Arterial Lines in the ICU


The appropriate justification for using a diagnostic or therapeutic intervention is that it provides benefit to patients, society, or both. For decades, indwelling arterial catheters have been used very commonly in patients in the ICU, despite a complete absence of data addressing whether they confer any such benefits. Both of the main uses of arterial catheters, BP monitoring and blood sampling for laboratory testing, can be done without these invasive devices. Prominent among complications of arterial catheters are bloodstream infections and arterial thrombosis. To my knowledge, only a single observational study has assessed a patient-centered outcome related to arterial catheter use, and it found no evidence that they reduce hospital mortality in any patient subgroup. Given the potential dangers, widespread use, and uncertainty about consequences of arterial catheter use in ICUs, equipoise exists and randomized trials are needed. Multiple studies in different, well-characterized, patient subgroups are needed to clarify whether arterial catheters influence outcomes. These studies should assess the range of relevant outcomes, including mortality, medical resource use, patient comfort, complications, and costs.

Ultrasonographically guided peripheral intravenous cannulation of children and adults: a systematic review and meta-analysis. .


Peripheral intravenous cannulation is procedurally challenging and painful. We perform a systematic review to evaluate ultrasonographic guidance as an aid to peripheral intravenous cannulation.

METHODS: We searched MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, ClinicalTrials.gov, and Google.ca. We included randomized trials evaluating ultrasonographically guided peripheral intravenous cannulation and reporting risk of peripheral intravenous cannulation failure, number of attempts, procedure time, or time from randomization to peripheral intravenous cannulation. We separately analyzed pediatric and adult data and emergency department (ED), ICU, and operating room data. Quality assessment used the Cochrane Risk of Bias Tool.
RESULTS: We identified 4,664 citations, assessed 403 full texts for eligibility, and included 9 trials. Five had low risk, 1 high risk, and 3 unclear risk of bias. A pediatric ED trial found that ultrasonography decreased mean difference (MD) in the number of attempts (MD -2.00; 95% confidence interval [CI] -2.73 to -1.27) and procedure time (MD -8.10 minutes; 95% CI -12.48 to -3.72 minutes). In an operating room pediatric trial, ultrasonography decreased risk of first-attempt failure (risk ratio 0.23; 95% CI 0.08 to 0.69), number of attempts (MD -1.50; 95% CI -2.52 to -0.48), and procedure time (MD -5.95; 95% CI -10.21 to -1.69). Meta-analysis of adult ED trials suggests that ultrasonography decreases the number of attempts (MD -0.43; 95% CI -0.81 to -0.05). Ultrasonography decreased risk of failure (risk ratio 0.47; 95% CI 0.26 to 0.87) in an adult ICU trial.
CONCLUSION: Ultrasonography may decrease peripheral intravenous cannulation attempts and procedure time in children in ED and operating room settings. Few outcomes reached statistical significance. Larger well-controlled trials are needed.

Source: Annals of Emergency Medicine.

 

Dexmedetomidine Use in the ICU Are We There Yet?


Abstract

Background Long-term sedation with midazolam or propofol in intensive care units (ICUs) has serious adverse effects. Dexmedetomidine, an alpha-2 agonist available for ICU sedation, may reduce the duration of mechanical ventilation and enhance patient comfort.

MethodsObjective: The objective was to determine the efficacy of dexmedetomidine versus midazolam or propofol (preferred usual care) in maintaining sedation, reducing duration of mechanical ventilation, and improving patients’ interaction with nursing care.

Design: Two phase 3 multicenter, randomized, double-blind trials were conducted.

Setting: The MIDEX (Midazolam vs. Dexmedetomidine) trial compared midazolam with dexmedetomidine in ICUs of 44 centers in nine European countries. The PRODEX (Propofol vs. Dexmedetomidine) trial compared propofol with dexmedetomidine in 31 centers in six European countries and two centers in Russia.

Subjects: The subjects were adult ICU patients who were receiving mechanical ventilation and who needed light to moderate sedation for more than 24 hours.

