Hypotension, hypoxia, and head injury: frequency, duration, and consequences

BACKGROUND

Retrospective studies have suggested an association between systemic hypotension and hypoxia and worsened outcome from traumatic brain injury. Little is known, however, about the frequency and duration of these potentially preventable causes of secondary brain injury.

HYPOTHESIS

Early episodes of hypoxia and hypotension occurring during initial resuscitation will have a significant impact on outcome following traumatic brain injury.

DESIGN

Prospective cohort study.

SETTING

Urban level I trauma center.

PATIENTS

Patients with a traumatic brain injury who had a Glasgow Coma Score of 12 or less within the first 24 hours of admission to the hospital and computed tomographic scan results demonstrating intracranial pathologic features. Patients who died in the emergency department were excluded from the study.

MAIN OUTCOME MEASURES

Automated blood pressure and pulse oximetry readings were collected prospectively from the time of arrival through initial resuscitation. The number and duration of hypotensive (systolic blood pressure, < or =90 mm Hg) and hypoxic (oxygen saturation, < or =92%) events were analyzed for their association with mortality and neurological outcome.

RESULTS

One hundred seven patients met the enrollment criteria (median Glasgow Coma Score, 7). Overall mortality was 43%. Twenty-six patients (24%) had hypotension while in the emergency department, with an average of 1.5 episodes per patient (mean duration, 9.1 minutes). Of these 26 patients with hypotension, 17 (65%) died (P =.01). When the number of hypotensive episodes increased from 1 to 2 or more, the odds ratio for death increased from 2.1 to 8.1. Forty-one patients (38%) had hypoxia, with an average of 2.1 episodes per patient (mean duration, 8.7 minutes). Of these 41 patients with hypoxia, 18 (44%) died (P =.68).

CONCLUSIONS

Hypotension, but not hypoxia, occurring in the initial phase of resuscitation is significantly (P =.009) associated with increased mortality following brain injury, even when episodes are relatively short. These prospective data reinforce the need for early continuous monitoring and improved treatment of hypotension in brain-injured patients.

Nintedanib in patients with progressive fibrosing interstitial lung diseases-subgroup analyses by interstitial lung disease diagnosis in the INBUILD trial: a randomised, double-blind, placebo-controlled, parallel-group trial

BACKGROUND

The INBUILD trial investigated the efficacy and safety of nintedanib versus placebo in patients with progressive fibrosing interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis (IPF). We aimed to establish the effects of nintedanib in subgroups based on ILD diagnosis.

METHODS

The INBUILD trial was a randomised, double-blind, placebo-controlled, parallel group trial done at 153 sites in 15 countries. Participants had an investigator-diagnosed fibrosing ILD other than IPF, with chest imaging features of fibrosis of more than 10% extent on high resolution CT (HRCT), forced vital capacity (FVC) of 45% or more predicted, and diffusing capacity of the lung for carbon monoxide (DLco) of at least 30% and less than 80% predicted. Participants fulfilled protocol-defined criteria for ILD progression in the 24 months before screening, despite management considered appropriate in clinical practice for the individual ILD. Participants were randomly assigned 1:1 by means of a pseudo-random number generator to receive nintedanib 150 mg twice daily or placebo for at least 52 weeks. Participants, investigators, and other personnel involved in the trial and analysis were masked to treatment assignment until after database lock. In this subgroup analysis, we assessed the rate of decline in FVC (mL/year) over 52 weeks in patients who received at least one dose of nintedanib or placebo in five prespecified subgroups based on the ILD diagnoses documented by the investigators: hypersensitivity pneumonitis, autoimmune ILDs, idiopathic non-specific interstitial pneumonia, unclassifiable idiopathic interstitial pneumonia, and other ILDs. The trial has been completed and is registered with ClinicalTrials.gov, number NCT02999178.

FINDINGS

Participants were recruited between Feb 23, 2017, and April 27, 2018. Of 663 participants who received at least one dose of nintedanib or placebo, 173 (26%) had chronic hypersensitivity pneumonitis, 170 (26%) an autoimmune ILD, 125 (19%) idiopathic non-specific interstitial pneumonia, 114 (17%) unclassifiable idiopathic interstitial pneumonia, and 81 (12%) other ILDs. The effect of nintedanib versus placebo on reducing the rate of FVC decline (mL/year) was consistent across the five subgroups by ILD diagnosis in the overall population (hypersensitivity pneumonitis 73·1 [95% CI -8·6 to 154·8]; autoimmune ILDs 104·0 [21·1 to 186·9]; idiopathic non-specific interstitial pneumonia 141·6 [46·0 to 237·2]; unclassifiable idiopathic interstitial pneumonia 68·3 [-31·4 to 168·1]; and other ILDs 197·1 [77·6 to 316·7]; p=0·41 for treatment by subgroup by time interaction). Adverse events reported in the subgroups were consistent with those reported in the overall population.

