The management of cerebral perfusion pressure and intracranial pressure after severe head injury

Effect of intraarterial papaverine and/or angioplasty on the cerebral veins in patients with vasospasm after subarachnoid hemorrhage due to ruptured intracranial aneurysms

Object

The goal in this study was to determine if there was a change in intracranial venous diameters after endo-vascular treatment of carotid distribution vasospasm caused by subarachnoid hemorrhage.

Methods

The venous diameters were measured in all patients who received intraarterial papaverine and/or balloon angioplasty for treatment of vasospasm during the study period of 3 years. To evaluate the veins of Labbé and Trolard, the straight sinus, and the superior sagittal sinus (SSS), measurements were performed in a blinded manner with the aid of a magnification loupe. Predetermined sites were evaluated on angiograms obtained before and after endovascular treatment. Forty-three treatments in 26 patients were included: 18 patients (33 territories) were treated with intraarterial papaverine alone, four (four territories) were treated with balloon angioplasty alone, and four (six territories) were treated with both papaverine infusion and angioplasty.

The mean measured venous diameters increased significantly after addition of papaverine (10.9%), and also after combined papaverine and angioplasty (4.2%). There was no statistically significant increase in the mean venous diameters after angioplasty alone. If the initial intracranial pressure (ICP) was less than 15 mm Hg before treatment, the veins showed a greater tendency to dilate than if the initial ICP measurements were greater than 15 mm Hg. The straight sinus and the SSS increased more in diameter than the veins of Labbé and Trolard. There was no statistically significant correlation between the change in venous diameters with treatment and ICP.

Conclusions

Endovascular treatment produces measurable increases in intracranial venous diameters. However, these changes do not correlate with changes in ICP.

A single dose, three-arm, placebo-controlled, phase I study of the bradykinin B2 receptor antagonist Anatibant (LF16-0687Ms) in patients with severe traumatic brain injury

Traumatic brain injury (TBI) mortality and morbidity remains a public health challenge. Because experimental studies support an important role of bradykinin (BK) in the neurological deterioration that follows TBI, a double-blind, randomized, placebo-controlled study of Anatibant (LF16- 0687Ms), a selective and potent antagonist of the BK B(2) receptor, was conducted in severe (Glasgow Coma Scale [GCS] < 8) TBI patients (n = 25) at six sites in the United States. At 8-12 h after injury (9.9 +/- 2.8 h), patients received a single subcutaneous injection of Anatibant (3.75 mg or 22.5 mg, n = 10 each) or placebo (n = 5). The primary objective was to investigate the pharmacokinetics of Anatibant; general safety, local tolerability, levels of the bradykinin metabolite BK1-5 in plasma and cerebrospinal fluid (CSF), intracranial pressure (ICP), and cerebral perfusion pressure were also assessed. We observed a dose-proportionality of the pharmacokinetics, Cmax, and AUC of Anatibant. V(d)/F, Cl/F, and t(1/2) were independent on the dose and protein binding was >97.7%. Anatibant, administered as single subcutaneous injections of 3.75 g and 22.5 mg, was well tolerated in severe TBI patients with no unexpected clinical adverse events or biological abnormalities observed. Interestingly, plasma and CSF levels of BK1-5 were significantly and markedly increased after trauma (e.g., 34,700 +/- 35,300 fmol/mL in plasma vs. 34.9 +/- 5.6 fmol/mL previously reported for normal volunteers), supporting the use of Anatibant as a treatment of secondary brain damage. To address this issue, a dose-response trial that would investigate the effects of Anatibant on the incidence of raised ICP and on functional outcome in severe TBI patients is needed.

Hospitalizations for critically ill children with traumatic brain injuries: A longitudinal analysis*

OBJECTIVE

This study examines the incidence, utilization of procedures, and outcomes for critically ill children hospitalized with traumatic brain injury over the period 1988-1999 to describe the benefits of improved treatment.

DESIGN

Retrospective analysis of hospital discharges was conducted using data from the Health Care Cost and Utilization Project Nationwide Inpatient Sample that approximates a 20% sample of U.S. acute care hospitals.

SETTING

Hospital inpatient stays from all types of U.S. community hospitals.

