Noncardiac surgery: postoperative arrhythmias

Causes of Perioperative Cardiac Arrest: Mnemonic, Classification, Monitoring, and Actions

Perioperative cardiac arrest (POCA) is a catastrophic complication that requires immediate recognition and correction of the underlying cause to improve patient outcomes. While the hypoxia, hypovolemia, hydrogen ions (acidosis), hypo-/hyperkalemia, and hypothermia (Hs) and toxins, tamponade (cardiac), tension pneumothorax, thrombosis (pulmonary), and thrombosis (coronary) (Ts) mnemonic is a valuable tool for rapid differential diagnosis, it does not cover all possible causes leading to POCA. To address this limitation, we propose using the preload-contractility-afterload-rate and rhythm (PCARR) construct to categorize POCA, which is comprehensive, systemic, and physiologically logical. We provide evidence for each component in the PCARR construct and emphasize that it complements the Hs and Ts mnemonic rather than replacing it. Furthermore, we discuss the significance of utilizing monitored variables such as electrocardiography, pulse oxygen saturation, end-tidal carbon dioxide, and blood pressure to identify clues to the underlying cause of POCA. To aid in investigating POCA causes, we suggest the Anesthetic care, Surgery, Echocardiography, Relevant Check and History (A-SERCH) list of actions. We recommend combining the Hs and Ts mnemonic, the PCARR construct, monitoring, and the A-SERCH list of actions in a rational manner to investigate POCA causes. These proposals require real-world testing to assess their feasibility.

External Validation of the Revised Cardiac Risk Index and the Geriatric-Sensitive Perioperative Cardiac Risk Index in Oldest Old Patients Following Surgery Under Spinal Anaesthesia; a Retrospective Cross-Sectional Cohort Study

Background

The Revised Cardiac Risk Index (RCRI) and the Geriatric Sensitive Cardiac Risk Index (GSCRI) estimate the risk of postoperative major adverse cardiac events (MACE) regardless of the type of anesthesia and without specifying the oldest old patients. Since spinal anesthesia (SA) is a preferred technique in geriatrics, we aimed to test the external validity of these indices in patients ≥ 80 years old who underwent surgery under SA and tried to identify other potential risk factors for postoperative MACE.

Methods

The performance of both indices to estimate postoperative in-hospital MACE risk was tested through discrimination, calibration, and clinical utility. We also investigated the correlation between both indices and postoperative ICU admission and length of hospital stay (LOS).

Results

The MACE incidence was 7.5%. Both indices had limited discriminative (AUC for RCRI and GSCRI were 0.69 and 0.68, respectively) and predictive abilities. The regression analysis showed that patients with atrial fibrillation (AF) were 3.77 and those with trauma surgery were 2.03 times more likely to exhibit MACE, and the odds of MACE increased by 9% for each additional year above 80. Introducing these factors into both indices (multivariable models) increased the discriminative ability (AUC reached 0.798 and 0.777 for RCRI and GSCRI, respectively). Bootstrap analysis showed that the predictive ability of the multivariate GSCRI but not the multivariate RCRI improved. Decision curve analysis (DCA) showed that multivariate GSCRI had superior clinical utility when compared with multivariate RCRI. Both indices correlated poorly with postoperative ICU admission and LOS.

Conclusion

Both indices had limited predictive and discriminative ability to estimate postoperative in-hospital MACE risk and correlated poorly with postoperative ICU admission and LOS, following surgery under SA in the oldest-old patients. Updated versions by introducing age, AF, and trauma surgery improved the GSCRI performance but not the RCRI.

OUP accepted manuscript

Tachyarrhythmias are common complications of critically ill patients treated on intensive care units. Landiolol is an ultra-short acting beta-blocker with a very high beta1-selectivity. Therefore, landiolol effectively reduces heart rate with only minimal negative effects on blood pressure and inotropy. This article describes two cases of successful treatment of supraventricular and ventricular tachycardias with landiolol in critically ill patients.

Preoperative levels of natriuretic peptides and the incidence of postoperative atrial fibrillation after noncardiac surgery: a prospective cohort study

BACKGROUND

Postoperative atrial fibrillation (POAF) is associated with clinically significant short- and long-term complications after noncardiac surgery. Our aim was to describe the incidence of clinically important POAF after noncardiac surgery and establish the prognostic value of N-terminal pro-brain-type natriuretic peptide (NT-proBNP) in this context.

METHODS

The Vascular events In noncardiac Surgery patIents cOhort evaluatioN (VISION) Study was a prospective cohort study involving patients aged 45 years and older who had inpatient noncardiac surgery that was performed between August 2007 and November 2013. We determined 30-day incidence of clinically important POAF (i.e., resulting in angina, congestive heart failure, symptomatic hypotension or requiring treatment) using logistic regression models to analyze the association between preoperative NT-proBNP and POAF.

RESULTS

In 37 664 patients with no history of atrial fibrillation, we found that the incidence of POAF was 1.0% (95% confidence interval [CI] 0.9%-1.1%; 369 events); 3.2% (95% CI 2.3%-4.4%) in patients undergoing major thoracic surgery, 1.3% (95% CI 1.2%-1.5%) in patients undergoing major nonthoracic surgery and 0.2% (95% CI 0.1%-0.3%) in patients undergoing low-risk surgery. In a subgroup of 9789 patients with preoperative NT-proBNP measurements, the biomarker improved the prediction of POAF risk over conventional prognostic factors (likelihood ratio test p < 0.001; fraction of new information from NT-proBNP was 16%). Compared with a reference NT-proBNP measurement set at 100 ng/L, adjusted odds ratios for the occurrence of POAF were 1.31 (95% CI 1.15-1.49) at 200 ng/L, 2.07 (95% CI 1.27-3.36) at 1500 ng/L and 2.39 (95% CI 1.26-4.51) at 3000 ng/L.

