Postoperative Pulmonary Dysfunction in Adults After Cardiac Surgery With Cardiopulmonary Bypass: Clinical Significance and Implications for Practice

Bilateral sternal infusion of ropivacaine and length of stay in ICU after cardiac surgery with increased respiratory risk: A randomised controlled trial

BACKGROUND

The continuous bilateral infusion of a local anaesthetic solution around the sternotomy wound (bilateral sternal) is an innovative technique for reducing pain after sternotomy.

OBJECTIVE

To assess the effects of the technique on the need for intensive care in cardiac patients at increased risk of respiratory complications.

DESIGN

Randomised, observer-blind controlled trial.

SETTING

Single centre, French University Hospital.

PATIENTS

In total, 120 adults scheduled for open-heart surgery, with one of the following conditions: age more than 75 years, BMI >30 kg m, chronic obstructive pulmonary disease, active smoking habit.

INTERVENTION

Either a bilateral sternal infusion of 0.2% ropivacaine (3 ml h through each catheter; 'intervention' group), or standardised care only ('control' group). Analgesia was provided with paracetamol and self-administered intravenous morphine.

MAIN OUTCOME MEASURES

The length of time to readiness for discharge from ICU, blindly assessed by a committee of experts.

RESULTS

No effect was found between groups for the primary outcome (P = 0.680, intention to treat); the median values were 42.4 and 37.7 h, respectively for the control and intervention groups (P = 0.873). Similar nonsignificant trends were noted for other postoperative delays. Significant effects favouring the intervention were noted for dynamic pain, patient satisfaction, occurrence of nausea and vomiting, occurrence of delirium or mental confusion and occurrence of pulmonary complications. In 12 patients, although no symptoms actually occurred, the total ropivacaine plasma level exceeded the lowest value for which neurological symptoms have been observed in healthy volunteers.

CONCLUSION

Because of a small size effect, and despite significant analgesic effects, this strategy failed to reduce the time spent in ICU.

TRIAL REGISTRATION

EudraCT (N°: 2012-005225-69); ClinicalTrials.gov (NCT01828788).

Chronic Obstructive Pulmonary Disease and Off-Pump Coronary Surgery

PURPOSE

To determine to what extent chronic obstructive pulmonary disease (COPD) affects mortality and morbidity rates in patients treated with off-pump coronary artery bypass graft (CABG).

METHODS

A total of 321 patients treated with off-pump CABG were included in the present study. Of the 321 patients, 46 patients had COPD and they were designated as Group 1 and the remaining 275 patients did not have COPD and they were considered as Group 2. We compared the data obtained from the patients in both groups.

RESULTS

While preoperative spirometry values and arterial blood gas oxygen saturation levels were significantly lower, the partial values of carbon dioxide were higher in Group 1. Likewise, extubation time, the amount of drainage and blood transfusion, inotropic support, prolonged intubation, pulmonary complications, the use of bronchodilators, and steroids were statistically higher in Group 1 when compared with Group 2. Overall, there was no marked difference between the two groups in terms of mortality incidence.

CONCLUSION

We found similar morbidity and mortality rates among the patients with COPD and without COPD when they were treated with off-pump CABG. Therefore, the present results indicate that the presence of COPD is not associated with in-hospital mortality or severe morbidity post-CABG by off-pump approach.

Vitamin C to Improve Organ Dysfunction in Cardiac Surgery Patients-Review and Pragmatic Approach

The pleiotropic biochemical and antioxidant functions of vitamin C have sparked recent interest in its application in intensive care. Vitamin C protects important organ systems (cardiovascular, neurologic and renal systems) during inflammation and oxidative stress. It also influences coagulation and inflammation; its application might prevent organ damage. The current evidence of vitamin C's effect on pathophysiological reactions during various acute stress events (such as sepsis, shock, trauma, burn and ischemia-reperfusion injury) questions whether the application of vitamin C might be especially beneficial for cardiac surgery patients who are routinely exposed to ischemia/reperfusion and subsequent inflammation, systematically affecting different organ systems. This review covers current knowledge about the role of vitamin C in cardiac surgery patients with focus on its influence on organ dysfunctions. The relationships between vitamin C and clinical health outcomes are reviewed with special emphasis on its application in cardiac surgery. Additionally, this review pragmatically discusses evidence on the administration of vitamin C in every day clinical practice, tackling the issues of safety, monitoring, dosage, and appropriate application strategy.

The effect of high-flow nasal oxygen on hospital length of stay in cardiac surgical patients at high risk for respiratory complications: a randomised controlled trial

There has been increased interest in the prophylactic and therapeutic use of high‐flow nasal oxygen in patients with, or at risk of, non‐hypercapnic respiratory failure. There are no randomised trials examining the efficacy of high‐flow nasal oxygen in high‐risk cardiac surgical patients. We sought to determine whether routine administration of high‐flow nasal oxygen, compared with standard oxygen therapy, leads to reduced hospital length of stay after cardiac surgery in patients with pre‐existing respiratory disease at high risk for postoperative pulmonary complications. Adult patients with pre‐existing respiratory disease undergoing elective cardiac surgery were randomly allocated to receive high‐flow nasal oxygen (n = 51) or standard oxygen therapy (n = 49). The primary outcome was hospital length of stay and all analyses were carried out on an intention‐to‐treat basis. Median (IQR [range]) hospital length of stay was 7 (6–9 [4–30]) days in the high‐flow nasal oxygen group and 9 (7–16 [4–120]) days in the standard oxygen group (p=0.012). Geometric mean hospital length of stay was 29% lower in the high‐flow nasal group (95%CI 11–44%, p = 0.004). High‐flow nasal oxygen was also associated with fewer intensive care unit re‐admissions (1/49 vs. 7/45; p = 0.026). When compared with standard care, prophylactic postoperative high‐flow nasal oxygen reduced hospital length of stay and intensive care unit re‐admission. This is the first randomised controlled trial examining the effect of prophylactic high‐flow nasal oxygen use on patient‐centred outcomes in cardiac surgical patients at high risk for postoperative respiratory complications.

Risk Factors and Outcomes Associated With Sepsis After Coronary Artery Bypass and Open Heart Valve Surgeries

PURPOSE

Sepsis causes significant morbidity and mortality after cardiac surgery and carries a significant burden on health care costs. There is a general association of increased risk of post-cardiac surgery sepsis in patients with postoperative complications. We sought to investigate significant patient and procedural risk factors and outcomes associated with sepsis after cardiac surgery.

MATERIALS AND METHODS

In this retrospective study, we analyzed 531 coronary artery bypass grafting and open heart valve surgery cases that developed postoperative sepsis in the National Surgical Quality Improvement Program database between 2007 and 2014. Patient-based and surgery-based parameters were analyzed for risk factors and outcomes reported in the 30 days postoperatively. The association between sepsis and patient outcomes was assessed in a propensity-matched cohort using univariable logistic regression.

RESULTS

Modifiable and nonmodifiable patient characteristics, including age >80, poor preoperative functional status, chronic diseases such as diabetes mellitus, congestive heart failure, chronic kidney disease with serum creatinine ⩾1.5, as well as serum albumin <3.5 and emergent nature of the case were associated with post-cardiac surgery sepsis. Surgical outcomes associated with sepsis included mortality (15.4% vs 4.5%), unplanned intubation (29.8% vs 8.2%), transfusion (53.4% vs 48.4%), acute kidney injury (7.1% vs 1.4%), postoperative dialysis (18.8% vs 3.5%), and return to the operating room (29.8% vs 8.2%).

