Preoperative serum potassium predicts the clinical outcome after non-cardiac surgery.

BACKGROUND: Potassium disorders have been linked to adverse outcomes in various medical conditions. However, the association of preoperative serum potassium with postoperative outcome is not well established. We aimed to examine the association between preoperative potassium with a 30-day mortality and adverse cardiovascular event (MACE). METHODS: We conducted a cohort study using a prospectively collected database of patients, undergoing surgical procedures from 1998 to 2013 in the VA Western New York Healthcare System, which are reported to the Veterans Affairs Surgical Quality Improvement Program (VASQIP). The patients were categorized into three groups based on their documented preoperative potassium concentrations. Hypokalemia was defined as serum potassium concentration <4 mmol/L and hyperkalemia was defined as serum potassium concentrations >5.5 mmol/L. The values within the range of 4.0-5.5 mmol/L were considered as normokalemia and used as the control group. Statistical analyses included Chi-square test, analysis of variance and multivariate logistic regression to estimate the risk of MACE within 30 days of surgery. RESULTS: Study included 5959 veterans who underwent surgery between 1998 and 2013. The patients in the hyperkalemics group had lower kidney function compared to the other two groups. The frequency of MACE was 13.6% in hypokalemics and 21.9% in hyperkalemics that were both significantly higher than 4.9% in controls. In multivariate logistic regression the hazard risk (HR) ratios of MACE were (2.17, 95% CI 1.75-2.70) for hypokalemics and (3.23, 95% CI 2.10-4.95) for hyperkalemics when compared to normokalemic controls. CONCLUSIONS: Preoperative hypokalemia and hyperkalemia are both independent predictors of MACE within 30 days.

Impact of Sedation on Cognitive Function in Mechanically Ventilated Patients.

The practice of sedation dosing strategy in mechanically ventilated patient has a profound effect on cognitive function. We conducted a comprehensive review of outcome of sedation on mental health function in critically ill patients on mechanical ventilation in the intensive care unit (ICU). We specifically evaluated current sedative dosing strategy and the development of delirium, post-traumatic stress disorders (PTSDs) and agitation. Based on this review, heavy dosing sedation strategy with benzodiazepines contributes to cognitive dysfunction. However, outcome for mental health dysfunction is mixed in regard to newer sedatives agents such as dexmedetomidine and propofol. Moreover, studies that examine the impact of sedatives for persistence of PTSD/delirium and its long-term cognitive and functional outcomes for post-ICU patients are frequently underpowered. Most studies suffer from low sample sizes and methodological variations. Therefore, larger randomized controlled trials are needed to properly assess the impact of sedation dosing strategy on cognitive function.

Applications of Nasal High-Flow Oxygen Therapy in Critically ill Adult Patients.

The use of nasal high-flow oxygen therapy (NHFOT) has become increasingly common in hospitals across Europe, Asia, and North America. These high utility devices provide an efficient and comfortable access points for providing supplemental oxygen to patients with variety of respiratory disorders. They are relatively easy to set up, and clinicians and patients alike give very positive feedback about their ease of use and comfort for patients in the hospital setting. However, it remains uncertain whether NHFOT improves patient survival or even reduces respiratory complications. Outcome data in adult populations are few and frequently underpowered to guide physicians for their widespread use in hospital setting. In this article, we present a review of the current technology and available studies pertinent to NHFOT.

A systematic review of GLP-1 agonists on the metabolic syndrome in women with polycystic ovaries.