Intervention: After enrollment, 251 and 249 subjects were randomly assigned midazolam and dexmedetomidine, respectively, in the MIDEX trial, and 247 and 251 subjects were randomly assigned propofol and dexmedetomidine, respectively, in the PRODEX trial. Sedation with dexmedetomidine, midazolam, or propofol; daily sedation stops; and spontaneous breathing trials were employed.

Outcomes: For each trial, investigators tested whether dexmedetomidine was noninferior to control with respect to proportion of time at target sedation level (measured by Richmond Agitation Sedation Scale) and superior to control with respect to duration of mechanical ventilation. Secondary end points were the ability of the patient to communicate pain (measured by using a visual analogue scale [VAS]) and length of ICU stay. Time at target sedation was analyzed in per-protocol (midazolam, n = 233, versus dexmedetomidine, n = 227; propofol, n = 214, versus dexmedetomidine, n = 223) population.

Results Dexmedetomidine/midazolam ratio in time at target sedation was 1.07 (95% confidence interval (CI) 0.97 to 1.18), and dexmedetomidine/propofol ratio in time at target sedation was 1.00 (95% CI 0.92 to 1.08). Median duration of mechanical ventilation appeared shorter with dexmedetomidine (123 hours, interquartile range (IQR) 67 to 337) versus midazolam (164 hours, IQR 92 to 380;P = 0.03) but not with dexmedetomidine (97 hours, IQR 45 to 257) versus propofol (118 hours, IQR 48 to 327; P= 0.24). Patient interaction (measured by using VAS) was improved with dexmedetomidine (estimated score difference versus midazolam 19.7, 95% CI 15.2 to 24.2; P <0.001; and versus propofol 11.2, 95% CI 6.4 to 15.9; P <0.001). Lengths of ICU and hospital stays and mortality rates were similar. Dexmedetomidine versus midazolam patients had more hypotension (51/247 [20.6%] versus 29/250 [11.6%]; P = 0.007) and bradycardia (35/247 [14.2%] versus 13/250 [5.2%]; P <0.001).

Conclusions Among ICU patients receiving prolonged mechanical ventilation, dexmedetomidine was not inferior to midazolam and propofol in maintaining light to moderate sedation. Dexmedetomidine reduced duration of mechanical ventilation compared with midazolam and improved the ability of patients to communicate pain compared with midazolam and propofol. Greater numbers of adverse effects were associated with dexmedetomidine.

 

Commentary

Sedation is commonly used in the intensive care unit (ICU) to reduce patient discomfort, improve tolerance with mechanical ventilation, prevent accidental device removal, and reduce metabolic demands during respiratory and hemodynamic instability.[1,2]Continuous and deep sedation have been associated with increased risk of delirium, longer duration of mechanical ventilation, increased length of ICU and hospital stays, and long-term risk of neurocognitive impairment, post-traumatic stress disorder, and mortality.[3–7] Sedation interruption and protocolized sedation have been associated with decreased length of ICU stay and reduced duration of mechanical ventilation.[4,5] Whether combining sedation interruption and protocolized sedation improves outcome is controversial. Whereas some studies show a benefit,[6] others show no difference.[8]

Commonly used first-line sedative medications, including propofol and midazolam, and less commonly used medications, such as lorazepam, have many side effects. There exists wide intra- and inter-individual variability,[9] resulting in unpredictable drug accumulation with benzodiazepines.[10] Lorazepam is associated with propylene glycol-related acidosis and nephrotoxicity. Propofol causes hypertriglyceridemia, pancreatitis, and propofol-related infusion syndrome.[11,12] Dexmedetomidine is a potent alpha-2 adrenoceptor agonist with an affinity for the alpha-2 adrenoceptor that is eight times higher than that of clonidine.[13] Prior data suggest that dexmedetomidine reduced duration of mechanical ventilation and resulted in earlier extubation.[14,15] In critically ill patients, use of dexmedetomidine has been associated with lower risk of delirium and coma compared with propofol, lorazepam, and midzolam.[15,16] However, safety and efficacy of prolonged dexmedetomidine infusion in the ICU have not been evaluated.

