Difficult airways can be managed with a range of devices, with video laryngoscopes (VLs) being the most common. The C-MAC® Video-Stylet (VS; Karl-Storz Germany), a hybrid between a flexible and a ...rigid intubation endoscope, has been recently introduced. The aim of this study is to investigate the performance of the VS compared to a VL (C-MAC Macintosh blade, Karl-Storz Germany) with regards to the learning curve for each device and its ability to manage a simulated difficult airway manikin. This is a single-center, prospective, randomized, crossover study involving twenty-one anesthesia residents performing intubations on a Bill 1™ (VBM, Germany) airway manikin model. After a standardized introduction, six randomized attempts with VL and VS were performed on the manikin. This was followed by intubation in a simulated difficult airway (cervical collar and inflated tongue) with both devices in a randomized fashion. The primary end-point of this study was the total time to intubation. All continuous variables were expressed as the median interquartile range and analyzed using the Mann-Whitney U test. A 2-way ANOVA with Bonferroni's post hoc test was used to compare both devices at each trial. All reported p values are two sided. The median total time to intubation on a simulated difficult airway was faster with the VS compared to VL (17 13.5-25 sec vs 23 18.5-26.5 sec, respectively; 95% CI; P = 0.031). Additionally, on a normal airway manikin, the VS has a comparable learning curve to the VL. In this manikin-based study, the novel VS was comparable to the VL in terms of learning curve in a normal airway. In a simulated difficult airway, the total time to intubation, though likely not clinically relevant, was faster with the VS to the VL. However, given the above findings, this study justifies further human clinical trials with the VS to see if similar benefits-faster time to intubation and similar learning curve to VL-are replicated clinically.
The impact of general anesthesia on cognitive impairment is controversial and complex. A large body of evidence supports the association between exposure to surgery under general anesthesia and ...development of delayed neurocognitive recovery in a subset of patients. Existing literature continues to debate whether these short-term effects on cognition can be attributed to anesthetic agents themselves, or whether other variables are causative of the observed changes in cognition. Furthermore, there is conflicting data on the relationship between anesthesia exposure and the development of long-term neurocognitive disorders, or development of incident dementia in the patient population with normal preoperative cognitive function. Patients with pre-existing cognitive impairment present a unique set of anesthetic considerations, including potential medication interactions, challenges with cooperation during assessment and non-general anesthesia techniques, and the possibility that pre-existing cognitive impairment may impart a susceptibility to further cognitive dysfunction.
This review highlights landmark and recent studies in the field, and explores potential mechanisms involved in perioperative cognitive disorders (also known as postoperative cognitive dysfunction, POCD). Specifically, we will review clinical and preclinical evidence which implicates alterations to tau protein, inflammation, calcium dysregulation, and mitochondrial dysfunction. As our population ages and the prevalence of Alzheimer's disease and other forms of dementia continues to increase, we require a greater understanding of potential modifiable factors that impact perioperative cognitive impairment.
Future research should aim to further characterize the associated risk factors and determine whether certain anesthetic approaches or other interventions may lower the potential risk which may be conferred by anesthesia and/or surgery in susceptible individuals.
Endotracheal intubation in the ICU is a challenging procedure and is frequently associated with life-threatening complications. The aim of this study was to investigate the effect of the C-MAC® video ...laryngoscope on laryngeal view and intubation success compared with direct laryngoscopy.
In a single-center, prospective, comparative before-after study in an anesthetist-lead surgical ICU of a tertiary university hospital, predictors of potentially difficult tracheal intubation, number of intubation attempts, success rate and glottic view were evaluated during a 2-year study period (first year, Macintosh laryngoscopy (ML); second year, C-MAC®).
A total of 274 critically ill patients requiring endotracheal intubation were included; 113 intubations using ML and 117 intubations using the C-MAC® were assessed. In patients with at least one predictor for difficult intubation, the C-MAC® resulted in more successful intubations on first attempt compared with ML (34/43, 79% vs. 21/38, 55%; P = 0.03). The visualization of the glottis with ML using Cormack and Lehane (C&L) grading was more frequently rated as difficult (20%, C&L grade 3 and 4) compared with the C-MAC® (7%, C&L grade 3 and 4) (P < 0.0001).
