A Breath-Based In Vitro Diagnostics for Lower Respiratory Tract Infection.

Lower Respiratory Tract Infections (LRTIs) represent the leading cause of death due to infectious diseases. Current diagnostic modalities primarily depend on clinical symptoms and lack specificity, especially in light of common colonization without overt infection. To address this, we developed a noninvasive diagnostic approach that employs BreathBiomics™, an advanced human breath sampling system, to detect protease activities induced by bacterial infection in the lower respiratory tract. Specifically, we engineered a high-sensitivity and high-specificity molecular sensor for human neutrophil elastase (HNE). The sensor undergoes cleavage in the presence of HNE, an event that is subsequently detected via Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS). Application of this methodology to clinical samples, breath specimens collected from intubated patients with LRTIs, demonstrated the detection of the cleaved sensor by MALDI-TOF MS. Our findings indicate that this novel approach offers a noninvasive and specific diagnostic strategy for people with LRTIs.

Embolic occlusion of internal carotid artery in conscious rats: Immediate effects of cerebral ischemia.

In most preclinical models of focal ischemic stroke, vascular occlusion is performed under general anesthesia. However, anesthetic agents exert confounding effects on mean arterial blood pressure (MABP), cerebrovascular tone, oxygen demand, and neurotransmitter receptor transduction. Moreover, the majority of studies do not use a blood clot, which more fully models embolic stroke. Here, we developed a blood clot injection model to produce large cerebral artery ischemia in unanesthetized rats. Under isoflurane anesthesia, an indwelling catheter was implanted in the internal carotid artery via a common carotid arteriotomy and preloaded with a 0.38-mm-diameter clot of 1.5, 3, or 6 cm length. After discontinuing anesthesia, the rat was returned to a home cage where it regained normal mobility, grooming, eating activity, and a stable recovery of MABP. One hour later, the clot was injected over a 10-s period and the rats were observed for 24 h. Clot injection produced a brief period of irritability, then 15-20 min of complete inactivity, followed by lethargic activity at 20-40 min, ipsilateral deviation of the head and neck at 1-2 h, and limb weakness and circling at 2-4 h. Neurologic deficits, elevated MABP, infarct volume, and increased hemisphere water content varied directly with clot size. Mortality after 6-cm clot injection (53%) was greater than that after 1.5-cm (10%) or 3-cm (20%) injection. Combined non-survivor groups had the greatest MABP, infarct volume, and water content. Among all groups, the pressor response correlated with infarct volume. The coefficient of variation of infarct volume with the 3-cm clot was less than that in published studies with the filament or standard clot models, and therefore may provide stronger statistical power for stroke translational studies. The more severe outcomes from the 6-cm clot model may be useful for the study of malignant stroke.

Human exhaled air diagnostic markers for respiratory tract infections in subjects receiving mechanical ventilation.

Diagnosing respiratory tract infections (RTIs) in critical care settings is essential for appropriate antibiotic treatment and lowering mortality. The current diagnostic method, which primarily relies on clinical symptoms, lacks sensitivity and specificity, resulting in incorrect or delayed diagnoses, putting patients at a heightened risk. In this study we developed a noninvasive diagnosis method based on collecting non-volatile compounds in human exhaled air. We hypothesized that non-volatile compound profiles could be effectively used for bacterial RTI diagnosis. Exhaled air samples were collected from subjects receiving mechanical ventilation diagnosed with or without bacterial RTI in intensive care units at the Johns Hopkins Hospital. Truncated proteoforms, a class of non-volatile compounds, were characterized by top-down proteomics, and significant features associated with RTI were identified using feature selection algorithms. The results showed that three truncated proteoforms, collagen type VI alpha three chain protein, matrix metalloproteinase-9, and putative homeodomain transcription factor II were independently associated with RTI with thep-values of 2.0 × 10-5, 1.1 × 10-4, and 1.7 × 10-3, respectively, using multiple logistic regression. Furthermore, a score system named 'TrunScore' was constructed by combining the three truncated proteoforms, and the diagnostic accuracy was significantly improved compared to that of individual truncated proteoforms, with an area under the receiver operator characteristic curve of 96.9%. This study supports the ability of this noninvasive breath analysis method to provide an accurate diagnosis for RTIs in subjects receiving mechanical ventilation. The results of this study open the doors to be able to potentially diagnose a broad range of diseases using this non-volatile breath analysis technique.

