Jahan Porhomayon

Postoperative complications in patients with obstructive sleep apnea: a meta-analysis

STUDY OBJECTIVE To determine whether a diagnosis of obstructive sleep apnea (OSA) imparts an increased risk of postoperative respiratory failure, cardiac events, and intensive care unit (ICU) transfer than patients with no OSA diagnosis. DESIGN Systematic review and meta-analysis. SETTING Academic Veterans Affairs Medical Center. MEASUREMENTS PubMed, EMBASE, CINAHL, and ISI Web of Knowledge databases were searched through April 2013 for studies that examined the relationship between OSA and postoperative respiratory and cardiac complications among adults. Either fixed or random-effects models were used to calculate the pooled risk estimates. Sensitivity analysis was conducted to examine the robustness of pooled outcomes. MAIN RESULTS Seventeen studies with a total of 7,162 patients were included. Overall, OSA was associated with significant increase in risk of respiratory failure [odds ratio (OR) 2.42; 95% confidence intervals (CI) 1.53 - 3.84; P = 0.0002] and cardiac events postoperatively (OR = 1.63; 95% CI 1.16 - 2.29; P = 0.005). Heterogeneity was low for these outcomes (I(2) = 5% and 0%, respectively). ICU transfer occurred also more frequently in patients with OSA (OR 2.46; 95% CI 1.29 - 4.68; P = 0.006). These results did not materially change in the sensitivity analyses according to various inclusion criteria. CONCLUSIONS Surgical patients with OSA are at increased risk of postoperative respiratory failure, cardiac events, and ICU transfer.

Sleep disorders in morbid obesity

The increasing prevalence of obesity has lead to an increase in the prevalence of sleep disordered breathing in the general population. The disproportionate structural characteristics of the pharyngeal airway and the diminished neural regulation of the pharyngeal dilating muscles during sleep predispose the obese patients to pharyngeal airway collapsibility. A subgroup of obese apneic patients is unable to compensate for the added load of obesity on the respiratory system, with resultant daytime hypercapnia. Weight loss using dietary modification and life style changes is the safest approach to reducing the severity of sleep apnea, but its efficacy is limited on the long run. Although it has inherent risks, bariatric surgery provides the most immediate result in alleviating sleep apnea. Obesity has been linked also to narcolepsy. The loss of neuropeptides co-localized in hypocretin neurons is suggested as the potential mechanism. Poor sleep quality, which leads to overall sleep loss and excessive daytime sleepiness has also become a frequent complaint in this population. Identifying abnormal nocturnal eating is critically important for patient care. Both sleep related eating disorder and night eating syndrome are treatable and represent potentially reversible forms of obesity.

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.

Pneumonia immunization in older adults: review of vaccine effectiveness and strategies.

Vaccination remains the primary preventive strategy in the elderly against Streptococcus pneumoniae and influenza infections. The effectiveness of this strategy in preventing pneumonia has been in doubt despite the increase in vaccination coverage among older adults. Randomized controlled trials (RCTs) and observational studies aimed at determining clinical outcomes and immune response following pneumococcal vaccination have yielded conflicting results. The protective efficacy of pneumococcal vaccination against pneumonia in older adults has not been firmly established due to a lack of RCTs specifically examining patients ≥ 65 years of age. Similarly, the reported benefits of influenza vaccination have been derived from observational data. The assessment of clinical benefit from influenza vaccination in the elderly population is complicated by varying cohorts, virulence of the influenza strain, and matching of vaccine and circulating viral strains. The presence of selection bias and use of nonspecific end points in these studies make the current evidence inconclusive in terms of overall benefit. The development of more immunogenic vaccines through new formulations or addition of adjuvants holds the promise of revolutionizing delivery and improving efficacy. Dismantling existing barriers through education, providing technology assistance predominantly to developing countries, and establishing clear regulatory guidance on pathways for approval are necessary to ensure timely production and equitable distribution.

Strategies in postoperative analgesia in the obese obstructive sleep apnea patient.

Objective:Obstructive sleep apnea (OSA) has become an epidemic worldwide, and OSA patients frequently present for surgery. Comorbidities such as cardiovascular disease, diabetes, hypertension, stroke, gastrointestinal disorder, metabolic syndrome, chronic pain, delirium, and pulmonary disorder increase the perioperative risk for OSA patients. Methods:This is a narrative review of the impact of sedative and analgesic therapy on the intraoperative and postoperative course of an obese OSA patient. Results:An understanding of postoperative complications related to OSA and drug interactions in the context of opioid and nonopioid selection may benefit pain practitioner and patients equally. Conclusions:Management of acute postoperative pain in OSA patient remains complex. A comprehensive strategy is needed to reduce the complications and adverse events related to administration of analgesics and anesthetics.

