Association of Mechanical Energy and Power with Postoperative Pulmonary Complications in Lung Resection Surgery: A Post Hoc Analysis of Randomized Clinical Trial Data

BACKGROUND

Mechanical power (MP), the rate of mechanical energy (ME) delivery, is a recently introduced unifying ventilator parameter consisting of tidal volume, airway pressures, and respiratory rates, which predicts pulmonary complications in several clinical contexts. However, ME has not been previously studied in the perioperative context, and neither parameter has been studied in the context of thoracic surgery utilizing one-lung ventilation.

METHODS

The relationships between ME variables and postoperative pulmonary complications were evaluated in this post hoc analysis of data from a multicenter randomized clinical trial of lung resection surgery conducted between 2020 and 2021 (n = 1,170). Time-weighted average MP and ME (the area under the MP time curve) were obtained for individual patients. The primary analysis was the association of time-weighted average MP and ME with pulmonary complications within 7 postoperative days. Multivariable logistic regression was performed to examine the relationships between energy variables and the primary outcome.

RESULTS

In 1,055 patients analyzed, pulmonary complications occurred in 41% (431 of 1,055). The median (interquartile ranges) ME and time-weighted average MP in patients who developed postoperative pulmonary complications versus those who did not were 1,146 (811 to 1,530) J versus 924 (730 to 1,240) J (P < 0.001), and 6.9 (5.5 to 8.7) J/min versus 6.7 (5.2 to 8.5) J/min (P = 0.091), respectively. ME was independently associated with postoperative pulmonary complications (ORadjusted, 1.44 [95% CI, 1.16 to 1.80]; P = 0.001). However, the association between time-weighted average MP and postoperative pulmonary complications was time-dependent, and time-weighted average MP was significantly associated with postoperative pulmonary complications in cases utilizing longer periods of mechanical ventilation (210 min or greater; ORadjusted, 1.46 [95% CI, 1.11 to 1.93]; P = 0.007). Normalization of ME and time-weighted average MP either to predicted body weight or to respiratory system compliance did not alter these associations.

CONCLUSIONS

ME and, in cases requiring longer periods of mechanical ventilation, MP were independently associated with postoperative pulmonary complications in thoracic surgery.

EDITOR’S PERSPECTIVE

Comparison of tracheal versus esophageal temperatures during laparoscopic surgery

PURPOSE

Recently, endotracheal tubes with an embedded temperature sensor in the inner surface of the tube cuff (temperature tracheal tubes) have been developed. We sought to assess whether temperature tracheal tubes show a good agreement with esophageal temperature probes during surgery.

METHODS

We enrolled 40 patients who underwent laparoscopic surgery in an observational study. The tracheas of all patients were intubated with a temperature tracheal tube, and an esophageal temperature probe was inserted into the esophagus. Tracheal and esophageal temperatures were recorded at 15-min intervals until the end of surgery. Temperatures from both devices were analyzed using Bland-Altman analysis, four-quadrant plots, and polar plots.

RESULTS

We analyzed 261 data points from 36 patients. Temperatures ranges were 34.2 °C to 36.6 °C for the tracheal temperature tube and 34.7 °C to 37.2 °C for the esophageal temperature probe. Bland-Altman analysis showed an acceptable agreement between the two devices, with an overall mean bias (95% limit of agreement) of -0.3 °C (-0.8 °C to 0.1 °C) and a percentage error of 3%; the trending ability (temperature changes over time) between the two devices showed a concordance rate of 94% in four-quadrant plot (cut-off ≥ 92%), but this was higher than the acceptable mean angular bias of 177° (cut-off <  ± 5°) and radial limits of agreement of 52° (cut-off <  ± 30°) in the polar plot. Bronchoscopy during extubation and patient interviews at six hours postoperatively revealed no serious injuries related to the use of the temperature tracheal tube.

CONCLUSION

The temperature tracheal tube showed an acceptable overall mean bias of -0.3 °C and a percentage error of 3%, but incompatible trending ability with the esophageal temperature probe.

STUDY REGISTRATION

cris.nih.go.kr (KCT0007265); 22 April 2022.

Anesthesia and cancer recurrence: a narrative review

Cancer is a leading cause of death worldwide. With the increasingly aging population, the number of emerging cancer cases is expected to increase markedly in the foreseeable future. Surgical resection with adjuvant therapy is the best available option for the potential cure of many solid tumors; thus, approximately 80% of patients with cancer undergo at least one surgical procedure during their disease. Agents used in general anesthesia can modulate cytokine release, transcription factors, and/or oncogenes. This can affect host immunity and the capability of cancer cells to survive and migrate, not only during surgery but for up to several weeks after surgery. However, it remains unknown whether exposure to anesthetic agents affects cancer recurrence or metastasis. This review explores the current literature to explain whether and how the choice of anesthetic and perioperative medication affect cancer surgery outcomes.

Effect of Sevoflurane Anesthesia on Diastolic Function: A Prospective Observational Study

BACKGROUND

The effect of sevoflurane on left ventricular diastolic function is not well understood. We hypothesized that parameters of diastolic function may improve under sevoflurane anesthesia in patients with preexisting diastolic dysfunction compared to patients with normal diastolic function.

METHODS

This observational study included 60 patients undergoing breast surgery or laparoscopic cholecystectomy. Patients were assigned to diastolic dysfunction (n = 34) or normal (n = 26) groups of septal e' < 8 or ≥ 8.0 cm/s on the first thoracic echocardiography (TTE) performed before anesthesia. During anesthesia, sevoflurane was maintained at 1 to 2 minimum alveolar concentration (MAC) to maintain the bispectral index at 40 to 50. At the end of surgery, the second TTE was performed under 0.8 to 1 MAC of sevoflurane with the patient breathing spontaneously without ventilator support. Primary end point was the percentage change (Δ) of e' on 2 TTEs (Δe'). Secondary end points were ΔE/e', Δleft atrial volume index (ΔLAVI), and Δtricuspid regurgitation maximum velocity (ΔTR Vmax). These percentage changes (Δ) were compared between diastolic dysfunction and normal groups.

RESULTS

e' (Δe': 30 [6, 64] vs 0 [-18, 11]%; P < .001), mitral inflow E wave velocity (E), mitral inflow E/A ratio (E/A), and mitral E velocity deceleration time (DT) improved significantly in diastolic dysfunction group compared to normal group. LAVI decreased in diastolic dysfunction group but did not reach statistical significance between the 2 groups (ΔLAVI:-15 [-31, -3] vs -4 [-20, 10]%, P = .091). ΔE/e' was not different between the 2 groups (11 [-16, 26] vs 12 [-9, 22]%, P = .853) (all: median [interquartile range, IQR]). TR was minimal in both groups.

CONCLUSIONS

In this study, echocardiographic parameters of diastolic function, including septal e', E, E/A, and DT, improved with sevoflurane anesthesia in patients with preexisting diastolic dysfunction, but remained unchanged in patients with normal diastolic function.

The arousal effect of sugammadex reversal of neuromuscular blockade differs with anesthetic depth in propofol-remifentanil anesthesia: a randomized controlled trial

Sugammadex reverses neuromuscular blockade by encapsulating steroidal neuromuscular blockers; therefore, it does not pharmacologically affect sedation levels. However, some clinicians avoid using it because of sudden unwanted acting out or patient arousal. Previous studies suggested sugammadex-induced awakening, but frontal muscle contraction after sugammadex administration compromised reliability of results obtained from EEG-based anesthesia depth monitoring tools like bispectral index (BIS). We hypothesized that sugammadex would affect patients' arousal depending on their baseline levels of sedation. We evaluated arousal signs after sugammadex administration with BIS between 25 - 35 and 45 - 55 under steady-state propofol-remifentanil anesthesia at the end of a surgery (n = 33 in each group). After sugammadex administration, twelve patients with a BIS of 45 - 55 showed clinical signs of awakening but none with a BIS of 25 - 35 (36.4% vs. 0%, P = 0.001). The distribution of the modified observer's assessment of alertness/sedation scale scores was also significantly different between the two groups (P < 0.001). Changes in the BIS were significantly greater in the BIS 45 - 55 than in the 25 - 35 group (median difference, 7; 95% CI 2 - 19, P = 0.002). Arousal after sugammadex was affected by patient sedation levels, and clinical signs of awakening appeared only in those with BIS 45 - 55. Unwanted arousal of the patient should be considered when using sugammadex under shallow anesthesia.Clinical trial registry number: Clinical Trial Registry of Korea ( https://cris.nih.go.kr ; Principal investigator: Jieae Kim; Registration number: KCT0006248; Date of first registration: 11/06/2021).

