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

Non-human primate models of human respiratory infections

Respiratory pathogens represent a great burden for humanity and a potential source of new pandemics, as illustrated by the recent emergence of coronavirus disease 2019 (COVID-19). In recent decades, biotechnological advances have led to the development of numerous innovative therapeutic molecules and vaccine immunogens. However, we still lack effective treatments and vaccines against many respiratory pathogens. More than ever, there is a need for a fast, predictive, preclinical pipeline, to keep pace with emerging diseases. Animal models are key for the preclinical development of disease management strategies. The predictive value of these models depends on their ability to reproduce the features of the human disease, the mode of transmission of the infectious agent and the availability of technologies for monitoring infection. This review focuses on the use of non-human primates as relevant preclinical models for the development of prevention and treatment for human respiratory infections.

The risk factors for the postoperative pulmonary infection in patients with hypertensive cerebral hemorrhage: A retrospective analysis

ABSTRACT

The risk factors for the pulmonary infections after hypertensive cerebral hemorrhage remains unclear. We aimed to investigate the potential risk factors for the postoperative pulmonary infection in patients with hypertensive cerebral hemorrhage.Patients with hypertensive cerebral hemorrhage undergone surgery from January 2018 to December 2019 were included. Related personal and medical information were collected. Univariate and multivariate logistic regression analyses were performed to identify the potential risk factors for the postoperative pulmonary infection.A total of 264 patients were included, and the incidence of pulmonary infection for patients with hypertensive cerebral hemorrhage after surgery was 19.70%. Escherichia coli is the most common bacteria of pulmonary infection. Multivariate regression analysis revealed that the preoperative hypoalbuminemia (OR2.89, 1.67∼4.78), tracheotomy (OR5.31, 1.24∼11.79), diabetes (OR4.92, 1.32∼9.80), preoperative GCS (OR5.66, 2.84∼11.21), and the duration of mechanical ventilation (OR2.78, 2.32∼3.61) were the independent risk factors for the pulmonary infection in patients with hypertensive cerebral hemorrhage (all P < .05).Patients with hypertensive intracerebral hemorrhage after surgery have a higher risk of postoperative pulmonary infections, and there are many related risk factors, which should be taken seriously in clinical practice.

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.

Comparison of effect of dexmedetomidine and lidocaine on intracranial and systemic hemodynamic response to chest physiotherapy and tracheal suctioning in patients with severe traumatic brain injury

PURPOSE

Chest physiotherapy and tracheal suction cause sympathetic stimulation and increase heart rate (HR), mean arterial pressure (MAP) and intracranial pressure (ICP) which may have deleterious effect in the head injured. We planned to compare the effect of intravenous dexmedetomidine and lidocaine on intracerebral and systemic hemodynamic response to chest physiotherapy (CP) and tracheal suctioning (TS) in patients with severe traumatic brain injury (sTBI).

METHODS

Prospective, randomized study in patients with sTBI, 18-60 years of age, undergoing mechanical ventilation and intraparenchymal ICP monitoring. Patients were randomized to receive either iv dexmedetomidine 0.5 mcg/kg (group I; n = 30) or iv lidocaine 2 mg/kg (group II; n = 30) over 10 min. After infusion of test drug, CP with vibrator and manual compression was performed for 2 min and TS was done over next 15-20 s. The hemodynamic response was recorded before, during and at interval of 1 min for 10 min after CP and TS. A 20% change in hemodynamic parameters was considered significant.

RESULTS

The baseline hemodynamic (HR, MAP), intracranial (ICP, CPP) and respiratory (SPO₂, AWP_peak) parameters were normal and comparable in both the groups. After dexmedetomidine infusion, MAP and CPP decreased significantly from baseline value. In group II, there was no significant change in HR, MAP, ICP and CPP. At end of CP and TS, HR, MAP and CPP in group I was lower as compared to group II. During the 10-min observation period following CP and TS, MAP and CPP in group I remained significantly lower as compared to baseline and group II. There was no significant change in value of other measured parameters.

CONCLUSIONS

Both dexmedetomidine and lidocaine were effective to blunt rise in HR, MAP and ICP in response to CP and TS in patients with sTBI. However, intravenous dexmedetomidine caused significant decrease in MAP and CPP as compared to the baseline and lidocaine.

Effects of Closed Endotracheal Suctioning on Systemic and Cerebral Oxygenation and Hemodynamics in Children

OBJECTIVES

To evaluate the effects of closed endotracheal tube suctioning on systemic oxygen saturation, cerebral regional oxygen saturation, and somatic regional (renal) oxygen saturation and hemodynamic variables in children.

DESIGN

Prospective observational.

SETTING

A tertiary care PICU.

SUBJECTS

Children aged 0-18 years, requiring invasive mechanical ventilation and with an arterial line.

INTERVENTIONS

Closed endotracheal suction.

MEASUREMENTS AND MAIN RESULTS

The study included 19 sedated and intubated children, 0-18 years old. They were enrolled in an ongoing prospective observational study. We used near-infrared spectroscopy for cerebral regional oxygen saturation and somatic regional (renal) oxygen saturation. The timing of each closed endotracheal tube suctioning event was accurately identified from video recordings. We extracted systemic oxygen saturation, cerebral regional oxygen saturation, somatic regional (renal) oxygen saturation, heart rate, and systolic blood pressure and diastolic blood pressure for 5 minutes before and 5 minutes after each event and used these data for analysis. One-minute average values of these variables were used for repeated-measures analysis. We analyzed 287 endotracheal tube suctioning episodes in 19 children. Saline was instilled into the endotracheal tube during 61 episodes. The mean heart rate (107.0 ± 18.7 vs 110.2 ± 10.4; p < 0.05), mean arterial blood pressure (81.5 ± 16.1 vs 83.0 ± 15.6 mm Hg; p < 0.05), and the mean cerebral regional oxygen saturation (64.8 ± 8.3 vs 65.8 ± 8.3; p < 0.05) were increased after suctioning. The mean systemic oxygen saturation (96.9 ± 2.7 vs 96.7 ± 2.7; p = 0.013) was decreased, whereas the mean somatic regional (renal) oxygen saturation was not significantly different after endotracheal tube suctioning. Repeated-measures analysis revealed transient increases in heart rate, respiratory rate, systolic blood pressure, and diastolic blood pressure; a sustained increase in cerebral regional oxygen saturation; and transient decreases in systemic oxygen saturation and somatic regional (renal) oxygen saturation. Saline instillation did not affect oxygenation or hemodynamic variables.

CONCLUSIONS

Closed endotracheal tube suctioning in sedated children is associated with transient but clinically insignificant changes in heart rate, blood pressure, cerebral regional oxygen saturation, systemic oxygen saturation, and somatic regional (renal) oxygen saturation. Saline instillation during endotracheal tube suctioning had no adverse effects on systemic or cerebral oxygenation.

Anesthetic management of labor and delivery in patients with elevated intracranial pressure

The anesthetic management of labor and delivery in patients with elevated intracranial pressure is complex. This review discusses the etiologies of diffuse and focal pathologies which lead to elevated intracranial pressure in pregnancy. The role of neuraxial and general anesthesia in the management of labor and delivery is also examined. Finally, a comprehensive review of strategies to minimize increases in intracranial pressure during general anesthesia for cesarean delivery is presented.

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.