Salah Zeineldine

Smoking and the Risk of Mortality and Vascular and Respiratory Events in Patients Undergoing Major Surgery

IMPORTANCE The effects of smoking on postoperative outcomes in patients undergoing major surgery are not fully established. The association between smoking and adverse postoperative outcomes has been confirmed. Whether the associations are dose dependent or restricted to patients with smoking-related disease remains to be determined. OBJECTIVE To evaluate the association between current and past smoking on the risk of postoperative mortality and vascular and respiratory events in patients undergoing major surgery. DESIGN Cohort study using the American College of Surgeons National Surgical Quality Improvement Program database. We obtained data on smoking history, perioperative risk factors, and 30-day postoperative outcomes. We assessed the effects of current and past smoking (>1 year prior) on postoperative outcomes after adjustment for potential confounders and effect mediators (eg, cardiovascular disease, chronic obstructive pulmonary disease, and cancer). We also determined whether the effects are dose dependent through analysis of pack-year quintiles. SETTING AND PARTICIPANTS A total of 607,558 adult patients undergoing major surgery in non-Veterans Affairs hospitals across the United States, Canada, Lebanon, and the United Arab Emirates during 2008 and 2009. MAIN OUTCOMES AND MEASURES The primary outcome measure was 30-day postoperative mortality; secondary outcome measures included arterial events (myocardial infarction or cerebrovascular accident), venous events (deep vein thrombosis or pulmonary embolism), and respiratory events (pneumonia, unplanned intubation, or ventilator requirement >48 hours). RESULTS The sample included 125,192 current (20.6%) and 78,763 past (13.0%) smokers. Increased odds of postoperative mortality were noted in current smokers only (odds ratio, 1.17 [95% CI, 1.10-1.24]). When we compared current and past smokers, the adjusted odds ratios were higher in the former for arterial events (1.65 [95% CI, 1.51-1.81] vs 1.20 [1.09-1.31], respectively) and respiratory events (1.45 [1.40-1.51] vs 1.13 [1.08-1.18], respectively). No effects on venous events were observed. The effects of smoking mediated through smoking-related disease were minimal. The increased adjusted odds of mortality in current smokers were evident from a smoking history of less than 10 pack-years, whereas the effects of smoking on arterial and respiratory events were incremental with increased pack-years. CONCLUSIONS AND RELEVANCE Smoking cessation at least 1 year before major surgery abolishes the increased risk of postoperative mortality and decreases the risk of arterial and respiratory events evident in current smokers. These findings should be carried forward to evaluate the value and cost-effectiveness of intervention in this setting. Our study should increase awareness of the detrimental effects of smoking-and the benefits of its cessation-on morbidity and mortality in the surgical setting.

Critical Care Clinicians’ Knowledge of Evidence-Based Guidelines for Preventing Ventilator-Associated Pneumonia

BACKGROUND Ventilator-associated pneumonia is the most common hospital-acquired infection among patients receiving mechanical ventilation in an intensive care unit. Different initiatives for the prevention of ventilator-associated pneumonia have been developed and recommended. OBJECTIVE To evaluate knowledge of critical care providers (physicians, nurses, and respiratory therapists in the intensive care unit) about evidence-based guidelines for preventing ventilator-associated pneumonia. METHODS Ten physicians, 41 nurses, and 18 respiratory therapists working in the intensive care unit of a major tertiary care university hospital center completed an anonymous questionnaire on 9 nonpharmacological guidelines for prevention of ventilator-associated pneumonia. RESULTS The mean (SD) total scores of physicians, nurses, and respiratory therapists were 80.2% (11.4%), 78.1% (10.6%), and 80.5% (6%), respectively, with no significant differences between them. Furthermore, within each category of health care professionals, the scores of professionals with less than 5 years of intensive care experience did not differ significantly from the scores of professionals with more than 5 years of intensive care experience. CONCLUSIONS A health care delivery model that includes physicians, nurses, and respiratory therapists in the intensive care unit can result in an adequate level of knowledge on evidence-based nonpharmacological guidelines for the prevention of ventilator-associated pneumonia.

Metabolic and Respiratory Variables during Pressure Support versus Synchronized Intermittent Mandatory Ventilation

Background: Mechanically ventilated patients interact and respond differently to different modes of ventilatory support. Objectives: To assess changes in metabolic and respiratory variables during equivalent changes with either pressure support ventilation (PSV) or volume-cycled synchronized intermittent mandatory ventilation (SIMV) in non-tracheostomized patients without known obstructive pulmonary disease receiving short-term mechanical ventilation in the intensive care unit. Methods: Fourteen patients receiving volume-cycled SIMV at 12 breaths/min (SIMV100%) were included in the study. The PSV level (PSV100%) resulting in a minute volume and respiratory rate equivalent to that during SIMV100% was determined for each patient. Then each patient underwent trials at 66% and 33% of initial ventilator support with volume-cycled SIMV (SIMV66% and SIMV33%) and PSV (PSV66% and PSV33%) in random order. At the end of each trial, oxygen consumption (v̇O2), carbon dioxide production (v̇CO2), measured energy expenditures (MEE), peak inspiratory flow, total respiratory frequency, tidal volume, minute ventilation, occlusion pressure (P0.1) and inspiratory duty cycle (Ti/Ttot) were measured. Results: There were smaller changes in v̇O2, v̇CO2 and MEE when equivalent changes were applied with PSV (15.7 ± 4.4; 12.5 ± 2.2 and 15 ± 3.5%) compared with volume-cycled SIMV (32.7 ± 7.7; 23 ± 5.2 and 30.7 ± 6.8%; p < 0.05). P0.1 and Ti/Ttot were significantly smaller during PSV (2.64 ± 0.28 and 0.38 ± 0.03 cm H2O) than volume-cycled SIMV (4.01 ± 0.21 and 0.43 ± 0.02 cm H2O; p < 0.05). Conclusions: Changes in the level of PSV resulted in smaller changes in metabolic and respiratory variables compared with equivalent changes in the level of volume-cycled SIMV support. PSV may be more suitable for progressive respiratory muscle reloading.

