Many patients in the intensive care unit (ICU) receive oxygen through a breathing
machine. Doctors, nurses, and respiratory therapist adjust the amount of oxygen given
through the breathing machine to target oxygen levels, but the ideal oxygen level to target
is unknown. To understand which oxygen level is best for patients, we conducted a
research study called the PILOT study. A total of 2,541 patients on breathing machines in
the Vanderbilt intensive care unit participated in the study and had their clinicians target
an oxygen level of 90%, 94%, or 98%. The results of the study suggested that patients
did equally well when their clinicians targeted an oxygen level of 90%, 94%, or 98%.
Background: Invasive mechanical ventilation in critically ill adults involves adjusting
the fraction of inspired oxygen to maintain arterial oxygen saturation. The oxygen-
saturation target that will optimize clinical outcomes in this patient population remains
unknown.

Methods

In a pragmatic, cluster-randomized, cluster-crossover trial conducted in the
emergency department and medical intensive care unit at an academic center, we
assigned adults who were receiving mechanical ventilation to a lower target for oxygen
saturation as measured by pulse oximetry (Spo2) (90%; goal range, 88 to 92%), an
intermediate target (94%; goal range, 92 to 96%), or a higher target (98%; goal range, 96
to 100%). The primary outcome was the number of days alive and free of mechanical
ventilation (ventilator-free days) through day 28. The secondary outcome was death by
day 28, with data censored at hospital discharge.

Results

A total of 2541 patients were included in the primary analysis. The median number of ventilator-free days was 20 (interquartile range, 0 to 25) in the lower-target group, 21 (interquartile range, 0 to 25) in the intermediate-target group, and 21 (interquartile range, 0 to 26) in the higher-target group (P = 0.81). In-hospital death by day 28 occurred in 281 of the 808 patients (34.8%) in the lower-target group, 292 of the 859 patients (34.0%) in the intermediate-target group, and 290 of the 874 patients (33.2%) in the higher-target group. The incidences of cardiac arrest, arrhythmia, myocardial infarction, stroke, and pneumothorax were similar in the three groups.

Conclusions

Among critically ill adults receiving invasive mechanical ventilation, the number of ventilator-free days did not differ among groups in which a lower, intermediate, or higher Spo2 target was used.

ClinicalTrials.gov Identifier:
NCT03537937.
Manuscript Title: Oxygen-Saturation Targets for Critically Ill Adults Receiving
Mechanical Ventilation
Journal: New England Journal of Medicine

PMID: 36278971

Patients in the emergency department and intensive care unit who are suspected of having infections are treated with antibiotics. Most patients received either cefepime or piperacillin-tazobactam, antibiotics targeting resistant gram-negative bacteria. The two antibiotics are believed to have different risks. Cefepime may cause “neurotoxicity” (symptoms like agitation or coma). Piperacillin-tazobactam may cause kidney injury. To learn whether cefepime or piperacillin-tazobactam affects the chances of experiencing neurotoxicity or kidney injury, we conducted a research study called the ACORN study. A total of 1,172 patients receiving antibiotics for resistant gram-negative bacteria in the Vanderbilt Emergency Department or Intensive Care Unit participated in the study. The results of the study suggested that cefepime does cause neurotoxicity but piperacillin- tazobactam does not cause kidney injury and may be a safer alternative for patients being treated in the emergency department or intensive care unit.

Importance

Cefepime and piperacillin-tazobactam are commonly administered to hospitalized adults for empirical treatment of infection. Although piperacillin-tazobactam has been hypothesized to cause acute kidney injury and cefepime has been hypothesized to cause neurological dysfunction, their comparative safety has not been evaluated in a randomized clinical trial.

Objective

To determine whether the choice between cefepime and piperacillin- tazobactam affects the risks of acute kidney injury or neurological dysfunction. Design, setting, and participants: The Antibiotic Choice on Renal Outcomes (ACORN) randomized clinical trial compared cefepime vs piperacillin-tazobactam in adults for whom a clinician initiated an order for antipseudomonal antibiotics within 12 hours of presentation to the hospital in the emergency department or medical intensive care unit at an academic medical center in the US between November 10, 2021, and October 7, 2022. The final date of follow-up was November 4, 2022.

