Refractory intracranial hypertension due to fentanyl administration following closed head injury

Severe cerebral edema related to oral methadone: A case report and literature review

Introduction

Opioids are widely used for pain management, and increased intracranial pressure (ICP) has been evidenced in some cases. We reported a patient with severe cerebral edema after initiating methadone and its complete resolution upon discontinuing the medication. Additionally, a review of the literature is made.

Case report

A 53-year-old woman patient with a history of systemic lupus erythematosus developed mechanic chronic lower back pain, refractory to conventional treatments. She presented improvement with oxycodone. She withdrew this medication due to a lack of supplies in her country (Colombia) and showed withdrawal symptoms. She consulted the emergency department, where oral methadone was started and symptom control was achieved. Three days after admission, she presented intense headaches and emesis. A brain CT scan was performed in which severe cerebral edema was appreciated. Methadone was discontinued, and neurological symptoms quickly disappeared. A follow-up brain CT scan was performed later, finding full resolution of the edema.

Conclusion

A case of severe cerebral edema associated with the initiation of oral methadone and its rapid resolution without neurological sequelae after its withdrawal is presented, clinicians must be attentive to this adverse event.

Traumatic Brain Injury and Opioids: Twin Plagues of the Twenty-First Century

Traumatic brain injury (TBI) and opioid use disorder (OUD) comprise twin plagues causing considerable morbidity and mortality worldwide. As interactions between TBI and OUD are to our knowledge uncharted, we review the possible mechanisms by which TBI may stimulate the development of OUD and discuss the interaction or crosstalk between these two processes. Central nervous system damage due to TBI appears to drive adverse effects of subsequent OUD and opioid use/misuse affecting several molecular pathways. Pain, a neurological consequence of TBI, is a risk factor that increases the likelihood of opioid use/misuse after TBI. Other comorbidities including depression, anxiety, posttraumatic stress disorder, and sleep disturbances are also associated with deleterious outcomes. We examine the hypothesis that a TBI "first hit" induces a neuroinflammatory process involving microglial priming, which, on a second hit related to opioid exposure, exacerbates neuroinflammation, modifies synaptic plasticity, and spreads tau aggregates to promote neurodegeneration. As TBI also impairs myelin repair by oligodendrocytes, it may reduce or degrade white matter integrity in the reward circuit resulting in behavioral changes. Along with approaches focused on specific patient symptoms, understanding the CNS effects following TBI offers a promise of improved management for individuals with OUD.

Toxin-Induced Coma and Central Nervous System Depression

Many medications and toxins may induce central nervous system (CNS) depression. Even when the intention is to induce CNS depression, other nervous system adverse effects may occur, such as with anesthetics. Pain medications produce characteristic CNS toxicities. Sedative hypnotics may induce altered mentation among systemic toxicities. Stimulants may mimic coma when discontinued abruptly. Acute and chronic carbon monoxide poisoning can lead to altered mental status and prolonged cognitive difficulties. Some medications and environmental toxins can mimic brain death. High clinical suspicion and early recognition of these effects is vital to treatment, most of which is supportive.

Effect of Fentanyl Boluses on Cerebral Oxygenation and Hemodynamics in Preterm Infants: A Prospective Observational Study

BACKGROUND

Fentanyl is a commonly used off-label medication for pain control and sedation in preterm infants. Yet, the effect of fentanyl on cerebral hemodynamics in preterm neonates remains unexplored.

OBJECTIVE

To evaluate the effect of a bolus dose of fentanyl on the regional cerebral oxygen saturation (RcSO2), cerebral fractional tissue oxygen extraction (cFTOE) and left ventricular output (LVO) as compared with pre-administration baseline in preterm infants.

METHODS

This was a prospective observational study conducted in a level III Canadian NICU from September 2017 to February 2019. Preterm infants born <37 weeks of gestation and scheduled to receive a fentanyl bolus (1-2 μg/kg/dose) were eligible. Infants with major congenital anomalies, medically unstable and those who had received fentanyl in the previous 48 h were excluded.

OUTCOMES

The primary outcome was the difference between RcSO2 measured 5 min prior to and RcSO2 measured at defined time points after administration of fentanyl.

RESULTS

Twenty-eight infants were enrolled during the study period (median gestational age 28 weeks; interquartile range [IQR] 25-29 weeks; median birth weight 1,035 g [IQR 830-1,292 g]; median age 4 days [IQR 3-7 days]). Mean (±standard deviation) baseline RcSO2 was 73.6% (±11.8), cFTOE was 21.9 (±11.2) and LVO was 380 (±147) mL/kg/min prior to fentanyl infusion. One-way ANOVA showed no statistically significant difference between baseline and any of the post-fentanyl cerebral oxygenation, tissue oxygen extraction or cardiac output measures (p > 0.05).