INTERPRETATION

We determined that the incidence of clinically important POAF after noncardiac surgery was 1.0%. We also found that preoperative NT-proBNP levels were associated with POAF independent of established prognostic factors. Trial registration: ClinicalTrials.gov, no. NCT00512109.

Perioperative stroke-related mortality after non-cardiovascular, non-neurological procedures: A retrospective risk factor evaluation of common surgical comorbidities

BACKGROUND

Perioperative stroke-related mortality in the non-cardiovascular, non-neurological surgery population is an uncommon, yet devastating outcome. A combination of emboli and hypoperfusion may cause large vessel occlusions leading to perioperative strokes and mortality. Identifying independent risk factors for perioperative stroke-related mortality may enhance risk-stratification algorithms and preventative therapies.

OBJECTIVES

This study utilised cause-of-death data to determine independent risk scores for common surgical comorbidities that may lead to perioperative stroke-related mortality, including atrial fibrillation and asymptomatic carotid stenosis.

METHODS

This retrospective, IRB-exempt, case-control study evaluated non-cardiovascular, non-neurological surgical patients in a claims-based database. ICD-10-CM and ICD-9-CM codes identified cause of death and comorbidity incidences, respectively. A multivariate regression analysis then established adjusted independent risk scores of each comorbidity in relation to perioperative stroke-related mortality.

RESULTS

Patients with atrial fibrillation were more likely (1.7 aOR, 95% CI (1.1, 2.8) p = 0.02) to die from perioperative stroke-related mortality than from other causes. No association was found with asymptomatic carotid stenosis. Further, in-hospital strokes (25.9 aOR, 95% CI (16.0, 41.8) p < 0.001) or diabetes (1.8 aOR, 95% CI (1.1, 2.9) p = 0.02) may increase perioperative stroke-related mortality risk.

CONCLUSIONS

Atrial fibrillation, diabetes and in-hospital strokes may be independent risk factors for perioperative stroke-related mortality in the non-cardiovascular, non-neurological surgery population.

Postoperative atrial fibrillation is related to a worse outcome in patients undergoing surgery for hip fracture

Few information exist about incidence and prognostic significance of postoperative atrial fibrillation (POAF) in patients undergoing hip fracture surgery. In the period comprised between January 2012 and December 2016, we evaluated 3129 patients referred for hip fracture. At hospital admission 277 were in permanent atrial fibrillation and were excluded from the study. POAF was defined as symptomatic or asymptomatic AF of duration > 10 min occurring during hospitalization after hip surgery. In-hospital and 1-year outcomes of POAF patients were compared to that of an age- and sex-matched hip fracture control group. Survival rates were estimated by Kaplan-Meier curves and differences between groups compared by log-rank test. One hundred and four patients (mean age 83.7 years, men 27%) developed POAF (3.6%). Time of onset after surgery was on average 2 days after surgery. Eight POAF patients died during hospitalization. 81.7% were discharged in sinus rhythm. Patients with POAF had a longer time to surgery (3.8 ± 3.3 vs. 2.4 ± 1.6 days, p = 0.0007) and length of hospital stay (19.7 ± 10.4 vs. 14.4 ± 5.1 days p < 0.0001) in comparison to control group. Eight patients had AF recurrence during follow-up. 1-year mortality was significantly higher in POAF group in comparison to control group (39.3. vs 20.9%, p < 0.001). Postoperative atrial fibrillation in patients undergoing hip fracture surgery is associated with a longer length of hospital stay in comparison to patients who maintain stable sinus rhythm. Moreover, these patients had a significant higher mortality at 1-year follow-up.

Open kidney cancer surgery and perioperative cardiac arrhythmias

Introduction

Although cardiac arrhythmias during anesthesia are often observed, the literature focuses mainly on cardio-thoracic surgery. We aimed to evaluate the incidence of arrhythmias appearing in the perioperative period in patients undergoing urological surgery and furthermore to define whether combining general with epidural anesthesia prevents them.

Material and methods

The study included 50 adults, without a prior cardiac or arrhythmia history, undergoing an open kidney cancer surgery, who were randomly allocated to receive either general or combined epidural/general anesthesia. A Holter monitor was applied the evening before the surgery, tracing continuously for a period of 24 hours (7PM–7PM). ClinicalTrials.gov NCT02988219

Results

There was no statistical difference in the arrhythmia occurrence between the randomization groups. Among 65.21% the following arrhythmias were observed: 27 – bradycardia, 4 – sinus pause, 6 – ventricular extrasystoles (>1000/24 hours), 3 – supraventricular extrasystoles (>200/24 hours). The patients with arrhythmia were older and often with hypertension (p <0.01). A longer surgery duration predisposed to arrhythmia appearance (122.5 vs. 99 minutes), (p <0.01). The temperature measured at the beginning and at the end of the surgery was significantly lower among the participants with arrhythmia (p = 0.02, p = 0.01). The gender, body mass index (BMI), laboratory tests and the intake of intravenous fluids did not influence the occurrence of arrhythmia.

Conclusions

Perioperative cardiac arrhythmias (usually sinus arrhythmias) are common during an open kidney surgery and occur regardless of the anesthetic technique and usually do not require any treatment. Age, hypertension, long operation time or low body temperature predispose the patient to perioperative cardiac arrhythmias during surgery.

