Propofol infusion syndrome resuscitation with extracorporeal life support: a case report and review of the literature

Neuroimaging of Propofol Infusion Syndrome: A Case Report and Review of Literature

A school-age boy with a complex medical history underwent a minor elective surgical procedure. Propofol was used for sedation during the procedure. The patient could not be awakened post-operatively. Laboratory findings demonstrated metabolic lactic acidosis, leukocytosis with bandemia, and transaminitis. Neuroimaging demonstrated findings that were consistent with hypoxic-ischemic or toxic-metabolic brain injury involving the bilateral basal ganglia, hippocampi, and cerebellum. The patient's condition progressively worsened over the course of the following few weeks, and brain death was confirmed by scintigraphy seven weeks later. Prompt neuroimaging in unresponsive patients with suspected propofol infusion syndrome (PRIS) is of critical importance in detecting neurologic injuries, excluding alternative diagnoses, and determining prognostication.

Propofol Infusion Syndrome: Efficacy of a Prospective Screening Protocol

Propofol infusion syndrome (PIS) is a potentially lethal complication of propofol marked by rhabdomyolysis, metabolic acidosis, and cardiac arrhythmias or collapse. The objective of this study was to determine the effectiveness of a prospective screening protocol to prevent PIS. All trauma patients admitted who received propofol as a continuous infusion were prospectively screened from November 1, 2013 to December 31, 2015. Variables studied included demographics, injury severity, laboratory values, infusion rates, and mortality. Serum creatine phosphokinase (CPK) and lactate were drawn daily. Propofol was stopped for a positive screen defined as an increase in CPK to greater than 5000 IU/L or lactate greater than 4 mmol/L. Positive and negative cohorts were compared. Two hundred and twenty-five patients met the inclusion criteria and 12 patients (5.3%) had propofol stopped because of elevated CPK. No differences were identified in demographics, transfusions, injury severity, hospital length of stay, or propofol dose. The positive screened group had longer intensive care unit length of stay (20 vs 13 days; P = 0.002) and increased vent days (14.5 vs 10 days; P = 0.008). Max serum osmolality (334 vs 305 mosm/kg; P = 0.049) and max serum CPK (6782 vs 1058 IU/L; P < 0.0001) were higher in the positive cohort. No cases of PIS occurred, and mortality (16.7 vs 15.5%; P = 0.999) was not different between the cohorts. The screening protocol was effective in eliminating PIS. Serial CPK evaluations provided an effective screening tool and serum lactate can be dropped from screening.

Treatment of Refractory and Super-refractory Status Epilepticus

Refractory and super-refractory status epilepticus (SE) are serious illnesses with a high risk of morbidity and even fatality. In the setting of refractory generalized convulsive SE (GCSE), there is ample justification to use continuous infusions of highly sedating medications-usually midazolam, pentobarbital, or propofol. Each of these medications has advantages and disadvantages, and the particulars of their use remain controversial. Continuous EEG monitoring is crucial in guiding the management of these critically ill patients: in diagnosis, in detecting relapse, and in adjusting medications. Forms of SE other than GCSE (and its continuation in a "subtle" or nonconvulsive form) should usually be treated far less aggressively, often with nonsedating anti-seizure drugs (ASDs). Management of "non-classic" NCSE in ICUs is very complicated and controversial, and some cases may require aggressive treatment. One of the largest problems in refractory SE (RSE) treatment is withdrawing coma-inducing drugs, as the prolonged ICU courses they prompt often lead to additional complications. In drug withdrawal after control of convulsive SE, nonsedating ASDs can assist; medical management is crucial; and some brief seizures may have to be tolerated. For the most refractory of cases, immunotherapy, ketamine, ketogenic diet, and focal surgery are among several newer or less standard treatments that can be considered. The morbidity and mortality of RSE is substantial, but many patients survive and even return to normal function, so RSE should be treated promptly and as aggressively as the individual patient and type of SE indicate.

