You've encountered it at ABEM General Hospital, but now a SCUBA diver actually comes into your ED and you're concerned for DCS. What next?
Evaluation:
Symptom nature and timing are key in detailed history. Transient neurocognitive symptoms at depth suggest nitrogen narcosis or oxygen toxicity. Neurological symptoms within 10 minutes of surfacing suggest AGE. Widely variable symptoms within 24 hours of surfacing suggest DCS. Symptom onset greater than 24 hours suggests alternative diagnosis (still discuss with Hyperbaric Medicine or DAN).
Thorough physical exam. DCS may manifest only as localized pain. Look for marine envenomation or trauma to the area.
Neurological exam including detailed sensation and ataxia/balance - get the patient on their feet!
Unbiased differential. E.g. DCS may cause chest pain or SOB, but divers still have heart attacks. SCUBA setting may raise alert for AGE, but divers still have strokes. People go to the tropics to dive, but they also eat local fish (Scombroid and Ciguatera for a future pearl).
Management:
Early consult to Hyperbaric Medicine. In settings with no such team available, a good resource is the Divers Alert Network (DAN) Emergency Hotline at 1-919-684-9111
100% O2 via NRB or highest available delivery. You're not titrating to spO2, you're creating a diffusion gradient for tissue inert gas washout.
IV access and isotonic Fluids. PO if tolerable and unable to obtain IV access.
NSAIDs unless otherwise contraindicated. No special regimen. Standard dosing Ibuprofen or Naproxen are fine. Toradol is ok if limitations to PO.
Horizontal positioning in bed for AGE. Trendelenburg is not recommended.
Manage end organ effects as applicable. E.g. Spinal DCS may yield bladder retention requiring foley
Give consideration to activity specific considerations: hypothermia, restrictive clothing, etc
IV lidocaine has mixed evidence for neuroprotection in AGE. Discuss with Hyperbaricist before starting.
Pre-hospital considerations:
Transport should occur via ground or pressurized air transit capable of 1.0 ATA (sea level) cabin pressure. If non-pressurized aircraft transport is absolutely necessary, maintain continuous oxygen supplementation and altitude less than 2000 feet. This also applies to the inter-hospital setting.
O2 delivery by best means available to include SCUBA regulator mouthpiece or even a rebreather apparatus if present.
PO fluids if tolerable and no IV available.
Predicting NIV Failure
Norepinephrine (NE) is widely accepted as the first-line vasopressor for the management of septic shock, supported by the Surviving Sepsis Guidelines (1). The use of vasopressin as a second-line agent is also supported by the Surviving Sepsis Campaign, although the appropriate “triggers” for its addition remain vague. The SSG recommend adding vasopressin when NE infusion rates reach 0.25-0.6 mcg/kg/min, citing a catecholamine-sparing effect and potentially improved mortality (1, 2, 3).
What’s New?
The OVISS study (“Optimal vasopressin initiation in septic shock. The OVISS reinforcement learning study”) used machine learning to derive and internally validate a set of rules guiding the addition of vasopressin to NE for patients with septic shock using multiple databases of patient encounters across multiple institutions (4).
The machine learning model suggested initiation of vasopressin in more patients (87% vs 31%), earlier, and in less sick patients than was seen to be common practice:
Practice consistent with the above triggers was associated with decreased odds of in-hospital mortality (AOR 0.81, 95% CI 0.73-0.91).
Limitations
This was not a prospective study or RCT and was only internally validated. Using databases may limit the number of clinical variables available for analysis, and clinical judgment (how the patient looks) is not reflected.
