Endotracheal Lidocaine in Preventing Endotracheal Suctioning-induced Changes in Cerebral Hemodynamics in Patients with Severe Head Trauma

Initial Diagnosis and Management of Acutely Elevated Intracranial Pressure

Acutely elevated intracranial pressure (ICP) may have devastating effects on patient mortality and neurologic outcomes, yet its initial detection remains difficult because of the variety of manifestations that it can cause disease states it is associated with. Several treatment guidelines exist for specific disease processes such as trauma or ischemic stroke, but their recommendations may not apply to other causes. In the acute setting, management decisions must often be made before the underlying cause is known. In this review, we present an organized, evidence-based approach to the recognition and management of patients with suspected or confirmed elevated ICP in the first minutes to hours of resuscitation. We explore the utility of invasive and noninvasive methods of diagnosis, including history, physical examination, imaging, and ICP monitors. We synthesize various guidelines and expert recommendations and identify core management principles including noninvasive maneuvers, neuroprotective intubation and ventilation strategies, and pharmacologic therapies such as ketamine, lidocaine, corticosteroids, and the hyperosmolar agents mannitol and hypertonic saline. Although an in-depth discussion of the definitive management of each etiology is beyond the scope of this review, our goal is to provide an empirical approach to these time-sensitive, critical presentations in their initial stages.

Anesthesia Considerations in Neurological Emergencies

Airway obstruction and respiratory failure are common complications of neurological emergencies. Anesthesia is often employed for airway management, surgical and endovascular interventions or in the intensive care units in patients with altered mental status or those requiring burst suppression. This article provides a summary of the unique airway management and anesthesia considerations and controversies for neurologic emergencies in general, as well as for specific commonly encountered conditions: elevated intracranial pressure, neuromuscular respiratory failure, acute ischemic stroke, and acute cervical spinal cord injury.

Effects of Routine Position Changes and Tracheal Suctioning on Intracranial Pressure in Traumatic Brain Injury Patients

Patient position change and tracheal suctioning are routine interventions in mechanically ventilated traumatic brain injury (TBI) patients. We sought to better understand the impact of these interventions on intracranial pressure (ICP) and cerebral hemodynamics. We conducted a prospective study in TBI patients requiring ICP monitoring. The timing of position changes and suctioning episodes were recorded with concurrent blood pressure and ICP measurements. We collected data on 460 patient position changes and 204 suctioning episodes over 2404 h in 18 ventilated patients (mean age 34 [13] years, median Glasgow Coma Score 4 [3-7]). We recorded 24 (20-31) positioning and 11 (6-18) suctioning episodes per patient, with 54% and 39% of position changes associated with ICP ≥22 mm Hg and cerebral perfusion pressure (CPP) <60 mm Hg, respectively, and 22% and 27% of suctioning episodes associated with an ICP ≥22 mm Hg and CPP <60 mm Hg. The median change in ICP was 11 (6-16) mm Hg after position changes and 3 (1-9) mm Hg after suctioning. Reduction in CPP to <60 mm Hg lasted ≥10 min in 17% of positioning and 11% of suctioning episodes. The baseline ICP and its amplitude were both predictive of a rise in ICP ≥22 mm Hg after positioning and suctioning episodes, whereas cerebral autoregulation was not. Baseline CPP was predictive of a decrease in CPP <60 mm Hg after both interventions. Increases in ICP and reductions in CPP are common following patient positioning and tracheal suctioning episodes. Frequently, these changes are substantial and sustained.

Does Tracheal Lidocaine Instillation Reduce Intracranial Pressure Changes After Tracheal Suctioning in Severe Head Trauma? A Prospective, Randomized Crossover Study

OBJECTIVES

Tracheal suctioning is a routine procedure in mechanically ventilated children, however, in severe head-injured patients it can result in potential deleterious increase in intracranial pressure. We aimed to assess the effect of tracheal lidocaine administration on intracranial pressure during tracheal suctioning.

DESIGN

Prospective randomized controlled crossover study.

SETTING

PICU of a tertiary hospital.

PATIENTS

Eleven patients with severe head trauma (Glasgow Coma Scale score 4-8) INTERVENTIONS:: Lidocaine (1.5 mg/kg) or saline solution was endotracheally instilled before a standardized tracheal suctioning maneuver. Each patient received both treatments in a crossover design. Cerebral hemodynamic and systemic and ventilatory effects were assessed at four time points: in baseline (T0), within 2 minutes (T1), 5 minutes (T2), and 15 minutes after tracheal instillation (T3). The 2-minute time interval around tracheal suctioning was used to assess each treatment efficacy MEASUREMENTS AND MAIN RESULTS:: The time course of intracranial pressure was different throughout the study in both treatment groups, with a significant increase of intracranial pressure from 14.82 ± 3.48 to 23.27 ± 9.06 with lidocaine (p = 0.003) and from 14.73 ± 2.41 to 30.45 ± 13.14 with saline (p = 0.02). The mean variation in intracranial pressure immediately after tracheal suctioning was smaller with lidocaine instillation than saline (8.45 vs 15.72 mm Hg; p = 0.006). Patients treated with lidocaine returned to baseline intracranial pressure value at 5 minutes after tracheal suctioning whereas those receiving saline solution returned to baseline intracranial pressure value at 15 minutes. Although patients treated with lidocaine had no significant hemodynamic changes, patients receiving saline solution experienced a higher mean value of mean arterial pressure (99.36 vs 81.73 mm Hg; p = 0.004) at T1.