CONCLUSION

Administration of fentanyl bolus for procedural pain and sedation was not shown to significantly affect cerebral oxygenation, cerebral tissue oxygen extraction or cardiac output in stable preterm infants.

Hypoxia mediated pulmonary edema: potential influence of oxidative stress, sympathetic activation and cerebral blood flow

BACKGROUND

Neurogenic pulmonary edema (NPE) is a non-cardiogenic form of pulmonary edema that can occur consequent to central neurologic insults including stroke, traumatic brain injury, and seizure. NPE is a public health concern due to high morbidity and mortality, yet the mechanism(s) are unknown. We hypothesized that NPE, evoked by cerebral hypoxia in the presence of systemic normoxia, would be accompanied by sympathetic activation, oxidative stress, and compensatory antioxidant mechanisms.

METHODS

Thirteen Walker hounds were assigned to cerebral hypoxia (SaO2 ~ 55 %) with systemic normoxia (SaO2 ~ 90 %) (CH; n = 6), cerebral and systemic (global) hypoxia (SaO2 ~ 60 %) (GH; n = 4), or cerebral and systemic normoxia (SaO2 ~ 90 %) (CON; n = 3). Femoral venous (CH and CON) perfusate was delivered via cardiopulmonary bypass to the brain and GH was induced by FiO2 = 10 % to maintain the SaO2 at ~60 %. Lung wet to lung dry weight ratios (LWW/LDW) were assessed as an index of pulmonary edema in addition to hemodynamic measurements. Plasma catecholamines were measured as markers of sympathetic nervous system (SNS) activity. Total glutathione, protein carbonyls, and malondialdehyde were assessed as indicators of oxidative stress. Brain and lung compensatory antioxidants were measured with immunoblotting.

RESULTS

Compared to CON, LWW/LDW and pulmonary artery pressure were greater in CH and GH. Expression of hemeoxygenase-1 in brain was higher in CH compared to GH and CON, despite no group differences in oxidative damage in any tissue. Catecholamines tended to be higher in CH and GH.

CONCLUSION

Cerebral hypoxia, with systemic normoxia, is not systematically associated with an increase in oxidative stress and compensatory antioxidant enzymes in lung, suggesting oxidative stress did not contribute to NPE in lung. However, increased SNS activity may play a role in the induction of NPE during hypoxia.

Differential effects of early postinjury treatment with neuroprotective drugs in a mouse model using diffuse reflectance spectroscopy

The time required for the arrival of an ambulance crew and administration of first aid is critical to clinical outcome, particularly in the case of head injury victims requiring neuroprotective drugs following a car accident, falls, and assaults. Short response times of the medical team, together with proper treatment, can limit injury severity and even save a life before transportation to the nearest medical center. We present a comparative evaluation of five different neuroprotective drugs frequently used in intensive care and operating units in the early phase following traumatic brain injury (TBI): hypertonic saline (HTS), mannitol, morphine, melatonin, and minocycline. The effectiveness of these drugs in terms of changes in brain tissue morphology (cell organelle size, density, distribution, etc.) and biochemical tissue properties (chromophores' content) was experimentally evaluated through analysis of the spectral reduced scattering and optical absorption coefficient parameters in the near-infrared (NIR) optical range (650 to 1000 nm). Experiments were conducted on anesthetized male mice subjected to a noninvasive closed head weight-drop model of focal TBI ([Formula: see text] and [Formula: see text] control) and monitored using an NIR diffuse reflectance spectroscopy system utilizing independent source-detector separation and location. After 10 min of baseline measurement, focal TBI was induced and measurements were conducted for 20 min. Subsequently, a neuroprotective drug was administrated and measurements were recorded for another 30 min. This work's major findings are threefold: first, minocycline was found to improve hemodynamic outcome at the earliest time postinjury. Second, HTS decreased brain water content and inhibited the increase in intracranial pressure. Third, the efficacy of neuroprotective drugs can be monitored noninvasively with diffuse reflectance spectroscopy. The demonstrated ability to noninvasively detect cerebral physiological properties following early administration of neuroprotective drugs underlines the need for more extensive investigation of the combined use of clinical drugs in larger-scale preclinical experiments to find the most beneficial drug treatment for brain injury patients.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.