Bottom Line
Consider adding vasopressin for patients with vasodilatory shock with low MAP despite NE >0.2mcg/kg/min and adequate fluid resuscitation, though more evidence is needed for a strong recommendation. As dual-pressor therapy may be riskier via peripheral IV and vasopressin does not have a direct antidote for extravasation, consider central line placement when adding vasopressin (5,6)
Whether you agree or disagree that “roc rocks and succ sucks,” evidence shows that approximately 3-4% of intubated patients experience awareness while paralyzed [1,2], and more of these patients are in the rocuronium subgroup [2,3,4]. Rocuronium acts in a dose-dependent fashion; the relatively standard 1-1.2 mg/kg in emergency department rapid sequence intubation (RSI) can result in a duration of paralysis can of up to 60-90 minutes. Commonly used sedatives in RSI, however, such as etomidate and ketamine, wear off quickly, before before rocuronium's paralytic effects have abated.
A recent single-center study showed that the majority of patients (60%) receiving rocuronium for paralysis during rapid sequence intubation (RSI) received no additional sedation until more than 15 minutes after induction, whether in the ED or ICU [5].
Patients experiencing awareness during paralysis with post-traumatic stress disorder [1,2] including distress from being restrained, feeling procedures, and feeling of impending death.
Bottom line: Start appropriate dose sedation promptly after RSI, especially with rocuronium, to avoid short- and long-term distress to patients.
Have you ever wondered what happened to your mechanically ventilated patients who developed diarrhea. Apparently, a multicenter study involving 2650 patients from 44 ICUs in the US, Canada and Saudi Arabia investigated the prevalence of diarrhea among these patients.
This study was the Editor’s choice for June 2025.
Results:
The mean age for the population was 59.8 (16.5) years, with APACHE II Score of 22.0 (7.8). Up to 61% of the patients received vasopressors or inotropes on day 1, which mean these patients are relatively ill.
Up to 60% of patients had diarrhea during their ICU stay, with 15% had diarrhea on day 1 or 2.
Initiating laxatives and antibiotics (who in the ICU would not receive vitamin V and Vitamin Z?) were associated with increased risk of diarrhea: HR for laxatives 1.28 (1.13–1.44), p<0.001; HR for antibiotics 1.41 (1.20–1.67), P< 0.001.
Furthermore, enteral feeding with high/moderate protein concentration was also associated with diarrhea (HR 1.13, 1.00-1.28, P=0.045.
Not surprisingly, diarrhea was associated with higher number of C. Diff testing.
Although patients with diarrhea were associated with longer ICU stay (15 [10-23] days) vs. those without diarrhea (8 [6-12] days), it was not associated with higher mortality (HR 0.70, 95% CI 0.57-0.86, P<0.001)
Discussion:
1. The authors did not report the rates of positive C. Diff. infection in these patients during ICU stay, although they did report that for another study in this population, the rate of positive C. Diff. infection during ICU stay was 2.2%. If only 2.2% had C. Diff. infection while up to 60% had diarrhea. Consequently, for every 30 patients with diarrhea, only one patient had C. Diff. infection. Therefore, do we have to check C. Diff. in those ICU patients with diarrhea every time?
2. The authors hypothesized that patients with diarrhea had longer ICU stay and lower mortality because they survived long enough to develop diarrhea. Thus, diarrhea is bad for clinicians, but may not be too bad for patients?
Conclusion:
Diarrhea is common among invasively ventilated patients. Patients who received laxatives, antibiotics, enteral feeding with high protein amount are at higher risk for diarrhea.
PEEP is often titrated up along with FiO2 to increase oxygen saturation. Although the potential negative hemodynamic effect of high PEEP is often recognized, it is important to also note that high PEEP can also paradoxically worsen oxygen saturation.
The primary physiologic explanation for this phenomenon in a patient with pulmonary disease is due to the varying impact of PEEP on the intra- vs. extra-alveolar blood vessels. PEEP preferentially distends more normal/compliant lung which causes compression of intra-alveolar vessel at excessively high levels of PEEP. This causes pulmonary blood to be diverted to areas of lower vascular resistance (e.g. consolidated lung which is less distended due to its worsened compliance) and lower VQ matching. Essentially, blood flow to normal/healthy lung is decreased and is instead increased to diseased lung, worsening hypoxemia.
Bottom line:
High PEEP can potentially worsen hypoxemia and should be considered as an etiology for worsening oxygen saturation, particularly when the hypoxemia is out of proportion to the patient’s radiographic findings.
