All right. Hello, everyone. Thanks for having me. I live here in San Francisco, so I didn't have to go very far. But welcome to San Francisco. And for those of you who celebrate, Happy New Year. As mentioned previously, my talk is entitled Epidemiology of Patients with Substance Use Disorder in the ICU, Special Focus on Non-Opioids. I was asked to include a slide about myself. So here I am. My name is Kathy LeSaint. I am an associate clinical professor at the University of California, San Francisco. I am a clinical attending in the emergency department. I also consult on the medical toxicology team at Zuckerberg San Francisco General Hospital and Trauma Center. I also work out of the California Poison Control System, San Francisco Division. My academic work is focused on improving the care for patients with substance use disorder, both in the pre-hospital and in-hospital setting. I work on a number of quality improvement initiatives related to that. I received grant funding for project implementation from SAMHSA and from the California Department of Health Care Services. Quality improvement initiatives, mostly for patients with opioid use disorder. I do not receive any commercial funding. I have several learning objectives for this talk. The first is to understand why a talk on the epidemiology of patients with substance use disorder in the ICU is inherently very complex. We'll briefly review the data on visits related to alcohol and opioid use disorder because a talk on epidemiology would not be complete without those. We'll review the current data on visits related to other substances and then also explore healthcare utilization of these patients in the ICU. And we'll talk briefly about the morbidity and mortality of patients who use substances and are admitted to the critical care setting. The bottom line, again, as I previously mentioned, is that the epidemiology of patients with substance use disorder in the ICU is largely unknown. But this topic is very important, right? In a comprehensive review in 2020, authors found that at least a quarter of admissions to the ICU were related to substance use. And this is huge for our economy and our society in terms of the burden. Costing almost a quarter of all hospital charges. Along the same lines, 13% of admissions to the ICU were related to illicit substances, generating 11% of all hospital charges. And alcohol was responsible for 9.5% of ICU admissions and generating also a significant proportion of hospital charges. So this topic is important. But the epidemiology is very complicated. Substance use is inherently tied to concomitant conditions. It's strongly associated with injury and trauma. It's not uncommon for patients who have substance use to be admitted for injuries and falls and drownings and homicide and suicide. In fact, up to half of all trauma beds in the United States are related to alcohol-related traffic accidents. Substance use in and of itself is also a risk factor for medical complications and comorbidities. For example, substance use is strongly tied and is a risk factor for diabetic ketoacidosis. And it's related to longer ICU stays compared to patients with DKA without substance use. Opioid-related hospitalizations account for 1.5% of all sepsis-related ICU deaths. So again, substance use is tied to medical complications, making the data hard to parse out. Patients with substance use have intoxication and withdrawal effects. And again, their hospital courses are very complicated. The other part about why the epidemiology is complicated and also may not be complete to present to you today is that the substance use at times and maybe oftentimes goes undetected. Patient history is limited in those who are mechanically ventilated. Patients might not be forthcoming. We might not be able to gather all the data on substance use in the ICU. And of course, there are testing limitations. You all know this. Patients who present to the ICU with altered mentation get a urine drug screen immunoassay. And that test is fraught with inconsistencies and it's not comprehensive. Comprehensive urine and serum drug testing are sometimes send-outs, takes days to come back. Sometimes they don't come back before the patient gets discharged from the ICU. So it's a complicated topic. Not supposed to talk a ton about opioids, but I have to mention it because the data regarding other substances is pretty similar to that in patients with opioid use alone. Alcohol too. I mean, this makes sense. Alcohol use is the most, alcohol is the most frequently used substance in the United States and contributes to 16 to 31% of all ICU stays. Some studies quote up to 40 to 45%. Of course, the opioid epidemic continues to be a huge major public burden in the United States and related deaths have increased and so a lot of the literature is on patients with opioids or opioid use disorder. We know that opioid overdose-related admissions to the ICU increase dramatically in a short time period and continues to increase and mortality as well. So big topics, hard to ignore. This is just my one slide on alcohol because we can have a whole hour-long talk on just alcohol and its contributions to ICU stays. Alcohol in and of itself is linked to poor clinical outcomes from the ICU. Longer ICU and hospital lengths of stays, more frequent hospital-acquired infections and surgical complications, increased risks of severe infection, and higher rates of in-hospital mortality. Again, briefly, I'm not supposed to mention opioids in this talk, but a talk really wouldn't be complete and the data on other substances really does echo the data on patients who use opioids alone. And so opioid-related ICU admissions account for approximately 30% of all substance use-related