Inhaled volatile anesthetics in the intensive care unit

The discovery and utilization of volatile anesthetics has significantly transformed surgical practices since their inception in the mid-19th century.Recently,a paradigm shift is observed as volatile anesthetics extend beyond traditional confines of the operating theatres,finding diverse applications in intensive care settings.In the dynamic landscape of intensive care,volatile anesthetics emerge as a promising avenue for addressing complex sedation requirements,managing refractory lung pathologies including acute respiratory distress syndrome and status asthmaticus,conditions of high sedative requirements including burns,high opioid or alcohol use and neurological conditions such as status epilepticus.Volatile anesthetics can be administered through either inhaled route via anesthetic machines/devices or through extracorporeal membrane oxygenation circuitry,providing intensivists with multiple options to tailor therapy.Furthermore,their unique pharmacokinetic profiles render them titratable and empower clinicians to individualize management with heightened accuracy,mitigating risks associated with conventional sedation modalities.Despite the amounting enthusiasm for the use of these therapies,barriers to widespread utilization include expanding equipment availability,staff familiarity and training of safe use.This article delves into the realm of applying inhaled volatile anesthetics in the intensive care unit through discussing their pharmacology,administration considerations in intensive care settings,complication considerations,and listing indications and evidence of the use of volatile anesthetics in the critically ill patient population.

Clonidine use during dexmedetomidine weaning:A systematic review

BACKGROUND Dexmedetomidine is a centrally acting alpha-2A adrenergic agonist that is commonly used as a sedative and anxiolytic in the intensive care unit(ICU),with prolonged use increasing risk of withdrawal symptoms upon sudden discontinuation.As clonidine is an enterally available alpha-2A adrenergic agonist,it may be a suitable agent to taper off dexmedetomidine and reduce withdrawal syndromes.The appropriate dosing and conversion strategies for using enteral clonidine in this context are not known.The objective of this systematic review is to summarize the evidence of enteral clonidine application during dexmedetomidine weaning for prevention of withdrawal symptoms.AIM To systematically review the practice,dosing schema,and outcomes of enteral clonidine use during dexmedetomidine weaning in critically ill adults.METHODS This was a systematic review of enteral clonidine used during dexmedetomidine weaning in critically ill adults(≥18 years).Randomized controlled trials,prospective cohorts,and retrospective cohorts evaluating the use of clonidine to wean patients from dexmedetomidine in the critically ill were included.The primary outcomes of interest were dosing and titration schema of enteral clonidine and dexmedetomidine and risk factors for dexmedetomidine withdrawal.Other secondary outcomes included prevalence of adverse events associated with enteral clonidine use,re-initiation of dexmedetomidine,duration of mechanical ventilation,and ICU length of stay.RESULTS A total of 3427 studies were screened for inclusion with three meeting inclusion criteria with a total of 88 patients.All three studies were observational,two being prospective and one retrospective.In all included studies,the choice to start enteral clonidine to wean off dexmedetomidine was made at the discretion of the physician.Weaning time ranged from 13 to 167 h on average.Enteral clonidine was started in the prospective studies in a similar protocolized method,with 0.3 mg every 6 h.After starting clonidine,patients remained on dexmedetomidine for a median of 1-28 h.Following the termination of dexmedetomidine,two trials tapered enteral clonidine by increasing the interval every 24 h from 6 h to 8h,12h,and 24 h,followed by clonidine discontinuation.For indicators of enteral clonidine withdrawal,the previously tolerable dosage was reinstated for several days before resuming the taper on the same protocol.The adverse events associated with enteral clonidine use were higher than patients on dexmedetomidine taper alone with increased agitation.The re-initiation of dexmedetomidine was not documented in any study.Only 17(37%)patients were mechanically ventilated with median duration of 3.5 d for 13 patients in one of the 2 studies.ICU lengths of stay were similar.CONCLUSION Enteral clonidine is a strategy to wean critically ill patients from dexmedetomidine.There is an association of increased withdrawal symptoms and agitation with the use of a clonidine taper.

