Sedation options for the morbidly obese intensive care unit patient: a concise survey and an agenda for development

Optimal strategies for assessing and managing pain, agitation, and delirium in the critically ill surgical patient: What you need to know

ABSTRACT

Pain, agitation, and delirium (PAD) are primary drivers of outcome in the ICU, and expertise in managing these entities successfully is crucial to the intensivist's toolbox. In addition, there are unique aspects of surgical patients that impact assessment and management of PAD. In this review, we address the continuous spectrum of assessment, and management of critically ill surgical patients, with a focus on limiting PAD, particularly incorporating mobility as an anchor to ICU liberation. Finally, we touch on the impact of PAD in specific populations, including opioid use disorder, traumatic brain injury, pregnancy, obesity, alcohol withdrawal, and geriatric patients. The goal of the review is to provide rapid access to information regarding PAD and tools to assess and manage these important elements of critical care of surgical patients.

Temporal Trends and Variability in Ketamine Use for Mechanically Ventilated Adults in the United States

Rationale The epidemiology of continuous ketamine use in the management of critically ill adults receiving invasive mechanical ventilation (MV) in the U.S. is unknown. Objective To quantify the temporal trends and variation across U.S. hospitals in continuous ketamine use. Methods We performed a retrospective cohort study of adults (age ≥18) receiving MV who were discharged (alive or dead) from U.S. hospitals contributing data to the Premier Healthcare Database between January 2008 and September 2018. We used mixed effects multivariable logistic regression modeling (fixed effects: patient and hospital characteristics; random effect: discharge hospital) to evaluate the associations of discharge quarter and discharge hospital with continuous ketamine use (defined as a charge for intravenous ketamine on ≥2 consecutive calendar days). Results We identified 2,059,599 MV adults across 842 hospitals; of these, 7,927 (0.4%) received continuous ketamine. Ketamine use increased over time from 0.07% of all patients in quarter 1 2008 to 1.1% of all patients in quarter 3 2018. After adjustment, the odds of receiving continuous ketamine were consistently increased starting in quarter 4 2011 (odds ratio [95% confidence interval]: 1.83 [1.09-3.06] vs quarter 1 2008, p=0.023) with >10-fold increased odds starting in quarter 2 2017. Out of 842 hospitals, 486 (57.7%) used continuous ketamine on at least one cohort patient during the study period. Across these hospitals ever using ketamine, median use was 0.2% (IQR 0.08%-0.5%) with 5 hospitals using continuous ketamine in >5% of patients. The adjusted median odds ratio for discharge hospital was 3.72 (95% confidence interval: 3.37-4.13) which was higher than the odds ratio for any patient or hospital covariable other than discharge quarter. Conclusions In U.S. hospitals, use of continuous infusion ketamine increased markedly over time in critically ill patients receiving MV, with substantial variability between hospitals. Given the unique properties of ketamine as a sedative, further research is needed to assess its safety and utility in critically ill populations.

Hemodynamic and respiratory effects of dexmedetomidine sedation in critically ill Covid-19 patients: A retrospective cohort study

INTRODUCTION

Dexmedetomidine has been suggested to be a promising sedative for patients with Covid-19 infection (CV19). However, use of dexmedetomidine is limited by its heart rate (HR) and arterial blood pressure lowering effects. Moreover, CV19 is associated with cardiac manifestations including bradyarrythmias. The hemodynamic effects of dexmedetomidine have not been previously studied in CV19 patients. We evaluated the effects of dexmedetomidine on hemodynamic and respiratory parameters of CV19 patients.

METHODS

In this single center study, all CV19 patients receiving dexmedetomidine for sedation during a one year period were included. Our primary outcomes included changes in HR, mean arterial pressure (MAP), respiratory rate (RR), partial oxygen pressure of arterial blood/fraction of inspired oxygen-ratio (PF-ratio), and Richmond Agitation and Sedation Score (RASS) during dexmedetomidine administration.

RESULTS

We identified 39 patients with a mean (SD) age of 58.3 (12.7) years. After initiation of dexmedetomidine, HR decreased by 16.9 (3.3) beats/min (95% CI 9.5-22.4; p < 0.001). During the 12-hour follow-up period, HR decrease was significant at 2 to 12 h. Incident bradycardia (<45/min) was reported in 12 (30.8%) patients and it was associated with lower plasma C-reactive protein, Pro-calcitonin, and troponin T levels. There was no change in MAP compared to baseline. Dexmedetomidine administration was associated with improvement of PF-ratio (p < 0.001) and with decrease of RASS (p = 0.004).

CONCLUSIONS

Dexmedetomidine is an effective sedative for CV19 patients and may improve their oxygenation. However, dexmedetomidine administration is associated with marked decline in HR and with a high incidence of bradycardia in patients with CV19.