admissions. This is across the board in the literature. And I've already mentioned that the numbers of patients with opioid overdose requiring critical care has increased significantly in the recent years. In probably the largest comprehensive review that I found of 50,000 ICU patients in the largest public database for ICU for critical care patients, the authors did a cross-sectional analysis over the course of 12 years and found several risk factors that were highly associated with ICU admission for patient with opioid overdose. In parentheses are adjusted odd ratios and 95% confidence interval. The highest association for patients with opioid overdose leading to ICU admissions is drug use disorder, followed by psychiatric illness, bipolar disorder and major depressive disorder, followed by Medicaid, health insurance, a history of illicit substance use and a concurrent use of illicit substances. And of course opioid-related ICU admissions come with a number of comorbidities. The strongest ones associated with hospitalizations include aspiration pneumonia, rhabdomyolysis, septic shock, anoxic brain injury. And the average cost in this time period cited by authors, which was six years, the average cost for ICU overdose admission nearly doubled. Okay, so what about the characteristics of patients with other substance-related ICU admissions? We talked about alcohol, we talked about opioids, what about other things? Well, it's really hard to find the literature on substance use in the ICU and take out alcohol and opioids. This is because they really account for a very large majority of ICU stays. And so the data is really limited. And I've mentioned this before, this is one of the limitations of studying the epidemiology. In this study of nearly 800 people over a several year period, the authors looked at alcohol and, like looked at all substances, alcohol, opioids and all. And they found that admission reasons, they found the admission reason for, the reason for admission to ICU was most likely related to acute overdose followed by respiratory failure and rhabdomyolysis. And I highlighted these because this is very similar to studies looking at patients with opioid use and opioid overdose alone. So very similar. The drug types usually involved in patients who are admitted to the ICU include opioids. You see it's actually 31%, so high. Alcohol is the number one, opioids would be second. And interestingly, cocaine is 30%. And when I looked at that, I was like, hmm, why is cocaine? Actually, cocaine use has decreased significantly in just the last few years here in the United States. In the last three decades before 2019, we saw a steady rise up to, and the population using cocaine was around two for every like 100,000 people. Just in the last three years, did we start seeing a decrease in cocaine use to less than one person per 100,000, actually 0.78. So I thought that was pretty interesting, but it still is a large burden of ICU stays. And why, cocaine is like, to me, the scary stimulant. And when I think of like beta blockers, propranolol being the really scary one with sodium channel blockade, cocaine is the scary one with cardiac-specific issues that can happen to patients. So I just have one slide just to briefly touch why cocaine is making up such a large proportion of patients in the ICU. This is because cocaine has, in addition to its sympathomimetic properties, causing agitation, hypertension, tachycardia, it also has cardiac-specific acute effects. It inhibits sodium channels, and so delays depolarization of the cardiac myocyte, causing arrhythmias. Also does so by blocking potassium channels as well, so it's classified as a von Williams class III arrhythmic. It is also associated with acute myocardial infarction as well. And cocaine, it causes increased heart rate, blood pressure, contractility. It is responsible for coronary vasospasm and vasoconstriction. It is also associated with increased myocardial oxygen demand. In addition to its cardiac effects, it also has peripheral effects as well, so it causes acute hypertension and coronary spasms. So again, cocaine is the scary stimulant to me, and makes sense why it contributes to so many ICU stays. In the study looking at all comers, and all comers with substance use admitted to the ICU, we found that the demographics are similar to patients when looking at just opioids. Patients are middle-aged, predominantly male, and have Medicaid health insurance. And their hospital care can be complicated by intubation, transfusion, vasopressors, and surgery, but really the demographics are very similar to when looking at patients with opioid overdose alone. Young, male, and with Medicaid or Medicare. I just thought this was an interesting slide from some of the studies, and some interesting characteristics of patients who are admitted to the ICU. One third of them are employed. We again see the comorbid psychiatric illness as a risk factor, or as being associated with ICU stays. What was very interesting to me is that, again, looking at the healthcare utilization of patients with substance use, you can see that they make a very big impact. ER visits, about half of patients who are admitted to the ICU had ER visits in the last year related to alcohol or other substance use. So not their first presentation. A large number of them had hospital admissions in the last year, and some even had ICU admissions in the past year as well. And so again, there's a large social and economic burden that these patients present. Here's another look at other substances implicated from another study, in a tertiary care hospital in the United States over a six month period. In this study, the authors did parse out alcohol and put it in its own category, and then other