PURPOSE: Glucagon-like peptides receptor agonists are currently approved as anti-obesity agents, yet the experience with their use in polycystic ovarian syndromes (PCOS)-related obesity and insulin resistance is still limited. METHODS: We examined the effects of liraglutide on obesity, insulin resistance, and androgen levels in PCOS through a meta-analysis. RESULTS: Seven RCTs where women with PCOS were treated with liraglutide were identified. The variables that were examined before and after a 90-day treatment included waist circumference, body mass index (BMI), fasting insulin concentrations, insulin resistance using homeostatic model (HOMA-IR), serum testosterone, and sex hormone-binding globulin (SHBG). The analysis included 178 women. Only 172 patients had post-treatment measurements. While BMI significantly dropped by -1.65 (0.72-2.58) Kg/m(2) after 3 months treatment with liraglutide, waist circumference did not change significantly. Similarly, fasting insulin levels, insulin sensitivity, and SHBG did not change significantly. However, serum testosterone decreased by 0.29 nmol/L in 88 women (P = 0.0003). CONCLUSION: In a limited number of the women with PCOS, BMI and serum testosterone are only variables that significantly decrease after 3 months of treatment with GLP-1 receptor agonists. Larger sample size studies with longer durations of treatment may be required to examine potential benefits of these medications in improving insulin sensitivity.

The role of perioperative transfusion on long-term survival of veterans undergoing surgery.

OBJECTIVE: To examine the influence of perioperative blood transfusions on perioperative outcomes and late survival. BACKGROUND: Perioperative blood transfusion has been reported to have a negative impact on perioperative morbidity but its long-term effect on survival is unknown. The purpose of this study was to evaluate the effects of perioperative transfusion on perioperative outcomes and survival. METHODS: We studied 12,345 surgical procedures from Veteran Administration Surgical Quality Improvement Program database from July 1998 through 2010. Patients with transfusion were compared with a severity-matched control group. We performed the Fisher exact test for comparison of categorical values and Wilcoxon rank sum test for continuous values. Multivariate regression was used to eliminate other confounding factors. The predictive value of multivariate risk model was tested with receiver-operator curves. Patients were matched using an optimal 1:1 digit-matching algorithm. All analyses were performed with NCSS-2007 version 1-12. P < 0.05 was considered statistically significant. RESULTS: The 848 patients who received perioperative transfusions had higher unadjusted rates of mortality and decreased long-term survival. The odds ratio (OR) for 10 years mortality in transfused group was 2.92 and after adjusting for preoperative risk factors decreased to 1.40 (P < 0.01). However, after data were filtered for any perioperative complications, such an association was seen before, OR = 2.05 (P = 0.006), and was lost after propensity matching, OR = 1.19 (P = 0.35). CONCLUSIONS: After filtering out perioperative complications and adjusting for preoperative morbidity, our final analysis did not reveal an increased long-term mortality. We conclude that transfusion may reduce long-term survival through its effects on perioperative complications.

THE IMPACT OF ENDOTRACHEAL TUBE VS. LARYNGEAL MASK AIRWAY ON THE INCIDENCE OF POSTOPERATIVE NAUSEA AND VOMITING: A SYSTEMIC REVIEW AND META-ANALYSIS.

OBJECTIVE: To investigate the impact of Endotracheal tube (ETT) vs. Laryngeal Mask Airway (LMA) on postoperative nausea and vomiting (PONV) in patients undergoing surgery with general anesthesia. METHODS: Key words searching from databases such as Medline, Embase, and Cochrane library provided 14 studies focusing on the use of EET vs. LMA for general anesthesia. Pooled estimate of relative risk with 95% confidence interval using random effect model was conducted. RESULTS: 14 studies were selected for meta-analysis with a total of 1866 patients. 9 studies focused on the outcome of PONV in adult patients. It showed incidence of PONV with of LMA and ETT in adult of about 204/690 (30%) and 145/725 (20%) respectively with [Odds Ratio (OR) = 1.69, 95% CI, 0.76-3.75, P = 0.20]. Heterogeneity was high (I2 = 87%). Five studies focused on the outcome of PONV in pediatric patients with PONV in LMA and ETT group of 85/229 (37%) and 72/222 (32%) respectively with (OR = 1.30, 95% CI, 0.61-2.76, P = 0.50). Heterogeneity was moderate at (I2 = 53%). When all patients were combined heterogeneity was high at 81% with OR = 1.56, 95% CI, 0.87-2.79, P = 0.14. CONCLUSION: Risk of PONV shows an increase trend toward the use of LMA. Larger randomized trials are needed to assess the impact of airway devices on PONV.