Interventions

Patients were randomized in a 1:1 ratio to cefepime or piperacillin- tazobactam.

Main outcomes and measures

The primary outcome was the highest stage of acute kidney injury or death by day 14, measured on a 5-level ordinal scale ranging from no acute kidney injury to death. The 2 secondary outcomes were the incidence of major adverse kidney events at day 14 and the number of days alive and free of delirium and
coma within 14 days.

Results

There were 2511 patients included in the primary analysis (median age, 58 years [IQR, 43-69 years]; 42.7% were female; 16.3% were Non-Hispanic Black; 5.4% were Hispanic; 94.7% were enrolled in the emergency department; and 77.2% were receiving vancomycin at enrollment). The highest stage of acute kidney injury or death was not significantly different between the cefepime group and the piperacillin-tazobactam group; there were 85 patients (n = 1214; 7.0%) in the cefepime group with stage 3 acute kidney injury and 92 (7.6%) who died vs 97 patients (n = 1297; 7.5%) in the piperacillin- tazobactam group with stage 3 acute kidney injury and 78 (6.0%) who died (odds ratio, 0.95 [95% CI, 0.80 to 1.13], P = .56). The incidence of major adverse kidney events at day 14 did not differ between groups (124 patients [10.2%] in the cefepime group vs 114 patients [8.8%] in the piperacillin-tazobactam group; absolute difference, 1.4% [95% CI, -1.0% to 3.8%]). Patients in the cefepime group experienced fewer days alive and free of delirium and coma within 14 days (mean [SD], 11.9 [4.6] days vs 12.2 [4.3] days in the piperacillin-tazobactam group; odds ratio, 0.79 [95% CI, 0.65 to 0.95]).

Conclusions and relevance

Among hospitalized adults in this randomized clinical trial, treatment with piperacillin-tazobactam did not increase the incidence of acute kidney injury or death. Treatment with cefepime resulted in more neurological dysfunction.

ClinicalTrials.gov Identifier: NCT05094154.
Manuscript Title: Cefepime vs Piperacillin-Tazobactam in Adults Hospitalized With
Acute Infection: The ACORN Randomized Clinical Trial.
Journal: JAMA
PMID: 37837651

Location: NIH Collaboratory Grand Rounds
Presenter(s): Jon Casey and Matthew Prekker

Journal: New England Journal of Medicine
PMID: 37326325

Journal: Critical Care Explorations
PMID: 37457916

Journal: American Journal of Respiratory and Critical Care Medicine
PMID: 36877594

Location: Critical Care Reviews Meeting 2023
Presenter(s): Matthew Prekker and Matt Semler

Journal: CHEST Critical Care
oPMID: 36993496

Journal: BMJ Open
PMID: 36898748

Journal: Critical Care Explorations
PMID: 36895888

Journal: Critical Care Explorations
PMID: 36895888

Journal: BMJ Open
PMID: 36639210

Journal: American Journal of Respiratory and Critical Care Medicine
PMID: 35882061

Journal: NEJM
PMID: 36278971

Journal: Nutrition in Clinical Practice
PMID: 35801708

To support seriously ill patients with a breathing machine, doctors must place a breathing tube.  One-in-five times doctors cannot place the breathing tube on the first try.  When the breathing tube cannot be placed on the first try, the risks to the patient for low oxygen levels or blood pressure are higher.  Doctors use two different rod-like devices to help guide a breathing tube it the right place.  One is called a “bougie” and another is called a “stylet”.  Both have been used for many years, but whether one was better than the other for placing a breathing tube on the first attempt was not known.  The BOUGIE trial compared use of a bougie with use of a stylet for 1100 patients in 7 emergency departments and 8 intensive care units across the United States.  The study showed that using a bougie and using a stylet were equally safe and effective.