Systemic Complications Following Status Epilepticus

PURPOSE OF REVIEW

Status epilepticus (SE) is a multisystem disorder. Initially, complications of a massive catecholamine release followed by the side effects of medical therapies, impact patients' outcomes. The aim of this article is to provide an updated summary of the systemic complications following SE.

RECENT FINDINGS

In recent years, the importance of the multifaceted nature of SE and its relationship with clinical outcomes has been increasingly recognized. The cumulative systemic effects of prolonged seizures and their treatment contribute to morbidity and mortality in this condition. Most systemic complications after SE are predictable. Anticipating their occurrence and respecting a number of simple guidelines may improve the prognosis of these patients.

Editor's Choice-The cardiovascular implications of sedatives in the cardiac intensive care unit

Patients admitted to the cardiac intensive care unit frequently develop multi-organ system dysfunction associated with their cardiac disease. In many cases, invasive mechanical ventilation is required, which often necessitates sedation for patient-ventilator synchrony, reduction of work of breathing, and patient comfort. In this paper, we describe the use of common sedatives available in the endotracheally intubated critically ill patient and emphasize the clinical and cardiovascular effects. We review γ-aminobutyric acid agonists such as etomidate, benzodiazepines, and propofol, the centrally acting α₂-agonist dexmedetomidine, and the N-methyl-D-aspartate receptor antagonist ketamine. Additionally, we outline the use of opioids and their role in potentiating other sedatives. We note that some sedatives are associated with increased delirium rates, and emphasize that judicious strategies minimizing sedative use are associated with decreases in morbidity and mortality. We also discuss standardized sedation assessment scales and highlight the importance of sedation weaning. Finally, we offer recommendations for sedation use during therapeutic hypothermia, and discuss the use of adjuvant neuromuscular blocking agents.

Adverse Drug Reactions in the Intensive Care Unit

Adverse drug reactions (ADRs) are undesirable effects of medications used in normal doses [1]. ADRs can occur during treatment in an intensive care unit (ICU) or result in ICU admissions. A meta-analysis of 4139 studies suggests the incidence of ADRs among hospitalized patients is 17% [2]. Because of underreporting and misdiagnosis, the incidence of ADRs may be much higher and has been reported to be as high as 36% [3]. Critically ill patients are at especially high risk because of medical complexity, numerous high-alert medications, complex and often challenging drug dosing and medication regimens, and opportunity for error related to the distractions of the ICU environment [4]. Table 1 summarizes the ADRs included in this chapter.

Propofol Infusion Syndrome in Refractory Status Epilepticus: A Case Report and Topical Review

Propofol infusion syndrome (PRIS) is a fatal complication when doses of propofol administration exceed 4 mg/kg/h for more than 48 hours. Propofol overdosage is not uncommon in patients with refractory status epilepticus (RSE). We describe a case of refractory status epilepticus complicated by propofol infusion syndrome and collect from 5 databases all reports of refractory status epilepticus cases that were treated by propofol and developed the syndrome and outline whether refractory status epilepticus treatment with propofol is standardized according to international recommendations, compare it with alternative medications, and discuss how this syndrome can be treated and prevented. A total of 21 patients who developed this syndrome reported arrhythmia in all cases (100%), rhabdomyolysis in 9 cases (42%), lactic acidosis in 13 cases (62%), renal failure in 8 cases (38%), lipemia in 7 cases (33%), and elevated hepatic enzymes in 6 cases (28%). 13 patients died (66%). Propofol is still given in a dosage higher than what is internationally recommended, and new treatment modalities such as renal replacement therapy, blood exchange, and extracorporeal membrane oxygenation seem to be promising. In conclusion, propofol should be carefully titrated, the maximal infusion rate needs to be reassessed, and combination of different sedative agents may be considered.