Postoperative Management in Patients with Pheochromocytoma and Paraganglioma

Pheochromocytomas and paragangliomas (PPGLs) are rare catecholamine-secreting neuroendocrine tumors of the adrenal medulla and sympathetic/parasympathetic ganglion cells, respectively. Excessive release of catecholamines leads to episodic symptoms and signs of PPGL, which include hypertension, headache, palpitations, and diaphoresis. Intraoperatively, large amounts of catecholamines are released into the bloodstream through handling and manipulation of the tumor(s). In contrast, there could also be an abrupt decline in catecholamine levels after tumor resection. Because of such binary manifestations of PPGL, patients may develop perplexing and substantially devastating cardiovascular complications during the perioperative period. These complications include hypertension, hypotension, arrhythmias, myocardial infarction, heart failure, and cerebrovascular accident. Other complications seen in the postoperative period include fever, hypoglycemia, cortisol deficiency, urinary retention, etc. In the interest of safe patient care, such emergencies require precise diagnosis and treatment. Surgeons, anesthesiologists, and intensivists must be aware of the clinical manifestations and complications associated with a sudden increase or decrease in catecholamine levels and should work closely together to be able to provide appropriate management to minimize morbidity and mortality associated with PPGLs.

A comparison of the incidence of supraventricular arrhythmias between thoracic paravertebral and intercostal nerve blocks in patients undergoing thoracoscopic surgery: A randomised trial

BACKGROUND

Postoperative supraventricular arrhythmias are common in patients after thoracoscopic lobectomy. Inadequate pain control has long been recognised as a significant risk factor for arrhythmias. The performance of ultrasound-guided (USG) thoracic paravertebral block (PVB) is increasing as an ideal technique for postoperative analgesia.

OBJECTIVE

We conducted this study to evaluate whether a single-shot USG thoracic PVB would result in fewer postoperative supraventricular tachycardias (SVT) than intercostal nerve blocks (ICNBs) after thoracoscopic pulmonary resection.

DESIGN

A randomised controlled study.

SETTING

A single university hospital.

PATIENTS

Sixty-eight patients undergoing thoracoscopic lobectomy were randomised into two equal groups of 34.

INTERVENTIONS

For postoperative pain control, all patients received a total of 0.3 ml kg of a mixture containing 0.5% ropivacaine and 1/200 000 epinephrine after placement of needles for either a single thoracic PVB or two individual ICNBs, both guided by ultrasound. Data were obtained during the first 48 postoperative hours.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of SVT after thoracoscopic pulmonary resection.

RESULTS

During the first 48 postoperative hours, the incidences of SVT and atrial fibrillation were lower in the USG thoracic PVB group (14.7 vs. 46.9%, P = 0.004 and 3.0 vs. 18.8%, P = 0.037, respectively). The requirement for β-receptor blockade was more frequent in the ICNBs group than in the PVB group (5.9 vs. 25%, P = 0.033).

CONCLUSION

After placement of the needle using ultrasound guidance, a single-shot thoracic PVB is a well tolerated and effective technique to reduce the incidences of postoperative SVT and atrial fibrillation in patients undergoing thoracoscopic pulmonary resection.

TRIAL REGISTRATION

http://www.chictr.org/cn/, registration number: ChiCTR-IOR-17010952.

Readmissions after colorectal surgery: not all are equal

PURPOSE

This study aims to assess factors associated with preventable readmissions after colorectal resection.

METHODS

All readmissions following colorectal resection from May 2013 to May 2016 at an academic medical center were reviewed. Readmissions that could be prevented were identified. Factors associated with preventable readmission were assessed using logistic regression.

RESULTS

Of 686 patients discharged during the study period, there were 75 patients (11%) with unplanned readmission. Twenty-nine readmissions (39%) were preventable-these readmissions were due to dehydration or acute kidney injury, pain, ostomy complications, and gastrointestinal bleeding. On regression analysis, the strongest preoperative risk factors associated with preventable readmission were urgent or emergent operation (OR 4.0, 95% CI 1.6-9.9), recent myocardial infarction (OR 2.9, 95% CI 1.0-9.0), total or subtotal colectomy (OR 2.8, 95% CI 1.1-7.3), and American Society of Anesthesiologist score ≥ 3 (OR 2.2, 95% CI 1.0-4.7). Intraoperative risk factors associated with preventable readmission included intraoperative stapler complication (OR 24.2, 95% CI 1.5-397). Postoperative risk factors associated with preventable readmission included postoperative arrhythmia (OR 5.6, 95% CI 2.0-16.1), and postoperative anemia (OR 2.6, 95% CI 1.2-5.7). On multivariable analysis while controlling for procedure type, urgent or emergent operation (OR 2.9, 95% CI 1.1-8.2), intraoperative stapler complication (OR 37.5, 95% CI 2.3-627.8), and postoperative arrhythmia (OR 4, 95% CI 1.3-12.8) remained statistically significant.

CONCLUSION

Approximately 40% of readmissions following colorectal surgery are potentially preventable. Since specific patients and factors that are associated with preventable readmission can be identified, resources should be targeted to factors associated with preventable readmissions.

Risk of Ischemic Stroke After Perioperative Atrial Fibrillation in Total Knee and Hip Arthroplasty Patients

BACKGROUND

To determine if new-onset perioperative atrial fibrillation during arthroplasty represents a benign response to intraoperative cardiac stress or is a risk factor for stroke, we evaluated the subsequent risk of ischemic stroke in patients with new-onset atrial fibrillation occurring during primary total knee arthroplasty (TKA) and total hip arthroplasty (THA).