Importance: For critically ill adults undergoing emergency tracheal intubation, failure to intubate the trachea on the first attempt occurs in up to 20% of cases and is associated with severe hypoxemia and cardiac arrest. Whether using a tracheal tube introducer (“bougie”) increases the likelihood of successful intubation compared with using an endotracheal tube with stylet remains uncertain.

Objective: To determine the effect of use of a bougie vs an endotracheal tube with stylet on successful intubation on the first attempt.

Design, setting, and participants: The Bougie or Stylet in Patients Undergoing Intubation Emergently (BOUGIE) trial was a multicenter, randomized clinical trial among 1102 critically ill adults undergoing tracheal intubation in 7 emergency departments and 8 intensive care units in the US between April 29, 2019, and February 14, 2021; the date of final follow-up was March 14, 2021.

Interventions: Patients were randomly assigned to use of a bougie (n = 556) or use of an endotracheal tube with stylet (n = 546).

Main outcomes and measures: The primary outcome was successful intubation on the first attempt. The secondary outcome was the incidence of severe hypoxemia, defined as a peripheral oxygen saturation less than 80%.

Results: Among 1106 patients randomized, 1102 (99.6%) completed the trial and were included in the primary analysis (median age, 58 years; 41.0% women). Successful intubation on the first attempt occurred in 447 patients (80.4%) in the bougie group and 453 patients (83.0%) in the stylet group (absolute risk difference, -2.6 percentage points [95% CI, -7.3 to 2.2]; P = .27). A total of 58 patients (11.0%) in the bougie group experienced severe hypoxemia, compared with 46 patients (8.8%) in the stylet group (absolute risk difference, 2.2 percentage points [95% CI, -1.6 to 6.0]). Esophageal intubation occurred in 4 patients (0.7%) in the bougie group and 5 patients (0.9%) in the stylet group, pneumothorax was present after intubation in 14 patients (2.5%) in the bougie group and 15 patients (2.7%) in the stylet group, and injury to oral, glottic, or thoracic structures occurred in 0 patients in the bougie group and 3 patients (0.5%) in the stylet group.

Conclusions and relevance: Among critically ill adults undergoing tracheal intubation, use of a bougie did not significantly increase the incidence of successful intubation on the first attempt compared with use of an endotracheal tube with stylet.

Trial registration: ClinicalTrials.gov Identifier: NCT03928925.

For patients being placed on a breathing machine, a breathing tube must be placed in the mouth.  During placement of a breathing tube, low oxygen levels may occur.  Whether placing a breathing tube while the patient’s head and shoulders were elevated (“ramped position”) could prevent low oxygen levels compared to placement of a breathing tube with the patient laying flat (“sniffing position”) was not known.  Among 260 patients in 4 intensive care units, the CHECK-UP trial found that placing a breathing tube in the ramped position did not prevent low oxygen levels.  Placing a breathing tube in the ramped position appeared to be more difficult than placing a breathing tube with the patient in the sniffing position.  These findings suggest that, for many patients in the intensive care unit, placing a breathing tube in the sniffing position may be simpler and easier than in the ramped position.

Background: Hypoxemia is the most common complication during endotracheal intubation of critically ill adults. Intubation in the ramped position has been hypothesized to prevent hypoxemia by increasing functional residual capacity and decreasing the duration of intubation, but has never been studied outside of the operating room.

Methods: Multicenter, randomized trial comparing the ramped position (head of the bed elevated to 25°) with the sniffing position (torso supine, neck flexed, and head extended) among 260 adults undergoing endotracheal intubation by pulmonary and critical care medicine fellows in four ICUs between July 22, 2015, and July 19, 2016. The primary outcome was lowest arterial oxygen saturation between induction and 2 minutes after intubation. Secondary outcomes included Cormack-Lehane grade of glottic view, difficulty of intubation, and number of laryngoscopy attempts.

