concepts, such as "scoop and run" versus "field stabilization," without any regard for the type and anatomic location of injury involved, the efficiency and skill of rescuers, the proximity and actual capabilities of definitive care resources, and the logistics of the prehospital setting. The failure to understand and delineate these variables has led to conflicting studies and has confused the analysis of potential therapeutic modalities and management strategies. In view of this, a survey is provided of three major cities, each with intensive, academic physician involvement in their EMS systems, and the approach and rationale for their prehospital care strategies are summarized. In all three systems, patients generally are categorized according to three major injury types (penetrating, blunt, and thermal) and then further subcategorized with regard to anatomical involvement, specifically those involving potential (or known) internal truncal injuries versus those with isolated head trauma or isolated extremity injury. For all three, high-flow O2 delivery and aggressive, advanced airway management (by endotracheal intubation whenever feasible) are keystones of management. In cases of potential or known internal truncal injury, the priority is also expeditious transport to facilities with definitive surgical care with the establishment of IV access and rapid fluid infusions en route.(ABSTRACT TRUNCATED AT 250 WORDS)

Prehospital endotracheal intubation: rationale for training emergency medical personnel

Endotracheal intubation by emergency medical services (EMS) personnel in the prehospital setting decreases morbidity and helps to improve the outcome of critically ill patients, especially those with cardiac or respiratory arrest, multiple injuries, or severe head trauma. The endotracheal tube facilitates better oxygenation and ventilation because it enhances lung inflation and protects the lungs from aspiration. No other alternative modality is as efficacious. Compared to physicians in general, properly instructed, well-supervised paramedics can be trained to perform this procedure safely and more efficiently in the emergency setting. The use of the endotracheal tube in the prehospital setting should be strongly encouraged and the training of EMS personnel in this skill should be given high priority.