The preventive effect of dexmedetomidine on paroxysmal sympathetic hyperactivity in severe traumatic brain injury patients who have undergone surgery: a retrospective study

Diagnosis and management of paroxysmal sympathetic hyperactivity: a narrative review of recent literature

Paroxysmal sympathoexcitatory syndrome is a clinical syndrome, recognized in a subgroup of survivors of severe acquired brain injury, of simultaneous, paroxysmal transient increases in sympathetic [elevated heart rate, blood pressure, respiratory rate, temperature, sweating] and motor [posturing] activity. Coupled with the absence of uniform treatment guidelines, it is prone to underdiagnosis and misdiagnosis, leading to the adoption of inappropriate treatment protocols, which may adversely affect the prognosis of patients. This narrative review summarized the existing literature and provided a comprehensive account of the research history and terminology of PSH, epidemiology and pathogenesis, diagnostic criteria, therapeutic options, and prognosis, hoping to bring new ideas to the clinical treatment of PSH.

The Role of Dexmedetomidine in Paroxysmal Sympathetic Hyperactivity: A Systematic Review

OBJECTIVE

The objective was to evaluate the efficacy and safety of dexmedetomidine in the treatment and prophylaxis of paroxysmal sympathetic hyperactivity (PSH).

DATA SOURCES

A review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria and queried Embase, MEDLINE (PubMed), Cochrane CENTRAL, Web of Science, SciELO, Korean Journal Index (Clarivate), Global Index Medicus, and CINAHL Plus for results through June 2023.

STUDY SELECTION AND DATA EXTRACTION

Studies providing efficacy or safety data associated with dexmedetomidine with a reported diagnosis of PSH were included. Exclusion of studies in pediatric populations, without quantitative and qualitative outcome data, and not readily translatable to English was adhered to.

DATA SYNTHESIS

Thirteen observational studies of 178 patients were included in the qualitative analysis. Reductions in PSH frequency or symptom severity were reported in 44 of 48 patients who received dexmedetomidine for acute treatment. Prophylactic use of dexmedetomidine was associated with reductions in PSH-Assessment Measure (PSH-AM) scores in postsurgical patients with traumatic brain injuries (TBIs). Adverse events associated with dexmedetomidine were either absent or reported as none.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review supports the safe and effective use of dexmedetomidine in the treatment and prophylaxis of PSH. Further investigation is required to determine optimal dosing strategies and the extent to which PSH etiology correlated to the efficacy of dexmedetomidine.

CONCLUSIONS

The use of dexmedetomidine appears to be both efficacious and safe for the treatment and prevention of PSH in patients experiencing a TBI. Additional research is needed to elucidate dosing strategies, titration parameters, and duration of therapy.

The effect of dexmedetomidine on the postoperative recovery of patients with severe traumatic brain injury undergoing craniotomy treatment: a retrospective study

BACKGROUND

Traumatic brain injury (TBI) has been a worldwide problem for neurosurgeons. Patients with severe TBI may undergo craniotomy. These patients often require sedation after craniotomy. Dexmedetomidine (DEX) has been used in patients receiving anesthesia and in intensive care units. Not much is known about the postoperative effect of DEX in patients with severe TBIs undergoing craniotomy. The purpose of this study was to explore the effects of postoperative DEX administration on severe TBI patients who underwent craniotomy.

METHODS

Patients who underwent craniectomy for severe TBI at our hospital between January 2019 and February 2022 were included in this study. The patients were admitted to the intensive care unit (ICU) after surgery to receive sedative medication. The patients were then divided into DEX and control groups. We analyzed the sedation, hemodynamics, and other conditions of the patients (hypoxemia, duration of ventilation during endotracheal intubation, whether tracheotomy was performed, and the duration in the ICU) during their ICU stay. Other conditions, such as delirium after the patients were transferred to the general ward, were also analyzed.

RESULTS

A total of 122 patients were included in this study. Among them, 53 patients received DEX, and the remaining 69 did not. The incidence of delirium in the general ward in the DEX group was significantly lower than that in the control group (P < 0.05). The incidence of bradycardia in the control group was significantly lower than that in the DEX group (P < 0.05). Other data from the DEX group and the control group (hypotension, hypoxemia, etc.) were not significantly different (P > 0.05).