Results: The median lowest arterial oxygen saturation was 93% (interquartile range [IQR], 84%-99%) with the ramped position vs 92% (IQR, 79%-98%) with the sniffing position (P = .27). The ramped position appeared to increase the incidence of grade III or IV view (25.4% vs 11.5%, P = .01), increase the incidence of difficult intubation (12.3% vs 4.6%, P = .04), and decrease the rate of intubation on the first attempt (76.2% vs 85.4%, P = .02), respectively.

Conclusions: In this multicenter trial, the ramped position did not improve oxygenation during endotracheal intubation of critically ill adults compared with the sniffing position. The ramped position may worsen glottic view and increase the number of laryngoscopy attempts required for successful intubation.

Trial registry: ClinicalTrials.gov; No.: NCT02497729; URL: www.clinicaltrials.gov.

Keywords: endotracheal intubation; hypoxemia; randomized trial.

Manuscript Title: “A Multicenter, Randomized Trial of Ramped Position vs Sniffing Position During Endotracheal Intubation of Critically Ill Adults.”

Journal: Chest

PMID: 28487139

Low oxygen level is the most common complication that arises when a critically ill patient is being placed on a breathing machine. Whether providing oxygen and ventilation with a bag-mask device prior to placement of a breathing tube prevents low oxygen levels had been unknown.  Among 401 patients in 7 intensive care units, the PreVent trial found that providing oxygen and ventilation with a bag-mask device was safe, maintained higher oxygen level and prevented dangerously low oxygen levels.  These findings may improve the safety of breathing tube placement for many seriously ill adults.

Background: Hypoxemia is the most common complication during tracheal intubation of critically ill adults and may increase the risk of cardiac arrest and death. Whether positive-pressure ventilation with a bag-mask device (bag-mask ventilation) during tracheal intubation of critically ill adults prevents hypoxemia without increasing the risk of aspiration remains controversial.

Methods: In a multicenter, randomized trial conducted in seven intensive care units in the United States, we randomly assigned adults undergoing tracheal intubation to receive either ventilation with a bag-mask device or no ventilation between induction and laryngoscopy. The primary outcome was the lowest oxygen saturation observed during the interval between induction and 2 minutes after tracheal intubation. The secondary outcome was the incidence of severe hypoxemia, defined as an oxygen saturation of less than 80%.

Results: Among the 401 patients enrolled, the median lowest oxygen saturation was 96% (interquartile range, 87 to 99) in the bag-mask ventilation group and 93% (interquartile range, 81 to 99) in the no-ventilation group (P = 0.01). A total of 21 patients (10.9%) in the bag-mask ventilation group had severe hypoxemia, as compared with 45 patients (22.8%) in the no-ventilation group (relative risk, 0.48; 95% confidence interval [CI], 0.30 to 0.77). Operator-reported aspiration occurred during 2.5% of intubations in the bag-mask ventilation group and during 4.0% in the no-ventilation group (P = 0.41). The incidence of new opacity on chest radiography in the 48 hours after tracheal intubation was 16.4% and 14.8%, respectively (P = 0.73).

Conclusions: Among critically ill adults undergoing tracheal intubation, patients receiving bag-mask ventilation had higher oxygen saturations and a lower incidence of severe hypoxemia than those receiving no ventilation. (Funded by Vanderbilt Institute for Clinical and Translational Research and others; PreVent ClinicalTrials.gov number, NCT03026322.).

Manuscript Title: “Bag-Mask Ventilation during Tracheal Intubation of Critically Ill Adults.”

Journal: New England Journal of Medicine

PMID: 30779528

People who survive critical illness frequently suffer from problems with their strength, thinking, and mental health for months after returning home from the hospital.  To test whether a structured program with specific follow-up visits and resources could prevent the need to be readmitted to the hospital for patients who had previously been treated for critical illness in the ICU, we conducted this pilot study. The study found that patients enrolled in the recovery program received more interventions than those not in the program and went a slightly longer time without hospital readmission. Patients in the ICU recovery program also appeared to experience a lower frequency of death or hospital readmission within 30 days.  Although uncertain because this was only a pilot study, these findings suggest that future research is needed to determine whether programs to help patients recovering from critical illness can prevent death and readmission and improve patients physical, mental, and social function.

