Approach to Sedation and Analgesia in COVID-19 Patients on Venovenous Extracorporeal Membrane Oxygenation

International Analgesia and Sedation Weaning and Withdrawal Practices in Critically Ill Adults: The Adult Iatrogenic Withdrawal Study in the ICU

OBJECTIVES

Iatrogenic withdrawal syndrome (IWS) associated with opioid and sedative use for medical purposes has a reported high prevalence and associated morbidity. This study aimed to determine the prevalence, utilization, and characteristics of opioid and sedative weaning and IWS policies/protocols in the adult ICU population.

DESIGN

International, multicenter, observational, point prevalence study.

SETTING

Adult ICUs.

PATIENTS

All patients aged 18 years and older in the ICU on the date of data collection who received parenteral opioids or sedatives in the previous 24 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

ICUs selected 1 day for data collection between June 1 and September 30, 2021. Patient demographic data, opioid and sedative medication use, and weaning and IWS assessment data were collected for the previous 24 hours. The primary outcome was the proportion of patients weaned from opioids and sedatives using an institutional policy/protocol on the data collection day. There were 2,402 patients in 229 ICUs from 11 countries screened for opioid and sedative use; 1,506 (63%) patients received parenteral opioids, and/or sedatives in the previous 24 hours. There were 90 (39%) ICUs with a weaning policy/protocol which was used in 176 (12%) patients, and 23 (10%) ICUs with an IWS policy/protocol which was used in 9 (0.6%) patients. The weaning policy/protocol for 47 (52%) ICUs did not define when to initiate weaning, and the policy/protocol for 24 (27%) ICUs did not specify the degree of weaning. A weaning policy/protocol was used in 34% (176/521) and IWS policy/protocol in 9% (9/97) of patients admitted to an ICU with such a policy/protocol. Among 485 patients eligible for weaning policy/protocol utilization based on duration of opioid/sedative use initiation criterion within individual ICU policies/protocols 176 (36%) had it used, and among 54 patients on opioids and/or sedatives ≥ 72 hours, 9 (17%) had an IWS policy/protocol used by the data collection day.

CONCLUSIONS

This international observational study found that a small proportion of ICUs use policies/protocols for opioid and sedative weaning or IWS, and even when these policies/protocols are in place, they are implemented in a small percentage of patients.

Comparison of Sedation and Analgesia Requirements in Patients With SARS-CoV-2 Versus Non-SARS-CoV-2 Acute Respiratory Distress Syndrome on Veno-Venous ECMO

BACKGROUND

Increased analgosedation requirements have been described in patients with acute respiratory distress syndrome (ARDS) on extracorporeal membrane oxygenation (ECMO) support due to unique pharmacokinetic challenges. There is a paucity of data comparing sedation requirements in patients on ECMO for ARDS secondary to SARS-CoV-2 versus other etiologies of respiratory failure.

OBJECTIVE

To compare sedation and analgesia requirements in adult patients with SARS-CoV-2 versus non-SARS-CoV-2 ARDS requiring veno-venous (VV) ECMO support.

METHODS

We performed a retrospective cohort study of adult patients receiving sedation and analgesia on VV-ECMO support. Patients were excluded if cannulated at an outside hospital for greater than 24 hours, expired within 48 hours of ECMO cannulation, or received neuromuscular blocking agents for greater than 7 consecutive days following ECMO cannulation.

RESULTS

We evaluated 108 patients on VV-ECMO support, including 44 with non-SARS-CoV-2 ARDS and 64 with SARS-CoV-2 ARDS. The median daily dexmedetomidine requirements were significantly higher in the SARS-CoV-2 cohort (16.7 vs 13.4 mcg/kg/day, P = 0.03), while the median propofol daily requirements were significantly higher in the non-SARS-CoV-2 cohort (40.3 vs 53.5 mg/kg/day, P < 0.01). There was no difference in daily requirements of opioids, benzodiazepines, and ketamine between groups. Use of adjunct agents to facilitate weaning was significantly higher in the SARS-CoV-2 cohort (78.1% vs 43.2%, P < 0.01).

CONCLUSION AND RELEVANCE

Patients with ARDS on VV-ECMO support require multiple analgosedative agents with concomitant use of nonparenteral adjunct agents. Further studies are needed to evaluate optimal analgosedation strategies in patients on ECMO support.