Endotracheal intubation sedation in the intensive care unit

Endotracheal intubation is one of the most common,yet most dangerous procedure performed in the intensive care unit(ICU).Complications of ICU intubations include severe hypotension,hypoxemia,and cardiac arrest.Multiple observational studies have evaluated risk factors associated with these complications.Among the risk factors identified,the choice of sedative agents administered,a modifiable risk factor,has been reported to affect these complications(hypotension).Propofol,etomidate,and ketamine or in combination with benzodiazepines and opioids are commonly used sedative agents administered for endotracheal intubation.Propofol demonstrates rapid onset and offset,however,has drawbacks of profound vasodilation and associated cardiac depression.Etomidate is commonly used in the critically ill population.However,it is known to cause reversible inhibition of 11β-hydroxylase which suppresses the adrenal production of cortisol for at least 24 h.This added organ impairment with the use of etomidate has been a potential contributing factor for the associated increased morbidity and mortality observed with its use.Ketamine is known to provide analgesia with sedation and has minimal respiratory and cardiovascular effects.However,its use can lead to tachycardia and hypertension which may be deleterious in a patient with heart disease or cause unpleasant hallucinations.Moreover,unlike propofol or etomidate,ketamine requires organ dependent elimination by the liver and kidney which may be problematic in the critically ill.Lately,a combination of ketamine and propofol,“Ketofol”,has been increasingly used as it provides a balancing effect on hemodynamics without any of the side effects known to be associated with the parent drugs.Furthermore,the doses of both drugs are reduced.In situations where a difficult airway is anticipated,awake intubation with the help of a fiberoptic scope or video laryngoscope is considered.Dexmedetomidine is a commonly used sedative agent for these procedures.

Vasopressin in vasoplegic shock:A systematic review

BACKGROUNDVasoplegic shock is a challenging complication of cardiac surgery and is oftenresistant to conventional therapies for shock. Norepinephrine and epinephrine arestandards of care for vasoplegic shock, but vasopressin has increasingly been usedas a primary pressor in vasoplegic shock because of its unique pharmacology andlack of inotropic activity. It remains unclear whether vasopressin has distinctbenefits over standard of care for patients with vasoplegic shock.AIMTo summarize the available literature evaluating vasopressin vs non-vasopressinalternatives on the clinical and patient-centered outcomes of vasoplegic shock inadult intensive care unit (ICU) patients.METHODSThis was a systematic review of vasopressin in adults (≥ 18 years) with vasoplegicshock after cardiac surgery. Randomized controlled trials, prospective cohorts,and retrospective cohorts comparing vasopressin to norepinephrine, epinephrine,methylene blue, hydroxocobalamin, or other pressors were included. The primaryoutcomes of interest were 30-d mortality, atrial/ventricular arrhythmias, stroke,ICU length of stay, duration of vasopressor therapy, incidence of acute kidneyinjury stage II-III, and mechanical ventilation for greater than 48 h.RESULTSA total of 1161 studies were screened for inclusion with 3 meeting inclusioncriteria with a total of 708 patients. Two studies were randomized controlled trials and one was a retrospective cohort study. Primary outcomes of 30-d mortality,stroke, ventricular arrhythmias, and duration of mechanical ventilation weresimilar between groups. Conflicting results were observed for acute kidney injurystage II-III, atrial arrhythmias, duration of vasopressors, and ICU length of staywith higher certainty of evidence in favor of vasopressin serving a protective rolefor these outcomes.CONCLUSIONVasopressin was not found to be superior to alternative pressor therapy for any ofthe included outcomes. Results are limited by mixed methodologies, small overallsample size, and heterogenous populations.

Acute exacerbation of interstitial lung disease in the intensive care unit

Acute exacerbations of interstitial lung disease(AE-ILD)represent an acute,frequent and often highly morbid event in the disease course of ILD patients.Admission in the intensive care unit(ICU)is very common and the need for mechanical ventilation arises early.While non-invasive ventilation has shown promise in staving off intubation in selected patients,it is unclear whether mechanical ventilation can alter the exacerbation course unless it is a bridge to lung transplantation.Risk stratification using clinical and radiographic findings,and early palliative care involvement,are important in ICU care.In this review,we discuss many of the pathophysiological aspects of AE-ILD and raise the hypothesis that ventilation strategies used in acute respiratory distress syndrome might be implemented in AE-ILD.We present possible decision-making and management algorithms that can be used by the intensivist when caring for these patients.