Objectives: To examine the effect of an interdisciplinary ICU recovery program on process measures and clinical outcomes.

Design: A prospective, single-center, randomized pilot trial.

Setting: Academic, tertiary-care medical center.

Patients: Adult patients admitted to the medical ICU for at least 48 hours with a predicted risk of 30-day same-hospital readmission of at least 15%.

Interventions: Patients randomized to the ICU recovery program group were offered a structured 10-intervention program, including an inpatient visit by a nurse practitioner, an informational pamphlet, a 24 hours a day, 7 days a week phone number for the recovery team, and an outpatient ICU recovery clinic visit with a critical care physician, nurse practitioner, pharmacist, psychologist, and case manager. For patients randomized to the usual care group, all aspects of care were determined by treating clinicians.

Measurements and main results: Among the primary analysis of enrolled patients who survived to hospital discharge, patients randomized to the ICU recovery program (n = 111) and usual care (n = 121) were similar at baseline. Patients in the ICU recovery program group received a median of two interventions compared with one intervention in the usual care group (p < 0.001). A total of 16 patients (14.4%) in the ICU recovery program group and 26 patients (21.5%) in the usual care group were readmitted to the study hospital within 30 days of discharge (p = 0.16). For these patients, the median time to readmission was 21.5 days (interquartile range, 11.5-26.2 d) in the ICU recovery program group and 7 days (interquartile range, 4-21.2 d) in the usual care group (p = 0.03). Four patients (3.6%) in the ICU recovery program and 14 patients (11.6%) in the usual care group were readmitted within 7 days of hospital discharge (p = 0.02). The composite outcome of death or readmission within 30 days of hospital discharge occurred in 20 patients (18%) in the ICU recovery program group and 36 patients (29.8%) in usual care group (p = 0.04).

Conclusions: This randomized pilot trial found that a multidisciplinary ICU recovery program could deliver more interventions for post ICU recovery than usual care. The finding of longer time-to-readmission with an ICU recovery program should be examined in future trials.

Manuscript Title: “Randomized Clinical Trial of an ICU Recovery Pilot Program for Survivors of Critical Illness.”

Journal: Critical Care Medicine

PMID: 31385881

Patients being treated for sepsis, a serious infection that can lower blood pressure, are often treated with fluids through an IV. Previous studies have shown that a positive fluid balance, or more fluids taken in than out, may be connected to problems with kidney and lung function. The BALANCE pilot trial enrolled 30 patients; 15 patients received fluid in a conservative and restrictive manner, and 15 patients were given the typical fluid care. Results showed that the conservative fluid approach did not decrease fluid balance for patients with sepsis.  These findings suggest that future research on fluid treatment for sepsis will need to find ways to achieve bigger differences in the amount of fluid being received between the approaches being examined.

Rationale: The feasibility and clinical outcomes of conservative fluid management after sepsis resuscitation remain unknown.

Objectives: To evaluate the effect of a conservative fluid management protocol on fluid balance and intensive care unit (ICU)-free days among patients with sepsis.

Methods: In a single-center phase II/III randomized trial, we enrolled adults with suspected infection, ≥2 systemic inflammatory response syndrome criteria, and either shock (mean arterial pressure <60 mm Hg or vasopressors) or respiratory insufficiency (mechanical ventilation or oxygen saturation <97% and fraction of inspired oxygen ≥0.3). Patients were randomized 1:1 to usual care or a conservative fluid management protocol. The protocol restricted intravenous fluid administration during shock to treatment of oliguria or increasing vasopressor requirement. In the absence of shock, loop diuretic infusion targeted equal fluid input and output each study day. The primary outcomes were mean daily fluid balance (phase II) and ICU-free days (phase III).