Voice-Related Quality of Life Increases With a Talking Tracheostomy Tube: A Randomized Controlled Trial.

OBJECTIVE: The primary objective of our study was to determine the quality of life (QOL) using a talking tracheostomy tube. METHODS: Randomized clinical trial (NCT2018562). Adult intensive care unit patients who were mechanically ventilated, awake, alert, attempting to communicate, English-speaking, and could not tolerate one-way speaking valve were included. Intervention comprised a Blue Line Ultra Suctionaid (BLUSA) talking tracheostomy tube (Smiths Medical, Dublin, OH, US). Outcome measures included QOL scores measured using Quality of Life in Mechanically Ventilated Patients (QOL-MV) and Voice-Related Quality of Life (V-RQOL), Speech Intelligibility Test (SIT) scores, independence, and satisfaction. RESULTS: The change in V-RQOL scores from pre- to postintervention was higher among patients using a BLUSA (Smiths Medical) compared to those who did not (P = 0.001). The QOL-MV scores from pre- to postintervention were significantly higher among patients who used a BLUSA (Smiths Medical) compared to patients who did not use BLUSA (Smiths Medical) or a one-way speaking valve (P = 0.04). SIT scores decreased by 6.4 points for each 1-point increase in their Sequential Organ Failure Assessment scores (P = 0.04). The overall QOL-MV scores correlated moderately with the overall V-RQOL scores (correlation coefficient = 0.59). Cronbach alpha score for overall QOL-MV was 0.71. Seventy-three percent of the 22 intervention patients reported the ability to use the BLUSA (Smiths Medical) with some level of independence, whereas 41% reported some level of satisfaction with the use of BLUSA (Smiths Medical). The lengths of stay was longer in the intervention group. CONCLUSION: Our study suggests that BLUSA (Smiths Medical) talking tracheostomy tube improves patient-reported QOL in mechanically ventilated patients with a tracheostomy who cannot tolerate cuff deflation. LEVEL OF EVIDENCE: I Laryngoscope, 130:1249-1255, 2020.

Correction to: Intraoperative cerebral oximetry-based management for optimizing perioperative outcomes: a meta-analysis of randomized controlled trials.

In the article entitled "Intraoperative cerebral oximetry-based management for optimizing perioperative outcomes: a meta-analysis of randomized controlled trials" Can J Anesth 2018; 65: 529-42, we wish to clarify the following items.

Optimizing Mean Arterial Pressure in Acutely Comatose Patients Using Cerebral Autoregulation Multimodal Monitoring With Near-Infrared Spectroscopy.

OBJECTIVES: This study investigated whether comatose patients with greater duration and magnitude of clinically observed mean arterial pressure outside optimal mean arterial blood pressure have worse outcomes than those with mean arterial blood pressure closer to optimal mean arterial blood pressure calculated by bedside multimodal cerebral autoregulation monitoring using near-infrared spectroscopy. DESIGN: Prospective observational study. SETTING: Neurocritical Care Unit of the Johns Hopkins Hospital. SUBJECTS: Acutely comatose patients secondary to brain injury. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The cerebral oximetry index was continuously monitored with near-infrared spectroscopy for up to 3 days. Optimal mean arterial blood pressure was defined as that mean arterial blood pressure at the lowest cerebral oximetry index (nadir index) for each 24-hour period of monitoring. Kaplan-Meier analysis and proportional hazard regression models were used to determine if survival at 3 months was associated with a shorter duration of mean arterial blood pressure outside optimal mean arterial blood pressure and the absolute difference between clinically observed mean arterial blood pressure and optimal mean arterial blood pressure. A total 91 comatose patients were enrolled in the study. The most common etiology was intracerebral hemorrhage. Optimal mean arterial blood pressure could be calculated in 89 patients (97%), and the median optimal mean arterial blood pressure was 89.7 mm Hg (84.6-100 mm Hg). In multivariate proportional hazard analysis, duration outside optimal mean arterial blood pressure of greater than 80% of monitoring time (adjusted hazard ratio, 2.13; 95% CI, 1.04-4.41; p = 0.04) and absolute difference between clinically observed mean arterial blood pressure and optimal mean arterial blood pressure of more than 10 mm Hg (adjusted hazard ratio, 2.44; 95% CI, 1.21-4.92; p = 0.013) were independently associated with mortality at 3 months, after adjusting for brain herniation, admission Glasgow Coma Scale, duration on vasopressors and midline shift at septum. CONCLUSIONS: Comatose neurocritically ill adults with an absolute difference between clinically observed mean arterial blood pressure and optimal mean arterial blood pressure greater than 10 mm Hg and duration outside optimal mean arterial blood pressure greater than 80% had increased mortality at 3 months. Noninvasive near-infrared spectroscopy-based bedside calculation of optimal mean arterial blood pressure is feasible and might be a promising tool for cerebral autoregulation oriented-therapy in neurocritical care patients.