Secondary analysis of a multicenter, prospective, observational study ICE-CRASH study in Japan including adult patients admitted with moderate-to-severe accidental hypothermia between 2019 and 2022.
Some structural generalizability (median age 81 years!) issues with this study but well done overall.
Authors undertook some rather complex modeling to predict outcomes related to rapid rewarming, showing that “the rewarming rate and predicted probability of each outcome increased significantly up to 3°C/hr, but when the rewarming rate exceeded 3°C/hr, the predicted probability of each outcome was almost constant.”
Suggests that for those with severe hypothermia that an initially rapid rate of up to 3C/hr is a good target for a ceiling, but above this may be associated with less favorable risk:benefit ratio. Benefit in moderate hypothermia was not as clear.
Conclusion: The mode of rewarming in severe hypothermia should still be based on local protocols and capabilities (e.g. external, intravascular, extracorporeal rewarming) but the rate of rewarming up to 3C/hr is associated with better outcomes.
Following up Dr. Flint's pearl from the other day, the largest study to date looking at a lower Mean Arterial Pressure (MAP) target in elderly ICU patients is the “65” Trial, published in JAMA in 2020. This trial compared a MAP target of 60-65 to the usual goal of >65, in critically ill patients age 65 and older. It included 2,455 patients in 65 ICUs in the UK, and found no difference between the groups.
Bottom Line: Although most intensivists still target a MAP > 65 regardless of patient age, you do have some evidence to support you if you want to target 60-65 in patients over age sixty-five. However, there are some important limitations (well outlined in the PulmCrit article linked below), and therapy should always be optimized to the patient and markers of end organ perfusion.
The presence of an endotracheal tube by itself does not mandate sedation and many patients require no sedatives while intubated in the ICU. However, patients intubated in the emergency department usually require initial sedation while still paralyzed from RSI. Sedation can also help facilitate procedures and imaging in critically ill patients during initial management.
Current literature has found increased mortality and length of ventilator requirement in oversedated ED patients. The target sedation level for the general population remains a goal RASS (Richmond Agitation-Sedation Scale) of 0 to -1. Society of Critical Care Medicine guidelines from early 2025 recommend dexmedetomidine over propofol as the preferred sedative for light sedation and reducing delirium risk in intubated critically ill patients. A recent trial re-examined other clinical outcomes between these two common sedative agents.
A2B Randomized Clinical Trial - JAMA 2025
Clinical Question: Does alpha 2 adrenergic receptor agonist sedation (dexmedetomidine or clonidine) reduce duration of mechanical ventilation in mechanically ventilated patients compared to a propofol based regimen (usual care)?
Where: 41 UK ICU’s from December 2018 to October 2023
Who: 1438 adults receiving mechanical ventilation for less than 48 hours, receiving propofol and opioid for sedation/analgesia, expected to require mechanical ventilation for greater than 48 hours
Intervention: protocol driven sedation to reach a RASS score of -2 to +1 (either dexmedetomidine, clonidine, or propofol). Of note, propofol could be added to achieve deeper sedation goal if deemed necessary by care team.
Outcomes:
Bottom Line:
While either dexmedetomidine or propofol, with appropriate use of opiates for pain management, are appropriate agents in non-paralyzed mechanically-ventilated patients, propofol may be a more appropriate choice in patients with greater agitation while boarding in the emergency department. However, close attention is needed to avoid the overly deep analgosedation associated with increased mortality. Maintain a goal RASS of 0 to -1 with frequent re-evaluation of your ICU boarders.
When To Initiate RRT in the Critically Ill Patient
Patient-ventilator dyssynchrony is a sign of a disagreement between the patient's breathing and the ventilator's settings. Recognizing and fixing it is a critical skill to prevent lung injury and improve comfort. Ineffective triggering and double-trigger are two common types of dyssynchrony.
The patient tries to take a breath, but they are too weak to trigger the ventilator. This is the most common type of dyssynchrony. It causes increased work of breathing and discomfort.