Enhanced Recovery After Surgery Program and Opioid Consumption in Pulmonary Resection Surgery: A Retrospective Observational Study

BACKGROUND

Pulmonary resection surgery causes severe postoperative pain and usually requires opioid-based analgesia, particularly in the early postoperative period. However, the administration of large amounts of opioids is associated with various adverse events. We hypothesized that patients who underwent pulmonary resection under an enhanced recovery after surgery (ERAS) program consumed fewer opioids than patients who received conventional treatment.

METHODS

A total of 2147 patients underwent pulmonary resection surgery between August 2019 and December 2020. Two surgeons (25%) at our institution implemented the ERAS program for their patients. After screening, the patients were divided into the ERAS and conventional groups based on the treatment they received. The 2 groups were then compared after the stabilized inverse probability of treatment weighting. The primary end point was the total amount of opioid consumption from surgery to discharge. The secondary end points included daily average and highest pain intensity scores during exertion, opioid-related adverse events, and clinical outcomes, such as length of intensive care unit (ICU) stay, hospital stay, and postoperative complication grade defined by the Clavien-Dindo classification. Additionally, the number of patients discharged without opioids prescription was assessed.

RESULTS

Finally, 2120 patients were included in the analysis. The total amount of opioid consumption (median [interquartile range]) after surgery until discharge was lower in the ERAS group (n = 260) than that in the conventional group (n = 1860; morphine milligram equivalents, 44 [16-122] mg vs 208 [146-294] mg; median difference, -143 mg; 95% CI, -154 to -132; P < .001). The number of patients discharged without opioids prescription was higher in the ERAS group (156/260 [60%] vs 329/1860 [18%]; odds ratio, 7.0; 95% CI, 5.3-9.3; P < .001). On operation day, both average pain intensity score during exertion (3.0 ± 1.7 vs 3.5 ± 1.8; mean difference, -0.5; 95% CI, -0.8 to -0.3; P < .001) and the highest pain intensity score during exertion (5.5 ± 2.1 vs 6.4 ± 1.7; mean difference, -0.8; 95% CI, -1.0 to -0.5; P < .001) were lower in the ERAS group than in the conventional group. There were no significant differences in the length of ICU stay, hospital stay, or Clavien-Dindo classification grade.

CONCLUSIONS

Patients who underwent pulmonary resection under the ERAS program consumed fewer opioids than those who received conventional management while maintaining no significant differences in clinical outcomes.

Comparison of Early and Late Surgeries after Coronary Stent Implantation in Patients with Normal Preoperative Troponin Level: A Retrospective Study

Current guidelines recommend delaying noncardiac surgery for 6 months after drug eluting stent implantation. However, this recommendation is largely based on limited evidence and various event definitions. Whether early surgery within 6 months of coronary stent implantation increases myocardial injury in patients with normal preoperative high-sensitivity cardiac troponin I (hs-cTnI) has not yet been investigated. This retrospective study assessed patients who received coronary stent implantation and underwent noncardiac surgery (vascular, abdominal, or thoracic) between 2010 and 2017 with normal preoperative hs-cTnI (n = 186). Patients were divided into early (within 6 months of PCI) and late (after 6 months of PCI) groups. The primary endpoint was the incidence of myocardial injury as diagnosed by hs-cTnI within 3 days post-operation. The secondary outcomes were myocardial infarction, stent thrombosis, emergent coronary revascularization, major bleeding (bleeding requiring transfusion or intracranial bleeding), stroke, renal failure, heart failure, or death within 30 days post-operation. Inverse probability treatment weighting (IPTW) was carried out to adjust for the intergroup baseline differences. Myocardial injury occurred in 28.6% (8/28) and 27.8% (44/158) of the early and late groups, respectively, with no difference between groups (odds ratio [OR] 1.067, 95% confidence interval [CI] 0.404, 2.482; p = 0.886). Secondary outcomes did not differ between the groups. IPTW analysis also showed no differences in myocardial injury and secondary outcomes between the groups. In conclusion, early surgery within 6 months after coronary stent implantation did not increase the incidence of myocardial injury in patients with normal preoperative hs-cTnI.

An Adequate Infusion Rate of Remimazolam for Induction of General Anesthesia in Adult Patients: A Prospective Up-and-Down Dose-Finding Study

Remimazolam is a recently developed anesthetic agent for general anesthesia and sedation. Currently, the optimal infusion rate for the induction of general anesthesia within two minutes remains unclear. We estimated the 50% and 90% effective doses (ED₅₀ and ED₉₀) of remimazolam required for loss of responsiveness within two minutes in adult patients using the up-and-down method. The starting infusion rate of remimazolam was 0.1 mg/kg/min and was increased or decreased by 0.02 mg/kg/min intervals in the following patient according to the success or failure of the previous patient. Success was defined as a loss of responsiveness within two minutes. Patient enrollment continued until six crossover pairs were observed. The ED₅₀ and ED₉₀ were estimated by centered isotonic regression and the pooled adjacent violators algorithm with bootstrapping, respectively. Twenty patients were included in the analysis. The ED₅₀ and ED₉₀ of remimazolam for loss of responsiveness within two minutes were 0.07 mg/kg/min (90% CI: 0.05, 0.09 mg/kg/min) and 0.10 mg/kg/min (90% CI: 0.10, 0.15 mg/kg/min), respectively. Vital signs were stable with an infusion rate of 0.10 mg/kg/min, and no patients required inotrope/vasopressor. Intravenous infusion of remimazolam at a rate of 0.10 mg/kg/min can be an effective approach to inducing general anesthesia in adult patients.

Driving pressure-guided ventilation and postoperative pulmonary complications in thoracic surgery: a multicentre randomised clinical trial

BACKGROUND

Airway driving pressure, easily measured as plateau pressure minus PEEP, is a surrogate for alveolar stress and strain. However, the effect of its targeted reduction remains unclear.

METHODS

In this multicentre trial, patients undergoing lung resection surgery were randomised to either a driving pressure group (n=650) receiving an alveolar recruitment/individualised PEEP to deliver the lowest driving pressure or to a conventional protective ventilation group (n=650) with fixed PEEP of 5 cm H₂O. The primary outcome was a composite of pulmonary complications within 7 days postoperatively.

RESULTS

The modified intention-to-treat analysis included 1170 patients (mean [standard deviation, sd]; age, 63 [10] yr; 47% female). The mean driving pressure was 7.1 cm H₂O in the driving pressure group vs 9.2 cm H₂O in the protective ventilation group (mean difference [95% confidence interval, CI]; -2.1 [-2.4 to -1.9] cm H₂O; P<0.001). The incidence of pulmonary complications was not different between the two groups: driving pressure group (233/576, 40.5%) vs protective ventilation group (254/594, 42.8%) (risk difference -2.3%; 95% CI, -8.0% to 3.3%; P=0.42). Intraoperatively, lung compliance (mean [sd], 42.7 [12.4] vs 33.5 [11.1] ml cm H₂O^-1; P<0.001) and Pa_o2 (median [inter-quartile range], 21.5 [14.5 to 30.4] vs 19.5 [13.5 to 29.1] kPa; P=0.03) were higher and the need for rescue ventilation was less frequent (6.8% vs 10.8%; P=0.02) in the driving pressure group.

CONCLUSIONS

In lung resection surgery, a driving pressure-guided ventilation improved pulmonary mechanics intraoperatively, but did not reduce the incidence of postoperative pulmonary complications compared with a conventional protective ventilation.

CLINICAL TRIAL REGISTRATION

NCT04260451.

Safety of Rigid Bronchoscopy for Therapeutic Intervention at the Intensive Care Unit Bedside

Background and Objective: Although rigid bronchoscopy is generally performed in the operating room (OR), the intervention is sometimes emergently required at the intensive care unit (ICU) bedside. The aim of this study is to evaluate the safety of rigid bronchoscopy at the ICU bedside. Materials and Methods: We retrospectively analyzed medical records of patients who underwent rigid bronchoscopy while in the ICU from January 2014 to December 2020. According to the location of rigid bronchoscopic intervention, patients were classified into the ICU group (n = 171, cases emergently performed at the ICU bedside without anesthesiologists) and the OR group (n = 165, cases electively performed in the OR with anesthesiologists). The risk of intra- and post-procedural complications in the ICU group was analyzed using multivariable logistic regression, with the OR group as the reference category. Results: Of 336 patients, 175 (52.1%) were moribund and survival was not expected without intervention, and 170 (50.6%) received invasive respiratory support before the intervention. The most common reasons for intervention were post-intubation tracheal stenosis (39.3%) and malignant airway obstruction (34.5%). Although the overall rate of intra-procedural complications did not differ between the two groups (86.0% vs. 80.6%, p = 0.188), post-procedural complications were more frequent in the ICU group than in the OR group (24.0% vs. 12.1%, p = 0.005). Severe complications requiring unexpected invasive management occurred only post-procedurally and were more common in the ICU group (10.5% vs. 4.8%, p = 0.052). In the fully adjusted model, the ICU group had increased odds for severe post-procedural complications, but statistical significance was not observed (odds ratio, 2.54; 95% confidence interval, 0.73-8.88; p = 0.144). Conclusions: Although general anesthesia is generally considered the gold standard for rigid bronchoscopy, our findings indicate that rigid bronchoscopy may be safely performed at the ICU bedside in selective cases of emergency. Moreover, adequate patient selection and close post-procedural monitoring are required to prevent severe complications.