CONCLUSION

The use of DEX in the ICU can effectively reduce the incidence of delirium in patients who return to the general ward after craniotomy. DEX had no adverse effect on the prognosis of patients other than causing bradycardia.

Safety, Efficacy, and Clinical Outcomes of Dexmedetomidine for Sedation in Traumatic Brain Injury: A Scoping Review

Dexmedetomidine is a promising alternative sedative agent for moderate-severe Traumatic brain injury (TBI) patients. Although the data are limited, the posited benefits of dexmedetomidine in this population are a reduction in secondary brain injury compared with current standard sedative regimens. In this scoping review, we critically appraised the literature to examine the effects of dexmedetomidine in patients with moderate-severe TBI to examine the safety, efficacy, and cerebral and systemic physiological outcomes within this population. We sought to identify gaps in the literature and generate directions for future research. Two researchers and a librarian queried PubMed, Embase, Scopus, and APA PsycINFO databases. Of 920 studies imported for screening, 11 were identified for inclusion in the review. The primary outcomes in the included studied were cerebral physiology, systemic hemodynamics, sedation levels and delirium, and the presence of paroxysmal sympathetic hyperactivity. Dexmedetomidine dosing ranged from 0.2 to 1 ug/kg/h, with 3 studies using initial boluses of 0.8 to 1.0 ug/kg over 10 minutes. Dexmedetomidine used independently or as an adjunct seems to exhibit a similar hemodynamic safety profile compared with standard sedation regimens, albeit with transient episodes of bradycardia and hypotension, decrease episodes of agitation and may serve to alleviate symptoms of sympathetic hyperactivity. This scoping review suggests that dexmedetomidine is a safe and efficacious sedation strategy in patients with TBI. Given its rapid onset of action and anxiolytic properties, dexmedetomidine may serve as a feasible sedative for TBI patients.

Paroxysmal Sympathetic Hyperactivity After Acquired Brain Injury: An Integrative Review of Diagnostic and Management Challenges

Paroxysmal sympathetic hyperactivity (PSH) mainly occurs after acquired brain injury (ABI) and often presents with high fever, hypertension, tachycardia, tachypnea, sweating, and dystonia (increased muscle tone or spasticity). The pathophysiological mechanisms of PSH are not fully understood. Currently, there are several views: (1) disconnection theory, (2) excitatory/inhibitory ratio, (3) neuroendocrine function, and (4) neutrophil extracellular traps. Early diagnosis of PSH remains difficult, given the low specificity of its diagnostic tools and unclear pathogenesis. According to updated case analyses in recent years, PSH is now more commonly observed in patients with stroke, with tachycardia and hypertension as the main clinical manifestations, which is not fully consistent with previous data. To date, the PSH Assessment Measure tool is optimal for the early identification of PSH and stratification of symptom severity. Clinical strategies for the management of PSH are divided into three main points: (1) reduction of stimulation, (2) reduction of sympathetic excitatory afferents, and (3) inhibition of the effects of sympathetic hyperactivity on target organs. However, use of drugs and standards have not yet been harmonized. Further investigation on the relationship between PSH severity and long-term neurological prognosis in patients with ABI is required. This review aimed to determine the diagnostic and management challenges encountered in PSH after ABI.

Paroxysmal Sympathetic Hyperactivity After Acquired Brain Injury: An Integrative Literature Review

BACKGROUND

Paroxysmal sympathetic hyperactivity may occur in patients with acute brain injury and is associated with physical disability, poor clinical outcomes, prolonged hospitalization, and higher health care costs.

OBJECTIVE

To comprehensively review current literature and provide information about paroxysmal sympathetic hyperactivity for nurses.