Impact of antiepileptic drugs for seizure prophylaxis on short and long-term functional outcomes in patients with acute intracerebral hemorrhage: A meta-analysis and systematic review.

PURPOSE: The purpose of this analysis is to assess the effect of antiepileptics (AEDs) on seizure prevention and short and long term functional outcomes in patients with acute intracerebral hemorrhage. METHOD: The meta-analysis was conducted using the PRISMA guidelines. A literature search was performed of the PubMed, the Cochrane Library, and EMBASE databases. Search terms included "Anticonvulsants", "Intracerebral Hemorrhage", and related subject headings. Articles were screened and included if they were full-text and in English. Articles that did not perform multivariate regression were not included. Overall effect size was evaluated with forest plots and publication bias was assessed with the Begg's and Egger's tests. RESULTS: A total of 3912 articles were identified during the initial review. After screening, 54 articles remained for full review and 6 articles were included in the final analysis. No significant association between the use of AEDs after ICH and functional outcome (OR 1.53 [95%CI: 0.81-2.88] P = 0.18, I2 = 81.7%). Only one study evaluated the effect AEDs had in preventing post-ICH seizures. CONCLUSIONS: The use of prophylactic AEDs was not associated with improved short and long outcomes after acute ICH. This analysis supports the 2015 AHA/ASA recommendation against prophylactic AEDs (class III; level of evidence b).

Outcomes of Tracheostomy With Concomitant and Delayed Percutaneous Endoscopic Gastrostomy in the Neuroscience Critical Care Unit.

BACKGROUND: In patients with severe neurologic conditions, percutaneous endoscopic gastrostomy (PEG) is typically performed either alone or with a tracheostomy. The characteristics and outcomes of patients receiving PEG concomitantly with a tracheostomy (CTPEG) and those receiving delayed PEG (DPEG) after a tracheostomy were compared. METHODS: Retrospective cohort study in a 24-bed neuroscience critical care unit (NCCU) at a tertiary care hospital. Consecutive patients admitted to the NCCU from April 2007 to July 2013 who underwent percutaneous tracheostomy and gastrostomy by the percutaneous tracheostomy team were included and grouped according to the timing of PEG placement: CTPEG versus DPEG. RESULTS: Of the 290 patients, 234 (81%) received CTPEG. Demographic and clinical characteristics were similar among the 2 groups except for a lower median (interquartile range [IQR]) body mass index (BMI; 27 [22.67-31.60] versus 30.8 [24.55-40.06], P = .017) and lower rate of acute respiratory distress syndrome (3.85% vs 10.71%, P = .048) in the CTPEG cohort. Furthermore, 59% of CTPEG cohort were neurology patients while 63% of DPEG were neurosurgery patients, P = .004. Primary outcomes showed shorter mean NCCU length of stay (LOS; 25 [12] vs 33 [17] days, P < .001) and median hospital LOS (32 [25-43] vs 37 [31-56] days, P = .002) for the CTPEG cohort. Secondary outcomes showed higher predischarge prealbumin levels (15.6 [7.75] vs 11.58 [5.41], P = .021) and lower median overall hospital cost (US$123 860.20 [US$99 024-US$168 713.40] vs US$159 633.50 [US$121 312-US$240 213.10], P = .0003) in the CTPEG group. Anatomic contraindications were the most common reason for DPEG (30%). CONCLUSIONS: Among institutions with a tracheostomy team, the practice of tracheostomy with concomitant PEG placement may be considered as feasible as delayed PEG in carefully selected neurocritically ill patients with possible advantages of overall shorter NCCU and hospital LOS, higher predischarge prealbumin, and lower hospital costs. These findings may aid in decisions regarding the timing of PEG placement in the NCCU. Further prospective studies are warranted.