CONCLUSIONS

We identified multiple patient and surgical characteristics as well as postoperative outcomes associated with postoperative sepsis development in the high-risk population of patients undergoing cardiac surgery. Early identification of patients who are at high risk for postoperative sepsis can facilitate early treatment interventions.

Chronic obstructive pulmonary disease severity influences outcomes after off-pump coronary artery bypass

OBJECTIVE

To analyze the impact and severity of chronic obstructive pulmonary disease (COPD) on pulmonary function and postoperative clinical outcome based on the Global Initiative for Obstructive Lung Disease criteria in patients undergoing off-pump coronary artery bypass grafting (CABG).

METHODS

Patients were allocated into 3 groups according to presence and severity of COPD: no or mild COPD (n = 144); moderate COPD (n = 77); and severe COPD (n = 30). Spirometry values were obtained preoperatively and on postoperative days (PODs) 2 and 5. The incidences of pneumonia and reintubation, time of mechanical ventilation, and length of postoperative hospital stay were recorded.

RESULTS

Significant impairment in pulmonary function was observed in all groups on PODs 2 and 5 (P < .001). However, postoperative pulmonary dysfunction was significantly higher in the moderate and severe COPD groups compared with the no or mild COPD group (P < .05). On multivariable analysis, severe COPD was associated with an elevated risk for composite outcomes (odds ratio, 1.37; 95% confidence interval, 1.20-1.57; P < .001). A preoperative forced expiratory volume in 1 second (FEV₁) <50% of the predicted value was associated with poor outcome. A significant negative correlation was found between FEV₁ at POD 5 and postoperative length of stay (r = -0.5; P < .001).

CONCLUSIONS

More severe COPD was associated with greater impairment in pulmonary function and worse clinical outcomes after off-pump CABG surgery. A preoperative FEV₁ <50% of predicted value appears to be an important predictor of postoperative complications.

Utility of Perioperative Lung Ultrasound in Pediatric Cardiac Surgery

Background

Pediatric cardiac patients are at risk for perioperative respiratory insufficiency. The objective of this study was to assess the utility of perioperative lung ultrasound examination in pediatric cardiac surgery.

Methods

In this randomized, controlled trial, children (5 yr old or younger) undergoing cardiac surgery were allocated into a control (n = 61) or intervention (n = 61) group. The control group received only lung ultrasound examinations at the end of surgery and 6 to 12 h after surgery. The intervention group received lung ultrasound examinations and an ultrasound-guided recruitment maneuver depending on ultrasound findings after inducing anesthesia, at the end of surgery, and 6 to 12 h after surgery. Primary outcomes were incidences of intra- and postoperative desaturation, and postoperative pulmonary complications. Multiple comparisons were corrected (P ≤ 0.017) in the primary outcome analysis.

Results

Of the 120 children included in the analysis, postoperative desaturation (64% vs. 27%; P &lt; 0.001; odds ratio [OR], 0.210; 95% CI, 0.097 to 0.456) occurred more in the control group. The incidences of intraoperative desaturation (36% vs. 19%; P = 0.033; OR, 0.406; 95% CI, 0.176 to 0.939) and postoperative pulmonary complications (12% vs. 3%; P = 0.093; OR, 0.271; 95% CI, 0.054 to 1.361) were similar between the groups. Lung ultrasound scores were better in the intervention group than in the control group. Duration of mechanical ventilation was longer in the control group than in the intervention group (38 ± 43 vs. 26 ± 25 h; 95% CI of mean difference, 0 to 25; P = 0.048).

Conclusions

Perioperative lung ultrasound examination followed by ultrasound-guided recruitment maneuver helped decrease postoperative desaturation events and shorten the duration of mechanical ventilation in pediatric cardiac patients.

Nebulized Versus IV Amikacin as Adjunctive Antibiotic for Hospital and Ventilator-Acquired Pneumonia Postcardiac Surgeries: A Randomized Controlled Trial

OBJECTIVE

Nebulized antibiotics offer high efficacy due to significant local concentrations and safety with minimal blood levels. This study evaluates the efficacy and nephrotoxicity of nebulized versus IV amikacin in postcardiothoracic surgical patients with nosocomial pneumonia caused by multidrug-resistant Gram- negative bacilli.

DESIGN

Prospective, randomized, controlled study on surgical patients divided into two groups.

SETTING

Postcardiac surgery ICU.

INTERVENTIONS

The first gtroup was administered IV amikacin 20 mg/kg once daily. The second group was prescribed amikacin nebulizer 400 mg twice daily. Both groups were co-administered IV piperacillin/tazobactam empirically.

PATIENTS

Recruited patients were diagnosed by either hospital-acquired pneumonia or ventilator-associated pneumonia where 56 (42.1%) patients were diagnosed with hospital-acquired pneumonia, 51 (38.34%) patients were diagnosed with early ventilator-associated pneumonia, and 26 (19.54%) patients with late ventilator-associated pneumonia.

MEASUREMENTS AND MAIN RESULTS

Clinical cure in both groups assessed on day 7 of treatment was the primary outcome. Efficacy was additionally evaluated through assessing the length of hospital stay, ICU stay, days on amikacin, days on mechanical ventilator, mechanical ventilator-free days, days to reach clinical cure, and mortality rate. Lower nephrotoxicity in the nebulized group was observed through significant preservation of kidney function (p < 0.001). Although both groups were comparable regarding length of hospital stay, nebulizer group showed shorter ICU stay (p = 0.010), lower number of days to reach complete clinical cure (p = 0.001), fewer days on mechanical ventilator (p = 0.035), and fewer days on amikacin treatment (p = 0.022).

CONCLUSION

Nebulized amikacin showed better clinical cure rates, less ICU stay, and fewer days to reach complete recovery compared to IV amikacin for surgical patients with nosocomial pneumonia. It is also a less nephrotoxic option associated with less deterioration in kidney function.

Cardiopulmonary bypass does not induce lung dysfunction after pulmonary thrombarterectomy: role of pulmonary compliance

OBJECTIVES

Pulmonary endarterectomy is a heavy surgical procedure that is performed under cardiopulmonary bypass (CPB) and aimed to cure postembolic pulmonary hypertension. Reperfusion oedema is both the hallmark of successful surgical procedure and the most frequent postoperative complication. Post-CPB lung dysfunction was not mentioned in any report. We undertook a study to determine whether post-CPB lung dysfunction was present in these patients.

METHODS

In a retrospective cohort study with matching on some baseline covariates, we selected 41 patients who had undergone pulmonary endarterectomy and in whom pre-, intra- and postoperative records were complete. The control group was composed of 39 patients operated on from elective cardiac surgery during the same period and matched with a study group for age, gender, body mass index, blood creatinine, diabetes and baseline partial pressure of oxygen/fraction of inspired oxygen ratio. Criteria for post-CPB lung dysfunction were partial pressure of oxygen/fraction of inspired oxygen ratio decrease and bilateral basal oedema. Explanatory variables for post-CPB lung dysfunction were coronary arterial bypass, pleura opening, static pulmonary compliance measured at the time of thorax closed then retracted, fluid infusion, transfusion and vasopressors.