Respiratory perioperative management of patients with obstructive sleep apnea.

Obstructive sleep apnea (OSA) has become a major public health problem in the United State and Europe. However, perioperative strategies regarding diagnostic options and management of untreated OSA remain inadequate. Preoperative screening and identification of patients with undiagnosed OSA may lead to early perioperative interventions that may alter cardiopulmonary events associated with surgery and anesthesia.(1) Hence, clinicians need to become familiar with the preoperative screening and diagnosis of OSA. Perioperative management of a patient with OSA should be modified and may include regional anesthesia and alternative analgesic techniques such as nonsteroidal anti-inflammatory drugs that may reduce the need for systemic opioids. Additionally, supplemental oxygen and continuous pulse oximetry monitoring should be utilized to maintain baseline oxygen saturation. Postoperatively patients should remain in a semi-upright position and positive pressure therapy should be used in patients with high-risk OSA.

Early versus late initiation of renal replacement therapy in critically ill patients with acute kidney injury after cardiac surgery: a systematic review and meta-analysis.

OBJECTIVE: To investigate the impact of early versus late renal replacement therapy (RRT) on mortality in patients with acute kidney injury (AKI) after cardiac surgery. DESIGN: Meta-analysis of 9 retrospective cohort studies and 2 randomized clinical trials extracted from the Medline engine from 1950 to 2013. SETTING: University medical school. PARTICIPANTS: 841 Patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 841 patients were studied. Pooled estimates of the odds ratio with 95% confidence interval using a random-effect model were conducted as well as the heterogeneity, publication bias, and sensitivity analysis. Primary outcome was 28-day mortality, and secondary outcome was the intensive care unit (ICU) length of stay. The 28-days mortality rate was lower in the early RRT group (OR = 0.29, 95% CI, 0.16-0.52, p<0.0001, NNT = 5). Heterogeneity was high (I2 = 56%), and publication bias was low. Secondary outcome suggested 3.9 (1.5-6.3) days shorter ICU stay in the early RRT group, p<0.0001, with extremely high heterogeneity (I(2) = 99%), and low publication bias. Specifically, studies before 2000 and studies with mortality less than 50% in the late RRT group reported significantly higher odds ratio and mean difference than overall value favoring early RRT. CONCLUSION: Early initiation of RRT for patients with AKI after cardiac surgery revealed lower 28-days mortality and shorter ICU length of stay. However, this was based on 11 studies of various qualities with very high heterogeneity of results. Defining treatment guidelines needs further research with a larger and better database.

Bacterial and clinical characteristics of health care- and community-acquired bloodstream infections due to Pseudomonas aeruginosa.

Health care-associated infections, including Pseudomonas aeruginosa bloodstream infection, have been linked to delays in appropriate antibiotic therapy and an increased mortality rate. The objective of this study was to evaluate intrinsic virulence, bacterial resistance, and clinical outcomes of health care-associated bloodstream infections (HCABSIs) in comparison with those of community-acquired bloodstream infections (CABSIs) caused by P. aeruginosa. We conducted a retrospective multicenter study of consecutive P. aeruginosa bacteremia patients at two university-affiliated hospitals. Demographic, clinical, and treatment data were collected. Microbiologic analyses included in vitro susceptibility profiles and type III secretory (TTS) phenotypes. Sixty CABSI and 90 HCABSI episodes were analyzed. Patients with HCABSIs had more organ dysfunction at the time of bacteremia (P = 0.05) and were more likely to have been exposed to antimicrobial therapy (P < 0.001) than those with CABSIs. Ninety-two percent of the carbapenem-resistant P. aeruginosa infections were characterized as HCABSIs. The 30-day mortality rate for CABSIs was 26% versus 36% for HCABSIs (P = 0.38). The sequential organ failure assessment score at the time of bacteremia (hazard ratio [HR], 1.2; 95% confidence interval [CI], 1.1 to 1.3) and the TTS phenotype (HR 2.1; 95% CI, 1.1 to 3.9) were found to be independent predictors of the 30-day mortality rate. No mortality rate difference was observed between CABSIs and HCABSIs caused by P. aeruginosa. Severity of illness and expression of TTS proteins were the strongest predictors of the 30-day mortality rate due to P. aeruginosa bacteremia. Future P. aeruginosa bacteremia trials designed to neutralize TTS proteins are warranted.