METHODS

An integrative literature review was conducted according to Whittemore and Knafl's method. The search was conducted from October 2020 through January 2021. The main targets of the literature search were definition, incidence rate, causes, clinical characteristics, pathophysiology, diagnosis, and treatment of paroxysmal sympathetic hyperactivity in pediatric and adult patients. The results were reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

The most characteristic clinical features of paroxysmal sympathetic hyperactivity are hypertension, tachycardia, tachypnea, hyperthermia, diaphoresis, and abnormal motor posturing. Reported incidence rates of paroxysmal sympathetic hyperactivity in patients with brain injury range from 8% to 33%. Various diagnostic criteria have been proposed; most are based on clinical symptoms. Ruling out other causes of the signs and symptoms of paroxysmal sympathetic hyperactivity is important because the signs and symptoms are nonspecific. The major goals of paroxysmal sympathetic hyperactivity management are avoidance of stimuli that may trigger a paroxysmal episode, inhibition of sympathetic overactivity, and prevention of damage to other organs.

CONCLUSIONS

Critical care nurses should be aware of the signs and symptoms of paroxysmal sympathetic hyperactivity in patients with acute brain injury. Early identification is important to ensure timely treatment for patients with paroxysmal sympathetic hyperactivity.

Clinical characteristics and prognosis of paroxysmal sympathetic hyperactivity in patients with severe nontraumatic brain injury

OBJECTIVE

This prospective study investigated and analyzed the clinical characteristics and prognosis of paroxysmal sympathetic hyperactivity (PSH) in patients with severe nontraumatic brain injury.

METHODS

Patients presenting with severe nontraumatic brain injury with PSH from July 2018 to June 2019 were enrolled. A PSH assessment measure ≥ 8 points was used as the criterion for PSH. Clinical data, indicators related to PSH, treatment effects and the prognosis were prospectively collected and analyzed.

RESULTS

A total of 220 patients with severe nontraumatic brain injury were analyzed, and PSH occurred in 8 patients (3.6%).     The primary neurological diseases included acute cerebral infarction, anti-N-methyl-D-aspartate receptor encephalitis, hypoxic encephalopathy and acute disseminated encephalitis. The Glasgow Coma Scale score was lower than 8 in the 8 patients with PSH. Seven of these eight patients had a Glasgow outcome scale (GOS) score of 3 or less than 3, and one patient had a GOS of 5 after 6 months. The medicines that effectively controlled PSH included dexmedetomidine, clonazepam, midazolam and diazepam.

CONCLUSIONS

Although the incidence was lower for nontraumatic brain injury complicated with PSH than for traumatic brain injury, patients with PSH had a more severe disease state and poorer prognoses. Dexmedetomidine might effectively control PSH.

The neuroprotective effect of dexmedetomidine and its mechanism

Dexmedetomidine (DEX) is a highly selective α2 receptor agonist that is routinely used in the clinic for sedation and anesthesia. Recently, an increasing number of studies have shown that DEX has a protective effect against brain injury caused by traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), cerebral ischemia and ischemia–reperfusion (I/R), suggesting its potential as a neuroprotective agent. Here, we summarized the neuroprotective effects of DEX in several models of neurological damage and examined its mechanism based on the current literature. Ultimately, we found that the neuroprotective effect of DEX mainly involved inhibition of inflammatory reactions, reduction of apoptosis and autophagy, and protection of the blood–brain barrier and enhancement of stable cell structures in five way. Therefore, DEX can provide a crucial advantage in neurological recovery for patients with brain injury. The purpose of this study was to further clarify the neuroprotective mechanisms of DEX therefore suggesting its potential in the clinical management of the neurological injuries.

Assessment of the effects of dexmedetomidine on outcomes of traumatic brain injury using propensity score analysis

BACKGROUND

Dexmedetomidine was found to be protective against traumatic brain injury (TBI) in animal studies and safe for use in previous clinical studies, but whether it improves TBI patient survival remains to be determined. We sought to answer this question by analyzing data from the MIMIC clinical database.

METHODS

Data for TBI patients from the MIMIC III and MIMIC IV databases were extracted and divided into a dexmedetomidine group and a control group. In the former group, dexmedetomidine was used for sedation, while in the latter, it was not used. Parameters including patient age, the Acute Physiology score III, the Glasgow Coma Scale, other sedatives used, and pupillary response within 24 h were employed in propensity score matching to achieve a balance between groups for further analysis. In-hospital survival and 6-month survival were analyzed by Kaplan-Meier survival analysis and compared by log-rank test. Cox regression was used repeatedly for the univariate analysis, the multivariate analysis, the propensity score-matched analysis, and the inverse probability of treatment weighted analysis of survival data. Meanwhile, the influences of hypotension, bradycardia, infection, and seizure on outcome were also analyzed.