RESULTS

All patients operated on from pulmonary endarterectomy presented radiological oedema reperfusion in surgical unblocking areas. Among them, only 2 had bilateral basal oedema when compared to the 24 patients from the control group (P < 0.001). Partial pressure of oxygen/fraction of inspired oxygen ratio increased in the study group and decreased in the control group (30 ± 109 vs -67 ± 134 mmHg, P < 0.001). Control group patients with high-baseline pulmonary compliance were at risk for post-CPB lung dysfunction.

CONCLUSIONS

Patients operated on from pulmonary endarterectomy were saved from post-CPB lung dysfunction. The latter could be induced by a mechanical phenomenon.

Impact of intrathecal morphine analgesia on the incidence of pulmonary complications after cardiac surgery: a single center propensity-matched cohort study

Background

Acute pain and systemic opioids may both negatively impact respiratory function after cardiac surgery. This study analyzes the local practice of using intrathecal morphine analgesia (ITMA) with minimal parenteral opioid administration in cardiac surgery, specifically the impact on postoperative pulmonary complications (PPCs).

Methods

Data from adult patients who underwent elective cardiac surgery between January 2002, and December 2013 in a single center were analyzed. Propensity scores estimating the likelihood of receiving ITMA were used to match (1:1) patients with ITMA and patients with intravenous analgesia (IVA). Primary outcome was PPCs, a composite endpoint including pneumonia, adult respiratory distress syndrome, and any type of acute respiratory failure. Secondary outcomes were in-hospital mortality, cardiovascular complications, and length of stay in the intensive care unit (ICU) and hospital.

Results

From a total of 1′543 patients, 920 were treated with ITMA and 623 with IVA. No adverse event consequent to the spinal puncture was reported. Propensity score matching created 557 balanced pairs. The occurrence of PPCs in patients with ITMA was 8.1% vs. 12.8% in patients with IVA (odds ratio, 0.6; 95% CI, 0.40–0.89; p = 0.012). Fewer patients with ITMA had a prolonged stay in the ICU (> 4 days; 16.5% vs. 21.2%, p = 0.047) or in the hospital (> 15 days; 25.5% vs. 31.8%. p = 0.024). In-hospital mortality and cardiovascular complications did not differ significantly between the two groups.

Conclusion

In this study involving cardiac surgical patients, ITMA was safely applied and was associated with fewer PPCs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-017-0398-z) contains supplementary material, which is available to authorized users.

Early pulmonary compliance increase during cardiac surgery predicted post-operative lung dysfunction

Introduction:

Lung dysfunction following cardiac surgery is currently viewed as the consequence of atelectasis and lung injury. While the mechanism of atelectasis has been largely detailed, the pathogenesis of lung injury after cardiopulmonary bypass is still unclear. Based upon clinical and experimental studies, we hypothesized that lungs could be injured through a mechanical phenomenon.

Methods:

We recorded pulmonary compliance at six key moments of a heart operation in 62 adult patients undergoing elective cardiac surgery. We focused on the period lasting from anesthetic induction to aorta unclamping. We calculated the variation of static and dynamic pulmonary compliance caused by thorax opening; ΔCstat1 and ΔCdyn1 and that caused by cardiopulmonary bypass, ΔCstat2 and ΔCdyn2. Blood gases were performed under standardized ventilation after anesthetic induction and after surgical closure. The PaO2/FiO2 ratio was calculated. ∆PaO2/FiO2 was the criterion for lung dysfunction. We compared ΔCstat1 and ΔCdyn1 with both ∆PaO2/FiO2 and, respectively, ΔCstat2 and ΔCdyn2.

Results:

Static and dynamic compliance increased with the opening of the thorax and decreased with the start of cardiopulmonary bypass. The PaO2/FiO2 ratio diminished after surgery. ΔCstat1 and ΔCdyn1 were negatively correlated with both ∆PaO2/FiO2 (r=-0.42; p<0.001 and r=-0.44; p<0.001) and, respectively, with ΔCstat2 and ΔCdyn2 (r=-0.59; p<0.001 and r=-0.53; p<0.001).

Conclusions:

Increased pulmonary compliance induced by the opening of the thorax is correlated with worsened intrapulmonary shunt after cardiopulmonary bypass. A mechanical phenomenon could be partly responsible for post-operative hypoxemia.

Off-pump versus on-pump coronary artery bypass grafting in patients with diabetes: a meta-analysis

AIMS

The effects of off-pump CABG (OFF-CABG) versus on-pump CABG (ON-CABG) in diabetic patients remain controversial. The aim of our study was to compare mortality and postoperative morbidity between OFF-CABG and ON-CABG for diabetic patients.

METHODS

Electronic databases including PubMed, EMBASE and Cochrane Library for studies investigating clinical outcomes of OFF-CABG versus ON-CABG in diabetic patients were searched, collecting data from inception until June 2016. We pooled the odds ratios from individual studies and performed heterogeneity, quality assessment and publication bias analysis.

RESULTS

A total of 543,220 diabetic patients in 10 studies were included. The overall mortality (OR, 0.87; 95% CI, 0.58-1.31; p = 0.50) was comparable between the OFF-CABG and ON-CABG. OFF-CABG was associated with significantly fewer cerebrovascular accidents (OR, 0.45; 95% CI, 0.31-0.65; p < 0.0001), bleeding complications (OR, 0.59; 95% CI, 0.43-0.80; p < 0.001) and pulmonary complications. However, no differences in myocardial infarction (OR, 0.76; 95% CI, 0.52-1.12; p = 0.16), renal failure (OR, 0.74; 95% CI, 0.50-1.11; p = 0.14) and other postoperative morbidity outcomes were found.

CONCLUSIONS

OFF-CABG significantly reduces the incidence of postoperative cerebrovascular accidents and bleeding complications compared with ON-CABG in diabetic patients. No differences were found regarding mortality, myocardial infarction and renal failure between these two techniques. Our study suggests that OFF-CABG may be an optimal strategy for diabetic patients although adequately powered randomized trials are needed to further verify the finding.

Effects of Ulinastatin on Perioperative Inflammatory Response and Pulmonary Function in Cardiopulmonary Bypass Patients

The aim of this study was to investigate whether ulinastatin (UTL) has protective effects on perioperative proinflammatory cytokines and lung injury in cardiopulmonary bypass (CPB) patients. The study included 60 patients undergoing CPB who were randomly divided into a UTL group and a control group. Blood routine examination and inflammatory cytokines concentrations were detected after anesthetic induction (T1), immediately after aortic valve opening (T2), and 4 (T3) and 24 (T4) hours after weaning from CPB. Flow cytometry was used to detect TLR4 and HSP70 expressions. Arterial blood gas and respiratory function were analyzed at the same time points. Compared with the control group, the levels of IL-2, IL-8, TNF-α, NE, TLR4, PA - aDO2, and RI at T2 were significantly lower, whereas HSP70, PaO2, OI, Cd, and Cs were higher in the UTL group (all P < 0.05). Relative to the control group at T3, white blood cell count, TLR4, IL-2, IL-6, IL-8, TNF-α, NE, and RI decreased significantly, whereas IL-10, HSP70, PaO2, OI, and Cs increased in the UTL group (all P < 0.05). At T4, IL-2, IL-6, IL-8, TNF-α, TLR4, and PaCO2 in the UTL group were significantly lower, and PaO2, IL-10, HSP70, and Cs were higher than in the control group (all P < 0.05). Our data show strong evidence that UTL suppresses proinflammatory cytokine elevation and upregulates release of anti-inflammatory mediators, reducing pulmonary injury and improving pulmonary function after CPB.