Propofol-Associated Hypertriglyceridemia in Adults With Acute Respiratory Distress Syndrome on Extracorporeal Membrane Oxygenation

The incidence and risk factors for propofol-associated hypertriglyceridemia (HTG) in patients receiving extracorporeal membrane oxygenation (ECMO) have not been evaluated. The purpose of this study was to determine the incidence and risk factors for propofol-associated HTG in patients with acute respiratory distress syndrome (ARDS) on ECMO. This retrospective, cohort study included 167 adults admitted to a medical intensive care unit (ICU) from July 1, 2013 to September 1, 2021, who received 24 hours of concurrent propofol and ECMO therapy. The primary outcome was the incidence of propofol-associated HTG. Secondary outcomes included HTG risk factors, time to development and resolution of HTG, and incidence of pancreatitis. HTG occurred in 58 (34.7%) patients. Patients with HTG had longer durations of ECMO (19 vs. 13 days, p < 0.001), longer ICU length of stay (26.5 vs. 23 days, p = 0.002), and higher in-hospital mortality (51.7 vs. 34.9%, p = 0.047). Baseline sequential organ failure assessment score was associated with an increased risk of developing HTG (hazard ratio [HR] = 1.19, 95% confidence interval [CI] = 1.09-1.30; p < 0.001). Propofol-associated HTG occurred in one-third of patients receiving ECMO for ARDS. Higher baseline illness severity and ECMO duration were associated with an increased risk of propofol-associated HTG.

Veno-venous Extracorporeal Membrane Oxygenation: Anesthetic Considerations in Clinical Practice

Context

After the COVID-19 pandemic, multiple reviews have documented the success of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Patients who experience hypoxemia but have normal contractility may be switched to veno-venous-ECMO (VV-ECMO).

Purpose

In this review, we present three protocols for anesthesiologists. Firstly, transesophageal echocardiography (TEE) aids in cannulation and weaning off inotropes and fluids. Our main objective is to assist in patient selection for the Avalon Elite single catheter, which is inserted into the right internal jugular vein and terminates in the right atrium. Secondly, we propose appropriate anticoagulant doses. We outline day-to-day monitoring protocols to prevent heparin-induced thrombocytopenia (HIT) or resistance. Once the effects of neuromuscular paralysis subside, sedation should be reduced. Therefore, we describe techniques that may prevent delirium from progressing into permanent cognitive decline.

Methods

We conducted a PubMed search using the keywords VV-ECMO, TEE, Avalon Elite (Maquet, Germany), and quetiapine. We combined these findings with interviews conducted with nurses and anesthesiologists from two academic ECMO centers, focusing on anticoagulation and sedation.

Results

Our qualitative evidence synthesis reveals how TEE confirms cannulation while avoiding right atrial rupture or low flows. Additionally, we discovered that typically, after initial heparinization, activated partial thromboplastin time (PTT) is drawn every 1 to 2 hours or every 6 to 8 hours once stable. Daily thromboelastograms, along with platelet counts and antithrombin III levels, may detect HIT or resistance, respectively. These side effects can be prevented by discontinuing heparin on day two and initiating argatroban at a dose of 1 μg/kg/min while maintaining PTT between 61 - 80 seconds. The argatroban dose is adjusted by 10 - 20% if PTT is between 40 - 60 or 80 - 90 seconds. Perfusionists assist in establishing protocols following manufacturer guidelines. Lastly, we describe the replacement of narcotics and benzodiazepines with dexmedetomidine at a dose of 0.5 to 1 μg/kg/hour, limited by bradycardia, and the use of quetiapine starting at 25 mg per day and gradually increasing up to 200 mg twice a day, limited by prolonged QT interval.

Conclusions

The limitation of this review is that it necessarily covers a broad range of ECMO decisions faced by an anesthesiologist. However, its main advantage lies in the identification of straightforward argatroban protocols through interviews, as well as the discovery, via PubMed, of the usefulness of TEE in determining cannula position and contractility estimates for transitioning from VA-ECMO to VV-ECMO. Additionally, we emphasize the benefits in terms of morbidity and mortality of a seldom-discussed sedation supplement, quetiapine, to dexmedetomidine.

Sedation with Sevoflurane versus Propofol in COVID-19 Patients with Acute Respiratory Distress Syndrome: Results from a Randomized Clinical Trial

BACKGROUND

Acute respiratory distress syndrome (ARDS) related to COVID-19 (coronavirus disease 2019) led to intensive care units (ICUs) collapse. Amalgams of sedative agents (including volatile anesthetics) were used due to the clinical shortage of intravenous drugs (mainly propofol and midazolam).

METHODS

A multicenter, randomized 1:1, controlled clinical trial was designed to compare sedation using propofol and sevoflurane in patients with ARDS associated with COVID-19 infection in terms of oxygenation and mortality.

