Recreational drug use prevalent among intensive cardiac care unit admissions, study finds

30th August 2023

Recreational drug (RD) use was detected via the urine samples of approximately one in 10 patients (11%) admitted to an intensive cardiac care unit, according to the findings of a multi-centre French study.

Published online in the journal Heart, the study also found the presence of such drugs was independently associated with a higher risk of in-hospital major adverse events (MAEs).

The use of RDs is already known to be associated with a higher risk of cardiac arrhythmias. However, there is some uncertainty over the prevalence of RD use among patients admitted to hospital with heart problems, or to what extent this affects the likely course of their condition.

Impact of recreational drug use

The researchers aimed to assess the prevalence of RD use and its association with in-hospital MAEs in patients admitted to intensive cardiac care units. Among those admitted, systematic screening for RDs was performed by prospective urinary testing.

The primary outcome was the prevalence of RD detection. In-hospital MAEs were defined as death, resuscitated cardiac arrest or haemodynamic shock.

In 499 consecutive patients with a mean age of 63 years (70% male), 161 (11%) had a positive test for a RD, including cannabis (9.1%), opioids (2.1%), cocaine (1.7%), amphetamines (0.7%) and MDMA (0.6%). Despite these findings, only 57% of those testing positive declared recreational drug use. 

Patients who used RDs exhibited a higher MAE rate than non-users (13% vs 3%, respectively, p < 0.001).

After adjustment for comorbidities, RD use was independently associated with a higher rate of in-hospital MAEs (odds ratio, OR = 8.84, 95% CI 4.68 – 16.7, p < 0.001). In fact, cannabis, cocaine and MDMA, when assessed separately, were independently associated with in-hospital MAEs.

Multiple drug detection was frequent (28% of positive patients) and also associated with an even higher incidence of MAEs (OR = 12.7, 95% CI 4.80 – 35.6, p < 0.001).

Skeletal muscle reduces nearly 2% per day upon admission to intensive care

16th January 2023

A systematic review found that skeletal muscle levels reduce by nearly 2% every day during the first week of admission to intensive care

Skeletal muscle loss among critical care patients during the first week of admission to an intensive care unit (ICU) approaches 2 per cent according to the findings of a systematic review and meta-analysis by UK and German researchers.

Critical illness is defined as a state of ill health with vital organ dysfunction and a high risk of imminent death if care is not provided and the potential for reversibility. Moreover, among critically ill patients with sepsis, a considerable number will show signs of severe skeletal muscle wasting and/or ICU-acquired weakness (ICUAW). While the pathophysiology of ICU-AW is incompletely understood, the condition appears to be triggered by critical illness and there is some evidence that skeletal muscle loss is associated with an increased mortality risk. Despite the recognition that skeletal muscle losses occur among critically ill patients, there have been no attempts to summarised the published data on the daily amount of muscle that is lost in ICU patients, which methods are used to monitor muscle size in such patients and on the prevalence of ICU-AW in critically ill patients.

The researchers therefore undertook a systematic review of the topic and searched for studies in which there were at least 20 adult critically ill patients and where the investigators had measured a muscle mass-related variable at two time points during the ICU stay. 

Skeletal muscle loss among ICU patients

The literature search identified 52 relevant studies that included 3251 patients in which 1773 patients had data on on muscle wasting and 1478 on ICU-acquired weakness. Muscle mass was assessed by ultrasound in 85% of studies and the remainder by computed tomography.

During the first week of critical illness, patients were found to have lost an average of -1.75% (95% CI −2.05 −1.45) of their rectus femoris thickness and −2.10% (95% CI −3.17 −1.02) of their rectus femoris cross-sectional area, respectively, every day. In addition, quadriceps muscle thickness decreased by −1.82% (95% CI −2.97 − 0.66) each day and the daily loss in biceps brachii muscle cross-sectional area was −2.23% (95% CI −2.60 − 1.80) and −1.64% (95% CI −3.09, 0.19) for biceps brachii thickness.

Furthermore, the overall prevalence of ICU-acquired weakness was 48% (95% CI 39% – 56%).

The authors concluded that critically ill patients suffer from early and marked muscle wasting, which is about 2% per day but does vary between muscles and depends upon the measurement taken.

Citation
Fazzini B et al. The rate and assessment of muscle wasting during critical illness: a systematic review and meta-analysis. Crit Care 2023

Higher cystatin C levels associated with increased mortality in sepsis

17th October 2022

Higher cystatin C levels and kidney function derived measures upon ICU admission are associated with increased 90-day mortality in sepsis

Cystatin C (CC) is a serine protease inhibitor that can be used as a marker of glomerular filtration rate (GFR). In fact, there is a suggestion that measurement of cystatin C should be used for the initial prediction of GFR of a patient and among critically ill patients, serum CC levels significantly outperforms serum creatinine for the detection of an impaired GFR. Moreover, other work has shown that CC-based estimates of GFR in both the elderly and ethnically diverse populations in comparison to serum creatinine, was a better predictor of all-cause mortality. While GFR derived estimates from either CC or creatinine generally agree, a decrease in the CC estimate compared to that of creatinine has been suggested to be due to what has been described as shrunken pore syndrome (SPS). It has since been recognised that SPS has been associated with a substantial increase in mortality or morbidity in all investigated populations.