METHODS

Discharge data of all adult patients undergoing primary TKA or THA from 1997 to 2013 were queried via the New York Statewide Planning and Research Cooperative System database to find patients with new-onset perioperative atrial fibrillation. These patients were then followed up over time to determine their risk of ischemic stroke.

RESULTS

Of the 312,636 TKA and 215,610 THA unique patient admissions, 3646 (0.7%) had a diagnosis of new-onset perioperative atrial fibrillation. The cohort of patients with this finding was 58.9% female with an average age of 73.6 years and higher prevalence of vascular risk factors. Adjusting for validated stroke risk factors, the risk of ischemic stroke within 1 year after THA or TKA in patients with new-onset atrial fibrillation was 2.7 times higher than in those without a history of atrial fibrillation (odds ratio: 2.7, 95% confidence interval: 1.5-4.8). Hospital length of stay and charges for patients with new-onset atrial fibrillation were also greater than patients with either a prior diagnosis or no diagnosis of atrial fibrillation.

CONCLUSION

New-onset atrial fibrillation during TKA and THA may indicate risk of ischemic stroke following surgery that should warrant medical follow-up and may increase hospital length of stay and charges.

Postoperative Tachycardia: Clinically Meaningful or Benign Consequence of Orthopedic Surgery?

OBJECTIVE

To determine the clinical significance of tachycardia in the postoperative period.

PATIENTS AND METHODS

Individuals 18 years or older undergoing hip and knee arthroplasty were included in the study. Two data sets were collected from different time periods: development data set from January 1, 2011, through December 31, 2011, and validation data set from December 1, 2012, through September 1, 2014. We used the development data set to identify the optimal definition of tachycardia with the strongest association with the vascular composite outcome (pulmonary embolism and myocardial necrosis and infarction). The predictive value of this definition was assessed in the validation data set for each outcome of interest, pulmonary embolism, myocardial necrosis and infarction, and infection using multiple logistic regression to control for known risk factors.

RESULTS

In 1755 patients in the development data set, a maximum heart rate (HR) greater than 110 beats/min was found to be the best cutoff as a correlate of the composite vascular outcome. Of the 4621 patients who underwent arthroplasty in the validation data set, 40 (0.9%) had pulmonary embolism. The maximum HR greater than 110 beats/min had an odds ratio (OR) of 9.39 (95% CI, 4.67-18.87; sensitivity, 72.5%; specificity, 78.0%; positive predictive value, 2.8%; negative predictive value, 99.7%) for pulmonary embolism. Ninety-seven patients (2.1%) had myocardial necrosis (elevated troponin). The maximum HR greater than 110 beats/min had an OR of 4.71 (95% CI, 3.06-7.24; sensitivity, 47.4%; specificity, 78.1%; positive predictive value, 4.4%; negative predictive value, 98.6%) for this outcome. Thirteen (.3%) patients had myocardial infarction according to our predetermined definition, and the maximum HR greater than 110 beats/min had an OR of 1.72 (95% CI, 0.47-6.27).

CONCLUSION

Postoperative tachycardia within the first 4 days of surgery should not be dismissed as a postoperative variation in HR, but may precede clinically significant adverse outcomes.

Updates in perioperative medicine

BACKGROUND

As our surgical population becomes older and more medically complex, knowledge of the most recent perioperative literature is necessary to optimize perioperative care. We aim to summarize and critique literature published over the past year with the highest potential to impact the clinical practice of perioperative medicine.

METHODS

We reviewed articles published between January 2014 and April 2015, identified via MEDLINE search. The final 10 articles selected were determined by consensus among all authors, with criteria for inclusion including scientific rigor and relevance to perioperative medicine practice.

RESULTS

Key findings include: long term β-blockade should be continued prior to surgery, routine screening with postoperative troponin is not recommended, initiation/continuation of aspirin or clonidine in the perioperative period is not beneficial and may increase adverse outcomes, preoperative diagnosis and treatment of obstructive sleep apnea may reduce risk of postoperative cardiovascular complications, new pulmonary risk indices are available that accurately estimate postoperative pulmonary complications, postoperative atrial fibrillation is associated with increased long-term stroke risk, risk scores such as the CHADS2 (Congestive heart failure, Hypertension, Age ≥75 years, Diabetes Mellitus, previous stroke or transient ischemic attack) are superior to the Revised Cardiac Risk Index in predicting adverse postoperative outcomes for patients with nonvalvular atrial fibrillation, and utilization of bridging anticoagulation comes with a much higher risk of bleeding compared to patients who are not bridged.

CONCLUSIONS

The body of literature reviewed provides important information for clinicians caring for surgical patients across multiple fronts, including preoperative risk assessment, medication management, and postoperative medical care.

Risk factors and clinical outcomes of arrhythmias in the medical intensive care unit

BACKGROUND

The clinical impact of arrhythmias on the continuum of critical illness is unclear, and data in medical intensive care units (ICU) is lacking. In this study, we distinguish between different types of arrhythmias and evaluate if their distinction is of clinical importance based on ICU length of stay and mortality outcomes.

METHODS

We performed a retrospective analysis of 215 patients in a community-based teaching hospital medical ICU. Variables gathered include sociodemographic data, arrhythmias identified and interpreted by the study team, and admission diagnoses coded into clinical mediator categories based on theorized common risk pathways. Univariable and multivariable Poisson regression models were used to identify risk factors for developing arrhythmias by type, prolonged length of stay, and hospital mortality.