Glasgow Coma Scale Score Fluctuations are Inversely Associated With a NIRS-based Index of Cerebral Autoregulation in Acutely Comatose Patients.

BACKGROUND: The Glasgow Coma Scale (GCS) is an essential coma scale in critical care for determining the neurological status of patients and for estimating their long-term prognosis. Similarly, cerebral autoregulation (CA) monitoring has shown to be an accurate technique for predicting clinical outcomes. However, little is known about the relationship between CA measurements and GCS scores among neurological critically ill patients. This study aimed to explore the association between noninvasive CA multimodal monitoring measurements and GCS scores. METHODS: Acutely comatose patients with a variety of neurological injuries admitted to a neurocritical care unit were monitored using near-infrared spectroscopy-based multimodal monitoring for up to 72 hours. Regional cerebral oxygen saturation (rScO2), cerebral oximetry index (COx), GCS, and GCS motor data were measured hourly. COx was calculated as a Pearson correlation coefficient between low-frequency changes in rScO2 and mean arterial pressure. Mixed random effects models with random intercept was used to determine the relationship between hourly near-infrared spectroscopy-based measurements and GCS or GCS motor scores. RESULTS: A total of 871 observations (h) were analyzed from 57 patients with a variety of neurological conditions. Mean age was 58.7±14.2 years and the male to female ratio was 1:1.3. After adjusting for hemoglobin and partial pressure of carbon dioxide in arterial blood, COx was inversely associated with GCS (ß=-1.12, 95% confidence interval [CI], -1.94 to -0.31, P=0.007) and GCS motor score (ß=-1.06, 95% CI, -2.10 to -0.04, P=0.04). In contrast rScO2 was not associated with GCS (ß=-0.002, 95% CI, -0.01 to 0.01, P=0.76) or GCS motor score (ß=-0.001, 95% CI, -0.01 to 0.01, P=0.84). CONCLUSIONS: This study showed that fluctuations in GCS scores are inversely associated with fluctuations in COx; as COx increases (impaired autoregulation), more severe neurological impairment is observed. However, the difference in COx between high and low GCS is small and warrants further studies investigating this association. CA multimodal monitoring with COx may have the potential to be used as a surrogate of neurological status when the neurological examination is not reliable (ie, sedation and paralytic drug administration).

Antiepileptic drugs in critically ill patients.

BACKGROUND: The incidence of seizures in intensive care units ranges from 3.3% to 34%. It is therefore often necessary to initiate or continue anticonvulsant drugs in this setting. When a new anticonvulsant is initiated, drug factors, such as onset of action and side effects, and patient factors, such as age, renal, and hepatic function, should be taken into account. It is important to note that the altered physiology of critically ill patients as well as pharmacological and nonpharmacological interventions such as renal replacement therapy, extracorporeal membrane oxygenation, and target temperature management may lead to therapeutic failure or toxicity. This may be even more challenging with the availability of newer antiepileptics where the evidence for their use in critically ill patients is limited. MAIN BODY: This article reviews the pharmacokinetics and pharmacodynamics of antiepileptics as well as application of these principles when dosing antiepileptics and monitoring serum levels in critically ill patients. The selection of the most appropriate anticonvulsant to treat seizure and status epileptics as well as the prophylactic use of these agents in this setting are also discussed. Drug-drug interactions and the effect of nonpharmacological interventions such as renal replacement therapy, plasma exchange, and extracorporeal membrane oxygenation on anticonvulsant removal are also included. CONCLUSION: Optimal management of antiepileptic drugs in the intensive care unit is challenging given altered physiology, polypharmacy, and nonpharmacological interventions, and requires a multidisciplinary approach where appropriate and timely assessment, diagnosis, treatment, and monitoring plans are in place.

Intraoperative cerebral oximetry-based management for optimizing perioperative outcomes: a meta-analysis of randomized controlled trials.