Pre- and post-intervention study to assess the impact of a sedation protocol in critically ill surgical patients.

INTRODUCTION: Sedation and pain management for mechanically ventilated critically ill surgical patients pose many challenges for the intensivist. Even though daily interruption of sedatives and opioids is appropriate in medical intensive care unit (ICU) patients, it may not be feasible in the surgical patients with pain from surgical incision or trauma. Therefore we developed an analgesia/sedation based protocol for the surgical ICU population. METHODS: We performed a two-phase prospective observational control study. We evaluated a prescriber driven analgesia/sedation protocol (ASP) in a 12-bed surgical ICU. The pre-ASP group was sedated as usual (n = 100) and the post-ASP group was managed with the new ASP (n = 100). Each phase of the study lasted for 5 mo. Comparisons between the two groups were performed by χ(2) or Fisher's exact test for categorical variables and the Mann-Whitney test for nonparametric variables. A P value <0.05 was statistically significant. RESULTS: We found a significant reduction in the use of fentanyl (P < 0.001) and midazolam (P = 0.001). We achieved sedation goals of 86.8% in the post-ASP group compared to 74.4% in the pre-ASP (P < 0.001). Mean mechanical ventilations days in pre- and post-ASP group were 5.9 versus 3.8 (P = 0.033). CONCLUSION: In our cohort of critically ill surgery patients implementation of an ASP resulted in reduced use of continuously infused benzodiazepines and opioids, a decline in cumulative benzodiazepine and analgesic dosages, and a greater percentage of Richmond Agitation Sedation Scale scores at goal. We also showed reduced mechanical ventilation days.

Biomarkers of lung injury in critical care medicine: past, present, and future.

Acute lung injury is defined as inadequate oxygenation of the blood due to primary and secondary injuries of the lungs that limit normal gas exchange across the alveolar capillary membrane. The etiology of this clinical syndrome is generally either infectious or non-infectious. Early detection of the underlying pathophysiology of the disease and timely initiation of antibiotic therapy is crucial for treatment of infectious causes of acute lung injury. Inflammatory biomarkers have recently gained popularity in critical care medicine to differentiate these two clinically similar entities. We have reviewed a variety of biomarkers related to acute lung injury and their relative value in early diagnosis and management of these patients.

Guideline-concordant antimicrobial therapy for healthcare-associated pneumonia: a systematic review and meta-analysis.

BACKGROUND: The objective of this study was to perform a systematic review and meta-analysis of the impact of the 2005 American Thoracic Society/Infectious Diseases Society of America guideline-concordant antimicrobial therapy (GCAT) on mortality following healthcare-associated pneumonia (HCAP). METHODS: We searched MEDLINE, EMBASE, BIOSIS, Cochrane CENTRAL Register of Controlled Trials, and Scopus for clinical trials and observational studies comparing GCAT to other treatment regimens in adults with HCAP. The primary outcome chosen was 30-day mortality from any cause. Secondary outcomes assessed length of hospital stay and time to clinical stability. Random effects models were used to generate pooled odds ratios (ORs) and weighed mean differences (WMDs). Heterogeneity was evaluated by the I(2). RESULTS: A total of six studies were included in the analysis and involved 15,850 participants. Meta-analysis showed that GCAT was associated with increased 30-day mortality compared to non-GCAT (OR 1.80, 95 % confidence interval [CI] 1.26-2.7). There was no advantage in GCAT over non-GCAT in terms of hospital length of stay (WMD 1.18 days, 95 % CI -0.48 to 2.84) or time to clinical stability (WMD 0.17 days, 95 % CI -0.32 to 0.67). CONCLUSION: In hospitalized patients with HCAP, GCAT did not show survival benefit compared to non-GCAT. However, our results are limited by the cohort design of the selected studies and the degree of heterogeneity among them. Future trials are needed to identify risk factors for multidrug-resistant pathogens in HCAP patients who may benefit from broad-spectrum antimicrobial regimens.