RESULTS

Different types of survival analyses demonstrated the same trend. Dexmedetomidine significantly improved TBI patient survival. It caused no more incidents of hypotension, infection, and seizure. Hypotension was not correlated with in-hospital mortality, but was significantly correlated with 6-month mortality.

CONCLUSIONS

Dexmedetomidine may improve the survival of TBI patients. It should be used with careful avoidance of hypotension.

Comparing the Effect of Dexmedetomidine and Midazolam in Patients with Brain Injury

BACKGROUND

Studies have shown that dexmedetomidine improves neurological function. Whether dexmedetomidine reduces mortality or improves quantitative electroencephalography (qEEG) among patients post-craniotomy remains unclear.

METHODS

This single-center randomized study was conducted prospectively from 1 January 2019 to 31 December 2020. Patients who were transferred to the ICU after craniotomy within 24 h were included. The analgesic was titrated to a Critical care Pain Observation Tool (CPOT) score ≤2, and the sedative was titrated to a Richmond Agitation-Sedation Scale (RASS) score ≤-3 for at least 24 h. The qEEG signals were collected by four electrodes (F3, T3, F4, and T4 according to the international 10/20 EEG electrode practice). The primary outcome was 28-day mortality and qEEG results on day 1 and day 3 after sedation.

RESULTS

One hundred and fifty-one patients were enrolled in this study, of whom 77 were in the dexmedetomidine group and 74 in the midazolam group. No significant difference was found between the two groups in mortality at 28 days (14.3% vs. 24.3%; p = 0.117) as well as in the theta/beta ratio (TBR), the delta/alpha ratio (DAR), and the (delta + theta)/(alpha + beta) ratio (DTABR) between the two groups on day 1 or day 3. However, both the TBR and the DTABR were significantly increased in the dexmedetomidine group. The DTABR in the midazolam group was significantly increased. The DAR was significantly increased on the right side in the dexmedetomidine group (20.4 (11.6-43.3) vs. 35.1 (16.7-65.0), p = 0.006) as well as on both sides in the midazolam group (Left: 19.5 (10.1-35.8) vs. 37.3 (19.3-75.7), p = 0.006; Right: 18.9 (10.1-52.3) vs. 39.8 (17.5-99.9), p = 0.002).

CONCLUSION

Compared with midazolam, dexmedetomidine did not lead to a lower 28-day mortality or better qEEG results in brain injury patients after a craniotomy.

Analgesia in the Neurosurgical Intensive Care Unit

Acute pain in neurosurgical patients is an important issue. Opioids are the most used for pain treatment in the neurosurgical ICU. Potential side effects of opioid use such as oversedation, respiratory depression, hypercapnia, worsening intracranial pressure, nausea, and vomiting may be problems and could interfere with neurologic assessment. Consequently, reducing opioids and use of non-opioid analgesics and adjuvants (N-methyl-D-aspartate antagonists, α2 -adrenergic agonists, anticonvulsants, corticosteroids), as well as non-pharmacological therapies were introduced as a part of a multimodal regimen. Local and regional anesthesia is effective in opioid reduction during the early postoperative period. Among non-opioid agents, acetaminophen and non-steroidal anti-inflammatory drugs are used frequently. Adverse events associated with opioid use in neurosurgical patients are discussed. Larger controlled studies are needed to find optimal pain management tailored to neurologically impaired neurosurgical patients.