Lipid-free Fluoropolymer-based Propofol Emulsions and Lipid Reversal of Propofol Anesthesia in Rats

Background

Propofol, as a lipid-based emulsion, is effective at inducing anesthesia. It does, however, suffer from several drawbacks, including microbial growth, hyperlipidemia, and pain on injection. In this study, the authors examined the ability of four lipid-free propofol nanoemulsions to induce anesthesia in rats and tested whether a subsequent lipid bolus would accelerate emergence from anesthesia.

Methods

The authors administered five formulations of propofol intravenously to six rats, delivering five different doses five times each, in a repeated-measures randomized crossover design and measured time to loss and recovery of righting reflex. The formulations included (1) Diprivan (AstraZeneca, United Kingdom); (2) L3, incorporating a semifluorinated surfactant plus egg lecithin; (3) B8, incorporating a semifluorinated surfactant only; (4) F8, incorporating a semifluorinated surfactant plus perfluorooctyl bromide; and (5) L80, incorporating egg lecithin only. In a second phase of the study, the authors administered a lipid bolus immediately after a dose of B8 or Diprivan.

Results

All formulations except L80 impaired the righting reflex without apparent toxic effects. The authors estimated the threshold dose for induction by determining the x-intercept of the linear regression between time to recovery versus log dose. Threshold doses ranged from 5.8 (95% CI, 5.5 to 6.2) to 8.6 (95% CI, 7.2 to 10.2) mg/kg. A 15 ml/kg lipid bolus resulted in an accelerated clearance.

Conclusions

Three of the four novel lipid-free fluoropolymer-based formulations showed efficacy in producing anesthesia, which was comparable to that of Diprivan, and a lipid bolus hastened recovery. These novel propofol formulations have the potential to avoid complications seen with the existing lipid-based formulation.

Role of microRNA-134 in the neuroprotective effects of propofol against oxygen-glucose deprivation and related mechanisms

This study is to investigate the effects of propofol on primary hippocampal neurons under oxygen-glucose deprivation (OGD) condition and related mechanisms. The apoptotic process was detected with flow cytometry, and the cell viability was assessed with CCK-8 assay. The expression levels of microRNA (miRNA)-134 were detected with quantitative real-time PCR. Protein expression levels were detected by Western blot analysis. Dual-luciferase reporter assay was also performed to confirm the prediction of the target genes of miRNA-134. Our results from flow cytometry showed that the apoptosis rate was significantly increased in the primary hippocampal neurons under OGD condition. However, the treatments of propofol (25, 50, 100, and 150 µmol/L) suppressed the apoptotic process. Moreover, propofol restored the declined cell viability in the primary hippocampal neurons under OGD condition. In addition, compared with the OGD model group, the Bcl-2/Bax ratios were significantly elevated in the propofol-treated groups, indicating the protective effects of propofol against cellular apoptosis. Quantitative real-time PCR showed that propofol reduced the expression levels of miRNA-134 in the primary hippocampal neurons under OGD condition. Bioinformatics analysis revealed that BDNF might be a target of miRNA-134. The treatment of antago-miRNA-134 significantly down-regulated the expression level of BDNF. In line with this, dual-luciferase reporter assay suggested that miRNA-134 targeted BDNF in the 3'-TUR. Under OGD condition, propofol could down-regulate miRNA-134, and subsequently modulate the expression of BDNF, to exert neuroprotective effects.