INTERPRETATION

The INBUILD trial was not designed or powered to provide evidence for a benefit of nintedanib in specific diagnostic subgroups. However, its results suggest that nintedanib reduces the rate of ILD progression, as measured by FVC decline, in patients who have a chronic fibrosing ILD and progressive phenotype, irrespective of the underlying ILD diagnosis.

FUNDING

Boehringer Ingelheim.

The value of edema fluid protein measurement in patients with pulmonary edema

Alveolar fluid and plasma proteins were analyzed in 24 patients with florid pulmonary edema, in 21 of whom pulmonary capillary wedge pressure (Pcw) was also measured. In all patients with Pcw less than 20 mm Hg, the edema fluid to plasma protein ratio exceeded 0.6; the mean edema fluid to plasma protein ratio in the four patients with cardiogenic edema (increased Pcw) was 0.46. In the 21 patients in whom full data were available, the net intravascular filtration force (Pcw - plasma colloid osmotic pressure) was less than -4 mm Hg, the value at which (according to others) pulmonary edema should occur, in only 10. When the interstitial colloid osmotic pressure, approximated by the osmotic pressure of edema fluid protein, was added, the net filtration force became positive in 17 of 21 patients. Comparison of the protein concentrations of edema fluid and plasma aids in the diagnostic separation of increased permeability from high hydrostatic pressure edema and adds to our understanding of the relative osmotic and hydrostatic forces that contribute to pulmonary edema when the alveolar-capillary membrane is damaged.

Decreased mortality from brain abscesses since advent of computerized tomography

No deaths have occurred among 20 consecutive patients with intraparenchyma brain abscesses treated at the University of California, San Francisco, since computerized tomographic (CT) brain scanning became a routine diagnostic procedure (study period: July, 1974, to June, 1977). These patients have been compared to 18 consecutive cases treated without benefit of CT analysis (January, 1970, to June, 1974) in order to determine the factors responsible for the recently improved prognosis. The mortality rate was 44% for all cases and 36% for all operated patients treated before the availability of CT. Similar morbidity (about 33%) was seen in survivors from both series. No significant differences in the two groups were noted with respect to patient population and antibiotic or corticosteroid therapy. Among the factors that may have contributed to the improved results for patients diagnosed with CT are: less frequent occurrence of multiple abscesses, fewer patients with poor preoperative clinical status, and a greater incidence of total abscess removal. In addition, CT scanning provided more accurate diagnosis and localization of abscesses and aided in the rapid detection of postoperative complications that probably accounted for six out of eight deaths in the earlier series. Serial CT studies provide a means to optimize the timing for surgical intervention and plan appropriate medical therapy. It is noteworthy that two patients have been followed by serial CT scans to non-surgical cures.

Five year results of LINAC radiosurgery for arteriovenous malformations: outcome for large AVMS

PURPOSE

For radiosurgery of large arteriovenous malformations (AVMs), the optimal relationship of dose and volume to obliteration, complications, and hemorrhage is not well defined. Multivariate analysis was performed to assess the relationship of multiple AVM and treatment factors to the outcome of AVMs significantly larger than previously reported in the literature.

METHODS AND MATERIALS

73 patients with intracranial AVMs underwent LINAC radiosurgery. Over 50% of the AVMs were larger than 3 cm in diameter and the median and mean treatment volumes were 8.4 cc and 15.3 cc, respectively (range 0.4-143.4 cc). Minimum AVM treatment doses varied between 1000-2200 cGy (median: 1600 cGy).

RESULTS

The obliteration rates for treatment volumes < 4 cc, 4-13.9 cc, and > or = 14 cc were 67%, 58%, and 23%, respectively. AVM obliteration was significantly associated with higher minimum treatment dose and negatively associated with a history of prior embolization with particulate materials. No AVM receiving < 1400 cGy was obliterated. The incidence of post-radiosurgical imaging abnormalities and clinical complications rose with increasing treatment volume. For treatment volumes > 14 cc receiving > or = 1600 cGy, the incidence of post-radiosurgical MRI T2 abnormalities was 72% and the incidence of radiation necrosis requiring resection was 22%. The rate of post-radiosurgical hemorrhage was 2.7% per person-year for AVMs with treatment volumes < 14 cc and 7.5% per person-year for AVMs > or = 14 cc.