Paroxysmal sympathetic hyperactivity during traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of disability, morbidity, and mortality worldwide. Some of the more common etiologies of TBI include closed head injury, penetrating head injury, or an explosive blast head injury. Neuronal damage in TBI is related to both primary injury (caused by mechanical forces), and secondary injury (caused by the subsequent tissue and cellular damages). Recently, it has been well established that Paroxysmal Sympathetic Hyperactivity (PSH), also known as "Sympathetic Storm", is one of the main causes of secondary neuronal injury in TBI patients. The clinical manifestations of PSH include recurrent episodes of sympathetic hyperactivity characterized by tachycardia, systolic hypertension, hyperthermia, tachypnea with hyperpnea, and frank diaphoresis. Given the diverse manifestations of PSH and its notable impact on the outcome of TBI patients, we have comprehensively reviewed the current evidence and discussed the pathophysiology, clinical manifestations, time of onset and duration of PSH during TBI. This article reviews the different types of head injuries that most commonly lead to PSH, possible approaches to manage and minimize PSH complications in TBI and the current prognosis and outcomes of PSH in TBI patients.

Pharmacological Treatment for Paroxysmal Sympathetic Hyperactivity

BACKGROUND

Paroxysmal sympathetic hyperactivity, which affects up to 10% of all acquired brain injury survivors, is characterized by elevated heart rate, blood pressure, respiratory rate, and temperature; diaphoresis; and increased posturing. Pharmacological agents that have been studied in the management of this disorder include opiates, γ-aminobutyric acid agents, dopaminergic agents, and β blockers. Although paroxysmal sympathetic hyperactivity is a relatively common complication after acquired brain injury, there is a paucity of recommendations or comparisons of agents for the management of this disorder.

OBJECTIVE

To evaluate all relevant literature on pharmacological therapies used to manage patients with paroxysmal sympathetic hyperactivity to help elucidate possible best practices.

METHODS

Of the 27 studies evaluated for inclusion, 10 studies received full review: 4 retrospective cohort studies, 5 single case studies, and 1 case series.

RESULTS

Monotherapy is usually not effective in the management of paroxysmal sympathetic hyperactivity and multiple agents with different mechanisms of action should be considered. α2-Agonists such as dexmedetomidine may hold some slight clinical efficacy over agents like propofol, and with respect to oral medications, propranolol might convey some slight advantage compared to others. However, with the limited data available, these results must be interpreted with caution.

CONCLUSIONS

As the treatment of paroxysmal sympathetic hyperactivity is reactive to symptomatic evolution over time, critical care nurses play a vital role in the monitoring and treatment of these patients. Limited data exist on the management of paroxysmal sympathetic hyperactivity and larger robust data sets are needed to guide decision-making. (Critical Care Nurse. 2020;40[3]:e9-e16).

Admission Features Associated With Paroxysmal Sympathetic Hyperactivity After Traumatic Brain Injury: A Case-Control Study

OBJECTIVES

Paroxysmal sympathetic hyperactivity occurs in a subset of critically ill traumatic brain injury patients and has been associated with worse outcomes after traumatic brain injury. The goal of this study was to identify admission risk factors for the development of paroxysmal sympathetic hyperactivity in traumatic brain injury patients.

DESIGN

Retrospective case-control study of age- and Glasgow Coma Scale-matched traumatic brain injury patients.

SETTING

Neurotrauma ICU at the R. Adams Cowley Shock Trauma Center of the University of Maryland Medical System, January 2016 to July 2018.

PATIENTS

Critically ill adult traumatic brain injury patients who underwent inpatient monitoring for at least 14 days were included. Cases were identified based on treatment for paroxysmal sympathetic hyperactivity with institutional first-line therapies and were confirmed by retrospective tabulation of established paroxysmal sympathetic hyperactivity diagnostic and severity criteria. Cases were matched 1:1 by age and Glasgow Coma Scale to nonparoxysmal sympathetic hyperactivity traumatic brain injury controls, yielding 77 patients in each group.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Admission characteristics independently predictive of paroxysmal sympathetic hyperactivity included male sex, higher admission systolic blood pressure, and initial CT evidence of diffuse axonal injury, intraventricular hemorrhage/subarachnoid hemorrhage, complete cisternal effacement, and absence of contusion. Paroxysmal sympathetic hyperactivity cases demonstrated significantly worse neurologic outcomes upon hospital discharge despite being matched for injury severity at admission.

CONCLUSIONS

Several anatomical, epidemiologic, and physiologic risk factors for clinically relevant paroxysmal sympathetic hyperactivity can be identified on ICU admission. These features help characterize paroxysmal sympathetic hyperactivity as a clinical-pathophysiologic phenotype associated with worse outcomes after traumatic brain injury.