PURPOSE: Although evidence from observational studies in a variety of clinical settings supports the utility of cerebral oximetry as a predictor of outcomes, prospective clinical trials thus far have reported conflicting results. This systematic review and meta-analysis was designed to evaluate the influence of management associated with intraoperative cerebral oximetry on postoperative outcomes. The primary outcome was postoperative cognitive dysfunction (POCD), with secondary outcomes that included postoperative delirium, length of intensive care unit (ICU) stay, and hospital length of stay (LOS). SOURCE: After searching the PubMed, EMBASE, Cochrane Library, Scopus, and Google Scholar databases, all randomized controlled trials (RCTs) assessing the impact of intraoperative cerebral oximetry-guided management on clinical outcomes following surgery were identified. PRINCIPAL FINDINGS: Fifteen RCTs comprising 2,057 patients (1,018 in the intervention group and 1,039 in control group) were included. Intraoperative management guided by the use of cerebral oximetry was associated with a reduction in the incidence of POCD (risk ratio [RR] 0.54; 95% confidence interval [CI], 0.33 to 0.90; P = 0.02; I2 = 85%) and a significantly shorter length of ICU stay (standardized mean difference [SMD], -0.21 hr; 95% CI, -0.37 to -0.05; P = 0.009; I2 = 48%). In addition, overall hospital LOS (SMD, -0.06 days; 95% CI, -0.18 to 0.06; P = 0.29; I2 = 0%) and incidence of postoperative delirium (RR, 0.69; 95% CI, 0.36 to 1.32; P = 0.27; I2 = 0%) were not impacted by the use of intraoperative cerebral oximetry. CONCLUSIONS: Intraoperative cerebral oximetry appears to be associated with a reduction in POCD, although this result should be interpreted with caution given the significant heterogeneity in the studies examined. Further large (ideally multicentre) RCTs are needed to clarify whether POCD can be favourably impacted by the use of cerebral oximetry-guided management.

Determining the Upper and Lower Limits of Cerebral Autoregulation With Cerebral Oximetry Autoregulation Curves: A Case Series.

OBJECTIVE: Critical care guidelines recommend a single target value for mean arterial blood pressure in critically ill patients. However, growing evidence regarding cerebral autoregulation challenges this concept and supports individualizing mean arterial blood pressure targets to prevent brain and kidney hypo- or hyperperfusion. Regional cerebral oxygen saturation derived from near-infrared spectroscopy is an acceptable surrogate for cerebral blood flow and has been validated to measure cerebral autoregulation. This study suggests a novel mechanism to construct autoregulation curves based on near-infrared spectroscopy-measured cerebral oximetry. DESIGN: Case-series study. SETTING: Neurocritical care unit in a tertiary medical center. PATIENTS: Patients with acute neurologic injury and Glasgow coma scale score less than or equal to 8. MEASUREMENTS AND MAIN RESULTS: Autoregulation curves were plotted using the fractional-polynomial model in Stata after multimodal continuous monitoring of regional cerebral oxygen saturation and mean arterial blood pressure. Individualized autoregulation curves of seven patients exhibited varying upper and lower limits of autoregulation and provided useful clinical information on the autoregulation trend (curves moving to the right or left during the acute coma period). The median lower and upper limits of autoregulation were 86.5 mm Hg (interquartile range, 74-93.5) and 93.5 mm Hg (interquartile range, 83-99), respectively. CONCLUSIONS: This case-series study showed feasibility of delineating real trends of the cerebral autoregulation plateau and direct visualization of the cerebral autoregulation curve after at least 24 hours of recording without manipulation of mean arterial blood pressure by external stimuli. The integration of multimodal monitoring at the bedside with cerebral oximetry provides a noninvasive method to delineate daily individual cerebral autoregulation curves.

Epidemiology of septic meningitis associated with neuraxial anesthesia: a historical review and meta-analysis.