Effects of dietary weight loss on obstructive sleep apnea: a meta-analysis.

PURPOSE: Clinical and epidemiologic investigations suggest a strong association between obesity and obstructive sleep apnea (OSA). The purpose of this study is to evaluate the currently available literature reporting on the effectiveness of dietary weight loss in treating OSA among obese patients. METHODS: Relevant studies were identified by computerized searches of PubMed, EMBASE, CINAHL, Web of Science, and The Cochrane Central Register of Controlled Trials through September 2011 as well as the reference lists of all obtained articles. Information on study design, patient characteristics, pre- and post-dietary weight loss measures of OSA and body mass index (BMI), and study quality was obtained. Data were extracted by two independent analysts. Weighted averages using a random-effects model are reported with 95 % confidence intervals. RESULTS: Nine articles representing 577 patients were selected. Dietary weight loss program resulted in a pooled mean BMI reduction of 4.8 kg/m(2) (95 % confidence interval [CI] 3.8-5.9). The random-effects pooled apnea hypopnea (AHI) indices at pre- and post-dietary intervention were 52.5 (range 10.0-91.0) and 28.3 events/h (range 5.4-64.5), respectively (p < 0.001). Compared to control, the weighted mean difference of AHI was decreased by -14.3 events/h (95 % CI -23.5 to -5.1; p = 0.002) in favor of the dietary weight loss programs. CONCLUSIONS: Dietary weight loss programs are effective in reducing the severity of OSA but not adequate in relieving all respiratory events. Weight reduction programs should be considered as adjunct rather than curative therapy.

Weaning failure: my heart is not up to it.

Weaning patients from mechanical ventilation has been compared to a cardiac stress test. Weaning failure (WF) from a cardiac origin can be common in patients with limited cardiac reserve. Diuretic and vasodilator therapies are indicated for WF due to excessive preload, afterload, or myocardial ischemia. Alteration in intrathoracic pressure and lung volumes may also impact weaning process in a patient with poor cardiac function. Noninvasive ventilation decreases cardiac stress load and should be utilized in weaning patients with poor cardiac reserves. In fact, positive pressure therapy is now the standard of care for treating a patient with acute pulmonary edema and to decrease afterload (Frazier et al. Biol Res Nurs 2000; 1(4): 253-264; Pinsky MR. Chest 2005; 128(5 Suppl 2): 592S-597S.). Recently, biomarkers and echocardiography have been utilized to assess weaning success during spontaneous breathing trials. In this article, we describe the physiological alterations in cardiac and pulmonary systems during the weaning process and its impact on weaning outcome.

Echocardiography guided therapy for massive intra-operative pulmonary emboli during arterio-venous fistula/graft thrombectomy.

Various techniques' are currently employed for thrombectomies of the arterio-venous (AV) fistula/graft to restore flow. Sub massive or massive pulmonary emboli's have been reported following such procedures both intra-operatively and post-operatively. The hemodynamic responses depend not only on the size of the emboli's but also on the pre existing cardiac or pulmonary reserve of the patient. Rapid intra-operative echocardiography by anesthesiologist not only will help the clinicians with diagnosis but also can guide treatment plan as well as prognosis.