Comparison of adhesive single-lead ECG device and Holter test for atrial fibrillation monitoring

Background

There is insufficient validation of diagnostic benefits of extended monitoring with an adhesive single-lead ECG device compared to Holter test for routine medical care of AF patients.

Purpose

The study aimed to compare AF detection rates between 72-hour monitoring using an adhesive single-lead ECG device (mobiCARE MC-100, Seers Technology, Republic of Korea) and 24-hour Holter test among AF patients at outpatient clinics.

Methods

A total of 200 AF patients indicated for Holter test at cardiology outpatient clinics enrolled in the study. Study participants equipped both Holter and MC-100 for the first 24 hours (Figure 1). After then, only MC-100 continued ECG monitoring for additional 48 hours. AF detection during the first 24 hours was compared between two devices. The diagnostic benefits of extended monitoring with MC-100 were evaluated.

Results

During the first 24 hours, both monitoring methods detected AF in the same 40/200 (20.0%) patients (20 patients with paroxysmal and persistent AF each). Compared to 24-hour Holter, MC-100 increased AF detection rate by 1.5-fold (58/200; 29.0%) and 1.6-fold (64/200; 32.0%) with 48- and 72-hour monitoring, respectively (Figure 2A). With MC-100, the number of newly discovered patients with paroxysmal AF was 20/44 (45.5%), 18/44 (40.9%), and 6/44 (13.6%) for 24-, 48-, and 72-hour monitoring. Compared to 24-hour Holter, 72-hour monitoring with MC-100 increased the detection rate of paroxysmal AF by 2.2-fold (44/20). If only the episodes lasting over 30 seconds were counted as AF with MC-100, the detection rate of paroxysmal AF was decreased by 9.1% (Figure 2B).

Conclusion

Compared to Holter, AF detection rates could be improved with an adhesive single-lead device, especially for patients with paroxysmal AF. This device is expected to be useful for AF detection among patients whose conventional ECG tests were ineffective in documenting AF episodes.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Korea Medical Device Development Fund grant funded by the Korean government (the Ministry of Science and ICT, the Ministry of Trade, Industry and Energy, the Ministry of Health & Welfare, Republic of Korea, the Ministry of Food and Drug Safety)

The left atrial low-voltage area and persistent atrial fibrillation treated with pulmonary vein isolation alone

Background

There are limited data regarding the association between the burden of the left atrial low-voltage area (LVA) and the outcome of pulmonary vein isolation (PVI) alone in persistent atrial fibrillation (PeAF).

Purpose

The study aimed to investigate the impact of the burden of LVA on the patients with PeAF treated with PVI alone.

Methods

Using a retrospective cohort of PeAF patients who underwent PVI alone, both clinical and the left atrial voltage mapping data were reviewed. LVA was defined as an area of ≤0.5 mV (bipolar) when mapped during sinus rhythm and ≤0.2 mV during AF. The high burden of LVA was defined as a case when the LVA constitutes ≥10% of the total left atrial body area. The patients were categorized into either the high or low burden groups. The recurrence of any atrial tachyarrhythmia was followed up, and multivariable Cox's regression analysis was performed.

Results

A total of 50 and 25 patients were investigated for the low burden (LVA&lt;10%) and high burden (LVA≥10%) groups, respectively. Compared to the low burden group, the high burden group had a significantly less male proportion (56.0% versus 78.0%), a higher CHA2DS2-VASc score (median 3 versus 2), more chronic kidney disease (16.0% versus 2.0%), and a higher burden of LVA (20±11% versus 5±3%). During the median follow-up of 9.5 (6.2–16.2)months, there were 30.0% and 48.0% ofrecurrences for the low and high burden groups, respectively. Compared to the low burden group, the high burden group was associated with higher risks of both early and late recurrences (HR [95% CI] =2.67 [1.15–6.18] and 2.08 [1.03–4.20], respectively) (Figure 1). The best cut-off of LVA to predict 2-year recurrence was 10.1% (Figure 2).

Conclusion

The high burden of LVA was significantly associated with an increased risk of recurrence among PeAF patients treated with PVI alone. Tailored ablation in addition to PVI would be needed to improve outcomes in patients with PeAF having a high burden of LVA.

Funding Acknowledgement

Type of funding sources: None.

Protective effect of proton pump inhibitor against gastrointestinal bleeding in patients receiving oral anticoagulants: a systematic review and meta-analysis

Background

The concurrent use of proton pump inhibitor (PPI) in oral anticoagulant (OAC) treated patients may be associated with a lower risk of gastrointestinal bleeding (GIB), but evidence is still conflicting according to individual OACs.

Purpose

We conducted a meta-analysis to estimate the risk of GIB in patients with OAC and PPI co-therapy.

Methods

A systematic search of PubMed, EMBASE, and Cochrane was performed for studies reporting GIB risk in OAC and PPI co-therapy. Primary outcomes were total GIB and major GIB events. We calculated pooled estimates of GIB risk by a random-effect meta-analysis and reported as odds ratios (OR) and 95% CI. Stratified analyses according to the origin of GIB, ethnic groups, individual OACs, and the presence of underlying GIB risk factors were performed.

Results

A total of 10 studies (1 randomized controlled study and 9 observational studies) and 1,970,931 patients who received OAC were included. OAC and PPI co-therapy were associated with a lower risk of total GIB, and major GIB; OR (95% CI) was 0.67 (0.62–0.74) for total GIB and 0.68 (0.63–0.75) for major GIB, respectively. Among total GIB, only the risk of upper GIB was lower with OAC and PPI co-therapy (OR 0.67, 95% CI 0.64–0.70). No difference in the lower risk of primary GIB outcomes of PPI co-therapy was observed between Asians and non-Asians (p-for-difference, total GIB=0.695, major GIB=0.748, respectively) and among individual OACs except for edoxaban. The protective effect of PPI on total GIB was more significant in high-risk patients, defined as those with concurrent medication of antiplatelets or non-steroidal anti-inflammatory drugs (OR 0.62, 95% CI 0.52–0.73) and presence of high bleeding risk factors such as previous GIB history, HAS-BLED score ≥3, or underlying gastrointestinal diseases. (OR 0.65, 95% CI 0.61–0.70).

Conclusion

In patients who receive OAC, the use of PPI co-therapy was associated with a lower risk of total GIB and major GIB irrespective of ethnic group and OAC type except for edoxaban. PPI co-therapy can be considered particularly in patients on concomitant NSAID and antiplatelet use or patients with high GIB risk factors.

Funding Acknowledgement

Type of funding sources: None.

Increased risk of atrial fibrillation in patients with uterine fibroids: a nationwide population-based study

Background

Uterine fibroid, the most common benign neoplasm of the uterus, is associated with an elevated risk of cardiovascular disease. The link between incident atrial fibrillation (AF) and the uterine fibroid is unclear because earlier studies focused primarily on the development of atherosclerosis and hypertension. We aimed to investigate the risk of AF in patients with uterine fibroid.

Methods

This is a retrospective cohort study using the Korean National Health Insurance Service database (NHIS). From 2009 to 2012, a total of 2,574,349 women (20 to 40 years old) who underwent general health examinations were included. Diagnosis of uterine fibroids and surgical treatment status was defined by the international classification of diseases, 10th revision codes, and procedural codes from the Korean NHIS. The primary outcome was newly diagnosed AF. The risk of AF according to the uterine fibroids and their surgical treatment status was evaluated using Cox proportional-hazard models.

Results

Of the total population, the mean age was 29.76±4.27 years, and 20,682 (0.8%) were identified to have uterine fibroid. Incident AF was identified in 3,868 patients (61 in the fibroid group, 3,807 in the control group) during a mean follow-up of 7.3±1.1 years. Patients of the uterine fibroid group showed a higher incidence of AF compared to the control group (0.41 and 0.20 per 1000 person-years, respectively, Figure 1). Multivariate Cox-regression analysis presented that uterine fibroid was an independent risk factor of AF: hazard ratio (HR) 1.50, 95% confidence interval (CI) 1.16–1.93, p=0.002. Compared to the control group, uterine fibroid patients who underwent surgical treatment tend to show a lower risk for AF (HR 1.22, 95% CI 0.79–1.90) than patients without surgical treatment (HR 1.69, 95% CI 1.24–2.30), though statistical significance was indeterminate (Figure 2). After propensity score matching, patients of the uterine fibroid group showed higher risk of AF when compared to the control group (HR 1.77, 95% CI 1.32–2.63, p&lt;0.001), which was in line with our main results. The presence of uterine fibroid was consistently associated with higher risk of AF among all subgroups except for the stroke subgroup.