Look for a small dip in the pressure waveform and a simultaneous scoop out of the expiratory flow waveform that is not followed by a delivered breath.
Troubleshooting options:
The patient's own breath outlasts the ventilator's set inspiratory time (Ti), causing one patient effort to trigger two stacked breaths. This results in delivery of large tidal volumes, risking lung injury (volutrauma).
Look for two consecutive breaths on the ventilator screen without a full exhalation in between.
Troubleshooting options:
Dyssynchrony means the ventilator settings do not match the patient's needs. Watch the waveforms to diagnose the mismatch, then either adjust the ventilator or treat the underlying problem.
Acute respiratory distress syndrome (ARDS) is an acute, inflammatory lung injury that effects the lung diffusely and can be triggered by various insults. Aside from the Kigali modification, the most recent updated definition of ARDS was the Berlin definition in 2012. There have been many advances and changes in the understanding and clinical practice for managing patients with ARDS since then. In 2024, Matthay, et al. proposed the new global definition to build upon the Berlin criteria [1]. They addressed several important issues with the Berlin definition to improve the diagnostic criteria and improve ability for diagnosis in resource-limited settings.
ARDS Berlin Definition
Important updates for the Global definition of ARDS
Diagnostic Criteria for the New Global Definition of ARDS from Matthay et al.
The Global Definition of ARDS expands upon the Berlin definition. It was shown that this new definition improves diagnosis in resource-limited settings, allows for earlier detection, and better classification [2]. A retrospective study evaluating this new global definition found that there was a significant number of patients identified using this new definition who would have been missed using the Berlin definition [3]. These patients may benefit from ARDS directed therapies and further prospective studies will be needed to assess how this new definition effects clinical management of these patients using the new definition.
Pulse Checks in Cardiac Arrest: Your Fingers Are Not Reliable.
Summary: Whenever possible, use an ultrasound or an arterial line for pulse checks. Our fingers are not reliable.
Key points:
Multiple studies have demonstrated that manual pulse checks are not a reliable method to determine ROSC. Arterial lines and ultrasound are far more reliable methods. However, using more accurate measures of circulation lead to an additional dilemma: at what MAP, SBP, or ultrasound measured flow should we stop chest compressions? There is no agreed upon number, and as with most dilemmas in clinical medicine, the best answer is, “it depends”. However, a MAP > 50 or SBP > 60 for most patients is a reasonable choice to stop chest compressions. MAP < 50 or SBP < 60 are unlikely to provide adequate perfusion to the brain, and chest compressions should be resumed.
References:
A recent retrospective cohort study out of China investigated an escalating energy (200 > 300 > 360J) versus fixed energy (200 > 200 > 200 J) defibrillation strategy in OHCA with ventricular fibrillation requiring repeated defibrillations.
Notes:
Results:
Caveats:
We have known that resuscitation with balanced crystalloids was associated with better outcomes, than normal saline. However, I have believed that in the early phase of resuscitation, volume of any crystalloids is still better than little volume. Thus, a couple of liters of normal saline (0.9% saline) would not hurt. However, the recent secondary analysis from the Crystalloid Liberal or Vasopressors Early Resuscitation in Sepsis (CLOVERS) trial might have changed my practice.
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Settings:
60 ICU in the United States between 2018 to 2022. This is the secondary analysis of the Crystalloid Liberal or Vasopressors Early Resuscitation in Sepsis (CLOVERS) trial population
Participants: Patients with sepsis-induced hypotension after receiving fluid resuscitation (from 1-3 litters). Participants who received lactate ringers (622 patients) were compared with patients who received normal saline (690 patients).
Outcome measurement:
Death before discharge home by day 90.
Hospital-free days at 28 days
Study Results:
Dead occurred in 12.2% of LR group (76/622) vs. 15.9% (110/690) patients of the NS group, Adjusted Hazard Ratio 0.71 (95% CI 0.51-0.99, p=0.043)
Patients receiving LR had more hospital-free days at 28 days than those receiving 0.9% saline (16.6 ± 10.8 vs. 15.4 ± 11.4 d, respectively). The mean difference was 1.6 days (95% CI, 0.4–2.8; p = 0.009).