The PRODEX (Propofol vs. Dexmedetomidine) and MIDEX (Midazolam vs. Dexmedetomidine) trials attempted to answer this question with higher doses of dexmedetomidine for longer duration when compared with propofol and midazolam in mechanically ventilated patients. Both studies provide important clinical evidence that dexmedetomidine is an effective sedative agent compared with propofol and midazolam. Use of dexmedetomidine is associated with easier communication with patients, better assessment of pain (from the perspective of the caregiver), reduced delirium, and decreased time to extubation as compared with propofol. However, this finding did not translate into reduction of length of ICU or hospital stay. Among the strengths of the study are that it was a well-conducted, large, multicenter, double-blind, randomized controlled study. The trial employed frequent sedation assessment, daily sedation stops, and a double-dummy design to reduce the risk of bias.

Several important limitations to the study deserve further consideration. The weaning from mechanical ventilation and criteria for extubation were not standardized. Spontaneous breathing trials were performed in only about half of the sedation stops, as compared with approximately 60% of those screened in the Awakening and Breathing Controlled trial.[6] Whereas the incidence of neurocognitive disorders, including delirium, anxiety, and agitation, was evaluated throughout the study, the long-term neurocognitive and functional outcomes with dexmedetomidine have not been examined. Sedation was assessed from the caregivers’ perspective only, and future studies should include the patients’ perspective of quality of sedation. Also, this study included only patients with light to moderate sedation; thus, these findings may not be applicable to patients requiring deep sedation. In the first 24 hours of the PRODEX trial, discontinuation of dexmedetomidine was more frequent because of a lack of efficacy. As acknowledged by the authors of the PRODEX and MIDEX trials, most clinicians and centers do not consider dexmedetomidine an equivalent alternative to propofol and midazolam for long-term sedation. These trials, nevertheless, reassure clinicians regarding the safety of dexmedetomidine in terms of higher doses over a long period of time.

Recent guidelines of the Society of Critical Care Medicine recommend using non-benzodiazepine agents, such as propofol or dexmedetomidine, over benzodiazepines as a first-line sedative agent, and dexmedetomidine in patients at risk for delirium that is not related to alcohol and benzodiazepine use.[11] The opioid-sparing[11] effect of dexmedetomidine may reduce opioid requirements in critically ill patients. The most common side effects of dexmedetomidine are hypotension and bradycardia, and this limits its use in patients who are dependent on their cardiac output, such as patients in the acute phase of shock.

 

Recommendation

In carefully selected critically ill patients receiving prolonged mechanical ventilation, dexmedetomidine is safe and may be preferred as an alternative non-benzodiazepine agent to maintain light to moderate sedation. However, long-term outcomes, including neurocognitive effects, and the safety of dexmedetomidine are unknown.

Source: medscape.com

Music Therapy in the ICU — Another Way to Lower Sedation Use?


Awake intensive care unit patients who received music therapy were less anxious than those who did not.

 

Music therapy improves well-being in hospice patients, distracts patients during endoscopy, and helps treat depression in elders. Could it also decrease anxiety in critically ill patients?

Investigators randomized 373 awake and interactive intensive care unit (ICU) patients to one of three groups: patient-directed music through noise-cancelling headphones (with a visit by a music therapist to find preferred music and twice-daily prompts to listen to music), patient-initiated noise-cancelling headphone use only, or usual care. Anxiety was assessed daily with a 100-point visual-analog scale (VAS; range, 0 = “not anxious at all” to 100 = “most anxious ever”), and sedation doses and frequency were analyzed post hoc.

During a mean follow-up of 6 days, daily VAS scores of patients who received patient-directed music were significantly lower (by a mean of 19 points) than those of patients who received usual care; the headphones-alone group scored nonsignificantly lower (by a mean of 8 points) than the usual-care group. Sedation use was somewhat lower in the music-treated group.

Comment: As an editorialist notes, this trial has several limitations, including lack of a standardized sedation protocol and use of an unvalidated anxiety-assessment tool. Despite this, the results suggest that an inexpensive intervention like patient-directed music in the ICU could help limit use of sedating medications and all the complications associated with them.

