New research was presented at SCCM 2019, The Society of Critical Care Medicine’s Annual Congress, from February 17 to 20 in San Diego. The features below highlight some of the studies presented at the conference.


Predicting Opioid-Induced Respiratory Depression Risk

Research shows that opioid-induced respiratory depression (OIRD) is a potential cause of in-hospital cardiorespiratory arrest, often resulting in catastrophic outcomes. Study investigators who investigated the incidence of OIRD using continuous cardiorespiratory monitoring (heart rate, oxygen saturation, end-tidal carbon dioxide, and respiratory rate) in patients receiving opioid therapy used their findings to derive and validate by bootstrapping a novel risk prediction tool. Among the 41.4% of patients in whom respiratory depression occurred, a modified full analysis set found positive predictors of OIRD by univariate analysis to include age older than 70 years, male gender, major organ failure, chronic heart failure or cardiac disease, coronary artery disease, COPD or pulmonary disease, pneumonia, type II diabetes, hypertension, kidney failure, and opioid naivety. Negative predictors included BMI of 35 kg/m2 or higher and asthma. The multivariate regression model—including age older than 70 years, male gender, sleep disorders, hypertension, and opioid naivety—was used to develop a novel OIRD risk prediction tool. The study authors concluded that “implementation of improved monitoring strategies using this tool could prevent respiratory compromise, improve patient safety on [general care floors], and decrease the burden of rapid response calls and unplanned ICU admissions.”



The Epidemiology of Hospital-Onset Sepsis

With most prior epidemiologic studies of sepsis using administrative data with variable accuracy, no reliable differentiation between community-onset (CO) and hospital-onset (HO) disease, and a lack of granular clinical information, relatively little is known about HO sepsis. For a study, researchers compared the risk of in-hospital mortality for patients with HO sepsis with that of those with CO sepsis and without sepsis, controlling for demographics, comorbidities, infectious diagnoses, and severity-of-illness at sepsis onset or on admission among 2.3 million patients at 136 US hospitals. When compared with patients with CO sepsis, those with HO sepsis were younger (66 vs 68 years), but had more comorbidities (median Elixhauser score, 14 vs 11), including heart failure (26% vs 22%), renal disease (23% vs 20%), and cancer (17% vs 11%). HO sepsis patients had higher sequential organ failure assessment scores at sepsis onset (median 4 vs 3), higher rates of intra-abdominal infections (20% vs 15%), more positive blood cultures (26% vs 21%), longer hospital length of stay (19 vs 8 days) and ICU length of stay (6 vs 4 days), and higher in-hospital mortality (34% vs 17%). On multivariate analysis, HO sepsis was associated with higher risk of in-hospital mortality than CO sepsis (odds ratio, 2.10) and no sepsis (hazard ratio, 3.02).



Adjunctive Intermittent Pneumatic Compression for DVT

Data are lacking on whether or not adjunctive intermittent pneumatic compression would lead to a lower incidence of deep-vein thrombosis (DVT) in patients receiving pharmacologic thromboprophylaxis than pharmacologic thromboprophylaxis alone. To answer this question, researchers randomized adults, within 48 hours of ICU admission, to either intermittent pneumatic compression for at least 18 hours each day in addition to pharmacologic thromboprophylaxis with unfractionated or low-molecular-weight heparin (pneumatic compression group) or pharmacologic thromboprophylaxis alone (control group). The primary outcome—incident proximal lower-limb DVT, as detected on twice-weekly lower-limb ultrasonography after the third calendar day since randomization until ICU discharge, death, attainment of full mobility, or trial day 28, whichever occurred first—occurred in 3.9% of pneumatic compression patients and 4.2% of controls. Venous thromboembolism (pulmonary embolism or any lower-limb DVT) occurred in 10.4% of pneumatic compression patients and 9.4% of control patients, while 90-day, all-cause mortality occurred in 26.1% and 26.7%, respectively. The researchers concluded that adjunctive intermittent pneumatic compression did not result in significantly better outcomes than pharmacologic thromboprophylaxis alone in this patient population.



Antibiotics after Intubation in Young Children With RSV-LRTI

Evidence suggests that technology used to detect secondary bacterial infections is lagging in pediatric populations. To describe antibiotic prescribing practices during the first 2 days of mechanical ventilation among previously healthy young children with respiratory syncytial virus-associated lower respiratory tract infection, or RSV-LRTI, and evaluate associations between the prescription of antibiotics at onset of mechanical ventilation with clinical outcomes, study investigators compared such children with those not prescribed antibiotics during the first 2 days of mechanical ventilation among more than 2,000 PICU patients at 46 US children’s hospitals. The overall proportion of antibiotic prescription on both of the first 2 days of mechanical ventilation was 82%, varying from 36% to 100% across centers. Upon bivariate analysis, antibiotic prescription was associated with a shorter duration of mechanical ventilation and a shorter hospital length of stay. After adjustment for center, demographics, and vasoactive medication prescription, antibiotic prescription was associated with a 1.21-day shorter duration of mechanical ventilation and a 2.07-day shorter length of stay. Ultimately, 95% of children were prescribed antibiotics sometime during hospitalization, but timing, duration, and antibiotic choice varied markedly.



Preventing Hypoxemia During Tracheal Intubation

Among critically ill adults, hypoxemia has been found to be the most common complication during tracheal intubation. However, study results on whether or not bag-mask ventilation can prevent hypoxemia without increasing aspiration risk remain unclear. For a study, adults undergoing tracheal intubation were randomized to bag-mask ventilation or no ventilation between induction and laryngoscopy to compare the lowest oxygen saturation observed during the interval between induction and 2 minutes after tracheal intubation, as well as the incidence of severe hypoxemia. Median lowest oxygen saturations were 96% in the bag-mask ventilation group and 93% in the no-ventilation group. Severe hypoxemia occurred in 10.9% of bag-mask ventilation patients, compared with 22.8% of no-ventilation patients. Operator-reported aspiration occurred during 2.5% of intubations in the bag-mask ventilation group and during 4.0% in the no-ventilation group.