INTRODUCTION: Neuraxial anesthesia in the form of spinal and epidural are two of the most frequent forms of regional anesthesia. We aimed to describe and compare the relevant epidemiological, clinical and microbiological characteristics of all reported cases of septic meningitis associated with the use of spinal and epidural anesthetics. EVIDENCE ACQUISITION: We performed a systematic review of septic meningitis associated with neuraxial anesthesia. We included all relevant case-reports and observational studies in which authors described septic meningitis in association with spinal, epidural or combined neuraxial anesthesia using local anesthetics. EVIDENCE SYNTHESIS: A total of 234 cases of septic meningitis were reported following review of 71 case-report articles and 22 epidemiological studies. In total, there have been 199, 25 and 10 reported cases of septic meningitis associated to spinal, epidural and combined neuraxial anesthesia, respectively. The lack of use of surgical masks was the most common risk factor (41, 16.7%). Streptococcus salivarius was the most common bacteria (17.0%) related to spinal anesthesia and Staphylococcus aureus (26.7%) was the most common one related to epidural. The time to symptom onset was significantly reduced in spinal (median time, 24 hours IQR [8-72] vs. 96 hours IQR [84-240]; P=0.003) compared to epidural anesthesia. The overall mortality rate is 15.3% and 13.3% for reported cases related to spinal and epidural anesthesia, respectively. CONCLUSIONS: While the true incidence remains speculative, this review suggests that given increasing indications for spinals and epidurals, septic meningitis remains an important associated with neuraxial anesthesia.

Validation of Near-Infrared Spectroscopy for Monitoring Cerebral Autoregulation in Comatose Patients.

BACKGROUND: Transcranial Doppler (TCD) noninvasively measures cerebral blood flow (CBF) velocity and is a well-studied method to monitor cerebral autoregulation (CA). Near-infrared spectroscopy (NIRS) has emerged as a promising noninvasive method to determine CA continuously by using regional cerebral oxygen saturation (rSO2) as a surrogate for CBF. Little is known about its accuracy to determine CA in patients with intracranial lesions. The purpose of this study was to assess the accuracy of rSO2-based CA monitoring with TCD methods in comatose patients with acute neurological injury. METHODS: Thirty-three comatose patients were monitored at the bedside to measure CA using both TCD and NIRS. Patients were monitored daily for up to three days from coma onset. The cerebral oximetry index (COx) was calculated as the moving correlation between the slow waves of rSO2 and mean arterial pressure (MAP). The mean velocity index (Mx) was calculated as a similar coefficient between slow waves of TCD-measured CBF velocity and MAP. Optimal blood pressure was defined as the MAP with the lowest Mx and COx. Averaged Mx and COx as well as optimal MAP, based on both Mx and COx, were compared using Pearson's correlation. Bias analysis was performed between these same CA metrics. RESULTS: The median duration of monitoring was 60 min (interquartile range [IQR] 48-78). There was a moderate correlation between the averaged values of COx and Mx (R = 0.40, p = 0.005). Similarly, there was a strong correlation between optimal MAP calculated for COx and Mx (R = 0.87, p < 0.001). Bland-Altman analysis showed moderate agreement with bias (±standard deviation) of -0.107 (±0.191) for COx versus Mx and good agreement with bias of 1.90 (±7.94) for optimal MAP determined by COx versus Mx. CONCLUSIONS: Monitoring CA with NIRS-derived COx is correlated and had good agreement with previously validated TCD-based method. These results suggest that COx may be an acceptable substitute for Mx monitoring in patients with acute intracranial injury.

Cerebral Autoregulation-oriented Therapy at the Bedside: A Comprehensive Review.

This comprehensive review summarizes the evidence regarding use of cerebral autoregulation-directed therapy at the bedside and provides an evaluation of its impact on optimizing cerebral perfusion and associated functional outcomes. Multiple studies in adults and several in children have shown the feasibility of individualizing mean arterial blood pressure and cerebral perfusion pressure goals by using cerebral autoregulation monitoring to calculate optimal levels. Nine of these studies examined the association between cerebral perfusion pressure or mean arterial blood pressure being above or below their optimal levels and functional outcomes. Six of these nine studies (66%) showed that patients for whom median cerebral perfusion pressure or mean arterial blood pressure differed significantly from the optimum, defined by cerebral autoregulation monitoring, were more likely to have an unfavorable outcome. The evidence indicates that monitoring of continuous cerebral autoregulation at the bedside is feasible and has the potential to be used to direct blood pressure management in acutely ill patients.

Impact of intraoperative cefazolin on postoperative seizures after elective repair of unruptured cerebral aneurysm.

