Month: February 2019

Post Intensive Care Syndromes

This POPPI trial involved a multifaceted intervention that included promotion of a therapeutic environment by ICU staff and targeted stress support sessions delivered by trained ICU nurses to ICU patients who demonstrated acute stress symptom.

Overall, there was no significant difference in the primary outcome of PTSD symptom severity.

Neither was there any significant differences in secondary outcomes, including days alive and free from sedation at day 30, length of ICU stay, symptoms of depression and anxiety, and health-related quality of life. 

Future targeting may involve better selection of at-risk populations, timing, frequency, specific techniques, staff training, and implementation issues. Amelioration of agitation and delirium may also be worthwhile endeavours.

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Delirium and Surgery Duration

In a population-based cohort study over 8 years in Ontario, Canada, approximately 11% of older adults who received hip fracture surgery were diagnosed with postoperative delirium.

Prolonged duration of surgery and GA were associated with an increased risk. Additional risk factors included increasing age, male sex, and patient frailty. Each 30 minutes of surgery led to a 6% increase in delirium.

General anesthesia was associated with a marginally higher rate, a finding not always demonstrated in previous studies.

This association -if not necessarily causation- may be confounded by how they defined surgical duration (time in to out) and potential surgical or comorbid issues.

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Inhalational vs. Intravenous Anesthesia and Glioma Outcome

A retrospective study adds further to the ongoing research into potential outcome improvements from TIVA.

“Compared with maintenance of anesthesia with propofol, sevoflurane did not worsen progression-free or overall survival in patients with high grade glioma undergoing tumor resection. However, propofol might be beneficial in patients with poor preoperative Karnofsky performance status”.

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The TIVA vs. Inhalational debate is still unresolved. Some previous attempts to assimilate the evidence:

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Perioperative surgical home implementation and transfusion

A case control study in adolescents with idiopathic scoliosis undergoing spinal fusion analysed the impact of implementing blood‐conservation strategies within the perioperative surgical home on transfusion rates.

The standardized clinical pathway included judicious use of crystalloid management, restrictive transfusion strategy, routine use of cell saver, and standardized administration of anti‐fibrinolytics.

The primary outcome showed a significant decrease in perioperative blood transfusions.

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ER Airway Assessment using Mallampati Score

This literature review surveyed use of the Mallampati score in Emergency departments prior to airway control or procedural sedation. It was concluded that Mallampati score is inadequately sensitive for the identification of difficult laryngoscopy, difficult intubation, and difficult bag-valve-mask ventilation.

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  • Airway assessment is a series of measures, Mallampati being just one, and known to have inadequate sensitivity or specificity by anesthesia providers. The blog link below includes a full text link to a JAMA comprehensive review of difficult intubation prediction.

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Vasopressor Use In Septic Shock

A European survey of vasopressor practices in septic shock provides a benchmark for other studies.

Better than previously, 97% choose Norepinephrine per guidelines as the first choice. Targets were as recommended 60 – 65 mm Hg mean arterial pressure, higher in practice and in those with hypertension (MAP 75 – 80), this latter being subject to some debate. Preload dependency was commonly assessed before initiation. Recent guidelines that vasopressors can be started alongside volume repletion are often followed. 21% targeted organ perfusion as the target; only 7% used cardiac output targets.

The main reason for adding another agent was lack of response, the choices generally being Vasopressin (Epinephrine with weaker evidence). Whether excessive Norepinephrine can cause higher mortality needs further study.

Steroids are recommended in refractory shock by a majority, despite some conflicting evidence.

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Oliguria during Abdominal Surgery

The RELIEF study added a cautionary note to current restrictive ERAS fluid regimes in that they could increase acute kidney injury [AKI] ( link ), leading to the “modestly liberal” fluid recommendation.

This post hoc analysis analysed the implication of intra-operative oliguria during major abdominal surgery.

The conclusion: “Intraoperative oliguria, defined as urine output <0.5 ml kg−1 h−1, was relatively common and was associated with postoperative AKI. However, the predictive utility of oliguria for AKI was low, whilst its absence had a good predictive value for an AKI-free postoperative course”.

Oliguria represents a conundrum and may be approached by various volume or flow assessment techniques like Inferior Vena Cava diameter, pulse contour analysis or esophageal Doppler, or straight leg raising and fluid challenges.

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Achieving unconsciousness in assisted dying

This review article from Anaesthesia does not wade into the contentious ethics of assisted dying but seeks to determine the optimal method of guaranteeing humane unconsciousness, drawing analogies from the evidence on accidental awareness under anesthesia and capital punishment, while not equating such practices.

The authors discuss methods ranging from oral barbiturates to the more common intravenous anesthetic + neuromuscular blocking agents (+ Potassium). Variously propofol or midazolam, tubocurarine, succinylcholine, vecuronium or rocuronium have been employed.

Debate exists as to how unconsciousness can be guaranteed to a plane of surgical anesthesia, particularly with Midazolam. Ample cases exist that show failure, and even reawakening from intended assisted death. EEG monitoring is not routine but may be ideal; Bispectral Index (BIS) is fraught with uncertainty.

To ensure unconsciousness, the authors propose continuous infusion of supramaximal anesthetic to burst suppression or isoelectric EEG followed by confirmation of anesthesia, and only then neuromuscular blockade/Potassium.

Much as many medical organizations oppose it, assisted death where legal should be accompanied by measures to assure optimal and humane death. “Canadian colleagues are facing this reality post‐hoc, without having first been involved in framing the law‘.

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Initial Care of the Severely Injured Patient

A subscriber article from NEJM updates current approaches to major trauma.

Tourniquets fell out of favour due to limb ischemia in the past but with modern rapid evacuation are back as a standard of care to prevent limb exsanguination, along with hemostatic dressings.

Antifibrinolytics are now recognized as reducing hemorrhage and mortality but critically time sensitive, only recommended in the first 3 hours after trauma. Treatment with tranexamic acid (1 g administered IV over 10 minutes, followed by a 1 g intravenous infusion over 8 hours is recommended.

The long held ATLS advice to administer 2 liters of crystalloid fluid as initial hypotension treatment is now considered obsolete. Permissive hypotension until surgical control is accepted, with judicious plasma or blood for hypotension < 80 systolic.

Damage control surgery – stopping bleeding and contamination for more severe injury is performed without initial abdominal closure while Critical Care stabilizes hypothermia, acidosis and coagulopathy prior to subsequent surgeries.

The “golden hour’ concept is discussed, involving early hemorrhage control, including initial care, triage, rapid evacuation, and resuscitation.

Initial 1:1 ratio of blood:plasma is now standard, with rapid infusion by warming device. It is still not a substitute for surgery to control hemorrhage.

FAST (focused abdominal sonography for trauma), often including the chest, is now ubiquitous in the ER, as unstable patients cannot be sent to CT scanning departments.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging technique to control noncompressible, intracavitary hemorrhage below the diaphragm. Limb or bowel ischemia limits the time of occlusion.

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