PARTICIPANTS

The study sample included all children aged 0-21 with a primary or secondary ICD-9-CM diagnosis code for traumatic brain injury and a procedure code for either endotracheal intubation or mechanical ventilation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Deaths occurring during hospitalization were used to calculate mortality rates. Use of intracranial pressure monitoring and surgical openings of the skull were investigated as markers for the aggressiveness of treatment. Patients were further classified by insurance status, household income, and hospital characteristics. Over the 12-yr study period, mortality rates decreased 8 percentage points whereas utilization of intracranial pressure monitoring increased by 11 percentage points. The trend toward more aggressive management of traumatic brain injury corresponded with improved hospital outcomes over time. Lack of insurance was associated with vastly worse outcomes. An estimated 6,437 children survived their traumatic brain injury hospitalization because of improved treatment, and 1,418 children died because of increased mortality risk associated with being uninsured. Improved treatment was valued at approximately dollar 17 billion, whereas acute care hospitalization costs increased by dollar 1.5 billion (in constant 2000 dollars). Increased mortality in uninsured children was associated with a dollar 3.76 billion loss in economic benefits.

CONCLUSIONS

More aggressive management of pediatric traumatic brain injury appears to have contributed to reduced mortality rates over time and saved thousands of lives. Additional lives could be saved if mortality rates could be equalized between insured and uninsured children.

Non-invasive assessment of cerebral perfusion pressure in brain injured patients with moderate intracranial hypertension

BACKGROUND

A non-invasive estimation of cerebral perfusion pressure (CPP) using transcranial Doppler sonography was assessed in brain-injured patients by comparing conventional measurements of CPP (difference between mean arterial pressure and intracranial pressure) (CPPm) with the difference between AP(mean) and the critical closing pressure of the cerebral circulation (CPPe).

METHODS

Twenty adults with bilateral and diffuse brain injuries were included in the study. CPPe was estimated using a formula combining the phasic values of flow velocities and arterial pressure. In group A (n=10) the comparison was repeatedly performed under stable conditions. In group B (n=10) the comparison was performed during a CO(2) reactivity test. Covariance analysis was used to assess the relationships.

RESULTS

In group A, CPPe and CPPm were correlated (slope, 0.76; intercept, +10.9; 95% CI, -3.5 to +25.4). During the increase in intracranial pressure (group B) (+1.9 (sd 1.5) mm Hg per mm Hg of Pe'(co(2))) the relationship persisted (slope, 0.55; intercept, +32.6; 95% CI, +16.3 to +48.9) but the discrepancy between the two variables increased as reflected by the increase in bias and variability.

CONCLUSION

Non-invasive estimation of CPP can be used for brain monitoring of head-injured patients, but the accuracy of the method may depend on the level of intracranial hypertension.

Traumatic brain injury outcome: concepts for emergency care

Injury to the brain is the leading factor in mortality and morbidity from traumatic injury. The devastating personal, social, and financial consequences of traumatic brain injury (TBI) are compounded by the fact that most people with TBI are young and previously healthy. From the emergency physician's standpoint, patients with severe TBI are those with a presenting Glasgow Coma Scale score of less than 9. Over the past 30 years, mortality from severe traumatic brain injury for those patients who survive to the hospital has been reduced by half from nearly 50% to approximately 25%. Because most of the pathologic processes that determine outcome are fully active during the first hours after TBI, the decisions of emergency care providers may be crucial. This review addresses new concepts and information in the pathophysiology of TBI and secondary brain injury and demonstrates how emergency management may be linked to neurologic outcome.

Emergency management of the head trauma patient. Principles and practice

Management of the severely brain-injured dog or cat can be frustrating, especially considering the lack of proven effective therapies for head trauma patients. A working knowledge of the basic pathophysiology of head trauma and intracranial pressure (ICP) dynamics is essential to the logical treatment of head traumatized patients. Prevention and correction of hypotension and hypoxemia are necessary for preventing progressive increases in ICP. Mannitol is recommended in most cases of severe head trauma, but there is little evidence to support the use of glucocorticoids in acutely brain-injured dogs and cats. The role of surgical intervention for head-traumatized dogs and cats is still uncertain, but may be beneficial in some cases. Aggressive, expedient treatment and attentive patient monitoring are key aspects of successfully managing canine and feline head trauma patients.

[Treatment of intracranial hypertension in the case of severe craniocerebral injuries]

More than 50% of severely head-injured patients develop increased intracranial pressure, risking exacerbating ischaemic insults to the already injured brain. In approximately 10% of these cases, intracranial pressure may become unresponsive to medical or surgical treatment, with a resulting mortality of over 90%. The main emphasis should be on full intensive care, based on the prophylaxis of the devastating effects of secondary insults to the injured brain. Specific treatment should be directed towards controlling intracranial pressure and maintaining a cerebral perfusion pressure over 70 mmHg, while avoiding, where feasible, treatment modalities at risk of exacerbating cerebral ischaemia. Recently, an algorithm for treating intracranial hypertension under three different therapeutic situations has been suggested, based on the successive application of effective agents with increasing associated risks. Therapeutic modalities of this protocol are discussed.