CONCLUSIONS

This preliminary study showed that tracheal lidocaine instillation can attenuate increase in intracranial pressure induced by tracheal suctioning and favor a faster return to the intracranial pressure baseline levels without significant hemodynamic and ventilatory changes.

Traumatic Brain Injury in the Pediatric Intensive Care Unit

Head trauma is a leading cause of brain injury in children, and it can have profound lifelong physical, cognitive, and behavioral consequences. Optimal acute care of children with traumatic brain injury (TBI) requires rapid stabilization and early neurosurgical evaluation by a multidisciplinary team. Meticulous attention is required to limit secondary brain injury after the initial trauma. This review discusses pathophysiology, acute stabilization, and monitoring, as well as supportive and therapeutic measures to help minimize ongoing brain injury and optimize recovery in children with TBI. [Pediatr Ann. 2018;47(7):e274-e279.].

Alfentanil during rapid sequence induction with thiopental 4 mg/kg and rocuronium 0.6 mg/kg: tracheal intubation conditions

BACKGROUND

Opioids have become an integral part of anaesthesia induction. We aimed to determine the dose of alfentanil needed to obtain perfect tracheal intubation conditions during rapid sequence induction with standard doses of thiopental and rocuronium, where laryngoscopy was initiated 55 s after commencement of drug administration. The influence of covariates (sex, body weight, age, alfentanil plasma concentration at laryngoscopy) was tested.

METHODS

Eighty-four healthy individuals were randomly assigned to receive one of the seven assessor-blinded alfentanil doses (0, 10, 20, 30, 40, 50 and 60 μg/kg) in conjunction with thiopental 4 mg/kg and rocuronium 0.6 mg/kg. For drug administration, 15 s was allowed. Laryngoscopy was initiated 40 s after rocuronium and tracheal intubation concluded within 70 s after commencement of drug administration. Alfentanil doses associated with 50%, 90% and 95% probability of perfect intubation conditions were determined with logistic regression. Multiple logistic regressions were used to test the influence of covariates. The relationship between alfentanil dose and concentration at laryngoscopy was analysed with linear regression. The effects of covariates on plasma concentrations of alfentanil were tested with multiple linear regressions.

RESULTS

Perfect intubation conditions of 95% probability was obtained with 56 μg/kg (confidence intervals 44-68). None of the covariates were significant predictors of perfect intubation conditions. Alfentanil plasma concentration correlated with dose and increased with increasing body weight (1.7 ng/ml/kg).

CONCLUSION

Perfect intubation conditions during rapid sequence induction can be obtained with clinically relevant doses of alfentanil in most healthy patients anaesthetized with thiopental 4 mg/kg and rocuronium 0.6 mg/kg.

Neuroanesthesiology update

We review topics pertinent to the perioperative care of patients with neurological disorders. Our review addresses topics not only in the anesthesiology literature, but also in basic neurosciences, critical care medicine, neurology, neurosurgery, radiology, and internal medicine literature. We include literature published or available online up through December 8, 2013. As our review is not able to include all manuscripts, we focus on recurring themes and unique and pivotal investigations. We address the broad topics of general neuroanesthesia, stroke, traumatic brain injury, anesthetic neurotoxicity, neuroprotection, pharmacology, physiology, and nervous system monitoring.

Racemic ketamine in adult head injury patients: use in endotracheal suctioning

INTRODUCTION

Endotracheal suctioning (ETS) is essential for patient care in an ICU but may represent a cause of cerebral secondary injury. Ketamine has been historically contraindicated for its use in head injury patients, since an increase of intracranial pressure (ICP) was reported; nevertheless, its use was recently suggested in neurosurgical patients. In this prospective observational study we investigated the effect of ETS on ICP, cerebral perfusion pressure (CPP), jugular oxygen saturation (SjO2) and cerebral blood flow velocity (mVMCA) before and after the administration of ketamine.

METHODS

In the control phase, ETS was performed on patients sedated with propofol and remifentanil in continuous infusion. If a cough was present, patients were assigned to the intervention phase, and 100 γ/kg/min of racemic ketamine for 10 minutes was added before ETS.