substance use. Alcohol-related admissions accounted for 9.5%. Illicit drug-related visits accounted for 13.1%. You can see here polysubstance use accounted for most of the ICU admissions, followed, understandably, by opioids, and then cocaine and other stimulants. The demographics here are very similar to what we've seen before in other studies, and I just wanna just hammer down the point, most are male, most are middle-aged. In this study, they said patients, most patients were white, and again, we see the Medicare and Medicaid health insurance and so, again, we're seeing a trend here in the demographics. I've been asked to touch briefly on party drugs and emerging substances. The reality is that they account for really, a very, very small percent of ICU-related admissions. That being said, in urban areas, New York City, for example, in just the last couple of years, these substances have increased at least two-fold, the use of these substances, that is. MDMA, ecstasy and molly, LSD, ketamine. Back in 2018, we saw huge spikes in bath salts and other stimulants like NBOM or N-B-O-M-E. But again, very small percentage. You can see that, again, predominantly, we see alcohol, cocaine, alcohol, opioids, cocaine, and then these other stimulants and hallucinogens fall very, very far to the bottom of relating to ICU admissions. Briefly, I'm gonna, in the next couple of slides, to talk about the outcomes of the patients with substance use who are admitted to the ICU. You know, interestingly, a majority of those who come to the ICU with substance use are sent home or are well enough to leave against medical advice. That's 54% home, AMA 9% in very large studies. People go home, they do okay, even though there is a lot of morbidity associated maybe with their hospital course. And it'd be okay, and we can kind of talk about why. In one study, authors quoted about 11% of patients expired from their hospital course related to substance use. In another study, authors quoted as high as 25% of patients expire if they're admitted with substance use-related ICU admission. Compared to, though, the overall mortality in that population of patients in the ICU is 63%. So substance use alone, 25%, and then all comers to the ICU, 63%. The length of stay for patients who are admitted with substance use-related issues is actually less than the average ICU patient, right? So why is this? So people are going home, their length of stays are less when they're using substances and admitted to the ICU. And I think this is because what some of the demographics that I've presented to you, and it kind of makes sense. So in a study of ICU-related costs, authors found a significant interaction between age and substance use. Yeah, we looked, and we saw the age of patients was anywhere from like 40 to 50, as high as 60, but really in the 40s-year-old range is the average age of patients who are admitted to the ICU with substance use-related issue, right? These are young people without a lot of medical comorbidities, so end up doing pretty well after the substance is metabolized and out of their system. They're able to either sign out AMA or go home. They're young without medical comorbidities. Their length of stays were shorter. And so in this study, they had fewer hospital charges and fewer ICU days length of stay. Similarly, in another study looking at the healthcare utilization of all comers to the ICU we found that the total cost of hospitalization in 737 patients was greater than $7 million, and it sounds like a lot of money, and it is a lot of money, but the total mean hospitalization and the total hospital charges was much less than all other comers to the ICU, right? A significant number of patients were eventually discharged home and did not require long-term in-hospital or out-of-hospital care, and a significant number of patients left against medical advice. They were actually well enough to do so. So in conclusion, there have been many changes in the number and type of substance use admissions in the ICU over the years. Actually, you can even say in the last few years. Admissions to the ICU related to substance use make up at least 25%, if not near 30%, or even close to 40% of all ICU admissions. We talked about how ICU admissions tend to be young men, young men with coexisting psychiatric illness, have high severity of illness, but do overall generate less hospital charges when compared to those with non-substance use related admissions, and this may be related with lower length of stay, right? And I just put this on here. I know mortality compared to all other ICU patients is not as high, but it's still high, and it's still, again, a societal and economic burden on our communities. We talked about the substances implicated. I put an asterisk on the hallucinogens just for me to remember to mention that those party drugs and the emergent drugs really contribute to a very small number of ICU related admissions. For me, this talk represents opportunities for interventions, right? We still have a large proportion of patients who come to our ICUs with substance use. We, you know, having more governmental at the local or state or federal level could help us intervene by offering patients rehabilitation programs, training our providers on intensive counseling or motivational interviewing. The use of pharmacotherapy, either something like alternatives to opioids or using pharmacotherapy that is FDA approved for the treatment of use disorders, and or having close patient follow up with patient navigation, and so lots of avenues for us to improve on our care for patients with substance use disorder. And with that, I thank you.

epidemiology

substance use disorder

ICU admissions

alcohol

opioids

medical complications