Metabotyping Patients' Journeys Reveals Early Predisposition to Lung Injury after Cardiac Surgery

Cardiovascular disease is the leading cause of death worldwide and patients with severe symptoms undergo cardiac surgery. Even after uncomplicated surgeries, some patients experience postoperative complications such as lung injury. We hypothesized that the procedure elicits metabolic activity that can be related to the disease progression, which is commonly observed two-three days postoperatively. More than 700 blood samples were collected from 50 patients at nine time points pre-, intra-, and postoperatively. Dramatic metabolite shifts were observed during and immediately after the intervention. Prolonged surgical stress was linked to an augmented anaerobic environment. Time series analysis showed shifts in purine-, nicotinic acid-, tyrosine-, hyaluronic acid-, ketone-, fatty acid, and lipid metabolism. A characteristic 'metabolic biosignature' was identified correlating with the risk of developing postoperative complications two days before the first clinical signs of lung injury. Hence, this study demonstrates the link between intra- and postoperative time-dependent metabolite changes and later postoperative outcome. In addition, the results indicate that metabotyping patients' journeys early, during or just after the end of surgery, may have potential impact in hospitals for the early diagnosis of postoperative lung injury, and for the monitoring of therapeutics targeting disease progression.

Risk factors for postoperative pulmonary complications in coronary artery bypass graft surgery patients

Background

Despite numerous advances in anesthesia, surgical techniques, and postoperative care for coronary artery bypass graft (CABG) surgery, postoperative pulmonary complications (PPCs) still account for postoperative morbidity.

Objective

To determine current risk factors for PPCs in CABG surgery patients.

Methods

A retrospective cohort design was used. Health records were reviewed for patients ( n=315) who had CABG surgery at a large quaternary healthcare center over a 4 month period. Pre-, peri-, and postoperative risk factors for PPCs were recorded as binary variables. Data were further assessed according to PPCs and non-PPCs using logistic regression models.

Results

PPCs occurred in 99.4% of this CABG surgical cohort. Atelectasis, pleural effusion, atelectasis with pleural effusion, and pneumonia were the most frequent PPCs post CABG surgery. Age >65 years, diabetes, and ASA classification N3 were found to be related to the presence of atelectasis. No significant risk factors were related to the development of pleural effusion or atelectasis with pleural effusion. Postoperative pneumonia was associated with previous myocardial infarction, ventilation >10 h, and hospital stay >5 days. History of bronchitis and COPD were related to postoperative pneumothorax; history of heart failure, COPD, and other lung diseases were related to postoperative pulmonary edema.

Conclusion

These findings contribute to the understanding of PPCs in post-CABG surgery patients and assist in identification of patients at risk for developing PPCs.

Quantifying the effect of complications on patient flow, costs and surgical throughputs

BACKGROUND

Postoperative adverse events are known to increase length of stay and cost. However, research on how adverse events affect patient flow and operational performance has been relatively limited to date. Moreover, there is paucity of studies on the use of simulation in understanding the effect of complications on care processes and resources. In hospitals with scarcity of resources, postoperative complications can exert a substantial influence on hospital throughputs.

METHODS

This paper describes an evaluation method for assessing the effect of complications on patient flow within a cardiac surgical department. The method is illustrated by a case study where actual patient-level data are incorporated into a discrete event simulation (DES) model. The DES model uses patient data obtained from a large hospital in Oman to quantify the effect of complications on patient flow, costs and surgical throughputs. We evaluated the incremental increase in resources due to treatment of complications using Poisson regression. Several types of complications were examined such as cardiac complications, pulmonary complications, infection complications and neurological complications.

RESULTS

48 % of the patients in our dataset experienced one or more complications. The most common types of complications were ventricular arrhythmia (16 %) followed by new atrial arrhythmia (15.5 %) and prolonged ventilation longer than 24 h (12.5 %). The total number of additional days associated with infections was the highest, while cardiac complications have resulted in the lowest number of incremental days of hospital stay. Complications had a significant effect on perioperative operational performance such as surgery cancellations and waiting time. The effect was profound when complications occurred in the Cardiac Intensive Care (CICU) where a limited capacity was observed.

CONCLUSIONS

The study provides evidence supporting the need to incorporate adverse events data in resource planning to improve hospital performance.

Incidence and risk factors for aspiration pneumonia after cardiovascular surgery in elderly patients

OBJECTIVE

Pneumonia after cardiovascular surgery is the leading cause of mortality. Postoperative aspiration pneumonia becomes a critical issue in the management of cardiovascular surgery in the aging society. The aim of this study was to investigate the incidence and risk factors of aspiration pneumonia after cardiovascular surgery for elderly patients.

METHODS

This study consisted of 123 elderly patients (>65 years old) who survived their final extubation following cardiovascular surgery at Kinan Hospital. Patients were divided into aspiration pneumonia and no pneumonia groups. Postoperative aspiration pneumonia was diagnosed by two independent physicians according to the nursing- and healthcare-associated pneumonia guidelines by the Japanese Respiratory Society.

RESULTS

Among the patients, 12 (9.8 %) had aspiration pneumonia. There were no differences in patients' characteristics between the groups except for a history of cerebral vascular disorder (aspiration pneumonia 42 % vs no pneumonia 15 %, p = 0.04) and ejection fraction (EF) (aspiration pneumonia 56 ± 21 % vs no pneumonia 66 ± 13 %, p = 0.02). Only six (5 %) patients needed more than 12 h intubation. There was no difference in the operative factors between the groups. Neurological deficit was more frequently observed in the aspiration pneumonia group (33 vs 5 %, p = 0.005). Multivariable logistic regression analysis showed that the history of cerebral vascular disorder and neurological deficit after surgery was independent risk factors for aspiration pneumonia after cardiovascular surgery.

CONCLUSIONS

Our results could assist in screening elderly patients who should be more carefully evaluated before oral nutrition to minimize morbidity and mortality after cardiovascular surgery.

Continuous Positive Airway Pressure Versus Oxygen Therapy in the Cardiac Surgical Ward: A Randomized Trial

BACKGROUND

Noninvasive ventilation (NIV) is a common technique to manage patients with acute respiratory failure in the intensive care unit. However, use of NIV in general wards is less well described. The authors' aim was to demonstrate efficacy of NIV, applied in a cardiac surgery ward, in improving oxygenation in patients who developed hypoxemic acute respiratory failure after being discharged from the intensive care unit.

DESIGN

Randomized, open-label trial.

SETTING

University hospital.

PARTICIPANTS

Sixty-four patients with hypoxemia (PaO₂/F_IO₂ ratio between 100 and 250) admitted to the main ward after cardiac surgery.