Management and Challenges of Severe Traumatic Brain Injury

Traumatic brain injury (TBI) is the leading cause of death and disability in trauma patients, and can be classified into mild, moderate, and severe by the Glasgow coma scale (GCS). Prehospital, initial emergency department, and subsequent intensive care unit (ICU) management of severe TBI should focus on avoiding secondary brain injury from hypotension and hypoxia, with appropriate reversal of anticoagulation and surgical evacuation of mass lesions as indicated. Utilizing principles based on the Monro-Kellie doctrine and cerebral perfusion pressure (CPP), a surrogate for cerebral blood flow (CBF) should be maintained by optimizing mean arterial pressure (MAP), through fluids and vasopressors, and/or decreasing intracranial pressure (ICP), through bedside maneuvers, sedation, hyperosmolar therapy, cerebrospinal fluid (CSF) drainage, and, in refractory cases, barbiturate coma or decompressive craniectomy (DC). While controversial, direct ICP monitoring, in conjunction with clinical examination and imaging as indicated, should help guide severe TBI therapy, although new modalities, such as brain tissue oxygen (PbtO₂) monitoring, show great promise in providing strategies to optimize CBF. Optimization of the acute care of severe TBI should include recognition and treatment of paroxysmal sympathetic hyperactivity (PSH), early seizure prophylaxis, venous thromboembolism (VTE) prophylaxis, and nutrition optimization. Despite this, severe TBI remains a devastating injury and palliative care principles should be applied early. To better affect the challenging long-term outcomes of severe TBI, more and continued high quality research is required.

Identification and Management of Paroxysmal Sympathetic Hyperactivity After Traumatic Brain Injury

Paroxysmal sympathetic hyperactivity (PSH) has predominantly been described after traumatic brain injury (TBI), which is associated with hyperthermia, hypertension, tachycardia, tachypnea, diaphoresis, dystonia (hypertonia or spasticity), and even motor features such as extensor/flexion posturing. Despite the pathophysiology of PSH not being completely understood, most researchers gradually agree that PSH is driven by the loss of the inhibition of excitation in the sympathetic nervous system without parasympathetic involvement. Recently, advances in the clinical and diagnostic features of PSH in TBI patients have reached a broad clinical consensus in many neurology departments. These advances should provide a more unanimous foundation for the systematic research on this clinical syndrome and its clear management. Clinically, a great deal of attention has been paid to the definition and diagnostic criteria, epidemiology and pathophysiology, symptomatic treatment, and prevention and control of secondary brain injury of PSH in TBI patients. Potential benefits of treatment for PSH may result from the three main goals: eliminating predisposing causes, mitigating excessive sympathetic outflow, and supportive therapy. However, individual pathophysiological differences, therapeutic responses and outcomes, and precision medicine approaches to PSH management are varied and inconsistent between studies. Further, many potential therapeutic drugs might suppress manifestations of PSH in the process of TBI treatment. The purpose of this review is to present current and comprehensive studies of the identification of PSH after TBI in the early stage and provide a framework for symptomatic management of TBI patients with PSH.

Effects of dexmedetomidine vs sufentanil during percutaneous tracheostomy for traumatic brain injury patients: A prospective randomized controlled trial

BACKGROUND

Percutaneous tracheostomy, almost associated with cough reflex and hemodynamic fluctuations, is a common procedure for traumatic brain injury (TBI) patients, especially those in neurosurgery intensive care units (NICUs). However, there are currently a lack of effective preventive measures to reduce the risk of secondary brain injury. The aim of this study was to compare the effect of dexmedetomidine (DEX) vs sufentanil during percutaneous tracheostomy in TBI patients.