Discussion:
This study confirms that not only early resuscitation is important, but the fluid choice during the early resuscitation phase is also important, especially in patients with signs and symptoms of sepsis.
Thus, even during pre-hospital phase and in the ED, clinicians should consider to use LR or other balanced solutions if available.
Conclusion:
Among patients with sepsis-induced hypotension, resuscitation with Lactate Ringer was associated with better outcomes than normal saline.
DeMasi et al. published a review on the current evidence surrounding peri-intubation and intubation practices. While the actual approach and context to each patient will be different it is good to be aware of the actual evidence base for medical decision-making.
Preoxygenation
Between Induction and Laryngoscopy
During Laryngoscopy and Intubation of the Trachea
Medications
Interventions to Prevent Hypotension
Reversal of Factor Xa Inhibitor-Related Intracranial Hemorrhage: A Multicenter, Retrospective, Observational Study Comparing the Efficacy and Safety of Andexanet and PCCs
This study compared patients with a wide variety of intracranial hemorrhage types taking direct oral anticoagulants (e.g. apixaban or rivaroxaban) who then received andexanet versus prothrombin complex concentrates (PCCs)
Patients receiving andexanet (87.8%) had higher odds of achieving excellent/good hemostasis (odds ratio [OR] 1.60; 95% CI, 1.00-2.56; p = 0.048) compared with PCCs (81.8%). Patients treated with andexanet (7.9%) had higher odds of a thrombotic event (OR 1.91; 95% CI, 1.13-3.20; p = 0.014) compared to those treated with PCCs (4.2%).
This study found similar results to the previous ANNEXA-1 trial but included GCS < 7 or Neurosurgery within 12 hours of enrollment, which ANNEXA did not. This study was not designed to prove non-inferiority and should not change practice, especially given the eye-watering cost of Andexanet ($25,000+) versus PCCs (~$4000-6000)…. but betting they are working on one that will.
Duan et al recently published in Intensive Care Medicine the results of a trial looking at a PEEP of 5 cm H2O vs 10 cm H2O and impact on failure rate (progression to intubation) when using non-invasive ventilation (NIV). In their trial, the high PEEP group had a lower rate of intubation (32% vs 43%), and this was statistically significant. It is important to note that they excluded patients whose indication for NIV was heart failure, asthma, or COPD exacerbation.
Ultimately, how to choose the right PEEP is a very complex question and requires tailoring to your patient's physiology and clinical circumstances. For example, hypercarbic patients may benefit more from a maximization of their driving pressure (Pplat - PEEP), which can involve lowering their PEEPs, especially when trying to avoid gastric insufflation (remember, pressures of 30 cm of H2O or higher are very likely to open the LES).
Bottom Line: PEEP and other vent settings should be tailored to the patient's pathophysiology, but this trial suggests that in hypoxemic patients not getting NIV for heart failure, asthma, or COPD exacerbation, a higher PEEP (10 vs 5) may reduce the risk of intubation.
Sedation for the Mechanically Ventilated Adult ICU Patient
This large RCT compared High-Flow Nasal Oxygen (HFNO) against Noninvasive Ventilation (NIV) via face mask in 5 types of Acute Respiratory Failure (ARF): non-immunocompromised hypoxemia, immunocompromised hypoxemia, COPD with acidosis, acute cardiogenic pulmonary edema (ACPE), and COVID-19.
Bottom Line:
RENOVATE suggests HFNO might be a reasonable, more comfortable initial choice for non-immunocompromised hypoxemic ARF or COVID-19 ARF. However, exercise caution using HFNO first-line for COPD exacerbations with acidosis or immunocompromised hypoxemic ARF due to conflicting analyses and potential harm signals. The signal for HFNO benefit in ACPE is intriguing but needs confirmation before changing practice. Close monitoring for failure and timely escalation are essential regardless of the initial noninvasive strategy.