However, whether cystatin C-based estimates of GFR and SPS are linked to a higher mortality among intensive care unit (ICU) patients with sepsis is uncertain and was the subject of the present study by Swedish researchers. The team undertook a post hoc analysis of data from the FINNAKI study which was a prospective observational study of acute kidney injury patients. For the present analysis, included patients were those with severe sepsis either upon ICU admission or which developed during the period of study. Plasma samples were used to measure both cystatin C and creatinine levels and from which GFR estimates were calculated. The primary outcome was 90-day mortality, whereas secondary outcomes were the development of acute kidney injury (AKI) between 12 and 5 days after ICU admission and renal replacement therapy. CC plasma levels estimated GFR based on CC and creatine were divided into quartiles.

Cystatin C measurements and mortality

A total of 802 patients with a mean age of 65 years (35.9% female) were included. The presence of SPS was present in 9.9% of patients when using an estimated GFR_Cystatin to GFR_creatinine cut-off ratio of 0.6 and 20% when the cut-off was set at 0.70. A total of 176 patients developed AKI between 12 hours and 5 days after ICU admission.

For plasma CC levels in the highest quartile, there was a positive and significant association with increased 90-day mortality compared to the lowest quartile (hazard ratio, HR = 4.15, 95% CI 2.17 – 7.91, p < 0.001). Similarly, there was a significant association with 90-day mortality for the lowest quartile of CC estimated GFR compared to the highest (HR = 4.45, 95% CI 2.28 – 8.68, p < 0.001). The association with SPS was also significant whether the cut-off was 0.6 or 0.70. In contrast, there was no significant association between 90-mortality and creatinine-based GFR estimates. Even after corticosteroid use in the treatment of septic shock, the associations for serum CC and estimated GFR remained significant although the association for SPS with a cut off of 0.6 was no longer significant (p = 0.14). When the researchers if the association between CC levels and 90-mortality were also linked to the development of AKI within 5 days, the analysis revealed how this association was maintained for the highest quartile of serum CC levels (HR = 4.09, 95% CI 2.14 – 7.80, p < 0.001), as well as CC estimated GFR and SPS.

The authors concluded that higher cystatin C levels together with a reduced CC-based estimate of GFR and the presence of SPS in patients with SPS in ICU was associated with a higher 90-day mortality and that a higher incidence of AKI does not explain this association.

Citation
Linne E et al. Cystatin C and derived measures of renal function as risk factors for mortality and acute kidney injury in sepsis – A post-hoc analysis of the FINNAKI cohort J Crit Care 2022

Clinical judgement superior to risk-stratification for identifying ICU admission

17th August 2022

The clinical judgement of healthcare professions has greater predictive accuracy than risk models for intensive care unit admission

The clinical judgement of the healthcare professionals treating a patient has a better predictive accuracy for whether an individual should be admitted to an intensive care unit (ICU) compared with the use of a risk stratification model, according to a systematic review by a Dutch team based in Amsterdam.

The outcomes for critically ill patients are often time-sensitive and research suggests how emergency department patients whose transfer to intensive care exceeds 6 hours, not only increases the length of stay in hospital but also mortality.

Consequently, several early warning scoring (EWS) systems have been developed to help risk stratify patients within an emergency department (ED) to determine outcomes such as mortality or to predict the need for intensive care admission. But does the development of these models mean that clinical judgement is no longer necessary?

The available evidence to date suggests that such risk stratification models may be no better than clinical judgement. For example, one study found that a simple clinical assessment by healthcare staff was superior to a formalised triage system to predict short-term mortality among emergency department patients.

Similarly, in a study of the Canadian Syncope Risk Score (CSRS) used in an ED for syncope risk stratification, the authors found that the tool had similar predictive accuracy to clinical judgement. Determining whether risk stratification models perform better than simple clinical judgement was the aim the current study by the Dutch team.

They focused on several areas: the need for ICU admission, severe adverse events and finally, clinical deterioration and mortality. The team included studies in which the authors had compared either risk-stratification or an EWS with clinical judgement among adult patients in an acute setting, i.e., either at the ED or pre-hospital assessment.

The outcomes of interest were the need for ICU admission, severe adverse events, clinical deterioration and death.

Clinical judgement vs adverse patient outcomes

The literature search identified only 6 relevant studies with 6419 participants of which 4 studies were deemed to be at a high risk of bias. Due to the small number of studies, no meta-analysis was undertaken and descriptive analyses were used instead.

For ICU admission, in one sepsis study, the sensitivity of clinical judgement was 91% (95% CI 0.83 – 0.99) and specificity 71% (95% CI 0.60 – 0.82) which was superior to PIRO and MEDS (all p < 0.001). For the second sepsis study which considered mortality, there was no difference between clinicians and the risk-stratification models.

For the prediction of clinical deterioration, only one study was available and there was no difference between the two different forms of assessment.

Finally, for the prediction of severe adverse events (ICU admission, cardiac arrest and death), one study reported on the use of MEWS or the clinical judgement of nurses, and while sensitivities were similar (56.6% vs 61.8%, statistical significance was not reported), nurse’s judgement had a higher specificity (94.1% vs 88.5%, nurses vs MEWS).

The authors concluded that while there were only limited data available, it appeared that clinical judgement was superior to risk stratification models for predicting the need for ICU admission and for prediction of severe adverse events. However, both approaches were similar for prediction of clinical deterioration and mortality.

Citation
Veldhuis LI et al. Performance of early warning and risk stratification scores versus clinical judgement in the acute setting: a systematic review Emerg J Med 2022