Pharmacotherapy for Status Epilepticus

Status epilepticus (SE) represents the most severe form of epilepsy. It is one of the most common neurologic emergencies, with an incidence of up to 61 per 100,000 per year and an estimated mortality of 20 %. Clinically, tonic-clonic convulsive SE is divided into four subsequent stages: early, established, refractory, and super-refractory. Pharmacotherapy of status epilepticus, especially of its later stages, represents an "evidence-free zone," due to a lack of high-quality, controlled trials to inform clinical decisions. This comprehensive narrative review focuses on the pharmacotherapy of SE, presented according to the four-staged approach outlined above, and providing pharmacological properties and efficacy/safety data for each antiepileptic drug according to the strength of scientific evidence from the available literature. Data sources included MEDLINE and back-tracking of references in pertinent studies. Intravenous lorazepam or intramuscular midazolam effectively control early SE in approximately 63-73 % of patients. Despite a suboptimal safety profile, intravenous phenytoin or phenobarbital are widely used treatments for established SE; alternatives include valproate, levetiracetam, and lacosamide. Anesthetics are widely used in refractory and super-refractory SE, despite the current lack of trials in this field. Data on alternative treatments in the later stages are limited. Valproate and levetiracetam represent safe and effective alternatives to phenobarbital and phenytoin for treatment of established SE persisting despite first-line treatment with benzodiazepines. To date there are no class I data to support recommendations for most antiepileptic drugs for established, refractory, and super-refractory SE. Limiting the methodologic heterogeneity across studies is required and high-class randomized, controlled trials to inform clinicians about the best treatment in established and refractory status are needed.

Systemic complications of status epilepticus--An update

Systemic complications occur at every stage of status epilepticus, involve every organ system, and may worsen outcome. Initially, there is a massive catecholamine release and hyperadrenergic state that may result in neurocardiogenic, pulmonary, and, sometimes, musculoskeletal or renal injury. Further medical complications accompany the various treatments used to abort the seizures including the use of nonanesthetic antiseizure drugs and high-dose anesthetic infusions. Later, sequelae of prolonged immobility and critical illness occur and add to the cumulative morbidity of these patients. Clinicians should follow a protocol to guide screening for early markers of systemic injury, complications of specific pharmacologic and adjunctive treatments, and periodic surveillance for complications related to prolonged immobility. This article is part of a Special Issue entitled "Status Epilepticus".

Treatment of Generalized Convulsive Status Epilepticus in Pediatric Patients

Generalized convulsive status epilepticus (GCSE) is one of the most common neurologic emergencies and can be associated with significant morbidity and mortality if not treated promptly and aggressively. Management of GCSE is staged and generally involves the use of life support measures, identification and management of underlying causes, and rapid initiation of anticonvulsants. The purpose of this article is to review and evaluate published reports regarding the treatment of impending, established, refractory, and super-refractory GCSE in pediatric patients.

Propofol infusion syndrome in adults: a clinical update

Propofol infusion syndrome is a rare but extremely dangerous complication of propofol administration. Certain risk factors for the development of propofol infusion syndrome are described, such as appropriate propofol doses and durations of administration, carbohydrate depletion, severe illness, and concomitant administration of catecholamines and glucocorticosteroids. The pathophysiology of this condition includes impairment of mitochondrial beta-oxidation of fatty acids, disruption of the electron transport chain, and blockage of beta-adrenoreceptors and cardiac calcium channels. The disease commonly presents as an otherwise unexplained high anion gap metabolic acidosis, rhabdomyolysis, hyperkalemia, acute kidney injury, elevated liver enzymes, and cardiac dysfunction. Management of overt propofol infusion syndrome requires immediate discontinuation of propofol infusion and supportive management, including hemodialysis, hemodynamic support, and extracorporeal membrane oxygenation in refractory cases. However, we must emphasize that given the high mortality of propofol infusion syndrome, the best management is prevention. Clinicians should consider alternative sedative regimes to prolonged propofol infusions and remain within recommended maximal dose limits.

Therapeutic plasma exchange as treatment for propofol infusion syndrome

Propofol infusion syndrome (PRIS), a rare complication of propofol sedation, is associated with high mortality. There is no specific therapy. A 16-year-old with head injury and status epilepticus is described. Three days after seizure resolution, whilst receiving propofol, he developed severe lactic acidosis, rhabdomyolysis, and hemodynamic instability. Suspected PRIS was treated with a single session of therapeutic plasma exchange (TPE). This was associated with immediate improvement in hemodynamic status, resolution of lactic acidosis within 24 h, normalization of CPK over 10 days, and a subsequent full recovery. TPE is suggested as a novel therapy for PRIS.