INTERVENTIONS

Patients were randomized to receive standard treatment (oxygen, early mobilization, a program of breathing exercises and diuretics) or continuous positive airway pressure in addition to standard treatment. Continuous positive airway pressure was administered 3 times a day for 2 consecutive days. Every cycle lasted 1 to 3 hours. All patients completed their 1-year follow-up. Data were analyzed according to the intention-to-treat principle.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was the number of patients with PaO₂/F_IO₂<200 48 hours after randomization. Continuous positive airway pressure use was associated with a statistically significant reduction in the number of patients with PaO₂/F_IO₂<200 (4/33 [12%] v 14/31 [45%], p = 0.003). One patient in the control group died at the 30-day follow-up.

CONCLUSIONS

Among patients with acute respiratory failure following cardiac surgery, administration of continuous positive airway pressure in the main ward was associated with improved respiratory outcome. This was the first study that was performed in the main ward of post-surgical patients with acute respiratory failure.

Feasibility of preoperative inspiratory muscle training in patients undergoing coronary artery bypass surgery with a high risk of postoperative pulmonary complications: a randomized controlled pilot study

Objective: To determine in a pilot study the feasibility and effects of preoperative inspiratory muscle training in patients at high risk of postoperative pulmonary complications who were scheduled for coronary artery bypass graft surgery.

Design: Single-blind, randomized controlled pilot study.

Setting: University Medical Centre Utrecht, the Netherlands.

Subjects: Twenty-six patients at high risk of postoperative pulmonary complications were selected.

Intervention: The intervention group ( N = 14) received 2-4 weeks of preoperative inspiratory muscle training on top of the usual care received by the patients in the control group.

Main measures: Primary outcome variables of feasibility were the occurrence of adverse events, and patient satisfaction and motivation. Secondary outcome variables were postoperative pulmonary complications and length of hospital stay.

Results: The feasibility of inspiratory muscle training was good and no adverse events were observed. Treatment satisfaction and motivation, scored on 10-point scales, were 7.9 (± 0.7) and 8.2 (± 1.0), respectively. Postoperative atelectasis occurred in significantly fewer patients in the intervention group than in the control group (ϰ2DF1 = 3.85; P = 0.05): Length of hospital stay was 7.93 (± 1.94) days in the intervention group and 9.92 (± 5.78) days in the control group ( P = 0.24).

Conclusion: Inspiratory muscle training for 2-4 weeks before coronary artery bypass graft surgery was well tolerated by patients at risk of postoperative pulmonary complications and prevented the occurrence of atelectasis in these patients. A larger randomized clinical trial is warranted.

High thoracic anesthesia offers no major benefit over general anesthesia in on-pump cardiac surgery patients: a retrospective study

BACKGROUND

Thoracic epidural anesthesia (TEA) has been proposed to improve and facilitate early postoperative outcome in cardiac surgery. The aim of our study was to analyze early postoperative outcome data of patients undergoing cardiac surgery under general anesthesia (GA) with comparison to patients receiving combined TEA and GA.

METHODS

Medical records data from 288 patients who underwent elective on-pump cardiac surgery were retrieved and analyzed. Patients were divided into two study groups according to the type of anesthesia used: GA group (n = 141) and TEA group (n = 147). Early postoperative outcome data including quality of analgesia and major organ outcome parameters were compared between the study groups.

RESULTS

There was no major difference in early postoperative outcome data between the study groups, except for shorter time to extubation (6.0 ± 10.0 vs. 6.9 ± 8.8 h, respectively, P < 0.05) and hospital stay (10.7 ± 5.9 vs. 12.9 ± 8.8 days, respectively, P < 0.05) in TEA group compared to GA group. Also TEA group as compared to GA group had lower pain numeric rating scale scores (1 ± 1.1 vs. 1.4 ± 1.5 at 24 h, respectively, P < 0.05) and morphine requirements during the first 24 h after surgery (148.2 vs. 193 ± 85.4 μg/kg, respectively, P < 0.05).

CONCLUSION

Both anesthetic methods were equivalent in most postoperative outcome measures. Thoracic epidural analgesia provided superior pain relief, shorter time to extubation and earlier hospital discharge.

Mechanical ventilatory assistance may reduce dyspnea during walking especially in patients with impaired cardiopulmonary function early after cardiovascular surgery

BACKGROUND

To determine which patients effectively respond to ventilatory assistance (VA) and to examine the factors influencing patient response in patients who underwent cardiovascular (CV) surgery.

METHODS

We conducted the first walking session after surgery either with or without VA in a randomized order. The patients walked with 3cmH2O of inspiratory pressure support. We measured dyspnea and leg fatigue during initial walking either with or without VA by using a modified Borg scale. Ventilatory parameters were measured by mechanical ventilation before and immediately after walking. Lung function and maximal inspiratory pressure (MIP) were measured and chest radiographs were analyzed by the same cardiac surgeon on the same day as walking.

RESULTS

From the total of 74 patients who underwent CV surgery, 56 patients were successively enrolled in the study. Thirty-five out of 56 patients had dyspnea and 18 patients (30% of the total patients) effectively responded to VA (responders). Minute ventilation/estimated maximum voluntary ventilation immediately after walking significantly decreased with VA, and MIP was lower in responders than in non-responders after surgery. The responders revealed greater pulmonary edema scores than non-responders.

CONCLUSIONS

The findings of the present study suggest that VA may possibly facilitate successful mobilization early after CV surgery, especially in patients with impaired cardiopulmonary function.

Effect of Ultrafiltration on Pulmonary Function and Interleukins in Patients Undergoing Cardiopulmonary Bypass

OBJECTIVE

To evaluate the effect of ultrafiltration on interleukins, TNF-α levels, and pulmonary function in patients undergoing coronary artery bypass grafting (CABG).

DESIGN

Prospective, randomized, controlled trial.

SETTING

University hospital.

PARTICIPANTS

Forty patients undergoing CABG were randomized into a group assigned to receive ultrafiltration (UF) during cardiopulmonary bypass (CPB) or into another group (control) that underwent the same procedure but without ultrafiltration.

METHODS

Interleukins and TNF-α levels, pulmonary gas exchange, and ventilatory mechanics were measured in the preoperative, intraoperative, and postoperative periods. Interleukins and TNF-α also were analyzed in the perfusate of the test group.

MEASUREMENTS AND MAIN RESULTS

There were increases in IL-6 and IL-8 at 30 minutes after CPB and 6, 12, 24, and 36 hours after surgery, along with an increase in TNF-α at 30 minutes after CPB and 24, 36, and 48 hours after surgery in both groups. IL-1 increased at 30 minutes after CPB and 12 hours after surgery, while IL-6 increased 24 and 36 hours after surgery in the UF group. The analysis of the ultrafiltrate showed the presence of TNF-α and traces of IL-1β, IL-6, and IL-8. There were alterations in the oxygen index, alveolar-arterial oxygen difference, deadspace, pulmonary static compliance and airway resistance after anesthesia and sternotomy, as well as in airway resistance at 6 hours after surgery in both groups, with no difference between them.

CONCLUSIONS

Ultrafiltration increased the serum level of IL-1 and IL-6, while it did not interfere with gas exchange and pulmonary mechanics in CABG.