 

Source: Journal Watch General Medicine

Targeted versus Universal Decolonization to Prevent ICU Infection.


BACKGROUND

Both targeted decolonization and universal decolonization of patients in intensive care units (ICUs) are candidate strategies to prevent health care–associated infections, particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA).

METHODS

We conducted a pragmatic, cluster-randomized trial. Hospitals were randomly assigned to one of three strategies, with all adult ICUs in a given hospital assigned to the same strategy. Group 1 implemented MRSA screening and isolation; group 2, targeted decolonization (i.e., screening, isolation, and decolonization of MRSA carriers); and group 3, universal decolonization (i.e., no screening, and decolonization of all patients). Proportional-hazards models were used to assess differences in infection reductions across the study groups, with clustering according to hospital.

RESULTS

A total of 43 hospitals (including 74 ICUs and 74,256 patients during the intervention period) underwent randomization. In the intervention period versus the baseline period, modeled hazard ratios for MRSA clinical isolates were 0.92 for screening and isolation (crude rate, 3.2 vs. 3.4 isolates per 1000 days), 0.75 for targeted decolonization (3.2 vs. 4.3 isolates per 1000 days), and 0.63 for universal decolonization (2.1 vs. 3.4 isolates per 1000 days) (P=0.01 for test of all groups being equal). In the intervention versus baseline periods, hazard ratios for bloodstream infection with any pathogen in the three groups were 0.99 (crude rate, 4.1 vs. 4.2 infections per 1000 days), 0.78 (3.7 vs. 4.8 infections per 1000 days), and 0.56 (3.6 vs. 6.1 infections per 1000 days), respectively (P<0.001 for test of all groups being equal). Universal decolonization resulted in a significantly greater reduction in the rate of all bloodstream infections than either targeted decolonization or screening and isolation. One bloodstream infection was prevented per 54 patients who underwent decolonization. The reductions in rates of MRSA bloodstream infection were similar to those of all bloodstream infections, but the difference was not significant. Adverse events, which occurred in 7 patients, were mild and related to chlorhexidine.

CONCLUSIONS

In routine ICU practice, universal decolonization was more effective than targeted decolonization or screening and isolation in reducing rates of MRSA clinical isolates and bloodstream infection from any pathogen.

Source: NEJM

Hypoglycemia Associated with Death in Critically Ill Patients .


Moderate-to-severe hypoglycemia is tied to an increased risk for death among patients in the ICU, according to a study in the New England Journal of Medicine.

As part of the NICE-SUGAR trial, roughly 6000 ICU patients were randomized to intensive or conventional glucose control. Nearly half of all patients experienced moderate hypoglycemia (41–70 mg/dL), and 4% had severe hypoglycemia (40 mg/dL or less); the majority of these patients were in the intensive control group. The primary outcome — death within 90 days — was more frequent among those with severe hypoglycemia (35%) or moderate hypoglycemia (29%) than among those with no hypoglycemia (24%).

The authors conclude that “it would seem prudent to ensure that strategies for managing the blood glucose concentration in critically ill patients focus not only on the control of hyperglycemia but also on avoidance of both moderate and severe hypoglycemia.”

Source: NEJM

Tight Glycemic Control Doesn’t Improve Outcomes After Kids’ Cardiac Surgery.


Tight glucose control in pediatric ICU patients following cardiac surgery does not reduce morbidity or mortality, according to a study in the New England Journal of Medicine.

Nearly 1000 children (up to age 36 months) who were admitted to the cardiac ICU after undergoing cardiopulmonary bypass were randomized to receive either tight glycemic control with insulin or standard care. Those with diabetes were excluded.

Overall, the number of healthcare-associated infections (e.g., pneumonia, bloodstream infections) did not differ significantly between the groups. There were also no differences in 30-day or in-hospital mortality; length of ICU or hospital stay; or duration of mechanical ventilation or vasoactive support.

An NEJM editorialist argues why these findings should supersede those from a 2009 study showing a benefit with tight glycemic control. He concludes that the door “should be closed on the routine normalization of plasma glucose in critically ill adults and children.”

Source: NEJM