Conclusion

Patients with uterine fibroids are predisposed to an increased risk of AF compared to the control group. Careful monitoring of arrhythmia development would be warranted in patients of uterine fibroid and surgical treatment as it is associated with a modest risk decrement of incident AF.

Funding Acknowledgement

Type of funding sources: None.

Paradoxical association between lipid levels and incident atrial fibrillation according to statin usage

Background

In epidemiology studies, a higher level of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) is associated with a lower risk of atrial fibrillation (AF). Statin use might exert possible confounding effects in the paradoxical relationship; however, the inverse link between AF and cholesterol level that distinguishes statin users from non-users has not been evaluated.

Objective

We investigated the epidemiological relationships of TC–AF and LDL-C–AF in statin users and non-users, respectively.

Methods

From the Korean National Health Insurance Service database, we included 9,778,014 adults who underwent a health examination in 2009 and had no prior AF history. The levels of TC and LCL-C at the health exam were categorized in quartile (Q) and decile (D) values of the total study population. The study population was grouped into statin users and non-users, and TC–AF and LDL-C–AF relationships were evaluated.

Results

867,336 (8.9%) were on statin use among the total population. Statin users showed higher TC level (208.4±55.6 vs. 194.1±39.5 mg/dL, p&lt;0.001) and LDL-C level (123.0±102.2 vs. 121.3±226.3, p&lt;0.001) compared to non-users. Inverse associations of TC–AF and LCL-C–AF were observed; higher levels of TC and LDL-C were associated with a lower risk of AF. The hazard ratios (HR) and 95% confidence intervals (CI) were 0.797 (0.786–0.809) for the highest quartile of TC (Q4, TC ≥218) and 0.832 (0.82–0.843) for the highest quartile of LDL-C (Q4, LDL-C ≥135) when adjusted by age, sex, lifestyle behaviors, comorbidities, and low-income status. Statin users exhibited higher AF incidence rate than non-statin users, but the association in statin users generally tracked that seen among non-statin users demonstrating similar HR in Q4 of TC [0.812 (0.790–0.835) for statin users and 0.812 (0.798–0.826) for non-statin users] and LDL-C [0.842 (0.819–0.865) for statin users and 0.849 (0.835–0.863) for non-statin users].

Conclusion

The paradoxical relationship between lipid levels (TC and LDL-C) and incident AF remained consistent both in statin users and non-users. Further research is required to investigate an underlying mechanism for the cholesterol paradox of AF which still seems evident despite the pleiotropic effects of statin.

Funding Acknowledgement

Type of funding sources: None.

Fish oil supplements increase atrial fibrillation risk in healthy individuals: a population-based cohort study and Mendelian randomization analysis

Background

There is a paucity of information on the risk of atrial fibrillation (AF) in healthy individuals taking fish oil supplements.

Purpose

We aimed to investigate the epidemiologic and causal relationships between fish oil supplement intake and the long-term risk of AF.

Methods

From the population-based UK Biobank, we selected healthy individuals without a history of AF, other cardiac arrhythmias, or cardiovascular diseases, who were not taking lipid-lowering medications or dietary supplements other than fish oil. The 10-year risk of AF in Fish-Oil-Users vs. Non-Users was evaluated in the total population and propensity-score matched cohort. The causal relationship between n-3 polyunsaturated fatty acids (PUFA) and AF was evaluated using a two-sample summary-level Mendelian randomization analysis with fixed effects robust inverse-variance weighted method, using genetic instruments from previous studies genome-wide association studies for n-3 PUFA levels and AF, respectively.

Results

A total of 338,199 participants (aged 55.2±8.1, 44.3% men) were analysed. Of these, 35.0% (n=118,300) was taking fish oil supplements. The 10-year risk of AF was significantly higher in the Fish-Oil-Users than in the Non-Users (3.83% vs. 2.91%, adjusted hazard ratio [HR] 1.05, 95% CI [1.01–1.10], P=0.023). The result was consistent in the propensity-score matched cohort (propensity-score matched HR 1.06, 95% CI [1.00–1.12], P=0.043). The increased risk of AF by fish oil supplement was prominent in low-risk participants with healthy lifestyles. Among n-3 PUFA, the docosapentaenoic acid (DPA) showed significant causal estimates for the increased risk of AF (odds ratio [OR] 1.15, 95% CI [1.08–1.22], P&lt;0.001), while higher eicosapentaenoic acid (EPA) levels caused a decrease of AF risk (OR 0.85, 95% CI [0.80–0.90], P&lt;0.001).

Conclusion

Fish oil supplement intake significantly increased the long-term risk of AF in a healthy population. The causal effect of fish oil intake on the risk of AF may depend on the specific types of n-3 PUFA.

Funding Acknowledgement

Type of funding sources: None.

Impact of metabolic syndrome on the risk of ischemic stroke in non-anticoagulated atrial fibrillation patients having low CHA2DS2-VASc scores

Background

Metabolic syndrome (MetS) predisposes to a thromboembolic state. However, conflicting results have been reported on whether MetS confers an increased risk of ischemic stroke in atrial fibrillation (AF), especially in patients with low CHA2DS2-VASc score who are not indicated for oral anticoagulant therapy.

Purpose

We investigated the risk of ischemic stroke according to the presence of MetS, the number of MetS components (metabolic burden), and the individual metabolic components in non-anticoagulated AF patients with low CHA2DS2-VASc score.

Methods

A total of 76,015 oral anticoagulant-naïve AF patients with low CHA2DS2-VASc score (0,1 in male and 1 in female) were included from the Korean National Health Insurance Service database. The status of MetS and individual metabolic components were evaluated based on health examination data within two years of AF diagnosis. We estimated the risk of ischemic stroke according to MetS, metabolic burden, and an individual component of MetS using Cox proportional-hazards models.

Results

The mean age was 49.8±11.1 years and 52,388 (68.9%) were male. The average CHA2DS2-VASc score was 0.7±0.5 and MetS was prevalent among 21,570 (28.4%) of the study population. During a mean follow-up of 5.1 years, ischemic stroke was developed in 1,395 (1.84%) patients. MetS was associated with a higher risk of ischemic stroke after adjustment for age, sex, lifestyle behaviors, low income, and cardiovascular comorbidities: adjusted hazard ratio (aHR) 1.19, 95% confidence interval (CI) 1.06–1.33, p=0.002. A positive linear correlation was observed between metabolic burden and ischemic stroke risk. Patients with five MetS components showed the highest aHR of 1.55 (95% CI 1.14–2.11, Figure 1 and Figure 2), whereas those with a single MetS component had a marginal risk of ischemic stroke (aHR 1.18, 95% CI 0.99–1.41). Among individual metabolic components, elevated blood pressure and increased waist circumference was significantly associated with an increased risk of ischemic stroke: aHR (95% CI), 1.45 (1.30–1.62), p&lt;0.001, and 1.15 (1.03–1.30), p=0.016, respectively.

Conclusions

Among AF patients initially with CHA2DS2-VASc score 0 and 1 with no anticoagulation, the presence of MetS is associated with an increased risk of ischemic stroke. Given the linear incremental correlation between metabolic burden and ischemic stroke, special attention to the care of metabolic derangements is required in AF patients who are not indicated for anticoagulation.

Funding Acknowledgement

Type of funding sources: None.

Atrial fibrillation detection in ambulatory patients using a smart ring powered by deep learning analysis of continuous photoplethysmography monitoring

Background

Atrial fibrillation (AF) detection could be effective with photoplethysmography (PPG) signal monitoring by a wearable device.

Purpose

We aimed to validate the performance of AF detection among ambulatory patients who underwent electrical cardioversion for AF using a smart ring capable of continuous PPG monitoring and deep learning analysis.

Methods

In this prospective single-arm study, participants who underwent successful electrical cardioversion for AF were enrolled. The participants equipped a smart ring (CardioTracker, Sky Labs Inc., Seongnam, Republic of Korea) after the electrical cardioversion. The smart ring then continuously monitored PPG over 14 days to detect AF recurrence. The smart ring alarmed AF episodes based on deep learning analysis of PPG. The participants were asked to measure at least three daily ECGs using the smart ring to validate AF recurrence detected by PPG. All ECG snapshots were recorded along with lead I and saved with simultaneous PPG. ECG data were examined by the three cardiologists independently (SK, SRL, and EKC). The monitoring time, analyzable proportions of monitored signals, detection rates of AF episodes, and the diagnostic performance of PPG-based deep learning were evaluated. At the end of the monitoring, a survey on the use of the smart ring was performed.