-Secondary cerebral stress of systemic origin in children with severe craniocerebral injuries-

OBJECTIVE

To assess incidence of secondary brain insults of systemic origin (SBISOs) such as arterial hypotension, hypoxaemia, hypercarbia, and anaemia in severely head injured children; to assess their impact on mortality and morbidity in the short- and long-term.

STUDY DESIGN

Prospective, open study covering a 24-month period.

PATIENTS

Seventy-one children, under 15 years of age, admitted to a trauma centre for severe brain injury.

METHOD

Analysis of SBISOs and outcome.

RESULTS

Twenty-five children were admitted with SBISOs. The mortality rate was 37%. After hospitalization, 84% of the children with SBISOs vs 46% without SBISOs had severe disability (Glasgow outcome score = 1, 2 and 3). After 1 year, 20 out of the 45 children still alive were contacted. One of the four with SBISOs communicated a bad recovery. Fifteen children without SBISOs presented good recovery: GOS = 4-5, paediatric overall performance category (POPC scale) = 1-2.

CONCLUSION

Hypotension was associated with significant increase in mortality (x 3.6) in children with severe head injury. The consequences were worse when anaemia was associated.

The neurovascular complications of cocaine

BACKGROUND

Cocaine use has been temporally associated with neurovascular complications, including the rupture of intracerebral aneurysms. The purpose of the current study was to determine the type of neurovascular complications associated with cocaine use in our patient population, the temporal relationship between cocaine use and their onset, and whether cocaine users with subarachnoid hemorrhage (SAH) presented with smaller aneurysms at an earlier age than a control group of noncocaine users with SAH.

METHODS

Thirty-three patients who presented to the Detroit Medical Center with neurovascular sequelae associated with cocaine use were identified. All patients were chronic cocaine users who related a history of recent use confirmed by a drug screen. Cocaine users with SAH were compared to a control group of 44 patients with SAH who presented without evidence of cocaine use.

RESULTS

Sixteen patients presented with SAH. Twelve patients subsequently underwent four-vessel cerebral arteriogram revealing 14 aneurysms; six patients presented with intracerebral hemorrhage (ICH) and seven patients with evidence of ischemic stroke. Eighteen (54.5%) patients noted onset of their symptoms while using cocaine, 87.9% noted onset within 6 hours of use. Delayed presentation occurred predominantly in patients who suffered ischemic strokes. The average age of patients who used cocaine and presented with SAH secondary to a ruptured intracerebral aneurysm was 32.8 years with an average aneurysm diameter of 4.9 mm versus an average age of 52.2 years with an average aneurysm diameter of approximately 11.0 mm in noncocaine users. Population differences were statistically significant at the p < 0.05 level. Mortality was 27.3% for patients who presented with neurovascular sequelae of their cocaine use, with 77.8% of deaths occurring in patients who presented with SAH.

CONCLUSIONS

Chronic cocaine use appears to predispose patients who harbor incidental neurovascular anomalies to present at an earlier point in their natural history than similar non-cocaine users.

Out-of-hospital administration of mannitol to head-injured patients does not change systolic blood pressure

OBJECTIVE

To determine the effect of out-of-hospital mannitol administration on systolic blood pressure (BP) in the head-injured multiple-trauma patient.

METHODS

This was a prospective, randomized, double-blind, placebo-controlled clinical trial involving a university-based helicopter air medical service and level-1 trauma center hospital. Endotracheally intubated head-trauma victims with Glasgow Coma Scale (GCS) scores < 12 were enrolled from November 22, 1991, to November 20, 1992, if evaluated by the participating aeromedical transport team within 6 hours of injury. Patients were excluded if they were < 18 years old, had already received mannitol or another diuretic, were potentially pregnant, or were receiving CPR. All patients were intubated prior to study drug (mannitol [1 g/kg] or normal saline) use. Pulse and BP were measured every 15 minutes for 2 hours following study drug administration.

RESULTS

A total of 44 patients were enrolled. After exclusion of 3 patients who did not meet all inclusion criteria, there were 20 patients in the mannitol group and 21 patients in the placebo group. The groups were similar at baseline in age, pulse, systolic BP (baseline mannitol: 124 +/- 47 mm Hg; placebo: 128 +/- 32 mm Hg), GCS score, and Injury Severity Scale score. Systolic BP did not change significantly throughout the observation period in either group. This study had 83% power to detect a mean systolic BP drop to < 90 mm Hg.

CONCLUSION

Out-of-hospital administration of mannitol did not significantly change systolic BP in this group of head-injured multiple-trauma patients.

Traumatic brain injury

Traumatic brain injury (TBI) contributes significantly to the mortality and morbidity rates of traumatized patients. This article presents current concepts in the pathophysiology of TBI, including mechanisms of injury, biomolecular mediators of injury, and the occurrence of secondary injury. Emergency management, monitoring, and imaging of TBI also are reviewed.