RESULTS

Significant arrhythmia was detected in 28.8 % of subjects with most new arrhythmia events developing within the first 3 days of ICU stay. Acute myocardial ischemia and acute kidney injury at the time of ICU admission were associated with an increased risk of developing supraventricular arrhythmias (SVA) (RR = 2.02; 95 % CI 1.08-3.78 and RR = 1.93; 95 %CI 1.09-3.37, respectively). SVA in the first 3 days of ICU stay was associated with an increased risk of prolonged ICU stay (RR = 1.47; 95 % CI 1.09-1.97). After controlling for clinical mediators, development of SVA was not independently associated with in-hospital mortality. No mediators significantly increased the risk of developing ventricular arrhythmias (VA). VA were not associated to prolonged ICU stay but were associated with increased risk of hospital mortality (RR = 1.93; 95 % CI 1.18-3.15).

CONCLUSIONS

It is important to distinguish between supraventricular and ventricular arrhythmias for outcomes in the medical ICU setting. Developing a new VA increases the risk of in-hospital mortality independently. Developing a new SVA increases the risk of having a prolonged ICU stay but does not appear to increase in-hospital mortality independently. These findings suggest that the development of a VA should be considered an independent morbid event and not necessarily the end result of a complicated clinical course, while a new SVA may be considered a cardiac complication of the disease continuum which may add complexity to an ICU stay.

Use of ivabradine and atorvastatin in emergent orthopedic lower limb surgery and computed tomography coronary plaque imaging and novel biomarkers of cardiovascular stress and lipid metabolism for the study and prevention of perioperative myocardial infarction: study protocol for a randomized controlled trial

Background

The incidence of perioperative myocardial infarction (PMI) globally is known to be around 2 to 3% and can prolong hospitalization, increased morbidity and mortality. Little is known about the pathophysiology and risk factors for PMI. We investigate the presence of elevated novel cardiac markers and preoperative coronary artery plaque through contemporary laboratory techniques to determine the correlation with PMI, as well as studying ivabradine and atorvastatin as protective pharmacotherapies against PMI in the context of orthopedic surgery.

Methods/Design

We aim to enroll 200 patients aged above 60 years who suffer from neck of femur fracture requiring surgery. Patients will be randomized to four arms (no study drugs, atorvastatin only, ivabradine only and ivabradine and atorvastatin). Our primary outcome is incidence of PMI. All patients will receive an electrocardiogram, cardiac echocardiography, measurement of novel cardiac biomarkers and computed tomography (CT) coronary angiography. A telephone interview post discharge will be conducted at 30 days, 60 days and 1 year.

Discussion

We postulate that ivabradine and atorvastatin will reduce the rate and magnitude of PMI following surgery by reducing heart rate and attenuating catecholamine-induced tachycardia postoperatively. Secondly, we postulate that postoperative reduction in heart rate and catecholamine-induced tachycardia with ivabradine will correlate with a reduction in cardiovascular novel biomarkers which will reduce atrial stretch and postoperative incidence of arrhythmia. We aim to demonstrate that treatment with ivabradine and atorvastatin will cause a reduction in the incidence and magnitude of PMI, the benefit of which is derived primarily in patients with greater atherosclerotic burden as measured by higher CT coronary calcium scores.

Trial registration

This study protocol has been listed in the Australia New Zealand Clinical Trial Registry (registration number: ACTRN12612000340831) on 23 March 2012.

Perioperative atrial fibrillation and the long-term risk of ischemic stroke

IMPORTANCE

Clinically apparent atrial fibrillation increases the risk of ischemic stroke. In contrast, perioperative atrial fibrillation may be viewed as a transient response to physiological stress, and the long-term risk of stroke after perioperative atrial fibrillation is unclear.

OBJECTIVE

To examine the association between perioperative atrial fibrillation and the long-term risk of stroke.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study using administrative claims data on patients hospitalized for surgery (as defined by surgical diagnosis related group codes), and discharged alive and free of documented cerebrovascular disease or preexisting atrial fibrillation from nonfederal California acute care hospitals between 2007 and 2011. Patients undergoing cardiac vs other types of surgery were analyzed separately.

MAIN OUTCOMES AND MEASURES

Previously validated diagnosis codes were used to identify ischemic strokes after discharge from the index hospitalization for surgery. The primary predictor variable was atrial fibrillation newly diagnosed during the index hospitalization, as defined by previously validated present-on-admission codes. Patients were censored at postdischarge emergency department encounters or hospitalizations with a recorded diagnosis of atrial fibrillation.

RESULTS

Of 1,729,360 eligible patients, 24,711 (1.43%; 95% CI, 1.41%-1.45%) had new-onset perioperative atrial fibrillation during the index hospitalization and 13,952 (0.81%; 95% CI, 0.79%-0.82%) experienced a stroke after discharge. At 1 year after hospitalization for cardiac surgery, cumulative rates of stroke were 0.99% (95% CI, 0.81%-1.20%) in those with perioperative atrial fibrillation and 0.83% (95% CI, 0.76%-0.91%) in those without atrial fibrillation. At 1 year after noncardiac surgery, cumulative rates of stroke were 1.47% (95% CI, 1.24%-1.75%) in those with perioperative atrial fibrillation and 0.36% (95% CI, 0.35%-0.37%) in those without atrial fibrillation. In a Cox proportional hazards analysis accounting for potential confounders, perioperative atrial fibrillation was associated with subsequent stroke both after cardiac surgery (hazard ratio, 1.3; 95% CI, 1.1-1.6) and noncardiac surgery (hazard ratio, 2.0; 95% CI, 1.7-2.3). The association was significantly stronger for perioperative atrial fibrillation after noncardiac vs cardiac surgery (P < .001 for interaction).