Results: At the completion of phase II (n = 30), the difference in mean daily fluid balance between groups (-398 mL) was less than the prespecified threshold (-500 mL) and the trial was stopped. Patients in the conservative fluid management (n = 15) and usual care (n = 15) groups experienced similar cumulative fluid input (8450 mL vs 7049 mL; P = .90) of which only 14% was intravenous crystalloid or colloid. Loop diuretic infusion occurred more frequently in the conservative fluid management group (40% vs 0%; P = .02), and cumulative fluid output was 10 645 mL in the conservative fluid management group compared to 6286 mL in the usual care group (P = .39). Hemodynamic, respiratory, and renal function did not differ between the groups.

Conclusions: In this phase II trial, a conservative fluid management protocol did not decrease mean daily fluid balance by more than 500 mL among patients with sepsis.

Registration: Clinicaltrials.gov; NCT02159079.

Keywords: acute kidney injury; intravenous fluid; sepsis.

Conflict of interest statement

CONFLICTS OF INTEREST

All authors completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors declared no potential conflicts of interest with the current work. W.H.S. reported serving on advisory boards for Venaxis, Inc., Ferring Pharmaceuticals, and Cempra Pharmaceuticals, and as a consultant for Abbott Point-of-Care. T.W.R. reported serving on an advisory board for Avisa Pharma, LLC and as the Director of Medical Affairs for Cumberland Pharmaceuticals, Inc.

Manuscript Title: “Conservative Fluid Management After Sepsis Resuscitation: A Pilot Randomized Trial.”

Journal: Journal of Intensive Care Medicine

PMID: 30630380

Importance: Hypotension is common during tracheal intubation of critically ill adults and increases the risk of cardiac arrest and death. Whether administering an intravenous fluid bolus to critically ill adults undergoing tracheal intubation prevents severe hypotension, cardiac arrest, or death remains uncertain.

Objective: To determine the effect of fluid bolus administration on the incidence of severe hypotension, cardiac arrest, and death.

Design, setting, and participants: This randomized clinical trial enrolled 1067 critically ill adults undergoing tracheal intubation with sedation and positive pressure ventilation at 11 intensive care units in the US between February 1, 2019, and May 24, 2021. The date of final follow-up was June 21, 2021.

Interventions: Patients were randomly assigned to receive either a 500-mL intravenous fluid bolus (n = 538) or no fluid bolus (n = 527).

Main outcomes and measures: The primary outcome was cardiovascular collapse (defined as new or increased receipt of vasopressors or a systolic blood pressure <65 mm Hg between induction of anesthesia and 2 minutes after tracheal intubation, or cardiac arrest or death between induction of anesthesia and 1 hour after tracheal intubation). The secondary outcome was the incidence of death prior to day 28, which was censored at hospital discharge.

Results: Among 1067 patients randomized, 1065 (99.8%) completed the trial and were included in the primary analysis (median age, 62 years [IQR, 51-70 years]; 42.1% were women). Cardiovascular collapse occurred in 113 patients (21.0%) in the fluid bolus group and in 96 patients (18.2%) in the no fluid bolus group (absolute difference, 2.8% [95% CI, -2.2% to 7.7%]; P = .25). New or increased receipt of vasopressors occurred in 20.6% of patients in the fluid bolus group compared with 17.6% of patients in the no fluid bolus group, a systolic blood pressure of less than 65 mm Hg occurred in 3.9% vs 4.2%, respectively, cardiac arrest occurred in 1.7% vs 1.5%, and death occurred in 0.7% vs 0.6%. Death prior to day 28 (censored at hospital discharge) occurred in 218 patients (40.5%) in the fluid bolus group compared with 223 patients (42.3%) in the no fluid bolus group (absolute difference, -1.8% [95% CI, -7.9% to 4.3%]; P = .55).

Conclusions and relevance: Among critically ill adults undergoing tracheal intubation, administration of an intravenous fluid bolus compared with no fluid bolus did not significantly decrease the incidence of cardiovascular collapse.

Manuscript Title: “Effect of Fluid Bolus Administration on Cardiovascular Collapse Among Critically Ill Patients Undergoing Tracheal Intubation: A Randomized Clinical Trial”