Matrix Metalloproteinase-9 Production following Cardiopulmonary Bypass Was Not Associated with Pulmonary Dysfunction after Cardiac Surgery

BACKGROUND

Cardiopulmonary bypass (CPB) causes release of matrix metalloproteinase- (MMP-) 9, contributing to pulmonary infiltration and dysfunction. The aims were to investigate MMP-9 production and associated perioperative variables and oxygenation following CPB.

METHODS

Thirty patients undergoing elective cardiac surgery were included. Arterial blood was sampled at 6 sequential points (before anesthesia induction, before CPB and at 2, 4, 6, and 24 h after beginning CPB) for plasma MMP-9 concentrations by ELISA. The perioperative laboratory data and variables, including bypass time, PaO2/FiO2, and extubation time, were also recorded.

RESULTS

The plasma MMP-9 concentrations significantly elevated at 2-6 h after beginning CPB (P < 0.001) and returned to the preanesthesia level at 24 h (P = 0.23), with predominant neutrophil counts after surgery (P < 0.001). The plasma MMP-9 levels at 4 and 6 h were not correlated with prolonged CPB time and displayed no association with postoperative PaO2/FiO2, regardless of reduced ratio from preoperative 342.9 ± 81.2 to postoperative 207.3 ± 121.3 mmHg (P < 0.001).

CONCLUSION

Elective cardiac surgery with CPB induced short-term elevation of plasma MMP-9 concentrations within 24 hours, however, without significant correlation with CPB time and postoperative pulmonary dysfunction, despite predominantly increased neutrophils and reduced oxygenation.

Changes in Spirometry After Left Ventricular Assist Device Implantation

Left ventricular assist devices (LVADs) are increasingly being used as life-saving therapy in patients with end-stage heart failure. The changes in spirometry following LVAD implantation and subsequent unloading of the left ventricle and pulmonary circulation are unknown. In this study, we explored long-term changes in spirometry after LVAD placement. In this retrospective study, we compared baseline preoperative pulmonary function test (PFT) results to post-LVAD spirometric measurements. Our results indicated that pulmonary function tests were significantly reduced after LVAD placement (forced expiratory volume in one second [FEV1 ]: 1.9 vs.1.7, P = 0.016; forced vital capacity [FVC]: 2.61 vs. 2.38, P = 0.03; diffusing capacity of the lungs for carbon monoxide [DLCO]: 14.75 vs. 11.01, P = 0.01). Subgroup analysis revealed greater impairment in lung function in patients receiving HeartMate II (Thoratec, Pleasanton, CA, USA) LVADs compared with those receiving HeartWare (HeartWare, Framingham, MA, USA) devices. These unexpected findings may result from restriction of left anterior hemi-diaphragm; however, further prospective studies to validate our findings are warranted.

On-pump versus off-pump coronary artery bypass graft surgery among patients with type 2 diabetes in the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial

OBJECTIVES

Conclusive evidence is lacking regarding the benefits and risks of performing off-pump versus on-pump coronary artery bypass graft (CABG) for patients with diabetes. This study aims to compare clinical outcomes after off-pump and on-pump procedures for patients with diabetes.

METHODS

The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial enrolled patients with type 2 diabetes and documented coronary artery disease, 615 of whom underwent CABG during the trial. The procedural complications, 30-day outcomes, long-term clinical and functional outcomes were compared between the off-pump and on-pump groups overall and within a subset of patients matched on propensity score.

RESULTS

On-pump CABG was performed in 444 (72%) patients, and off-pump CABG in 171 (28%). The unadjusted 30-day rate of death/myocardial infarction (MI)/stroke was significantly higher after off-pump CABG (7.0 vs 2.9%, P = 0.02) despite fewer complications (10.3 vs 20.7%, P = 0.003). The long-term risk of death [adjusted hazard ratio (aHR): 1.41, P = 0.2197] and major cardiovascular events (death, MI or stroke) (aHR: 1.47, P = 0.1061) did not differ statistically between the off-pump and on-pump patients. Within the propensity-matched sample (153 pairs), patients who underwent off-pump CABG had a higher risk of the composite outcome of death, MI or stroke (aHR: 1.83, P = 0.046); the rates of procedural complications and death did not differ significantly, and there were no significant differences in the functional outcomes.

CONCLUSIONS

Patients with diabetes had greater risk of major cardiovascular events long-term after off-pump CABG than after on-pump CABG.

Direct extubation onto high-flow nasal cannulae post-cardiac surgery versus standard treatment in patients with a BMI ≥30: a randomised controlled trial

PURPOSE

Patients with a body mass index (BMI) ≥30 kg/m(2) experience more severe atelectasis following cardiac surgery than those with normal BMI and its resolution is slower. This study aimed to compare extubation of patients post-cardiac surgery with a BMI ≥30 kg/m(2) onto high-flow nasal cannulae (HFNC) with standard care to determine whether HFNC could assist in minimising post-operative atelectasis and improve respiratory function.

METHODS

In this randomised controlled trial, patients received HFNC or standard oxygen therapy post-extubation. The primary outcome was atelectasis on chest X-ray. Secondary outcomes included oxygenation, respiratory rate (RR), subjective dyspnoea, and failure of allocated treatment.

RESULTS

One hundred and fifty-five patients were randomised, 74 to control, 81 to HFNC. No difference was seen between groups in atelectasis scores on Days 1 or 5 (median scores = 2, p = 0.70 and p = 0.15, respectively). In the 24-h post-extubation, there was no difference in mean PaO2/FiO2 ratio (HFNC 227.9, control 253.3, p = 0.08), or RR (HFNC 17.2, control 16.7, p = 0.17). However, low dyspnoea levels were observed in each group at 8 h post-extubation, median (IQR) scores were 0 (0-1) for control and 1 (0-3) for HFNC (p = 0.008). Five patients failed allocated treatment in the control group compared with three in the treatment group [Odds ratio 0.53, (95 % CI 0.11, 2.24), p = 0.40].

CONCLUSIONS

In this study, prophylactic extubation onto HFNC post-cardiac surgery in patients with a BMI ≥30 kg/m(2) did not lead to improvements in respiratory function. Larger studies assessing the role of HFNC in preventing worsening of respiratory function and intubation are required.

Biomarkers of lung injury in cardiothoracic surgery

Diagnosis of pulmonary dysfunction is currently almost entirely based on a vast series of physiological changes, but comprehensive research is focused on determining biomarkers for early diagnosis of pulmonary dysfunction. Here we discuss the use of biomarkers of lung injury in cardiothoracic surgery and their ability to detect subtle pulmonary dysfunction in the perioperative period. Degranulation products of neutrophils are often used as biomarker since they have detrimental effects on the pulmonary tissue by themselves. However, these substances are not lung specific. Lung epithelium specific proteins offer more specificity and slowly find their way into clinical studies.

[Cardiac surgery in underlying chronic pulmonary disease. Prognostic implications and efficient preoperative evaluation]

Cardiac surgery in patients with chronic pulmonary diseases carries a high risk of postoperative pulmonary complications (ppc) because both are known to cause ppc. Autopsy studies have revealed ppc as the main cause of mortality in approximately 5-8% of patients after cardiac surgery. Not all pulmonary diseases are high risk comorbidities in cardiac surgery: whereas chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea significantly increase the risk of ppc, a well controlled asthma does not carry an additional risk of ppc. A thorough preoperative risk stratification is crucial for risk estimation and some validated risk calculators, such as the Canet risk score exist. Surprisingly the additional value of pulmonary function testing beyond a thorough patient history and physical examination is low. No validated thresholds exist in pulmonary function testing below which cardiac surgery should be denied if clearly indicated. Perioperative strategies for risk reduction should be applied to all patients whenever possible.