CONCLUSIONS AND RELEVANCE

Among patients hospitalized for surgery, perioperative atrial fibrillation was associated with an increased long-term risk of ischemic stroke, especially following noncardiac surgery.

Anesthetic management for esophageal resection

Surgical resection remains a standard treatment option for localized esophageal cancer. Surgical approaches to esophagectomy include transhiatal and transthoracic techniques as well as minimally invasive techniques that have been developed to reduce the morbidities associated with laparotomy and thoracotomy incisions. The perioperative mortality for esophagectomy remains high with cardiopulmonary and anastomotic complications as the most frequent and serious morbidities. This article reviews the management of patients presenting for esophagectomy, with a focus on evidence-based anesthetic and perioperative approaches for improving outcomes.

Postoperative atrial fibrillation

Postoperative atrial fibrillation (POAF) is common among surgical patients and associated with a worse outcome. Pathophysiology of POAF is not fully disclosed, and several perioperative factors could be involved. Direct cardiac stimulation from perioperative use of catecholamines or increased sympathetic outflow from volume loss/anaemia/pain may play a role. Metabolic alterations, such as hypo-/hyperglycaemia and electrolyte disturbances, may also contribute to POAF. Moreover, inflammation, both systemic and local, may play a role in its pathogenesis. Strategies to prevent POAF aim at reducing its incidence and ameliorate global outcome of surgical patients. Nonpharmacological prophylaxis includes an adequate control of postoperative pain, the use of thoracic epidural analgesia, optimization of perioperative oxygen delivery, and, possibly, modulation of surgery-associated inflammatory response with immunonutrition and antioxidants. Perioperative potassium and magnesium depletion should be corrected. The impact of those interventions on patients outcome needs to be further investigated.

Bradycardia in the early postoperative period of liver transplantation in children

The aim of this investigation was to describe the occurrence of bradycardia during the early postoperative period of liver transplantation in children. We retrospectively analyzed a cohort of 79 children with end-stage liver diseases who underwent liver transplantation. All children experienced >or=1 episode of a cardiac rate below the 2nd percentile of a 1-hour minimum duration, which was considered to be bradycardia. Patients <24 months were compared with older ones. The overall incidence of bradycardia was 37% (n = 31), including 25 patients who displayed bradycardia until postoperative day 3. In all cases, the electrocardiogram was normal, showing sinus rhythm. A comparison of the groups demonstrated an increased incidence of bradycardia among patients <24 months of age (P=.03). In all patients, there were no hemodynamic consequences; the cardiac rate returned to normal uneventfully. The explanations for bradycardia could not be applied to these patients because none of them had any volume change or electrolyte disturbances; liver function tests were not seriously altered. The mechanisms of this postoperative complications are unclear.

Incidence and prognostic impact of new-onset atrial fibrillation in patients with septic shock: a prospective observational study

Introduction

Since data regarding new-onset atrial fibrillation (AF) in septic shock patients are scarce, the purpose of the present study was to evaluate the incidence and prognostic impact of new-onset AF in this patient group.

Methods

We prospectively studied all patients with new-onset AF and all patients suffering from septic shock in a non-cardiac surgical intensive care unit (ICU) during a 13 month period.

Results

During the study period, 687 patients were admitted to the ICU, of which 58 patients were excluded from further analysis due to pre-existing chronic or intermittent AF. In 49 out of the remaining 629 patients (7.8%) new-onset AF occurred and 50 out of the 629 patients suffered from septic shock. 23 out of the 50 patients with septic shock (46%) developed new-onset AF. There was a steady, significant increase in C-reactive protein (CRP) levels before onset of AF in septic shock patients. ICU mortality in septic shock patients with new-onset AF was 10/23 (44%) compared with 6/27 (22%) in septic shock patients with maintained sinus rhythm (SR) (P = 0.14). During a 2-year follow-up there was a trend towards an increased mortality in septic shock patients with new-onset AF, but the difference did not reach statistical significance (P = 0.075). The median length of ICU stay among surviving patients was longer in patients with new-onset AF compared to those with maintained SR (30 versus 17 days, P = 0.017). The success rate to restore SR was 86%. Failure to restore SR was associated with increased ICU mortality (71.4% versus 21.4%, P = 0.015).

Conclusions

AF is a common complication in septic shock patients and is associated with an increased length of ICU stay among surviving patients. The increase in CRP levels before onset of AF may support the hypothesis that systemic inflammation is an important trigger for AF.

Risk factors and outcome of new-onset cardiac arrhythmias in vascular surgery patients

BACKGROUND

The pathophysiology of new-onset cardiac arrhythmias is complex and may bring about severe cardiovascular complications. The relevance of perioperative arrhythmias during vascular surgery has not been investigated. The aim of this study was to assess risk factors and prognosis of new-onset arrhythmias during vascular surgery.

METHODS

A total of 513 vascular surgery patients, without a history of arrhythmias, were included. Cardiac risk factors, inflammatory status, and left ventricular function (LVF; N-terminal pro-B-type natriuretic peptide and echocardiography) were assessed. Continuous electrocardiography (ECG) recordings for 72 hours were used to identify ischemia and new-onset arrhythmias: atrial fibrillation, sustained ventricular tachycardia, supraventricular tachycardia, and ventricular fibrillation. Logistic regression analysis was applied to identify preoperative risk factors for arrhythmias. Cox regression analysis assessed the impact of arrhythmias on cardiovascular event-free survival during 1.7 years.

