Anesthesiology

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Dental procedures under sedation can cause hypoxic events and even death. However, the mechanism of such hypoxic events is not well understood. WHAT THIS ARTICLE TELLS US THAT IS NEW: Apnea and hypopnea occur frequently during dental procedures under sedation. The majority of the events are not detectable with pulse oximetry. Insertion of a nasal tube with small diameter does not reduce the incidence of apnea/hypopnea. BACKGROUND: Intravenous sedation is effective in patients undergoing dental procedures, but fatal hypoxemic events have been documented...

No abstract text is available yet for this article.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: High tidal volumes and pressures may worsen acute lung injury, sometimes resulting in a trade-off between inflicted damage versus inadequate ventilation WHAT THIS ARTICLE TELLS US THAT IS NEW: In a rat model of experimental lung injury, gradually increasing tidal volume to a known injurious level may result in less (or in some circumstances, more) damage BACKGROUND:: This study hypothesized that, in experimental mild acute respiratory distress syndrome, lung damage caused by high tidal volume (VT) could be attenuated if VT increased slowly enough to progressively reduce mechanical heterogeneity and to allow the epithelial and endothelial cells, as well as the extracellular matrix of the lung to adapt...

No abstract text is available yet for this article.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Preclinical and clinical studies suggest that lidocaine might be neuroprotective, which could benefit surgical patients at risk of neurologic compromise WHAT THIS ARTICLE TELLS US THAT IS NEW: This multicenter trial of intravenous lidocaine administered during and after cardiac surgery did not show an effect on cognition at 6 weeks postoperatively BACKGROUND:: Cognitive decline after cardiac surgery occurs frequently and persists in a significant proportion of patients...

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Mesenchymal stromal cells are multipotent adult stem cells with the capacity to differentiate into multiple cell types and have immunomodulatory properties that have been shown to have substantial therapeutic promise in preclinical acute lung injury modelsMesenchymal stromal cells release extracellular vesicles, which are small, spherical membrane fragments comprising distinct populations including both exosomes and microvesicles, which have therapeutic effects in several disease modelsMesenchymal stromal cells are activated or primed by the injury microenvironment, which may be replicated by prior activation of the mesenchymal stromal cells WHAT THIS ARTICLE TELLS US THAT IS NEW: In a rat model of Escherichia coli-induced pneumonia, extracellular vesicles derived from human umbilical cord mesenchymal stromal cells primed with interferon-γ more effectively attenuated E...

No abstract text is available yet for this article.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Perioperative hypotension is associated with cardiovascular events in patients having noncardiac surgery, but it is unknown if the severity of preexisting coronary artery disease determines susceptibility to the cardiovascular risks of perioperative hypotension WHAT THIS ARTICLE TELLS US THAT IS NEW: In patients who had risk factors for, or known, coronary artery disease and were having noncardiac surgery, perioperative hypotension and degree of coronary artery disease on preoperative coronary computed tomographic angiography were independently associated with perioperative cardiovascular death and myocardial infarctionPerioperative hypotension was associated with cardiovascular events regardless of the degree of coronary artery disease on preoperative coronary computed tomographic angiography BACKGROUND:: Perioperative hypotension is associated with cardiovascular events in patients having noncardiac surgery...

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Children with obstructive sleep apnea are at greater risk for postoperative hypoxia and other respiratory events as compared with children without this disorderThere is some reason to believe that children with obstructive sleep apnea may be at greater risk for opioid-induced respiratory depression due to increased sensitivity to the drugs WHAT THIS ARTICLE TELLS US THAT IS NEW: The authors hypothesized that children with obstructive sleep apnea would be more sensitive to the effects of an opioid (remifentanil) on pupil size-a very good indicator of opioid effectsWhile remifentanil did reduce pupil size in the expected dose-related fashion, there were no differences between children with obstructive sleep apnea and those withoutWhile the authors did not observe any differences in the effect of remifentanil on respiration, the study was not designed to examine this factor in detail BACKGROUND:: Opioids are a mainstay of perioperative analgesia...

