Ketamine Infusions for Chronic Pain

A series of Ketamine infusion treatments for chronic pain have sprouted “Ketamine Clinics” globally but the longer outcome has not clearly been defined. Ketamine as an opioid-avoiding modality has often spurred the movement.

This review and meta-analysis summarizes the data, finding benefit in the short term (a few weeks) with less confidence on longer term pain relief, as well as higher incidences of nausea and psychotomimetic side effects:

“Evidence suggests that IV ketamine provides significant short-term analgesic benefit in patients with refractory chronic pain, with some evidence of a dose–response relationship. Larger, multicenter studies with longer follow-ups are needed to better select patients and determine the optimal treatment protocol.”

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Preoperative Opioid and Benzodiazepine Prescription Patterns and Mortality After Noncardiac Surgery

The risks from opioid and benzodiazepines may begin even earlier than the perioperative period. This retrospective analysis examined patients that received prescriptions for either in the year before surgery.

They found “opioid and benzodiazepine prescription fills in the 6 months before surgery are associated with increased short-and long-term mortality and an increased rate of persistent postoperative opioid consumption.”

It is suggested: “These patients should be considered for early referral to preoperative clinic and medication optimization to improve surgical outcomes.”


Pressure Support vs T-Piece Ventilation Strategies During Spontaneous Breathing Trials

All modern guidelines are in agreement with daily interruption of sedation in the ICU and spontaneous breathing trials but weaning strategies can differ.

This study found: “a spontaneous breathing trial consisting of 30 minutes of pressure support ventilation, compared with 2 hours of T-piece ventilation, led to significantly higher rates of successful extubation. These findings support the use of a shorter, less demanding ventilation strategy for spontaneous breathing trials.”


Preadmission Statin Use and 90-day Mortality in the Critically Ill

The many advantages of statins has led to trials of their use in many conditions like ARDS, renal outcomes and in the ICU.

This study is retrospective and would require randomized studies to confirm but has interesting suggestions:

ICU Preadmission statin use was associated with a lower 90-day mortality. This association was more evident in the rosuvastatin group and with noncardiovascular 90-day mortality; no differences were seen according to daily dosage intensity.


Ratio of Fresh Frozen Plasma to Red Blood Cells During Massive Transfusion and Survival Among Patients Without Traumatic Injury

There has been a dramatic shift away from excessive fluid resuscitation and also in favour of 1:1 ratios (or similar) of plasma to blood in trauma.

This retrospective study cautioned that this practice may not be generalizable to the non-trauma setting:

“High FFP:RBC transfusion ratios are applied mostly to patients without trauma, who account for nearly 90% of all massive transfusion events. Thirty-day survival was not significantly different in patients who received a high FFP:RBC ratio compared with those who received a low ratio.”


Pediatric Risk Stratification: Patient Comorbidities and Intrinsic Surgical Risk

A retrospective study of the Pediatric NSQIP delineated the impact of intrinsic surgical risk with patient co-morbidities, informing how intrinsic surgical risk can add to mortality prediction.

“Surgical procedures identified by specialty are not independent risk factors for perioperative mortality in pediatric patients. However, in multivariable predictive algorithms, the interaction of patient comorbidities with the intrinsic risk of the surgical procedure strongly predicts 30-day mortality.”


Mean Arterial Pressure and Acute Kidney Injury and a Composite of Myocardial Injury and Mortality in Postoperative Critically Ill Patients

Yet another study confirms the harmful effects of hypotension in terms of values and duration, as has been shown also in the anesthesia setting.

“Increasing amounts of hypotension(defined by lowest mean arterial pressures per day) were strongly associated with myocardial injury, mortality, and renal injury in postoperative critical care patients.”


The Restrictive IV Fluid Trial in Severe Sepsis and Septic Shock (RIFTS)

This was a small pilot study examining the impact of more restrictive fluid regimes in sepsis and septic shock, but its findings are in line with the recent trend for not overloading patients with fluids and a more early move to vasopressor support. Restrictive fluids were defined as ≤ 60 mL/kg of IV fluid over 72 hours.

“There were no differences between groups in the rate of new organ failure, hospital or ICU length of stay, or serious adverse events.”


Frailty in Older Patients Undergoing Emergency Laparotomy

Emergency laparotomy has been the subject of many surveys, notably the NELA audit in the UK, which identified areas for improvement.

This current study examined the specific impact of frailty, which should now be routinely and formally scored in older patients.

The conclusion is in line with so much other evidence documented in this blog:

“A fifth of older adults undergoing emergency laparotomy are frail. The presence of frailty is associated with greater risks of postoperative mortality and morbidity and is independent of age.”


Guidelines: management of acute respiratory distress syndrome

Proposed updated guidelines are presented in this full text article for ARDS management. The quotes below summarize:

Four recommendations (low tidal volume, plateau pressure limitation, no oscillatory ventilation, and prone position) had a high level of proof.

Four (high positive end-expiratory pressure [PEEP] in moderate and severe ARDS, muscle relaxants, recruitment maneuvers, and venovenous extracorporeal membrane oxygenation [ECMO]) a low level of proof.

Seven (surveillance, tidal volume for non ARDS mechanically ventilated patients, tidal volume limitation in the presence of low plateau pressure, PEEP > 5 cmH2O, high PEEP in the absence of deleterious effect, pressure mode allowing spontaneous ventilation after the acute phase, and nitric oxide) corresponded to a level of proof that did not allow use of the GRADE classification and were expert opinions. 

Lastly, for three aspects of ARDS management (driving pressure, early spontaneous ventilation, and extracorporeal carbon dioxide removal), the experts concluded that no sound recommendation was possible given current knowledge.

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