RESULTS

New-onset arrhythmias occurred in 55 (11%) of 513 patients: atrial fibrillation, ventricular tachycardia, supraventricular tachycardia, and ventricular fibrillation occurred in 4%, 7%, 1%, and 0.2%, respectively. Continuous ECG showed myocardial ischemia and arrhythmias in 17 (3%) of 513 patients. Arrhythmia was preceded by ischemia in 10 of 55 cases. Increased age and reduced LVF were risk factors for the development of arrhythmias. Multivariate analysis showed that perioperative arrhythmias were associated with long-term cardiovascular events, irrespective of the presence of perioperative ischemia (hazard ratio 2.2, 95% CI 1.3-3.8, P = .004).

CONCLUSION

New-onset perioperative arrhythmias are common after vascular surgery. The elderly and patients with reduced LVF show arrhythmias. Perioperative continuous ECG monitoring helps to identify this high-risk group at increased risk of cardiovascular events and death.

Atrial fibrillation following elective open abdominal aortic aneurysm repair

BACKGROUND

Atrial fibrillation is a common complication following major vascular surgery. It is often considered to be relatively benign but may represent the first sign of cardiac and non-cardiac complications. We conducted a retrospective study to determine the incidence and clinical associations of atrial fibrillation following open elective abdominal aortic aneurysm repair as well as its effect on prognosis.

METHODS

The case-notes of 200 consecutive patients undergoing open aneurysm repair were reviewed. Known pre-operative and intra-operative risk factors and potential post-operative associations with new-onset AF were recorded. Significant univariate correlates with AF were entered into a forward stepwise logistic regression model to test for independence. The effect of new-onset AF on long-term prognosis was assessed.

RESULTS

AF developed in 20 patients (10%) post-operatively. Previous cerebrovascular disease, aneurysm size and post-operative cardiac failure were associated with post-operative AF in univariate analyses. Cerebrovascular disease and post-operative cardiac failure were independently associated with new-onset AF. AF patients had a longer hospital stay. There was no difference in survival between those patients with and without new-onset AF.

CONCLUSION

New-onset AF is a common complication of open abdominal aortic aneurysm surgery and may indicate an underlying myocardial infarction. It is associated with a longer hospital stay and an increased risk of cardiac failure. Assessed and treated appropriately, it appears to have no effect on long-term prognosis.

Medication-related complications in the trauma patient

Trauma patients are twice as likely to have adverse reactions to medication as nontrauma patients. The need for medication in trauma patients is high. Surgery is often necessary, and immunosuppression and hypercoagulability may be present. Adverse drug events can be caused in part by altered pharmacokinetics, drug interactions, and polypharmacy. Medications may also have serious long-term adverse effects, which must be considered. It is not the purpose of this review article to discuss all adverse effects of all medications. This article will discuss the more common adverse effects of medications for trauma patients in the acute care setting, in the following categories: pain control, sedation, antibiotics, seizure prophylaxis in head trauma, atrial fibrillation, deep vein thrombosis and pulmonary embolism prophylaxis, hemodynamic support, adrenal insufficiency, factor VIIa.

The Changing Face of Postoperative Atrial Fibrillation Prevention

Atrial fibrillation is the most common postoperative arrhythmia with significant consequences on patient health. Postoperative atrial fibrillation (POAF) complicates up to 8% of all noncardiac surgeries, between 3% and 30% of noncardiac thoracic surgeries, and between 16% and 46% of cardiac surgeries. POAF has been associated with increased morbidity, mortality, and longer, more costly hospital stays. The risk of POAF after cardiac and noncardiac surgery may be affected by several epidemiologic and intraoperative factors, as well as by the presence of preexisting cardiovascular and pulmonary disorders. POAF is typically a transient, reversible phenomenon that may develop in patients who possess an electrophysiologic substrate for the arrhythmia that is present before or as a result of surgery. Numerous studies support the efficacy of beta-blockers in POAF prevention; they are currently the most common medication used in POAF prophylaxis. Perioperative amiodarone, sotalol, nondihydropyridine calcium channel blockers, and magnesium sulfate have been associated with a reduction in the occurrence of POAF. Biatrial pacing is a nonpharmacologic method that has been associated with a reduced risk of POAF. Additionally, recent studies have demonstrated that hydroxymethylglutaryl-CoA reductase inhibitors may decrease the risk of POAF. Finally, based on recent evidence that angiotensin converting enzyme inhibitors and angiotensin receptor blockers reduce the risk of permanent atrial fibrillation, these medications may also hold promise in POAF prophylaxis. However, there is a need for further large-scale investigations that incorporate standard methodologies and diagnostic criteria, which have been lacking in past trials.

Critical care issues in the patient after major joint replacement

Admission rates of orthopedic patients to intensive care units are increasing. Thus, an intensivist's familiarity with specific problems associated with major joint replacement surgery is of utmost importance in order to meet the needs of this particular patient population. In this article, the authors review the most commonly encountered complications after major hip and knee arthroplasty. Perioperative risk factors for morbidity and mortality and the epidemiology, diagnosis, and treatment of cardiopulmonary complications in this patient population are discussed. Procedure-specific complications such as fat embolism and acrylic bone cement-related issues are reviewed.

Postoperative arrhythmias in colorectal surgical patients: incidence and clinical correlates

OBJECTIVE

To determine the incidence and clinical correlates of postoperative cardiac arrhythmias in patients undergoing elective large bowel resection.