Results

A total of 35 participants (mean age 58.9 years, male 74.3%) were enrolled. Figure 1 illustrates an example of PPG monitoring and PPG-ECG snapshots by the smart ring. The study participation period was a median of 14 days and the wearing time of the smart ring was a median of 9.2 days (IQR 7.1–11.5 days). Signal artifacts during daily activity decreased the analyzable proportions of monitored PPG by 68.5%. Irregular pulse episodes were detected by the smart ring in 29 (82.9%) participants after a median of 1 day from the cardioversion (Figure 2). A total of 2532 PPG-ECG snapshots were acquired and 1623 (64.1%) were interpretable by both the cardiologists (using ECG) and the deep learning analysis (using PPG). Comparing PPG by simultaneous ECG, the performance of AF detection by the smart ring was 98.7% for sensitivity, 97.8% for specificity, 2.2% for false positives, and 1.3% for false negatives (Figure 2). After using the smart ring, 76.9% of the participants responded that they had no discomfort in using the smart ring in daily activity and another 76.9% responded that it was helpful to monitor their disease.

Conclusion

Despite the signal artifacts during daily activity, AF detection with PPG monitoring by a smart ring could be effective for AF screening among ambulatory patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This work was supported by Sky Labs Inc, Seongnam, Republic of Korea, and by the grant No. 0320202040 from the Seoul National University Hospital Research Fund.

Continuous Titration of Inspired Oxygen Using Oxygen Reserve Index to Decrease Oxygen Exposure During One-Lung Ventilation: A Randomized Controlled Trial

BACKGROUND

A high fraction of inspired oxygen (Fio2) is administered during one-lung ventilation (OLV). However, a high Fio2 is not physiologic and may lead to various complications. We hypothesized that continuous titration of Fio2 using the oxygen reserve index (ORI) reduces oxygen exposure compared to conventional management during OLV.

METHODS

In this randomized, double-blinded trial, patients undergoing thoracic surgery were assigned to an ORI (n = 64) or a control group (n = 60). In the ORI group, ORI was continuously displayed using multiwavelength pulse co-oximetry (Masimo) between 0 and 1 (0, no reserve; 1, maximum reserve), and Fio2 was titrated for a target ORI of 0.21 at 5-minute intervals during OLV. In the control group, Fio2 was adjusted using arterial blood gas analysis measured at 15 minutes after OLV initiation. The primary end point was the time-weighted average Fio2 during OLV.

RESULTS

Overall, time-weighted average Fio2 did not differ between the groups (control versus ORI: median [interquartile range], 0.87 [0.73-1.00] vs 0.82 [0.68-0.93]; P = .09). However, in a subgroup analysis, the ORI group reduced time-weighted average Fio2 after pulmonary vascular ligation compared to the control group (control versus ORI: median [interquartile range], 0.75 [0.70-1.00] vs 0.72 [0.59-0.89]; P = .0261). The incidence of intraoperative hypoxia (arterial oxygen saturation [Spo2] <94%; control versus ORI: 32% [19/60; 95% confidence interval (CI), 20-45] vs 19% [12/64; 95% CI, 10-31]; P = .09), and postoperative complications within the first 7 days did not differ between the groups.

CONCLUSIONS

ORI-guided continuous Fio2 titration does not reduce overall oxygen exposure during OLV.

Preemptive Administration of Albumin during Pancreatectomy Does Not Reduce Postoperative Complications: A Prospective Randomized Controlled Trial

Despite the empirical use of human albumin during pancreatectomy to replace intraoperative volume loss while preventing fluid overload and edema, its impact on postoperative outcomes remains unclear. In addition, most previous studies have focused on the effects of therapeutic albumin usage. Here, we investigated whether preemptive administration of human albumin to prevent edema during pancreatectomy could reduce the incidence of moderate postoperative complications. Adult patients undergoing pancreatectomy were assigned to either the albumin group (n = 100) or the control group (n = 100). Regardless of the preoperative albumin level, 200 mL of 20% albumin was administered to the albumin group after induction of anesthesia. The primary outcome was the incidence of moderate postoperative complications as defined by a Clavien–Dindo classification grade ≥ 2 at discharge. Intraoperative net-fluid balance, a known risk factor of postoperative complication after pancreatectomy, was lower in the albumin group than in the control group (p = 0.030), but the incidence of moderate postoperative complications was not different between the albumin and control groups (47/100 vs. 38/100, respectively; risk ratio: 1.24, 95% CI: 0.89 to 1.71; p = 0.198). Therefore, preemptive administration of human albumin to prevent fluid overload and edema during pancreatectomy is not recommended because of its lack of apparent benefit in improving postoperative outcomes.

The impact of pulmonary function tests on early postoperative complications in open lung resection surgery: an observational cohort study

We investigated whether pulmonary function tests (PFTs) can predict pulmonary complications and if they are, to find new cutoff values in current open lung resection surgery. In this observational study, patients underwent open lung resection surgery at a tertiary hospital were analyzed (n = 1544). Various PFTs were tested by area under the receiver-operating characteristic curve (AUC_ROC) to predict pulmonary complications until 30 days postoperatively. In results, PFTs were generally not effective to predict pulmonary complications (AUC_ROC: 0.58-0.66). Therefore, we could not determine new cutoff values, and used previously reported cutoffs for post-hoc analysis [predicted postoperative forced expiratory volume in one second (ppoFEV₁) < 40%, predicted postoperative diffusing capacity for carbon monoxide (ppoDL_CO) < 40%]. In multivariable analysis, old age, male sex, current smoker, intraoperative transfusion and use of inotropes were independent risk factors for pulmonary complications (model 1: AUC_ROC 0.737). Addition of ppoFEV₁ or ppoDL_CO < 40% to model 1 did not significantly increase predictive capability (model 2: AUC_ROC 0.751, P = 0.065). In propensity score-matched subgroups, patients with ppoFEV₁ or ppoDL_CO < 40% showed higher rates of pulmonary complications [13% (21/160) vs. 24% (38/160), P = 0.014], but no difference in in-hospital mortality [3% (8/241) vs. 6% (14/241), P = 0.210] or mean survival duration [61 (95% CI 57-66) vs. 65 (95% CI 60-70) months, P = 0.830] compared to patients with both > 40%. In conclusion, PFTs themselves were not effective predictors of pulmonary complications. Decision to proceed with surgical resection of lung cancer should be made on an individual basis considering other risk factors and the patient's goals.

Risk of atrial fibrillation in young adults aged 20 to 39 years with isolated diastolic, isolated systolic, and systolic-diastolic hypertension: a nationwide population-based study

Background

There is limited evidence regarding the comparative risks of incident atrial fibrillation (AF) associated with stage 1 isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic-diastolic hypertension (SDH), especially amongst young adults aged 20–39 years.

Purpose

To evaluate the association between early-stage of hypertension and AF in young adults aged 20–39 years.

Methods

From the Korean nationwide health screening database, 2,958,544 subjects aged 20–39 years who were not prescribed antihypertensive medication at the index examination in 2009 were included. Subjects were categorized into eight groups according to the 2017 American College of Cardiology/American Heart Association blood pressure (BP) guidelines: normal BP, elevated BP, stage 1 IDH, stage 1 ISH, stage 1 SDH, stage 2 IDH, stage 2 ISH, and stage 2 SDH. The primary outcome was new-onset AF during follow-up.

Results

During a median follow-up of 8.3 years, 7,347 subjects had incident AF (incidence rate, 0.3 per 1,000 person-years). Compared to the normal BP group, stage 1 IDH (adjusted hazard ratio [aHR], 1.160; 95% confidence interval [CI], 1.086–1.240) and stage 1 SDH (1.250; 1.165–1.341) were associated with higher risks of incident AF, but not stage 1 ISH. Stage 2 IDH, ISH, and SDH were associated with higher risks of incident AF by 24%, 37%, and 61%, respectively (Figure).

Conclusion

Among young adults, stage 1 IDH and SDH were associated with higher risks of incident AF compared to normal BP. The risk of incident AF with stage 2 IDH was similar to that of stage 1 SDH. Optimal BP control including diastolic BP is crucial for preventing new-onset AF, even amongst young adults.

Funding Acknowledgement

Type of funding sources: None.

Association between body mass index and the risk of atrial fibrillation and ischemic stroke according to age: a nationwide population-based cohort study

Background

Atrial fibrillation (AF) and ischemic stroke (IS) are two significant cardiovascular diseases that confer an enormous healthcare burden. A limited study comprehensively evaluated the association between full ranges of body mass index (BMI), including underweight, and AF or IS risks, especially in the different age subgroups.