PURPOSE: The impact of intraoperative cefazolin on postoperative seizures after elective repair of an unruptured cerebral aneurysm was evaluated. METHODS: Chart review of a prospectively accrued database was performed for patients admitted from January 1, 2003, through December 31, 2013. Patients were included in the study if they underwent elective repair of an unruptured aneurysm with surgical clipping or wrapping. The primary objective was to determine if the use of cefazolin increased patients' odds of having a seizure within six hours of surgical intervention. Univariate comparisons were conducted on all variables for patients who received cefazolin and patients who were treated with other antibiotics. Multivariable logistic regression was performed to assess the impact of cefazolin administered intraoperatively on postoperative seizures, while accounting for other covariates. RESULTS: Of the 520 patients included, 53 (10.2%) patients developed seizures within six hours after surgery. A total of 439 (84.4%) patients received cefazolin intraoperatively. There were no differences in baseline characteristics between the patients who received cefazolin compared with those who did not. The frequency of seizures did not significantly differ between patients treated with cefazolin versus other antibiotics (11.2% versus 4.9%, respectively; p = 0.08). Multivariable regression revealed that the use of cefazolin did not increase the odds of having a seizure postoperatively compared with patients treated with other antibiotics (odds ratio, 2.4; 95% confidence interval, 0.82-7.15). CONCLUSION: No relationship was found between the intraoperative use of cefazolin and the development of seizures during the six hours after the repair of unruptured cerebral aneurysms.

A Comparison of Regional Versus General Anesthesia for Lumbar Spine Surgery: A Meta-Analysis of Randomized Studies.

BACKGROUND: General anesthesia (GA) is commonly used for lumbar spine surgery. The advantages of regional anesthesia (RA) for lumbar spine surgery, as compared with GA, remain unclear. The aim of this meta-analysis was to determine the impact of the type of anesthesia on intraoperative events, incidence of postoperative complications, and recovery time of patients undergoing lumbar spine surgery. METHODS: Major databases (PubMed, EMBASE, Cochrane library, ISI Web of Science, and Google Scholar) were systematically searched for randomized clinical trials comparing regional versus GA for lumbar spine surgery. Study-level characteristics, intraoperative events, and postoperative complications were extracted from the articles. Meta-analysis was performed using random-effect models. RESULTS: Fifteen randomized clinical trials comprising 961 patients were included in this meta-analysis. The use of RA for lumbar spine surgery was significantly associated with lower incidence of postoperative nausea and vomiting at 24 hours (risk ratio [RR]=0.42; 95% confidence interval [CI]=0.23-0.77, P=0.005), as well as lower length of stay (standardized mean difference [SMD]=-0.73; 95% CI=-1.17 to -0.29, P=0.001) and intraoperative blood loss (SMD=-1.24; 95% CI=-2.27 to -0.21, P=0.02). There was no statistically significant association with lower pain score (SMD=-0.47; 95% CI=-2.13 to 1.19, P=0.58), lower incidence of urinary retention (RR=1.16; 95% CI=0.73-1.86, P=0.53) or analgesic requirement (RR=0.87; 95% CI=0.64-1.18, P=0.37). CONCLUSIONS: In summary, RA has several advantageous characteristics, including lower incidence of postoperative nausea and vomiting, length of stay, and blood loss. Further well-designed studies with more sample size are needed to clarify the associations with possible neurological complications.

Predicting the need for nonstandard tracheostomy tubes in critically ill patients.

PURPOSE: Few guidelines exist regarding the selection of a particular type or size of tracheostomy tube. Although nonstandard tubes can be placed over the percutaneous kit dilator, clinicians often place standard tracheostomy tubes and change to nonstandard tubes only after problems arise. This practice risks early tracheostomy tube change, possible bleeding, or loss of the airway. We sought to identify predictors of nonstandard tracheostomy tubes. MATERIALS AND METHODS: In this matched case-control study at an urban, academic, tertiary care medical center, we reviewed 1220 records of patients who received a tracheostomy. Seventy-seven patients received nonstandard tracheostomy tubes (cases), and 154 received standard tracheostomy tubes (controls). RESULTS: Sex, endotracheal tube size, severity of illness, and computed tomography scan measurement of the distance from the trachea to the skin at the level of the superior aspect of the anterior clavicle were significant predictors of nonstandard tracheostomy tubes. Specifically, trachea-to-skin distance >4.4 cm and endotracheal tube sizes ≥8.0 were associated with nonstandard tracheostomy. CONCLUSIONS: The findings suggest that clinicians should consider using nonstandard tracheostomy tubes as the first choice if the patient is male with an endotracheal tube size ≥8.0 and has a trachea-to-skin distance >4.4 cm on the computed tomography scan.