METHODS

The 196 TBI patients who underwent percutaneous tracheostomy were randomized divided into 3 groups: group D1 (n = 62, DEX infusion at 0.5 μg·kg for 10 minutes, then adjusted to 0.2-0.7 μg·kg·hour), group D2 (n = 68, DEX infusion at 1 μg·kg for 10 minutes, then adjusted to 0.2-0.7 μg·kg·hour), and group S (n = 66, sufentanil infusion 0.3 μg·kg for 10 minutes, then adjusted to 0.2-0.4 μg·kg·hour). The bispectral index (BIS) of all patients was maintained at 50 to 70 during surgery. Anesthesia onset time, hemodynamic variables, total cumulative dose of DEX/sufentanil, total doses of rescue propofol and fentanyl, time to first dose of rescue propofol and fentanyl, number of intraoperative patient movements and cough reflexes, adverse events, and surgeon satisfaction score were recorded.

RESULTS

Anesthesia onset time was significantly lower in group D2 than in both other groups (14.35 ± 3.23 vs 12.42 ± 2.12 vs 13.88 ± 3.51 minutes in groups D1, D2, and S, respectively; P < .001). Both heart rate and mean arterial pressure during percutaneous tracheostomy were more stable in group D2. Total doses of rescue propofol and fentanyl were significantly lower in group D2 than in group D1 (P < .001). The time to first dose of rescue propofol and fentanyl were significantly longer in group D2 than in both other groups (P < .001). The number of patient movements and cough reflexes during percutaneous tracheostomy were lower in group D2 than in both other groups (P < .001). The overall incidences of tachycardia and hypertension (which required higher doses of esmolol and urapidil, respectively) were also lower in group D2 than in both other groups (P < .05). Three patients in group S had respiratory depression compared to X in the D1 group and X in the D2 group. The surgeon satisfaction score was significantly higher in group D2 than in both other groups (P < .05).

CONCLUSIONS

During percutaneous tracheostomy, compared with sufentanil, DEX (1 μg·kg for 10 minutes, then adjusted to 0.2-0.7 μg·kg·hour) can provide the desired attenuation of the hemodynamic response without increased adverse events. Consequently, DEX could be used safely and effectively during percutaneous tracheostomy in TBI patients.

A study into the feasibility of using HRV variables to guide treatment in patients with paroxystic sympathetic hyperactivity in a neurointensive step-down unit

BACKGROUND

Patients suffering brain injury may experience paroxystic sympathetic hyperactivity, presenting diagnostic and therapeutic challenges in neurointensive rehabilitation. The syndrome has been modelled as peripheral and central excitatory:inhibitory ratios of autonomous nervous activity. Another model represents the symptoms as oscillations of the two components of the autonomous nervous system. In therapeutic framework, the syndrome is perceived as the patient misconstruing sensory input relating to body positioning.

OBJECTIVE

To investigate whether changes in frequency domain of heart rate variability reflect pharmacological and/or therapeutic measures in rehabilitation.

METHODS

ECG was recorded before and after pharmacological and therapeutic interventions in eight patients with high probability of the syndrome in a neurointensive step-down unit. Recordings were analysed off-line in frequency parameters. Appropriate statistical methods were applied.

RESULTS

Low, high frequency and the LF/HF ratio changed significantly following therapeutic as well as pharmacological interventions.

DISCUSSION

The cohort was small, the setting the immediate postictal period of intensive care with multidisciplinary rehabilitation. Still, changes in frequency domain were detected following therapeutic efforts. This opens up the venue of on-line monitoring of the intended therapeutic effect.

Paroxysmal sympathetic hyperactivity: An entity to keep in mind

Paroxysmal sympathetic hyperactivity (PSH) is a potentially life-threatening neurological emergency secondary to multiple acute acquired brain injuries. It is clinically characterized by the cyclic and simultaneous appearance of signs and symptoms secondary to exacerbated sympathetic discharge. The diagnosis is based on the clinical findings, and high alert rates are required. No widely available and validated homogeneous diagnostic criteria have been established to date. There have been recent consensus attempts to shed light on this obscure phenomenon. Its physiopathology is complex and has not been fully clarified. However, the excitation-inhibition model is the theory that best explains the different aspects of this condition, including the response to treatment with the available drugs. The key therapeutic references are the early recognition of the disorder, avoiding secondary injuries and the triggering of paroxysms. Once sympathetic crises occur, they must peremptorily aborted and prevented. of the later the syndrome is recognized, the poorer the patient outcome.