Bacterial and Clinical Characteristics of Health Care- and Community-Acquired Bloodstream Infections Due to Pseudomonas aeruginosa

ABSTRACT 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.

Diagnostic use of serum procalcitonin levels in pulmonary aspiration syndromes.

Objective: To assess the predictive accuracy of serum procalcitonin in distinguishing bacterial aspiration pneumonia from aspiration pneumonitis. Design: Prospective observational study. Setting: Intensive care unit of a university-affiliated hospital. Patients: Sixty-five consecutive patients admitted with pulmonary aspiration and seven control subjects intubated for airway protection. Interventions: None. Measurements and Main Results: Quantitative cultures from bronchoalveolar lavage fluid were conducted on all participants at the time of admission. Serial serum procalcitonin levels were measured on day 1 and day 3 using the procalcitonin enzyme-linked fluorescent assay. There were no differences in the median serum concentrations of procalcitonin between patients with positive bronchoalveolar lavage cultures (n = 32) and patients with negative bronchoalveolar lavage cultures (n = 33) on either day 1 or day 3 postadmission. The areas under the receiver operator characteristic curves were 0.59 (95% confidence interval, 0.47–0.72) and 0.63 (95% confidence interval, 0.5–0.75), respectively (p = .74). However, duration of mechanical ventilation and antibiotic therapy were shorter in those who had a decrease in their procalcitonin levels on day 3 from baseline compared with those who did not (6.7 ± 7.1 days and 11.1 ± 13.5 days, p = .03; and 8.2 ± 2.6 days vs. 12.8 ± 4.6 days; p < .001, respectively). Hospital mortality was associated with radiographic multilobar disease (adjusted odds ratio, 1.14; 95% confidence interval, 1.01–1.31; p = .04) and increasing procalcitonin levels (adjusted odds ratio, 5.63; 95% confidence interval, 1.56–20.29; p = .008). Conclusion: Serum procalcitonin levels had poor diagnostic value in separating bacterial aspiration pneumonia from aspiration pneumonitis based on quantitative bronchoalveolar lavage culture. However, serial measurements of serum procalcitonin may be helpful in predicting survival from pulmonary aspiration.

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.

The Management of Surgical Patients with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a leading public health problem in both developed and developing nations. However, awareness regarding diagnostic options, management, and consequences of untreated OSA remains inadequate in the perioperative period. Adverse surgical outcomes appear to be more frequent in OSA patients. Immediate postoperative complications may be partially attributed to the negative effects of sedative, analgesic, and anesthetic agents that can worsen OSA by decreasing pharyngeal tone and the arousal responses to hypoxia, hypercarbia, and obstruction. Rebound rapid eye movement sleep after anesthesia and the use of opioids may contribute to adverse events in the postoperative period. Even though data to guide clinicians in the perioperative period is scarce, heightened awareness is recommended.

Correlation between coagulopathy and outcome in severe head trauma in neurointensive care and trauma units

BACKGROUND Abnormal blood coagulation after traumatic brain injury is a common finding. Some studies have proposed these changes as useful predictors of outcome in patients with head trauma. This study aimed at evaluating the association of the routine tests of blood coagulation within the first hours after severe head trauma with prognosis of patients with severe head trauma. MATERIALS AND METHODS A total of 52 patients with severe head trauma (Glasgow Coma Scale [GCS], ≤8) were admitted at Tabriz University Hospital for 1 year. Patients with major accompanying trauma were excluded. On admission, serum levels of hemoglobin and hematocrit as well as the platelet count, prothrombin time (PT), partial thromboplastin time (PTT), and international normalized ratio (INR) were documented. The relation between these parameters with final outcome and also with GCS at admission, 24 hours, 48 hours, and 1 week after admission and discharge time and Glasgow Outcome Scale (GOS) were studied. RESULTS Thirty three patients were discharged, and 19 died. There were significant negative correlations between PT, PTT, and INR with all GCS and GOS scores. These correlations were significant and positive between the platelet count and all GCS and GOS scores. Median PT, PTT, and INR were significantly higher in nonsurvivors. Median serum platelets count was significantly lower in nonsurvivors. CONCLUSION On-admission PT, PTT, INR and platelet count may be used as predictors of outcome and prognosis of patients with severe head trauma.