The Effect of Preoperative Pneumonia on Postsurgical Mortality and Morbidity: A NSQIP Analysis

BackgroundCurrently, only indirect evidence suggests that preoperative pneumonia is a significant risk factor for poor postsurgical outcomes. Although this relationship is clinically intuitive, this is the first study that aims to quantify the extent to which pneumonia impacts morbidity and mortality. The objective of this study was to determine the impact of preoperative pneumonia on 30-day mortality and morbidity among both elective and emergency surgical patients.MethodsWe conducted a retrospective cohort study using 2008–2012 data from the American College of Surgeons National Surgical Quality Improvement Program database. Patients with preoperative pneumonia were matched to controls without preoperative pneumonia. Patient demographics and postoperative outcomes were extracted from the database, including 30-day mortality, specific morbidities (wound, cardiac, respiratory, urinary, central nervous system, thromboembolism and sepsis), composite morbidity, number of blood transfusions and number of patients that returned to the OR. Mortality and composite morbidity were further stratified.ResultsWe obtained data for 137,174 patients, of whom 6933 (0.50%) had preoperative pneumonia. Overall, 6111 were successfully matched to 24,444 patients with no pneumonia. Postoperative mortality and composite morbidity were both higher in patients with pneumonia than in those without pneumonia, with an odds ratio of 1.37 (95% CI 1.26–1.48) and 1.68 (95% CI 1.58–1.79), respectively.ConclusionPreoperative pneumonia significantly increased the rate of postoperative morbidity and mortality across several surgical settings and patient groups. It is our recommendation that elective surgery be delayed until after the pneumonia resolves.

Split-bolus contrast injection protocol enhances the visualization of the thoracic vasculature and reduced radiation dose during chest CT

OBJECTIVE To investigate the visualization of mediastinal lymph nodes during thoracic CT employing a multiphasic contrast media (CM) protocol. METHODS Institutional review board approved retrospective study consisting of 300 patients with known chest malignancy. Patients were allocated to one of two CM protocols: Protocol A, consisted of dual bolus (Phase 1:100 ml CM followed by 100 ml saline chaser) i.v. injected at 2.5 ml s-1; Protocol B employed 100 ml of CM using a multiphasic injection protocol (Phase 1 and 2:60 ml contrast and saline, followed by Phase 3 and 4:40 ml contrast and saline injected at 2.5 ml s-1) with a fixed scan delay of 70 s for each acquisition. Attenuation profiles of the thoracic arteries and veins were calculated as well as the arterio-venous contrast ratios (AVCR). Receiver operating characteristic (ROC), visual grading characteristic (VGC), and Cohens kappa analysis were assessed. RESULTS Arterial opacification was up to 24% (p < 0.032) higher in protocol B than A, whereas, in the veins it was significantly lower in protocol B than A, with a maximum reduction of up to 84% (p < 0.0001). There was no statistical significance between the central and peripheral pulmonary arteries [>263 Hounsfield units (HU)] in each protocol. Protocol B, demonstrated significant improvement in AVCR at various anatomical sites (p < 0.002). Radiation dose was significantly reduced in protocol B compared to A (p < 0.004). Both ROC and VGC demonstrated significantly higher Az score for protocol B compared to A (p < 0.0001) with an increased inter reader agreement from poor to excellent. CONCLUSION Employing a multiphasic CM protocol significantly improves opacification of the thoracic vasculature and visualization of mediastinal lymph nodes during thoracic CT. ADVANCES IN KNOWLEDGE Uniform opacification between thoracic arteries and veins increases the delineation between vasculature and lymph nodes, reduces radiation dose when employing a multiphase contrast media injection protocol.

Relaxantes musculares não despolarizantes melhoram a visibilidade em laringoscopia direta sem efeito sobre a ventilação via máscara facial

BACKGROUND Difficult or impossible face mask ventilation complicated with difficult tracheal intubation during anesthesia induction occurs in 0.4% of adult anesthesia cases, possibly leading to life-threatening complications. Because of such catastrophes, muscle relaxants have been recommended to be administered after confirming adequate face mask ventilation without a solid scientific validation of this principal. METHODS In this observational study, the ease of ventilation and the scores of direct laryngoscopy views before and after administration of cisatracurium were assessed in ninety young healthy adults, without anesthetic risks and without foreseen difficult intubation and who were scheduled for general elective surgeries. RESULTS Before muscle relaxation, 43 patients (48%) were Cormack Grade I, while the remaining 47 patients (52%) were either Cormack Grade II (28 patients, 31%) or Cormack Grade II (19 patients, 21%). Following muscle relaxation with cisatracurium, the number of patients with Cormack Grade I significantly increased from 43 patients (48%) to 65 patients (72%) (p=0.0013). Only 1 patient out of 19 patients (5%) improved his Cormack grade from Grade III to Grade I while 16 out 19 patients (84%) improved their Cormack grade from Grade III to Grade II after the use of cisatracurium. The quality of face mask ventilation did not differ with and without muscle relaxants in all patients. CONCLUSION The use of cisatracurium in healthy young adults undergoing general elective surgeries with no anticipated difficult endotracheal intubation had no effect on the quality of face mask ventilation despite resulting in a quantifiable improvement in the laryngeal view.