METHODS

Fifty-one consecutive patients undergoing elective open colorectal resection were recruited for this prospective observational study. Participating patients underwent daily three-lead electrocardiograms postoperatively. Data regarding potential risk factors for arrhythmias were recorded. Post-operative complications were recorded.

RESULTS

Thirteen (26%) patients developed a postoperative arrhythmia, most commonly atrial fibrillation. Significant univariate correlates with postoperative arrhythmias were: age (P<0.01), hypertension (P<0.01), pre-operative serum potassium levels (P<0.01), postoperative pulmonary oedema (P=0.03), postoperative serum potassium (P=0.03) and sodium (P<0.01). Arrhythmia patients were more likely to have other complications (P=0.02). Thirty-one percent of arrhythmia patients had underlying sepsis compared with 18% of controls (P=0.38).

CONCLUSION

Arrhythmias are common following elective large bowel resection. They occur in older patients and are associated with the development of other complications.

Atrial fibrillation in trauma patients requiring intensive care

OBJECTIVES

To evaluate the incidence and risk factors of atrial fibrillation (AF) in trauma patients.

DESIGN AND SETTING

Prospective observational study in a surgical intensive care unit (ICU).

PATIENTS

All trauma patients admitted in the surgical ICU except those who had AF at admission.

MEASUREMENTS AND RESULTS

AF occurred in 16/293 patients (5.5%). AF patients were older, had a higher number of regions traumatized, and received more fluid therapy, transfusion products, and catecholamines. They more frequently experienced systemic inflammatory response syndrome, sepsis, shock, and acute renal failure and had higher scores of severity (Simplified Acute Physiology Score, SAPS II; Injury Severity Score). ICU length of stay and resources use were also increased. ICU and hospital mortality rates were twice higher in AF patients whereas standardized mortality ratio (observed/expected mortality by SAPS II) was similar in the two groups. We found five independent risk factors of developing AF: catecholamine use (OR = 5.7, 95% CI 1.7-19.1), SAPS II of 30 or higher (OR = 11.6, 95% CI 1.3-103.0), three or more regions traumatized (OR = 6.2, 95% CI 1.8-21.4), age 40 years or higher (OR = 6.3, CI 1.4-28.7), and systemic inflammatory response syndrome (OR = 4.4, 95% CI 1.2-16.1).

CONCLUSIONS

In addition to age and catecholamine use, inflammation and severity of injury may be involved in the development of AF in trauma patients. Our results suggest that AF could rather be a marker of a higher severity of illness without major effect on mortality.

Amiodarone-induced acute lung toxicity in an ICU setting

Amiodarone is a highly effective antiarrhythmic drug, albeit notorious for its serious pulmonary toxicity. The incidence of amiodarone-induced pulmonary toxicity (APT) appears to be 1% per year (1). We report a case of very acute APT in a man suffering from postoperative atrial fibrillation.

Incidence and risk factors of atrial fibrillation in a surgical intensive care unit*

OBJECTIVE

To evaluate the incidence and risks factors of atrial fibrillation (AF).

DESIGN

Prospective, observational study.

SETTING

A surgical intensive care unit of a university hospital.

PATIENTS

All patients with new onset of AF admitted in the surgical intensive care unit during a 6-month period.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Of the 460 patients included in the study, AF developed in 24 patients (5.3%). According to univariate analysis, age, preexisting cardiovascular disease, and previous treatment by calcium-channel blockers were significant predictors of AF. Patients with AF received significantly more fluids and catecholamines and experienced more sepsis, shock, and acute renal failure. Severity (Simplified Acute Physiologic Score II), intensive care unit workload (OMEGA), intensive care unit and hospital length of stay, and mortality were significantly increased in patients who developed AF. Multivariate analysis identified five independent predictors of AF: advanced age, blunt thoracic trauma, shock, pulmonary artery catheter, and previous treatment by calcium-channel blockers.

CONCLUSIONS

In surgical intensive care unit patients, the incidence of AF is greater than in the general population but less than in the cardiac surgery unit. The onset of AF reflects the severity of the disease. Five independent risk factors of AF were identified in surgical intensive care unit patients. The withdrawal of a calcium-channel inhibitor was also an independent risk factor of AF, and the weaning of this treatment must be carefully evaluated. Blunt thoracic trauma increases the chances of developing AF, as does the presence of shock, especially septic shock.

The theory and practice of bloodless surgery

The application of blood conservation strategies to minimise or avoid allogeneic blood transfusion is seen internationally as a desirable objective. Bloodless surgery is a relatively new practice that facilitates that goal. However, the concept is either poorly understood or evokes negative connotations. Bloodless surgery is a term that has evolved in the medical literature to refer to a peri-operative team approach to avoid allogeneic transfusion and improve patient outcomes. Starting as an advocacy in the early 1960s, it has now grown into a serious practice being embraced by internationally respected clinicians and institutions. Central to its success is a coordinated multidisciplinary approach. It encompasses the peri-operative period with surgeons, anaesthetists, haematologists, intensivists, pathologists, transfusion specialists, pharmacists, technicians, and operating room and ward nurses utilising combinations of the numerous blood conservation techniques and transfusion alternatives now available. A comprehensive monograph on the subject of bloodless surgery along with detailed coverage of risks and benefits of each modality (some modalities are discussed in more detail elsewhere in this issue) is beyond the scope of this article. Accordingly, a brief overview of the history, theory and practice of bloodless surgery is presented, along with the clinical and institutional management requirements.