Use of the C-MAC® video laryngoscope improved laryngeal imaging and improved the intubating success rate on the first attempt in patients with predictors for difficult intubation in the ICU setting. Video laryngoscopy seems to be a useful tool in the ICU where potentially difficult endotracheal intubations regularly occur.
It is generally accepted that using a video laryngoscope is associated with an improved visualization of the glottis. However, correctly placing the endotracheal tube might be challenging. Channeled ...video laryngoscopic blades have an endotracheal tube already pre-loaded, allowing to advance the tube once the glottis is visualized. We hypothesized that use of a channel blade with pre-loaded endotracheal tube results in a faster intubation, compared to a curved Macintosh blade video laryngoscope.
After ethical approval and informed consent, patients were randomized to receive endotracheal Intubation with either the King Vision® video laryngoscope with curved blade (control) or channeled blade (channeled). Success rate, evaluation of the glottis view (percentage of glottic opening (POGO), Cormack&Lehane (C&L)) and intubating time were evaluated.
Over a two-month period, a total of 46 patients (control n = 23; channeled n = 23) were examined. The first attempt success rates were comparable between groups (control 100% (23/23) vs. channeled 96% (22/23); p = 0.31). Overall intubation time was significantly shorter with control (median 40 sec; IQR 24-58), compared to channeled (59 sec 40-74; p = 0.03). There were no differences in glottis visualization between groups.
Compared with the King Vision channeled blade, time for tracheal intubation was shorter with the control group using a non-channeled blade. First attempt success and visualization of the glottis were comparable. These data do not support the hypothesis that a channeled blade is superior to a curved video laryngoscopic blade without tube guidance.
ClinicalTrials.gov NCT02344030.
Purpose
Mem
sorb
™ is a novel device for carbon dioxide (CO
2
) removal from anesthesia circuits via a semipermeable polymeric membrane. We evaluated the performance of the mem
sorb
device for the ...removal of CO
2
in an Aisys™ CS
2
machine and compared it with a standard chemical granulate absorber (CGA) using a high-fidelity lung simulator.
Methods
We used an
in vitro
lung simulator (DUCt) to control CO
2
release by imitating alveolar gas exchange. The ventilator settings were identical for all measurements. The fresh gas flow (FGF) was randomized to either 0.5 L·min
−1
or 2 L·min
−1
, completing three trials for each FGF for either mem
sorb
or CGA. The EtCO
2
and F
I
CO
2
levels were recorded for 30 min in each setting.
Results
EtCO
2
was comparable between the groups with 2 L·min
−1
FGF over the observation period. F
I
CO
2
was significantly higher in the mem
sorb
group during the trial (2 L·min
−1
; 3.9 mm Hg; 95% CI, 4.4 to 3.3;
P
< 0.001). EtCO
2
with 0.5 L·min
−1
FGF was higher with mem
sorb
than with CGA over the observation period (3.7 mm Hg; 95% CI, 2.7 to 4.7;
P
= 0.004). With 0.5 L·min
−1
FGF, F
I
CO
2
was significantly higher in the mem
sorb
group compared with CGA over the whole observation period (6 mm Hg; 95% CI, 6.4 to 5.5;
P
< 0.001).
Discussion
CO
2
was successfully removed from the anesthesia circuit. F
I
CO
2
was significantly higher with mem
sorb
throughout the observation period. Nevertheless, the clinical impact of these observations remains unclear. Further clinical trials are required to determine the utility of the novel device.