Purpose

We investigated the association between BMI and AF and IS incidence according to the Korean population's age groups.

Methods

This was a nationwide population-based cohort study using data from the Korea National Health Insurance Service, including 9 194 477 healthy adults who underwent a medical examination in 2009. We stratified the study population into three age subgroups: age 20–39 (young, 33.1%), age 40–64 (middle-aged, 56.3%), and age over 65 years (elderly, 10.6%). In each age group, the individuals were categorized based on BMI (kg/m2) into underweight (&lt;18.5), normal (18.5 to &lt;23), overweight (23 to &lt;25), obese I (25 to &lt;30), and obese II (≥30). The first occurrences of AF and IS were followed up until December 31, 2018. According to BMI in each age group, the risks of AF and IS were analyzed by Cox proportional hazards regression with 95% confidence intervals (CI) by adjusting age, sex, lifestyle behaviors, and comorbidities.

Results

Overall, both underweight and higher BMI were associated with an increased risk of AF and stroke across all age groups. The increased risk of AF for patients with obese II was slightly accentuated compared to patients with normal BMI in the young population than elderly population (hazard ratio [HR] 1.78, 95% CI 1.63–1.94 for age 20–39 years; HR 1.55, 95% CI 1.48–1.61 for age ≥65 years, respectively). For underweight individuals, however, the increased risk of AF became more prominent in the elderly: HR and 95% CI was 1.12 (1.07–1.17) in the age over 65 years old, and 1.05 (0.94–1.16) in the age 20–39. Regarding IS, the young group presented a considerable increment in the magnitude of HRs in both underweight and higher BMI groups. However, the association between the BMI and stroke risk became attenuated in the elderly: HRs and 95% CI in underweight and obese II individuals were 1.10 (0.93–1.30) and 2.223 (1.99–2.49) in the age 20–39 group, whereas 0.97 (0.93–1.01) and 1.03 (0.98–1.08) in the age over 65 years old.

Conclusions

Underweight as well as obesity was associated with increased risks of AF and IS in the general population. In both AF and IS, the gradient of risks according to BMI was apparent at young ages; thus, maintaining normal body weight should be warranted in early life. An interplay of several factors other than BMI may contribute to ischemic stroke in the old ages, requiring integrated risk management in older patients.

Funding Acknowledgement

Type of funding sources: None.

Hypertension burden and the risk of new-onset atrial fibrillation: a nationwide population-based study

Funding Acknowledgements

Type of funding sources: None.

Background

The association between the cumulative hypertension burden and the development of atrial fibrillation (AF) is unclear.

Purpose

We aimed to investigate the relationship between hypertension burden and the development of incident AF.

Methods and Results: Using the Korean National Health Insurance Service database, we identified 3,726,172 subjects who underwent four consecutive annual health checkups between 2009 and 2013, with no history of AF. During the median follow-up of 5.2 years, AF was newly diagnosed in 22,012 patients (0.59% of the total study population, 1.168 per 1,000 person-years). Using the BP values at each health checkup, we determined the burden of hypertension (systolic blood pressure [SBP] ≥130 mmHg or diastolic blood pressure [DBP] ≥80 mmHg), stratified as 0 to 4 per the hypertension criteria. The subjects were grouped according to hypertension burden scale 1 to 4: 20% (n = 742,806), 19% (n = 704,623), 19% (n = 713,258), 21% (n = 766,204), and 21% (n = 799,281). Compared to normal people, subjects with hypertension burdens of 1, 2, 3, and 4 were associated with an 8%, 18%, 26%, and 27% increased risk of incident AF, respectively. On semi-quantitative analyses with further stratification of stage 1 (SBP 130-139 mmHg or DBP 80-89 mmHg) and stage 2 (SBP ≥140 mmHg or DBP ≥90 mmHg) hypertension, the risk of AF increased with the hypertension burden by up to 71%.

Conclusions

Both a sustained exposure and the degree of increased blood pressure were associated with an increased risk of incident AF. Tailored blood pressure management should be emphasized to reduce the risk of AF. Abstract Figure.

Phage Display Screening of Bovine Antibodies to Foot-and-Mouth Disease Virus and Their Application in a Competitive ELISA for Serodiagnosis

For serodiagnosis of foot-and-mouth disease virus (FMDV), monoclonal antibody (MAb)-based competitive ELISA (cELISA) is commonly used since it allows simple and reproducible detection of antibody response to FMDV. However, the use of mouse-origin MAb as a detection reagent is questionable, as antibody responses to FMDV in mice may differ in epitope structure and preference from those in natural hosts such as cattle and pigs. To take advantage of natural host-derived antibodies, a phage-displayed scFv library was constructed from FMDV-immune cattle and subjected to two separate pannings against inactivated FMDV type O and A. Subsequent ELISA screening revealed high-affinity scFv antibodies specific to a serotype (O or A) as well as those with pan-serotype specificity. When BvO17, an scFv antibody specific to FMDV type O, was tested as a detection reagent in cELISA, it successfully detected FMDV type O antibodies for both serum samples from vaccinated cattle and virus-challenged pigs with even higher sensitivity than a mouse MAb-based commercial FMDV type O antibody detection kit. These results demonstrate the feasibility of using natural host-derived antibodies such as bovine scFv instead of mouse MAb in cELISA for serological detection of antibody response to FMDV in the susceptible animals.

Anesthetic management of patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is the third most common cause of death worldwide. It has a prevalence of 14% among Koreans aged above 40 years and a prevalence of 31% among those aged above 65 years. However, only 6% of the COPD patients receive treatment. Most of the patients do not seek medical attention, as they think that dyspnea, cough, and productive sputum, which are the common symptoms of COPD, are normal aging phenomena. Smoking is a major risk factor for COPD, but environmental hazards and genetic susceptibility are also involved. With aging, lung injuries due to these risk factors accumulate, leading to increased prevalence of COPD. The major concerns regarding perioperative management of COPD patients include preoperative evaluation of cardiopulmonary risks, optimization of lung function, and evaluation of COPD-related physiological functions that are easily aggravated during anesthesia. These include respiratory muscle dysfunction, dynamic hyperinflation and auto-positive end-expiratory pressure, hypoxia-hypercarbia, and pulmonary hypertension-associated heart failure. Therefore, anesthesia for COPD patients should focus on preoperative evaluation, risk reduction measures, and prevention of postoperative pulmonary complications.

Cultural dance significantly improves hypertension management

Hypertension (HT), uncontrolled blood pressure (&gt;140/90 mmHg), is the leading preventable cause of premature death globally and a major risk factor for coronary heart disease, stroke, and other conditions. European and African regions have the highest prevalence rates at about 40% of adults. The U.S. has comparable rates and disturbing disparities in non-White minority groups. Native Hawaiians (NH), an indigenous U.S. population, are 70% more likely to have HT; 4 times more likely to have coronary heart disease or stroke than Whites. Hula, the cultural dance of NH, offers promise of a culturally responsive strategy for HT control.

We conducted a randomized clinical trial with a waitlist control to test the impact of a hula-based cultural dance intervention (CDI) on systolic blood pressure (SBP) in 263 NH with HT. All participants received HT education (e.g. diet, exercise, medication) during 3 1-hr sessions over 2 weeks, then randomly assigned to CDI (n = 131) or waitlist control (WC; n = 132). The CDI received 6 months of hula (2 1-hr sessions/week x 3 months, then 1 lesson/mth x 3 months with self-directed practice), with group activities to reinforce HT education. WC only received the initial HT education, then offered hula after the study. Assessments were done at 0-, 3- and 6-month, with 12-month for CDI only.

Baseline characteristics were balanced between groups, except for weight. Adjusting for weight and baseline SBP in intent-to-treat analysis, CDI achieved significant reductions (p &lt; .05) in SBP (-15.3 mmHg; SE = 1.6) compared to WC (-11.8 mmHg, SE = 1.7). From 6 to 12 months, CDI maintained their SBP (mean change: 1.47 mmHg, SE = 1.26; p = .16) improvements at 12 months. CDI were more likely to achieve SBP reduction ≥ 10 mmHg than WC, 60% vs 48% (p = .03), respectively.

A CDI based on the NH cultural dance significantly improved HTN management in NH with uncontrolled SBP. Improvements were comparable to the best proven non-medication treatment of HT.

Key messages

Improving elevated blood pressure control with at-risk populations can be effectively and innovatively achieved by utilizing culturally responsive strategies, such as cultural dance interventions. Leveraging and aligning community strengths and health objectives leads to innovation and empowerment.