Spirometric values and chest pain intensity three days post-operative coronary artery bypass graft surgery

Aim

Coronary artery bypass graft surgery (CABG) is proved to have ventilatory complications and reduction in spirometric values. This study aimed to examine the hypothesis that reduction of post-operative chest pain intensity would be associated with improvement in the spirometric values for patient underwent CABG.

Materials and method

26 cardiac patients recruited for this study. Their convenience to the study inclusion criteria decided their eligibility. Through 3 days after elective CABG their spirometric values were measured along with their perception to chest pain intensity using 0–10 numeric rating scale. Collected data were recorded and analyzed statistically.

Results

Chest pain intensity showed progressive significant (P = 0.0001) reduction through the 3 days post-operative. On the other hand spirometric values also showed progressive improvement through the 3 days post-operative. This improvement was significant for all measured spirometric values except for the ratio of forced expiratory volume in the 1st second to the forced vital capacity (P = 0.134). There was no significant relationship between the chest pain intensity and spirometric values. This was applied to all measured spirometric values and to the 3 days postoperative.

Conclusion

The current study findings rejected the examined hypothesis that reduction of post-operative chest pain intensity would be associated with improvement in the spirometric values for patient underwent coronary artery bypass graft surgery. There was no significant relationship between the chest pain intensity and any of the spirometric values at any of the 3 post-operative days.

Postoperative pulmonary dysfunction and mechanical ventilation in cardiac surgery

Postoperative pulmonary dysfunction (PPD) is a frequent and significant complication after cardiac surgery. It contributes to morbidity and mortality and increases hospitalization stay and its associated costs. Its pathogenesis is not clear but it seems to be related to the development of a systemic inflammatory response with a subsequent pulmonary inflammation. Many factors have been described to contribute to this inflammatory response, including surgical procedure with sternotomy incision, effects of general anesthesia, topical cooling, and extracorporeal circulation (ECC) and mechanical ventilation (VM). Protective ventilation strategies can reduce the incidence of atelectasis (which still remains one of the principal causes of PDD) and pulmonary infections in surgical patients. In this way, the open lung approach (OLA), a protective ventilation strategy, has demonstrated attenuating the inflammatory response and improving gas exchange parameters and postoperative pulmonary functions with a better residual functional capacity (FRC) when compared with a conventional ventilatory strategy. Additionally, maintaining low frequency ventilation during ECC was shown to decrease the incidence of PDD after cardiac surgery, preserving lung function.

Effectiveness of preoperative physical therapy for elective cardiac surgery

&lt;LEAP&gt; highlights the findings and application of Cochrane reviews and other evidence pertinent to the practice of physical therapy. The Cochrane Library is a respected source of reliable evidence related to health care. Cochrane systematic reviews explore the evidence for and against the effectiveness and appropriateness of interventions—medications, surgery, education, nutrition, exercise—and the evidence for and against the use of diagnostic tests for specific conditions. Cochrane reviews are designed to facilitate the decisions of clinicians, patients, and others in health care by providing a careful review and interpretation of research studies published in the scientific literature.1Each article in thisPTJseries summarizes a Cochrane review or other scientific evidence resource on a single topic and will present clinical scenarios based on real patients to illustrate how the results of the review can be used to directly inform clinical decisions. This article focuses on the effectiveness of preoperative physical therapy for elective cardiac surgery.More specifically, does preoperative physical therapy prevent postoperative pulmonary complications in patients undergoing elective cardiac surgery, and, if so, what types of interventions are most effective, and do patients with certain characteristics benefit from therapy?

Hospital-acquired pneumonia in patients undergoing coronary artery bypass graft; comparison of the center for disease control clinical criteria with physicians' judgment

BACKGROUND

Following coronary artery bypass graft (CABG), patients are at high risk (3.2%-8.3%) for developing hospital-acquired pneumonia (HAP) with mortality rate of 24% to 50%. Some of routine features in patients undergoing CABG are similar to clinical criteria of Center of Disease Control (CDC) for diagnosis of pneumonia. This may lead to over-diagnosis of pneumonia in these patients.

OBJECTIVES

This study aimed to assess the frequency of CDC criteria for diagnosis of pneumonia in patients undergoing CABG.

PATIENTS AND METHODS

This study was performed on CABG candidates admitted to post cardiac surgery Intensive Care Unit (ICU) in a six-month period. Patient's records, Chest-X-Ray, and Laboratory tests were assessed for PNU1-CDC criteria for HAP diagnosis. At the same time, a physician who was unaware of the study protocol assessed the clinical diagnosis. Then the results were compared with CDC criteria-based diagnosis.

RESULTS

Of total 300 patients, 9 (3%) met CDC criteria for diagnosis of pneumonia while none of the cases were diagnosed as HAP according to the physicians' clinical diagnosis. All nine patients were discharged with proper general condition and no need of antibiotic therapy. This study showed that loss of consciousness, tachypnea, dyspnea, PaO2 < 60 mm Hg, PaO2/FiO2 < 240, and local infiltration in 24 hours of operation were misleading features of CDC criteria, which were not considered in physicians' clinical judgment to establish the diagnosis.

CONCLUSIONS

Our findings suggest that in Post-CABG patients, physicians could judge the occurrence of HAP more accurately in comparison to making the diagnosis based on CDC criteria alone. Expert physician may intentionally do not take some of these criteria into account according the patients' course of disease. Therefore, it is suggested that the value of these criteria in special group of patients like those undergoing CABG should be re-evaluated.

Evaluation of noninvasive positive pressure ventilation after extubation from moderate positive end-expiratory pressure level in patients undergoing cardiovascular surgery: a prospective observational study

BACKGROUND

It remains to be clarified if the application of noninvasive positive pressure ventilation (NPPV) is effective after extubation in patients with hypoxemic respiratory failure who require the sufficient level of positive end-expiratory pressure (PEEP). This study was aimed at examining the effect and the safety of NPPV application following extubation in patients requiring moderate PEEP level for sufficient oxygenation after cardiovascular surgery.

METHODS

With institutional ethic committee approval, the patients ventilated invasively for over 48 h after cardiovascular surgery were enrolled in this study. The patients who failed the first spontaneous breathing trial (SBT) at 5 cmH2O of PEEP, but passed the second SBT at 8 cmH2O of PEEP, received NPPV immediately after extubation following our weaning protocol. Respiratory parameters (partial pressure of arterial oxygen tension to inspiratory oxygen fraction ratio: P/F ratio, respiratory ratio, and partial pressure of arterial carbon dioxide: PaCO2) 2 h after extubation were evaluated with those just before extubation as the primary outcome. The rate of re-intubation, the frequency of respiratory failure and intolerance of NPPV, the duration of NPPV, and the length of intensive care unit (ICU) stay were also recorded.