Intracranial pressure changes induced during papaverine infusion for treatment of vasospasm

The authors reviewed the cases of 21 patients who received intraarterial infusions of papaverine to determine the drug's effects on intracranial pressure (ICP), mean arterial blood pressure, pulse rate, and cerebral perfusion pressure (CPP). The study focused on patients with aneurysmal subarachnoid hemorrhage who developed clinical signs and symptoms of vasospasm, which was documented by cerebral angiography. In 18 patients, an average dose of 300 mg papaverine was administered over 20 to 35 minutes using a No. 5 French catheter inserted into the high cervical internal carotid artery or vertebral artery. Two other patients received superselective infusions via a microcatheter placed in the anterior cerebral artery. Sixteen patients (76%) experienced good angiographic results, and 11 (52%) obtained objective clinical improvement within 48 hours. Significant elevations in ICP, blood pressure, and pulse rate were noted during papaverine infusion. In contrast, no statistically significant sustained change in CPP was observed, although it tended to decrease during papaverine infusion. In one elderly patient, infusion of the common carotid artery resulted in profound bradycardia and hypotension with a subsequent significant increase in ICP and a marked decrease in CPP. The increase in ICP in these patients correlates well with changes seen in animal models and is probably related to increased cerebral blood flow. A careful, titrated infusion of papaverine, with constant reference to the patient's ICP, blood pressure, and pulse rate, minimizes the transient increase in ICP while maintaining adequate blood pressure and CPP. Failure to monitor these parameters during the infusion, with appropriate modification of the rate of titration, could potentially produce an uncontrolled change in ICP or CPP.

[Concept of secondary cerebral injury of systemic origin]

The prevention and treatment of secondary insults to the brain of systemic origin in severely head injured patients remain of utmost importance. Head injury remains the leading cause of traumatic death, being responsible for 50-60% of fatalities. Head-injured patients not only suffer from the primary injury at the time of trauma, but also from the secondary, largely ischaemic, brain damage that occurs later. Some of these insults are of extracranial origin (or systemic), such as arterial hypotension, hypoxaemia, hypercarbia and anaemia. Their impact on mortality and morbidity is extremely high and requires greater efforts in improving the care of head-injured patients. Systemic insults occur either before the patient reaches hospital or during interfacility transfer or, in a surprisingly large number of cases, within hospital during emergency procedures, intrahospital transport or during their stay in intensive care units. Hypoxaemia, although quite easy to treat, is still common. This calls for better and earlier protection of the airway, more systematic administration of oxygen to trauma patients and wider use of pulse oximetry. Arterial hypotension has even more dramatic consequences in severe head injury. Recent studies indicate that short episodes of hypotension may induce severe brain ischaemia, that will be present even after complete systemic haemodynamic restoration. The treatment of hypotensive episodes should be immediate and aggressive. In some circumstances, restoration of an adequate cerebral perfusion pressure may not be obtained sufficiently rapidly with fluids alone and may require early use of vasopressors. Optimal haemodynamic resuscitation of the trauma patient with haemorrhagic hypotension and severe head injury remains a special challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of life-threatening trauma

The response to major traumatic injury is a clinical challenge for even a well-trained hospital team. Efficient, effective treatment must be initiated as life-threatening problems are identified, often without the benefit of a definitive diagnosis. Therapy focuses on maximizing oxygen delivery and oxygen utilization in a hypermetabolic patient by improving gas exchange and blood flow. An algorithmic approach to patient care during a fast-paced, high-stress resuscitation is known to optimize this therapy and to improve outcome. Even with their proven benefit in facilitating patient care, algorithms have inherent limitations that require attention and common sense on the part of the attending clinician. It is true that "trauma can take you anywhere" and even a minor injury, especially if improperly managed, can lead to life-threatening complications and death. No algorithm can include all of trauma and all the possible sequelae without being too difficult for practical application. The algorithms cannot include basic common sense, which, right or wrong, is assumed to be a part of each doctor's decision-making skills. The algorithms are inherently in series, whereas emergency patient care requires the management of complex problems in parallel. The clinician is required to understand the priorities outlined in the algorithms, to have the skill to identify life-threatening problems, to use the appropriate protocol, and to move forward or backward in the protocol when the patient's condition demands a change of focus and priority. The algorithms enhance but are not a substitute for up-to-date medical knowledge, familiarity with anatomy, good clinical skills, and experience. Finally, although these algorithms are based on years of clinical experience, they have not been tested with the appropriate prospective clinical studies needed to generate veterinary outcome statistics. Future modifications in algorithm protocol will be based on such studies.