Subcutaneously administered dexmedetomidine is efficiently absorbed and is associated with attenuated cardiovascular effects in healthy volunteers

PURPOSE

Palliative care patients often need sedation to alleviate intractable anxiety, stress, and pain. Dexmedetomidine is used for sedation of intensive care patients, but there is no prior information on its subcutaneous (SC) administration, a route that would be favored in palliative care. We compared the pharmacokinetics and cardiovascular, sympatholytic, and sedative effects of SC and intravenously (IV) administered dexmedetomidine in healthy volunteers.

METHODS

An open two-period, cross-over design with balanced randomization was used. Ten male subjects were randomized to receive 1 μg/kg dexmedetomidine both IV and SC. Concentrations of dexmedetomidine and catecholamines in plasma were measured. Pharmacokinetic variables were calculated with non-compartmental methods. In addition, cardiovascular and sedative drug effects were monitored.

RESULTS

Eight subjects completed both treatment periods. Peak concentrations of dexmedetomidine were observed 15 min after SC administration (median; range 15-240). The mean bioavailability of SC dexmedetomidine was 81% (AUC_0-∞ ratio × 100%, range 49-97%). The mean (SD) peak concentration of dexmedetomidine in plasma was 0.3 (0.1) ng/ml, and plasma concentrations associated with sedative effects (i.e., > 0.2 ng/ml) were maintained for 4 h after SC dosing. Plasma noradrenaline concentrations were significantly lower (P < 0.001) within 3 h after IV than after SC administration. Subjective scores for vigilance and performance were significantly lower 0-60 min after IV than SC dosing (P < 0.001 for both). The onset of the cardiovascular, sympatholytic, and sedative effects of dexmedetomidine was clearly less abrupt after SC than IV administration.

CONCLUSIONS

Dexmedetomidine is relatively rapidly and efficiently absorbed after SC administration. Subcutaneous dexmedetomidine may be a feasible alternative in palliative sedation, and causes attenuated cardiovascular effects compared to IV administration. CLINICALTRIALS.

GOV IDENTIFIER

NCT02724098 . EUDRA CT number 2015-004698-34 .

Prevention and care of respiratory failure in obese patients

With the increase in the global prevalence of obesity, there is a parallel rise in the proportion of obese patients admitted to intensive care units, referred for major surgery or requiring long-term non-invasive ventilation (NIV) at home for chronic respiratory failure. We describe the physiological effect of obesity on the respiratory system mainly in terms of respiratory mechanics, respiratory drive, and patency of the upper airways. Particular attention is given to the prevention and the clinical management of respiratory failure in obese patients with a main focus on invasive and NIV in intensive care during the perioperative period and long-term use of NIV on return home. We also address other aspects of care of obese patients, including antibiotic dosing and catheter-related infections.

The Effects of Short-Term Propofol and Dexmedetomidine on Lung Mechanics, Histology, and Biological Markers in Experimental Obesity

BACKGROUND

Administering anesthetics to the obese population requires caution because of a variety of reasons including possible interactions with the inflammatory process observed in obese patients. Propofol and dexmedetomidine have protective effects on pulmonary function and are widely used in short- and long-term sedation, particularly in intensive care unit settings in lean and obese subjects. However, the functional and biological effects of these drugs in obesity require further elucidation. In a model of diet-induced obesity, we compared the short-term effects of dexmedetomidine versus propofol on lung mechanics and histology, as well as biological markers of inflammation and oxidative stress modulation in obesity.

METHODS

Wistar rats (n = 56) were randomly fed a standard diet (lean) or experimental diet (obese) for 12 weeks. After this period, obese animals received sodium thiopental intraperitoneally and were randomly allocated into 4 subgroups: (1) nonventilated (n = 4) for molecular biology analysis only (control); (2) sodium thiopental (n = 8); (3) propofol (n = 8); and (4) dexmedetomidine (n = 8), which received continuous IV administration of the corresponding agents and were mechanically ventilated (tidal volume = 6 mL/kg body weight, fraction of inspired oxygen = 0.4, positive end-expiratory pressure = 3 cm H2O) for 1 hour.

RESULTS

Compared with lean animals, obese rats did not present increased body weight but had higher total body and trunk fat percentages, airway resistance, and interleukin-6 levels in the lung tissue (P = 0.02, P = 0.0027, and P = 0.01, respectively). In obese rats, propofol, but not dexmedetomidine, yielded increased airway resistance, bronchoconstriction index (P = 0.016, P = 0.02, respectively), tumor necrosis factor-α, and interleukin-6 levels, as well as lower levels of nuclear factor-erythroid 2-related factor-2 and glutathione peroxidase (P = 0.001, Bonferroni-corrected t test).

CONCLUSIONS

In this model of diet-induced obesity, a 1-hour propofol infusion yielded increased airway resistance, atelectasis, and lung inflammation, with depletion of antioxidative enzymes. However, unlike sodium thiopental and propofol, short-term infusion of dexmedetomidine had no impact on lung morphofunctional and biological variables.