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: The intraneural injection of local anesthetics is an accepted cause of nerve injury related to regional anesthesiaThe intrafascicular versus extrafascicular spread of local anesthetics is hypothesized to be necessary for nerve damage to occur WHAT THIS ARTICLE TELLS US THAT IS NEW: Using the ultrasound-guided injection of heparinized blood into the nerves of cadavers, the extrafascicular spread of injectate was observedIntrafascicular spread of injectate was rarely observed, making this an unlikely route of nerve damage after accidental intraneural injection BACKGROUND:: There is confusion regarding the spread of intraneurally injected local anesthetic agents during regional anesthesia...

No abstract text is available yet for this article.

No abstract text is available yet for this article.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Debriefing after an actual critical event is an established good practice in medicine, but a gap exists between principle and implementation. WHAT THIS ARTICLE TELLS US THAT IS NEW: Failure to debrief after critical events is common among anesthesia trainees and likely anesthesia teams. Communication breakdowns are associated with a high rate of the failure to debrief. BACKGROUND: Debriefing after an actual critical event is an established good practice in medicine, but a gap exists between principle and implementation...

No abstract text is available yet for this article.

This fourth and last installment of my history of basic airway management discusses the current (i.e., "modern") era of anesthesia and resuscitation, from 1960 to the present. These years were notable for the implementation of intermittent positive pressure ventilation inside and outside the operating room. Basic airway management in cardiopulmonary resuscitation (i.e., expired air ventilation) was de-emphasized, as the "A-B-C" (airway-breathing-circulation) protocol was replaced with the "C-A-B" (circulation-airway-breathing) intervention sequence...

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Obesity increases the propensity to atelectasis in acute respiratory distress syndrome, but the optimal approach to reversing this atelectasis is uncertain WHAT THIS ARTICLE TELLS US THAT IS NEW: A clinical crossover study comparing three approaches to titrate positive end-expiratory pressure (PEEP; according to a fixed table, according to end-expiratory esophageal pressure, and targeting the best compliance during a decremental PEEP trial) found that a recruitment maneuver followed by decremental PEEP minimized atelectasis and overdistension, and best restored compliance and oxygenation without causing hemodynamic impairment BACKGROUND:: Obese patients are characterized by normal chest-wall elastance and high pleural pressure and have been excluded from trials assessing best strategies to set positive end-expiratory pressure (PEEP) in acute respiratory distress syndrome (ARDS)...

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Presynaptic N-methyl-D-aspartate receptors contribute to opioid tolerance and hyperalgesia as well as neuropathic painThe α2δ-1 protein subunit enhances presynaptic N-methyl-D-aspartate receptor activity WHAT THIS ARTICLE TELLS US THAT IS NEW: Using mouse and rat models, it was demonstrated that α2δ-1 is essential for the increase in presynaptic N-methyl-D-aspartate receptor activity seen during chronic morphine exposureInhibiting α2δ-1 activity using gabapentin or genetically deleting the gene coding for α2δ-1 results in diminished opioid tolerance and hyperalgesia BACKGROUND:: Chronic use of μ-opioid receptor agonists paradoxically causes both hyperalgesia and the loss of analgesic efficacy...

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: The nociception level index (Medasense Biometrics Ltd., Ramat Gan, Israel), is a reliable measure of moderate to intense noxious stimulation during anesthesia and surgery WHAT THIS ARTICLE TELLS US THAT IS NEW: In a randomized trial in patients having major abdominal surgery, compared to standard practice, nociception level-guided analgesia resulted in 30% less intraoperative remifentanil consumption BACKGROUND:: The multidimensional index of nociception, the nociception level, outperforms blood pressure and heart rate in detection of nociceptive events during anesthesia...

No abstract text is available yet for this article.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: A decrease in frontoparietal functional connectivity has been demonstrated with multiple anesthetic agents, and this decrease has been proposed as a final common functional pathway to produce anesthesia.Two alternative measures of long-range cortical interaction are coherence and phase-amplitude coupling. Although phase-amplitude coupling within frontal cortex changes with propofol administration, the effects of propofol on phase-amplitude coupling between different cortical areas have not previously been reported...