RESULTS

In the control group ETS stimulated the cough reflex, with a median cough score of 2 (interquartile range (IQR) 1 to 2). Furthermore, it caused an increase in mean arterial pressure (MAP) (from 89.0 ± 11.6 to 96.4 ± 13.1 mmHg; P <0.001), ICP (from 11.0 ± 6.7 to 18.5 ± 8.9 mmHg; P <0.001), SjO2 (from 82.3 ± 7.5 to 89.1 ± 5.4; P = 0.01) and mVMCA (from 76.8 ± 20.4 to 90.2 ± 30.2 cm/sec; P = 0.04). CPP did not vary with ETS. In the intervention group, no significant variation of MAP, CPP, mVMCA, and SjO2 were observed in any step; after ETS, ICP increased if compared with baseline (15.1 ± 9.4 vs. 11.0 ± 6.4 mmHg; P <0.05). Cough score was significantly reduced in comparison with controls (P <0.0001).

CONCLUSIONS

Ketamine did not induce any significant variation in cerebral and systemic parameters. After ETS, it maintained cerebral hemodynamics without changes in CPP, mVMCA and SjO2, and prevented cough reflex. Nevertheless, ketamine was not completely effective when used to control ICP increase after administration of 100 γ/kg/min for 10 minutes.

Acute effects of physiotherapeutic respiratory maneuvers in critically ill patients with craniocerebral trauma

OBJECTIVE

To evaluate the effects of physiotherapeutic respiratory maneuvers on cerebral and cardiovascular hemodynamics and blood gas variables.

METHOD

A descriptive, longitudinal, prospective, nonrandomized clinical trial that included 20 critical patients with severe craniocerebral trauma who were receiving mechanical ventilation and who were admitted to the intensive care unit. Each patient was subjected to the physiotherapeutic maneuvers of vibrocompression and increased manual expiratory flow (5 minutes on each hemithorax), along with subsequent airway suctioning with prior instillation of saline solution, hyperinflation and hyperoxygenation. Variables related to cardiovascular and cerebral hemodynamics and blood gas variables were recorded after each vibrocompression, increased manual expiratory flow and airway suctioning maneuver and 10 minutes after the end of airway suctioning.

RESULTS

The hemodynamic and blood gas variables were maintained during vibrocompression and increased manual expiratory flow maneuvers; however, there were increases in mean arterial pressure, intracranial pressure, heart rate, pulmonary arterial pressure and pulmonary capillary pressure during airway suctioning. All of the values returned to baseline 10 minutes after the end of airway suctioning.

CONCLUSION

Respiratory physiotherapy can be safely performed on patients with severe craniocerebral trauma. Additional caution must be taken when performing airway suctioning because this technique alters cerebral and cardiovascular hemodynamics, even in sedated and paralyzed patients.

Aerosolized lidocaine during invasive mechanical ventilation: in vitro characterization and clinical efficiency to prevent systemic and cerebral hemodynamic changes induced by endotracheal suctioning in head-injured patients

BACKGROUND

In patients with severe brain injury, endotracheal suctioning (ETS) can increase intracranial pressure (ICP) and reduce cerebral perfusion pressure (CPP). The aim of this prospective, blinded clinical trial was to assess the effectiveness of aerosolized lidocaine to prevent increase of ICP induced by ETS in mechanically ventilated head-injured patients.

METHODS

First, we measured the particle size of aerosolized lidocaine produced by a vibrating plate nebulizer. Second, we measured the cerebral hemodynamic response to tracheal suctioning in patients in a neurosurgical intensive care unit with and without pretreatment of aerosolized lidocaine.

RESULTS

Particle size distribution of aerosolized lidocaine was suitable to reach the bronchotracheal target during mechanical ventilation. In 15 patients included in this study, aerosolized lidocaine by itself did not induce significant changes in ICP. ETS caused an increase in ICP (variation: 6±2 mm Hg, P<0.05) with a concomitant decrease in CPP (variation: 2±2 mm Hg, P<0.05) that was maximal at 1 minute after NaCl aerosolization. This was prevented by aerosolization of lidocaine (variation of ICP: 1±1 mm Hg, and CPP: -1±1 mm Hg, P<0.05).

CONCLUSIONS

Aerosolized lidocaine (2 mg/kg) can prevent ETS-induced increases in ICP, without modifying systemic and cerebral hemodynamics in deeply sedated patients.

Management of raised intracranial pressure

Appropriate management of raised intracranial pressure begins with stabilization of the patient and simultaneous assessment of the level of sensorium and the cause of raised intracranial pressure. Stabilization is initiated with securing the airway, ventilation and circulatory function. The identification of surgically remediable conditions is a priority. Emergent use of external ventricular drain or ventriculo-peritoneal shunt may be lifesaving in selected patients. In children with severe coma, signs of herniation or acutely elevated intracranial pressure, treatment should be started prior to imaging or invasive monitoring. Emergent use of hyperventilation and mannitol are life saving in such situations. Medical management involves careful use of head elevation, osmotic agents, and avoiding hypotonic fluids. Appropriate care also includes avoidance of aggravating factors. For refractory intracranial hypertension, barbiturate coma, hypothermia, or decompressive craniectomy should be considered.