RESULTS

Data from a total of 17 patients (10 in the propofol arm and 7 in the sevoflurane arm) showed a trend toward PaO₂/FiO₂ improvement and the sevoflurane arm's superiority in decreasing the likelihood of death (no statistical significance was found).

CONCLUSIONS

Intravenous agents are the most-used sedative agents in Spain, even though volatile anesthetics, such as sevoflurane and isoflurane, have shown beneficial effects in many clinical conditions. Growing evidence demonstrates the safety and potential benefits of using volatile anesthetics in critical situations.

Impact of COVID-19 on Sedation Requirements during Veno-Venous Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome

COVID-19-associated ARDS (C-ARDS) is mentioned to express higher analgosedation needs, in comparison to ARDS of other etiologies. The objective of this monocentric retrospective cohort study was to compare the analgosedation needs between C-ARDS and non-COVID-19 ARDS (non-C-ARDS) on veno-venous extracorporeal membrane oxygenation (VV-ECMO). Data were collected from the electronic medical records of all adult patients treated with C-ARDS in our Department of Intensive Care Medicine between March 2020 and April 2022. The control group included patients treated with non-C-ARDS between the years 2009 and 2020. A sedation sum score was created in order to describe the overall analgosedation needs. A total of 115 (31.5%) patients with C-ARDS and 250 (68.5%) with non-C-ARDS requiring VV-ECMO therapy were included in the study. The sedation sum score was significantly higher in the C-ARDS group (p < 0.001). COVID-19 was significantly associated with analgosedation in the univariable analysis. By contrast, the multivariable model did not show a significant association between COVID-19 and the sum score. The year of VV-ECMO support, BMI, SAPS II and prone positioning were significantly associated with sedation needs. The potential impact of COVID-19 remains unclear, and further studies are warranted in order to evaluate specific disease characteristics linked with analgesia and sedation.

Potential pharmacological confounders in the setting of death determined by neurologic criteria: a narrative review

Guidelines for the determination of death by neurologic criteria (DNC) require an absence of confounding factors if clinical examination alone is to be used. Drugs that depress the central nervous system suppress neurologic responses and spontaneous breathing and must be excluded or reversed prior to proceeding. If these confounding factors cannot be eliminated, ancillary testing is required. These drugs may be present after being administered as part of the treatment of critically ill patients. While measurement of serum drug concentrations can help guide the timing of assessments for DNC, they are not always available or feasible. In this article, we review sedative and opioid drugs that may confound DNC, along with pharmacokinetic factors that govern the duration of drug action. Pharmacokinetic parameters including a context-sensitive half-life of sedatives and opioids are highly variable in critically ill patients because of the multitude of clinical variables and conditions that can affect drug distribution and clearance. Patient-, disease-, and treatment-related factors that influence the distribution and clearance of these drugs are discussed including end organ function, age, obesity, hyperdynamic states, augmented renal clearance, fluid balance, hypothermia, and the role of prolonged drug infusions in critically ill patients. In these contexts, it is often difficult to predict how long after drug discontinuation the confounding effects will take to dissipate. We propose a conservative framework for evaluating when or if DNC can be determined by clinical criteria alone. When pharmacologic confounders cannot be reversed, or doing so is not feasible, ancillary testing to confirm the absence of brain blood flow should be obtained.

Awake Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome: Which Clinical Issues Should Be Taken Into Consideration

With the goal of protecting injured lungs and extrapulmonary organs, venovenous extracorporeal membrane oxygenation (VV-ECMO) has been increasingly adopted as a rescue therapy for patients with severe acute respiratory distress syndrome (ARDS) when conventional mechanical ventilation failed to provide effective oxygenation and decarbonation. In recent years, it has become a promising approach to respiratory support for awake, non-intubated, spontaneously breathing patients with respiratory failure, referred to as awake ECMO, to avoid possible detrimental effects associated with intubation, mechanical ventilation, and the adjunctive therapies. However, several complex clinical issues should be taken into consideration when initiating and implementing awake ECMO, such as selecting potential patients who appeared to benefit most; techniques to facilitating cannulation and maintain stable ECMO blood flow; approaches to manage pain, agitation, and delirium; and approaches to monitor and modulate respiratory drive. It is worth mentioning that there had also been some inherent disadvantages and limitations of awake ECMO compared to the conventional combination of ECMO and invasive mechanical ventilation. Here, we review the use of ECMO in awake, spontaneously breathing patients with severe ARDS, highlighting the issues involving bedside clinical practice, detailing some of the technical aspects, and summarizing the initial clinical experience gained over the past years.