CONCLUSION

As AVM size increases, the dose-volume range for the optimal balance between successful obliteration and the risk of complications and post-radiosurgical hemorrhage narrows.

Effects of the bradykinin antagonist Bradycor (deltibant, CP-1027) in severe traumatic brain injury: results of a multi-center, randomized, placebo-controlled trial. American Brain Injury Consortium Study Group

A phase II prospective, randomized, double blind clinical trial of Bradycor, a bradykinin antagonist, was conducted at 31 centers within North America in severely brain injured patients. Patients of Glasgow Coma Score (GCS) 3-8 (n = 139) with at least one reactive pupil were randomized to receive either Bradycor, 3 microg/kg/min or placebo as a continuous intravenous infusion for 5 days, with the infusion beginning within 12 h of the injury. The primary objective was to assess the efficacy of a continuous infusion of Bradycor (3.0 mc/kg/min) in preventing elevation of intracranial pressure (ICP). Other efficacy measures included the effect of Bradycor on the Therapy Intensity Level (TIL), mortality, and functional outcome. A secondary objective was to evaluate the safety of Bradycor in patients with severe brain injury. Randomization was carried out according to a computer generated randomization list. Patients were followed for the first 14 days of hospitalization with long-term outcome assessed at 3 and 6 months after injury. During the infusion and while the ICP monitor was in place, ICP measurements were recorded hourly along with blood pressure and heart rate. A modified version of the TIL was used to record therapeutic interventions hourly, while the ICP was being monitored. Outcome was assessed at 3 and 6 months after injury using the Glasgow Outcome Score (GOS). Bradycor was well tolerated in this patient population, and no adverse events were attributable to the compound. Although positive trends were seen for both ICP and TIL in the Bradycor group, these differences analyzed on a daily basis were not significant. However, a mixed model of variance which included treatment, day, treatment by day interaction, age and GCS revealed that the percentage time ICP of >15 mm Hg on days 4 and 5 was significantly lower in the Bradycor group compared to placebo (p = 0.035). There were fewer deaths in the Bradycor group, which had a 28-day all cause mortality of 20% versus 27% on placebo. Patients treated with Bradycor showed a 10.3% improvement in favorable outcome at 3 months and a 12% improvement in dichotomized GOS at 6 months (p = 0.26). The consistent positive trends seen in ICP, TIL, neuropsychological tests, and, most importantly, 3- and 6-month GOS provide supportive evidence that a bradykinin antagonist may play a neuroprotective role in severe brain injury.

Upward transtentorial herniation: seven cases and a literature review

Seven cases of upward transtentorial herniation occurred. In each patient, coma with reactive, miotic pupils, asymmetrical or absent caloric responses, and decerebrate posture indicated brain-stem compression. In this setting, the development of unequal, then midposition, fixed pupils signaled midbrain failure from upward herniation. Vertebral angiography showed upward displacement of the superior cerebellar arteries. Results of autopsy confirmed the existence of grooving of the vermis by the tentorial margins and, in one case, of anterior displacement and distortion of the midbrain. In five of 45 reported cases of upward herniation, the conditions were diagnosed antemortem. Instances of cerebellar hematoma and tumor predominated. In at least seven patients, performance of ventriculography may have precipitated herniation. Clinical details were provided in only nine patients and did not separate upward herniation from brain-stem compression. Cerebellar ischemic infarct found in one of our patients is a rarely reported cause of upward herniation.

Gadolinium-DTPA enhanced magnetic resonance imaging in acoustic neuroma diagnosis and management

Gadolinium-DTPA (Gd-DTPA) is a paramagnetic contrast agent that increases the intensity of acoustic neuromas (AN) on T1-weighted magnetic resonance imaging (MRI) scans. Over a 9-month period we have reviewed Gd-DTPA-enhanced MRI scans on 32 consecutive cases (35 tumors) involving the internal auditory canal (IAC) and cerebellopontine angle (CPA). The majority of patients (84%) were imaged on latest generation 1.5 Tesla scanners. Every tumor studied showed marked enhancement after Gd-DTPA administration. This improved contrast permitted identification of three small tumors that were not evident on unenhanced scans. Gd-DTPA appears to be particularly useful in the evaluation of recurrent or residual AN. In three patients with known residual tumor after planned subtotal excisions, the remaining tumor could only be differentiated from surrounding scar, cerebral spinal fluid (CSF), and brain parenchyma after contrast enhancement. In one of these, a small rim of tumor capsule left on the facial nerve was evident only on Gd-DTPA-enhanced T1 images. Gd-DTPA also provides a more reliable estimate of the depth of tumor penetration in the IAC. This information is useful in selecting candidates suitable for a hearing conservation approach.