Do the choices of airway affect the post-anesthetic occurrence of nausea after knee arthroplasty? A comparison between endotracheal tubes and laryngeal mask airways.

OBJECTIVES: The primary goal of this study was to assess the impact of airway devices on the incidence of nausea after knee arthroplasty and their interaction with the use of nitrous oxide. METHODS: Charts were reviewed for 499 patients after knee arthroplasty under general anesthesia. Demographic data, type of airway device, nitrous oxide, sevoflurane, desflurane, isoflurane, fentanyl, metoclopramide, ondansetron, dexamethasone, rocuronium and neostigmine were analyzed. Fisher's exact test was used to compare the categorical factors and t-test was used for continuous variables. Sinclair scores were used for post-operative nausea and vomiting (PONV) risk stratification. Multivariate logistic regression model was constructed to identify the factors contributing to the frequency of PONV. RESULTS: PONV was documented in 10.3% of patients. Nitrous oxide was associated with a higher frequency of PONV than those received air mixture (12.5% vs. 8.7%, P < 0.01). Prior to risk stratification, the frequency of PONV was 17% in the endotracheal tube (ETT) vs. 6.7% in the laryngeal mask airway (LMA) group (P < 0.01). Sinclair score was 0.51 +/- 0.17 for the ETT group and 0.74 +/- 0.12 for the LMA group (P < 0.001). After risk stratification and matching, the incidence of PONV was 15.8% with the use of ETT compared with 7.9% for LMA (P < 0.05). CONCLUSION: The frequency of PONV was almost twice with ETT as with LMA. Longer duration of anesthesia, neuromuscular blockade and non-standardized antiemetic regimen may have contributed to the increase PONV in ETT group. Prospective randomized studies are necessary to further explore whether and to which extend airway devices influence the incidence of PONV.

The use of practice guidelines by the American Society of Anesthesiologists for the identification of surgical patients at high risk of sleep apnea.

American Society of Anesthesiologists (ASA) has introduced a simple tool to assess the perioperative risk of surgery/anesthesia in patients with obstructive sleep apnea (OSA). We compared the surgical outcomes in patients at high risk of OSA with the matched controls. This was a case-control study conducted on 3593 surgical patients receiving a general anesthesia at a single institution. On the basis of a preoperative OSA scoring system using the ASA checklist, patients were classified as high-risk OSA (HR-OSA) or low-risk OSA (LR-OSA) groups. Apnea/hypopnea index of >5 h(-1) during a formal preoperative sleep study was used to confirm or rule out the diagnosis of OSA. Receiver operating characteristic curves were plotted to determine the predictive values as well as sensitivity and specificity of the ASA tool in predicting HR-OSA. The HR-OSA group was matched with the patients in LR-OSA using the propensity scoring and logistic regression. Patients were analyzed for premorbid conditions, intraoperative course and postoperative events using cross tabulation, logistic regression model and paired t test. The development of a composite respiratory complication in the postoperative period was considered as the primary end point. The ASA risk tool was found to have 95.1% sensitivity and 52.2% specificity. At a prevalence of 10%, the negative predictive value was 98.5%. Of the 3593 patients, 306 were identified as HR-OSA. The HR-OSA group was found to have a higher incidence of hypertension and diabetes preoperatively when compared with LR-OSA. Postoperatively, the HR-OSA group had higher incidence of hypoxia, reintubation, postoperative use of continuous positive airway pressure and a longer stay in the recovery room. The ASA checklist offers a highly sensitive tool to identify the patients at a higher risk of OSA during the perioperative period. Patients at HR-OSA have a higher incidence of adverse events in the postoperative period when compared with those with LR-OSA.

Acute quadriplegia after interscalene block secondary to cervical body erosion and epidural abscess.

Although the incidence of neurological complications after shoulder surgery with regional anesthesia remains low but serious negative outcomes have been reported in the literature. Here we report a case of acute quadriplegia secondary to cervical epidural abscess and possible neck manipulation.