Prediction of Pleural Adhesions by Lung Ultrasonography: An Observational Study

OBJECTIVE

Pleural adhesion makes video-assisted thoracoscopic surgery (VATS) an arduous procedure and can increase postoperative pain from accompanying adhesiolysis. For the present study, the feasibility of lung ultrasonography for the prediction of pleural adhesions and postoperative pain in VATS was investigated.

DESIGN

Blinded, prospective, observational study.

SETTING

Tertiary teaching hospital, Seoul, South Korea.

PARTICIPANTS

Sixty patients (American Society of Anesthesiologists physical status I to III) scheduled to undergo VATS were assessed for eligibility. After exclusions, 53 patients were enrolled and followed-up.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were evaluated with lung ultrasonography during deep spontaneous respiration before induction of anesthesia, and surgeons confirmed the presence of pleural adhesions during the surgery. Pain was evaluated using a numeric rating scale and by the amount of opioid consumption until 24 hours postoperatively. Lung ultrasonography showed acceptable predictability of pleural adhesions, with the area under the receiver operating characteristic curve (0.75, 95% confidence interval [CI] 0.67-0.83) and high specificity (0.97, 95% CI 0.91-0.99) but low sensitivity (0.53, 95% CI 0.38-0.68). The pain score was not different between sonographic adhesion (+) and (-) groups; however, the sonographic adhesion (+) group consumed more opioids until 24 hours postoperatively (fentanyl 675 [558-805] μg v 420 [356-476] μg; p < 0.001).

CONCLUSIONS

Lung ultrasonography may help with planning postoperative pain management in VATS; however, it was a better tool for ruling out rather than detecting pleural adhesions.

Driving Pressure during Thoracic Surgery: A Randomized Clinical Trial

WHAT WE ALREADY KNOW ABOUT THIS TOPIC

Driving pressure (plateau minus end-expiratory airway pressure) is a target in patients with acute respiratory distress syndrome, and is proposed as a target during general anesthesia for patients with normal lungs. It has not been reported for thoracic anesthesia where isolated, inflated lungs may be especially at risk.

WHAT THIS ARTICLE TELLS US THAT IS NEW

In a double-blinded, randomized trial (292 patients), minimized driving pressure compared with standard protective ventilation was associated with less postoperative pneumonia or acute respiratory distress syndrome.

BACKGROUND

Recently, several retrospective studies have suggested that pulmonary complication is related with driving pressure more than any other ventilatory parameter. Thus, the authors compared driving pressure-guided ventilation with conventional protective ventilation in thoracic surgery, where lung protection is of the utmost importance. The authors hypothesized that driving pressure-guided ventilation decreases postoperative pulmonary complications more than conventional protective ventilation.

METHODS

In this double-blind, randomized, controlled study, 292 patients scheduled for elective thoracic surgery were included in the analysis. The protective ventilation group (n = 147) received conventional protective ventilation during one-lung ventilation: tidal volume 6 ml/kg of ideal body weight, positive end-expiratory pressure (PEEP) 5 cm H2O, and recruitment maneuver. The driving pressure group (n = 145) received the same tidal volume and recruitment, but with individualized PEEP which produces the lowest driving pressure (plateau pressure-PEEP) during one-lung ventilation. The primary outcome was postoperative pulmonary complications based on the Melbourne Group Scale (at least 4) until postoperative day 3.

RESULTS

Melbourne Group Scale of at least 4 occurred in 8 of 145 patients (5.5%) in the driving pressure group, as compared with 18 of 147 (12.2%) in the protective ventilation group (P = 0.047, odds ratio 0.42; 95% CI, 0.18 to 0.99). The number of patients who developed pneumonia or acute respiratory distress syndrome was less in the driving pressure group than in the protective ventilation group (10/145 [6.9%] vs. 22/147 [15.0%], P = 0.028, odds ratio 0.42; 95% CI, 0.19 to 0.92).

CONCLUSIONS

Application of driving pressure-guided ventilation during one-lung ventilation was associated with a lower incidence of postoperative pulmonary complications compared with conventional protective ventilation in thoracic surgery.

Driving pressure guided ventilation

Protective ventilation is a prevailing ventilatory strategy these days and is comprised of small tidal volume, limited inspiratory pressure, and application of positive end-expiratory pressure (PEEP). However, several retrospective studies recently suggested that tidal volume, inspiratory pressure, and PEEP are not related to patient outcomes, or only related when they influence the driving pressure. Therefore, this review introduces the concept of driving pressure and looks into the possibility of driving pressure-guided ventilation as a new ventilatory strategy, especially in thoracic surgery where postoperative pulmonary complications are common, and thus, lung protection is of utmost importance.

Association between intraoperative hypotension and postoperative myocardial injury in patients with prior coronary stents undergoing high-risk surgery: a retrospective study

PURPOSE

We conducted a single-center retrospective study to evaluate the effects of intraoperative hypotension (IOH) on postoperative myocardial injury during major noncardiac surgery in patients with prior coronary stents with preoperatively normal cardiac troponin I levels. Although IOH is assumed to increase the risk of postoperative myocardial injury in patients with prior coronary stents, the level and duration of hazardous low blood pressure have not been clarified.

METHODS

Of 2517 patients with prior coronary stents undergoing noncardiac surgery between January 2010 and March 2017, we analyzed 195 undergoing major surgery (vascular, abdominal, and thoracic surgery) who had a normal preoperative high-sensitivity cardiac troponin I (hs-cTnI) level and were followed up postoperatively within 3 days. Postoperative myocardial injury was defined as a hs-cTnI level greater than the 99th percentile reference value. Primary IOH exposure was defined as a decrease of ≥ 50%, 40%, or 30% from the preinduction mean blood pressure. Additional definition of IOH was absolute mean blood pressure < 70, < 60 or < 50 mmHg. Multivariate logistic regression was used to model the exposure and myocardial injury.

RESULTS

Myocardial injury occurred in 53 (27.2%) cases. The predefined levels of IOH were not significantly associated with postoperative myocardial injury, but intraoperative continuous inotropes/vasopressors use was significantly higher in patients with myocardial injury (P = 0.004). Operation time ≥ 166 min (OR = 2.823, 95% CI 1.184-6.731, P = 0.019) and abdominal vascular surgery (OR = 2.693, 95% CI 1.213-5.976, P = 0.015) were independent risk factors for myocardial injury.

CONCLUSION

Although patients with prior coronary stents with normal hs-cTnI levels did not show association between varying levels of IOH and postoperative myocardial injury after noncardiac surgery, intraoperative need of continuous inotropes/vasopressors was higher in patients with postoperative myocardial injury. Abdominal vascular surgery and surgical time were independent risk factors for myocardial injury after surgery.

Systemic Oxygen Delivery during One-Lung Ventilation: Comparison between Propofol and Sevoflurane Anaesthesia in a Randomised Controlled Trial

Systemic oxygen delivery (DO₂) is a more comprehensive marker of patient status than arterial oxygen saturation (SaO₂), and DO₂ in the range of 330–500 mL min⁻¹ is reportedly adequate during anaesthesia. We measured DO₂ during one-lung ventilation (OLV) for thoracic surgery—where the risk of pulmonary shunt is significant, and hypoxia occurs frequently—and compared sevoflurane and propofol, the two most commonly used anaesthetics in terms of DO₂. Sevoflurane impairs hypoxic pulmonary vasoconstriction. Thus, our hypothesis was that propofol-based anaesthesia would show a higher DO₂ value than sevoflurane-based anaesthesia. This was a double-blinded randomised controlled trial conducted at a university hospital from 2017 to 2018. The study population consisted of patients scheduled for lobectomy under OLV (N = 120). Sevoflurane or propofol was titrated to a bispectral index of 40–50. Haemodynamic variables were measured during two-lung ventilation (TLV) and OLV at 15 and 45 min (OLV15 and OLV45, respectively) using oesophageal Doppler monitoring. The mean DO₂ (mL min⁻¹) was not different between the sevoflurane and propofol anaesthesia groups (TLV: 680 vs. 706; OLV15: 685 vs. 703; OLV45: 759 vs. 782, respectively). SaO₂ was not correlated with DO₂ (r = 0.09, p = 0.100). Patients with SaO₂ < 94% showed adequate DO₂ (641 ± 203 mL min⁻¹), and patients with high SaO₂ (> 97%) showed inadequate DO₂ (14% of measurements < 500 mL min⁻¹). In conclusion, DO₂ did not significantly differ between sevoflurane and propofol. SaO₂ was not correlated with DO₂ and was not informative regarding whether the patients were receiving an adequate oxygen supply. DO₂ may provide additional information on patient status, which may be especially important when patients show a low SaO₂.