Video laryngoscopes are commonly used to manage difficult airways, among other devices. However, they present a challenge when inserting the blade in patients with a limited mouth opening, and an ...adequate visualization of the glottis does not always translate into successful intubation. The C-MAC Video-Stylet-with its small diameter and flexible tip-offers an effective alternative. We describe the successful use of the novel C-MAC Video-Stylet to secure the airway in a patient with minimal mouth opening due to the side effects of previous neck surgery and radiation therapy.
The P450 eicosanoids epoxyeicosatrienoic acids (EETs) are produced in brain and perform important biological functions, including protection from ischemic injury. The beneficial effect of EETs, ...however, is limited by their metabolism via soluble epoxide hydrolase (sEH). We tested the hypothesis that sEH inhibition is protective against ischemic brain damage in vivo by a mechanism linked to enhanced cerebral blood flow (CBF). We determined expression and distribution of sEH immunoreactivity (IR) in brain, and examined the effect of sEH inhibitor 12-(3-adamantan-1-yl-ureido)-dodecanoic acid butyl ester (AUDA-BE) on CBF and infarct size after experimental stroke in mice. Mice were administered a single intraperitoneal injection of AUDA-BE (10 mg/kg) or vehicle at 30 mins before 2-h middle cerebral artery occlusion (MCAO) or at reperfusion, in the presence and absence of P450 epoxygenase inhibitor N-methylsulfonyl-6-(2-propargyloxyphenyl) hexanamide (MS-PPOH). Immunoreactivity for sEH was detected in vascular and non-vascular brain compartments, with predominant expression in neuronal cell bodies and processes. 12-(3-Adamantan-1-yl-ureido)-dodecanoic acid butyl ester was detected in plasma and brain for up to 24 h after intraperitoneal injection, which was associated with inhibition of sEH activity in brain tissue. Finally, AUDA-BE significantly reduced infarct size at 24 h after MCAO, which was prevented by MS-PPOH. However, regional CBF rates measured by iodoantipyrine (IAP) autoradiography at end ischemia revealed no differences between AUDA-BE- and vehicle-treated mice. The findings suggest that sEH inhibition is protective against ischemic injury by non-vascular mechanisms, and that sEH may serve as a therapeutic target in stroke.
Summary
Introduction
Collecting a blood sample is usually necessary to measure hemoglobin levels in children. Especially in small children, noninvasively measuring the hemoglobin level could be ...extraordinarily helpful, but its precision and accuracy in the clinical environment remain unclear. In this study, noninvasive hemoglobin measurement and blood gas analysis were compared to hemoglobin measurement in a clinical laboratory.
Methods
In 60 healthy preoperative children (0.2–7.6 years old), hemoglobin was measured using a noninvasive method (SpHb; Radical‐7 Pulse Co‐Oximeter), a blood gas analyzer (clinical standard, BGAHb; ABL 800 Flex), and a laboratory hematology analyzer (reference method, labHb; Siemens Advia). Agreement between the results was assessed by Bland–Altman analysis and by determining the percentage of outliers.
Results
Sixty SpHb measurements, 60 labHb measurements, and 59 BGAHb measurements were evaluated. In 38% of the children, the location of the SpHb sensor had to be changed more than twice for the signal quality to be sufficient. The bias/limits of agreement between SpHb and labHb were −0.65/−3.4 to 2.1 g·dl−1. Forty‐four percent of the SpHb values differed from the reference value by more than 1 g·dl−1. Age, difficulty of measurement, and the perfusion index (PI) had no influence on the accuracy of SpHb. The bias/limits of agreement between BGAHb and labHb were 1.14/−1.6 to 3.9 g·dl−1. Furthermore, 66% of the BGAHb values differed from the reference values by more than 1 g·dl−1. The absolute mean difference between SpHb and labHb (1.1 g·dl−1) was smaller than the absolute mean difference between BGAHb and labHb (1.5 g·dl−1/P = 0.024).
Conclusion
Noninvasive measurement of hemoglobin agrees more with the reference method than the measurement of hemoglobin using a blood gas analyzer. However, both methods can show clinically relevant differences from the reference method (ClinicalTrials.gov: NCT01693016).
PDF