RESULTS

While 51 postcardiovascular surgery patients were screened, 6 patients who met the criteria received NPPV after extubation. P/F ratio was increased significantly after extubation compared with that before extubation (325 ± 85 versus 245 ± 55 mmHg, p < 0.05). The other respiratory parameters did not change significantly. Re-intubation, respiratory failure, and intolerance of NPPV never occurred. The duration of NPPV and the length of ICU stay were 2.7 ± 0.7 (SD) and 7.5 (6 to 10) (interquartile range) days, respectively.

CONCLUSIONS

While further investigation should be warranted, NPPV could be applied effectively and safely after extubation in patients requiring the moderate PEEP level after cardiovascular surgery.

The role of remote ischemic preconditioning in organ protection after cardiac surgery: a meta-analysis

BACKGROUND

Remote ischemic preconditioning (RIPC) appears to protect distant organs from ischemia-reperfusion injury. We undertook meta-analysis of clinical studies to evaluate the effects of RIPC on organ protection and clinical outcomes in patients undergoing cardiac surgery.

METHODS

A review of evidence for cardiac, renal, and pulmonary protection after RIPC was performed. We also did meta-regressions on RIPC variables, such as duration of ischemia, cuff pressure, and timing of application of preconditioning. Secondary outcomes included length of hospital and intensive care unit stay, duration of mechanical ventilation, and mortality at 30 days.

RESULTS

Randomized control trials (n = 25) were included in the study for quantitative analysis of cardiac (n = 16), renal (n = 6), and pulmonary (n = 3) protection. RIPC provided statistically significant cardiac protection (standardized mean difference [SMD], -0.77; 95% confidence interval [CI], -1.15, -0.39; Z = 3.98; P < 0.0001) and on subgroup analysis, the protective effect remained consistent for all types of cardiac surgical procedures. However, there was no evidence of renal protection (SMD, 0.74; 95% CI, 0.53, 1.02; Z = 1.81; P = 0.07) or pulmonary protection (SMD, -0.03; 95% CI, -0.56, 0.50; Z = 0.12; P = 0.91). There was no statistical difference in the short-term clinical outcomes between the RIPC and control groups.

CONCLUSIONS

RIPC provides cardiac protection, but there is no evidence of renal or pulmonary protection in patients undergoing cardiac surgery using cardiopulmonary bypass. Larger multicenter trials are required to define the role of RIPC in surgical practice.

Análise de parâmetros funcionais pulmonares e da qualidade de vida na revascularização do miocárdio

INTRODUÇÃO: A cirurgia de revascularização do miocárdio resulta em importantes alterações na força e função dos músculos respiratórios e na qualidade de vida de indivíduos submetidos a tal procedimento. OBJETIVOS: Comparar a força muscular respiratória, o pico de fluxo expiratório e a qualidade de vida no pré e no pós-operatório de pacientes submetidos à revascularização do miocárdio e analisar a correlação destes parâmetros com a mecânica pulmonar e a capacidade funcional no período pós-operatório. MATERIAIS E MÉTODOS: Avaliou-se a força muscular respiratória, o pico de fluxo expiratório e a qualidade de vida de 12 pacientes submetidos a revascularização do miocárdio no pré-operatório e no quinto dia pós-operatório. O teste de caminhada de 6 minutos e avaliação da mecânica pulmonar foram analisados apenas no pós-operatório. RESULTADOS: Houve aumento da pressão expiratória máxima, do pico de fluxo expiratório e da qualidade de vida no pós-operatório em relação ao pré-operatório, sem diferenças na pressão inspiratória máxima. O pico de fluxo expiratório correlacionou-se positivamente com a pressão expiratória máxima. A qualidade de vida pré-operatória associou-se com o gênero e com a resistência das vias aéreas. Não houve correlação entre os fatores analisados no pré-operatório com a complacência pulmonar e com o teste de caminhada de 6 minutos. CONCLUSÃO: Pacientes submetidos a cirurgia de revascularização do miocárdio apresentam aumento da força muscular expiratória, do pico de fluxo expiratório e da qualidade de vida em comparação com o período anterior à cirurgia. Tais parâmetros não são bons preditores de complacência pulmonar e de capacidade funcional no período pós-operatório.

Preoperative mild cognitive dysfunction predicts pulmonary complications after coronary artery bypass graft surgery

OBJECTIVES

In elderly patients with mild cognitive impairment, noncompliance with respiratory exercises, ineffective expectoration, reluctance in mobilization, and difficulty in learning the use of drugs such as inhalers were observed in the early postoperative period after coronary artery bypass graft surgery. It was hypothesized that respiratory complications may be more frequent in these patients, and so the postoperative respiratory complications in patients with preoperative mild cognitive impairment were compared with the postoperative respiratory complications of a control group.

DESIGN

A prospective cohort control.

SETTING

A university hospital.

PARTICIPANTS

Patients undergoing elective coronary artery bypass graft surgery.

INTERVENTIONS

Investigators separated 48 patients>70 years old who were scheduled for elective coronary artery bypass graft surgery into two groups: patients with preoperative mild cognitive impairment (group A, n = 25) and patients with no cognitive impairment (control group; group B, n = 23). The patients' cognitive status was evaluated preoperatively by the Montreal Cognitive Assessment test.

MEASUREMENTS AND MAIN RESULTS

Pulmonary functions and respiratory complications were evaluated via chest x-rays and spirometry tests preoperatively and postoperatively. A significant difference was observed between the groups, particularly with regard to atelectasis and prolonged ventilation (p<0.001 and p<0.05). No significant impairment was observed in the spirometry tests of the control group. However, a significant deterioration was observed in the postoperative spirometry tests of patients with preoperative mild cognitive impairment.

CONCLUSIONS

This study suggested that mild cognitive impairment was associated with pulmonary complications after coronary artery bypass graft surgery.

The analgesic effects of a bilateral sternal infusion of ropivacaine after cardiac surgery

BACKGROUND AND OBJECTIVES

The aim of this study was to assess the effects of a continuous postoperative administration of local anesthetic through 2 catheters placed deeply under fascia at the lateral edges of the sternum, close to the emergence of the intercostal nerves. We focused on pain during mobilization, as this aspect is likely to interact with postoperative morbidity.

METHODS

Forty adult patients scheduled for open heart surgery with sternotomy were included in this randomized, placebo-controlled, double-blind study. A continuous fixed-rate infusion of 4 mL/hr of 0.2% ropivacaine or normal saline was administered during the first 48 postoperative hrs. All patients received acetaminophen and self-administered morphine. The efficacy outcomes were as follows: pain score during standardized mobilization and at rest; morphine consumption; spirometry and arterial blood gases; postoperative rehabilitation criteria, and patient satisfaction. Total ropivacaine plasma level was monitored throughout the study.

RESULTS

Pain scores were lower in the ropivacaine group during mobilization (P = 0.0004) and at rest (P = 0.0006), but the analgesic effects were mostly apparent during the second day after surgery, with a 41% overall reduction in movement-evoked pain levels. The bilateral sternal block also reduced morphine consumption. It improved the patients' satisfaction and rehabilitation, but no effects were noted on respiratory outcomes. No major adverse effect due to the treatment occurred, but the ropivacaine plasma level was greater than 4 mg/L in 1 patient.

CONCLUSIONS

This technique may find a role within the framework of multimodal analgesia after sternotomy, although further confirmatory studies are needed.