Disseminated granulomatous acanthamoeba infection presenting as an unusual skin lesion

A fatal case of disseminated granulomatous infection with a skin lesion and focal encephalitis due to Acanthamoeba astronyxis is reported. Indirect fluorescent antibody tests of both tissue and serum from the patient established the diagnosis. The administration of amphotericin B is ineffective in vitro and has not been effective in vivo. It is recommended that corticosteroid therapy be avoided because it may aggravate the disease. Physicians caring for diseases caused by free-living ameba may call the CDC Parasitic Drug Service.

Changes in Body Mass Index Over Time in People With and Without HIV Infection

Background

Excess weight gain is an important health concern among people with HIV (PWH) on antiretroviral therapy (ART). The extent to which ART contributes to body mass index (BMI) changes is incompletely understood.

Methods

We conducted a retrospective study of PWH initiating ART and demographically matched people without HIV (PWoH). Data on baseline BMI (kg/m2; categorized as underweight/normal, overweight, or obese) and ART class (integrase strand transfer inhibitor [INSTI], non-nucleoside reverse transcriptase inhibitor [NNRTI], protease inhibitor [PI]) were obtained from electronic health records. BMI was evaluated longitudinally using piecewise linear splines in mixed effects models by HIV status, baseline BMI, and ART class. Models were adjusted for sociodemographics, comorbidities, and substance use.

Results

The study included 8256 PWH and 129 966 PWoH (mean baseline age, 40.9 and 42.2 years, respectively; 88% men). In adjusted models, the average annual change in BMI in the first 2 years after ART initiation was 0.53 for PWH and 0.12 for PWoH (P < .001). BMI increases among PWH were observed for all ART classes: 0.69 for INSTIs, 0.69 for PIs, and 0.40 for NNRTIs vs 0.12 among PWoH. For PWH initiating INSTIs, BMI increases were observed regardless of baseline BMI. Overall BMI changes >2 years after ART initiation were similar by HIV status (0.02 average annual increase for PWH and PWoH).

Conclusions

PWH initiating ART gained excess weight in the first 2 years, emphasizing the importance of monitoring weight and cardiometabolic health among ART-treated PWH.

Monitoring in traumatic brain injury

In the past several years, improvements in technology have advanced the monitoring capabilities for patients with TBI. The primary goal of monitoring the patient with TBI is to prevent secondary insults to the brain, primarily cerebral ischemia. Cerebral ischemia may occur early and without clinical correlation and portends a poor outcome. Measurement of ICP is the cornerstone of monitoring in the patient with TBI. Monitoring of ICP provides a measurement of CPP and a rough estimation of CBF. However, with alterations in pressure autoregulation, measurement of CPP does not always allow for determination of CBF. To circumvent this problem, direct measurements of CBF can be performed using clearance techniques (133Xe, N2O, Xe-CT) or invasive monitoring techniques (LDF, TDF, NIRS). Although direct and quantitative, clearance techniques do not allow for continuous monitoring. Invasive CBF monitoring techniques are new, and artifactual results can be problematic. The techniques of jugular venous saturation monitoring and TCD are well established and are powerful adjuncts to ICP monitoring. They allow the clinician to monitor cerebral oxygen extraction and blood flow velocity, respectively, for any given CPP. Use of TCD may predict posttraumatic vasospasm before clinical sequelae. Jugular venous saturation monitoring may detect clinically occult episodes of cerebral ischemia and increased oxygen extraction. Jugular venous saturation monitoring optimizes the use of hyperventilation in the treatment of intracranial hypertension. Although PET and SPECT scanning allow direct measurement of CMRO2, these techniques have limited application currently. Similarly, microdialysis is in its infancy but has demonstrated great promise for metabolic monitoring. EEG and SEP are excellent adjuncts to the monitoring arsenal and provide immediate information on current brain function. With improvements in electronic telemetry, functional monitoring by EEG or SEP may become an important part of routine monitoring in TBI.