The effect of preventive use of corticosteroids on postoperative complications after esophagectomy: A retrospective cohort study

Corticosteroids have been empirically administered to reduce the rate of acute respiratory distress syndrome (ARDS) after esophagectomy. However, their efficacy remains controversial, and corticosteroids may increase the risk of graft dehiscence and infection, which are major concerns after esophagectomy. Therefore, we compared the incidence of composite complications (ARDS, graft dehiscence and infection) after esophagectomy between patients who received a preventive administration of corticosteroids and those who did not. All patients who underwent esophagectomy from 2010 to 2015 at a tertiary care university hospital were reviewed retrospectively (n = 980). Patients were divided into Steroid (n = 120) and Control (n = 860) groups based on the preventive administration of 100 mg hydrocortisone during surgery. The primary endpoint was the incidence of composite complications. The incidence of composite complications was not different between the Control and Steroid groups (17.4% vs. 21.7% respectively; P = 0.26). The incidence rates of complications in each category were not different between the Control and Steroid groups: ARDS (3.8% vs. 5.0%; P = 0.46), graft dehiscence (4.8% vs. 6.7%; P = 0.37), and infection (12.8% vs. 15.8%; P = 0.36). Propensity score matching revealed that composite complications (20.0% vs. 21.7%; P = 0.75), ARDS (4.3% vs. 5.2%; P = 0.76) and infection (16.5% vs. 15.7%; P = 0.86) were not different between the Control and Steroid group, but the incidence of graft dehiscence was higher in the Steroid group than in the Control group (0.9% vs. 7.0%; P = 0.0175). In conclusions, the preventive use of corticosteroids did not reduce the incidence of ARDS, but may be related to an increased incidence of graft dehiscence. Therefore, routine administration of corticosteroids to prevent ARDS is not recommended in esophagectomy.

Total Intravenous Anesthesia Maintained the Degree of Pre-Existing Mitral Regurgitation Better than Isoflurane Anesthesia in Cardiac Surgery: A Randomized Controlled Trial

Accurate assessment of mitral regurgitation (MR) is critical during mitral valve repair surgery. However, anesthesia may influence the degree of mitral regurgitation by changing pre- and after-load or cardiac contractility. Therefore, we compared changes in mitral regurgitation by total intravenous anesthesia (TIVA) and inhalation anesthesia in patients with pre-existing mitral regurgitation. This was a double-blind randomized controlled study conducted at a tertiary care center in 2018. Fifty-four mitral regurgitation patents undergoing elective cardiac surgery were randomly assigned to receive TIVA or isoflurane. Primary endpoint was change of regurgitation volume by anesthesia. The reduction of regurgitation volume by anesthesia was greater in the isoflurane group than in the TIVA group (mean (95% confidence interval CI): -0.20 (-6.15, 5.75) vs. -9.66 (-15.77, -3.56), mL·beat^-1, p = 0.0266) and this phenomenon was more prominent with severe mitral regurgitation (grade 3 or 4) (mean (95% CI): -0.33 (-9.10, 8.44) vs. -16.20 (-24.22, -8.18), mL·beat^-1, p = 0.0079). Among patients with MR grade 3 or 4, 94% remained the same with TIVA during anesthesia compared to 56% with isoflurane. In conclusion, TIVA maintained the pre-anesthetic state of mitral regurgitation relatively well, while the severity of mitral regurgitation tended to decrease with isoflurane anesthesia.

K-Sample comparisons using propensity analysis

In this paper, we investigate K-group comparisons on survival endpoints for observational studies. In clinical databases for observational studies, treatment for patients are chosen with probabilities varying depending on their baseline characteristics. This often results in noncomparable treatment groups because of imbalance in baseline characteristics of patients among treatment groups. In order to overcome this issue, we conduct propensity analysis and match the subjects with similar propensity scores across treatment groups or compare weighted group means (or weighted survival curves for censored outcome variables) using the inverse probability weighting (IPW). To this end, multinomial logistic regression has been a popular propensity analysis method to estimate the weights. We propose to use decision tree method as an alternative propensity analysis due to its simplicity and robustness. We also propose IPW rank statistics, called Dunnett-type test and ANOVA-type test, to compare 3 or more treatment groups on survival endpoints. Using simulations, we evaluate the finite sample performance of the weighted rank statistics combined with these propensity analysis methods. We demonstrate these methods with a real data example. The IPW method also allows us for unbiased estimation of population parameters of each treatment group. In this paper, we limit our discussions to survival outcomes, but all the methods can be easily modified for any type of outcomes, such as binary or continuous variables.

Low rates of osteoporosis treatment after hospitalization for hip fracture in Hawaii

We evaluated osteoporosis treatment and DEXA utilization rates of patients who were admitted for hip fracture in a single healthcare system in Hawaii from 2015 to 2016. We found that osteoporosis treatment and DEXA utilization rates were low, highlighting a critical gap in osteoporosis care after admission for hip fracture.

INTRODUCTION

The objective of this study was to evaluate osteoporosis care after an admission for hip fracture at three community hospitals within a single healthcare system in Hawaii.

METHODS

A retrospective chart review was conducted (n = 428) of patients ≥ 50 years and hospitalized for hip fractures between January 1, 2015, and May 31, 2016, at three major hospitals within Hawaii Pacific Health, a large healthcare system in Hawaii. Basic demographics were collected, and medications prescribed were quantified and described within 1 year of hip fracture. Logistic regression was used to evaluate the association between collected variables and the odds of osteoporosis treatment.

RESULTS

Only 115 (26.9%) patients were prescribed a medication for osteoporosis as a secondary prevention within a year of hospitalization for hip fracture. DEXA scans were performed in 137 (32.0%) patients. Most of the treated patients were prescribed oral bisphosphonates. Treatment facility, female gender, and higher BMI were found to be predictive factors for osteoporosis treatment.

CONCLUSION

The use of osteoporosis medication for secondary prevention after admission for hip fracture in Hawaii is low. Efforts need to be made to improve treatment rates, especially among males.

Non-intubated video-assisted thoracoscopic lung biopsy for interstitial lung disease: a single-center experience

Background

The mortality and morbidity associated with video-assisted thoracoscopic (VATS) lung biopsy for interstitial lung disease (ILD) are not negligible. We evaluated whether non-intubated VATS lung biopsy, which avoids intubation and general anesthesia, can be safely performed in ILD subjects.

Methods

This retrospective study compared the incidence of complications and surgical mortality between 25 consecutive intubated subjects and 10 non-intubated subjects (a total of 35 consecutive subjects) at a single institution.

Results

No major surgical complications or deaths were reported in either group, and non-intubated VATS biopsies were safely performed in subjects with relatively low carbon monoxide diffusing capacity (P=0.08) or poor American Society of Anesthesiologists physical status scores (ASA) (P=0.02).

Conclusions

These preliminary results suggest that non-intubated VATS lung biopsy is a safe and feasible option in patients with ILD.

Catheter probe endoscopic ultrasonography by using cold lubricating jelly-filled method for esophageal subepithelial tumors

Catheter probe endoscopic ultrasonography (C-EUS) by ultrasonographic jelly-filled method has been used to evaluate esophageal subepithelial tumors (SETs). Ultrasonographic jelly is safe on the skin, but its internal safety has not been demonstrated. The jelly stored at room temperature is easily injected into the esophagus through the instrument channel of the endoscope. However, using jelly stored at room temperature remains problematic because the jelly is drained rapidly. We used cold lubricating jelly and an intravenous extension tube to resolve these problems. In this study, we evaluated the safety and efficacy of cold lubricating jelly-filled method. The medical records of patients who underwent C-EUS by using water or cold lubricating jelly-filled method for esophageal SETs from March 2013 to September 2016 in Gangneung Asan hospital were reviewed. Clinical characteristics and EUS findings were evaluated retrospectively. Image quality and procedure time between water and cold lubricating jelly-filled method were compared retrospectively. This study included 138 patients (74 males, 64 females) with esophageal SET with a mean age of 57.1 ± 11.1 years. Thirty-four patients had lesions in the upper esophagus, 58 patients had lesions in the middle esophagus, and 46 patients had lesions in the lower esophagus. The EUS diagnoses were leiomyoma (82.6%), hemangioma (4.3%), extrinsic compressive lesion (3.6%), granulosa cell tumor (2.9%), ectopic calcification (1.4%), cyst (1.4%), lipoma (0.7%), varix (0.7%), and inconclusive lesion (2.2%). The mean image score in the cold lubricating jelly filled-method group was higher than that in the water-filled method group (3.2 ± 0.7 vs. 2.8 ± 0.7, P = 0.002). The procedure time in the cold lubricating jelly filled-method group was shorter than that in the water-filled method group (10 minutes 27 seconds ± 4 minutes 22 seconds versus 13 minutes 20 seconds ± 6 minutes 20 seconds, P = 0.045). No procedure-related complication was observed. C-EUS using the cold lubricating jelly-filled method seems to provide better image quality and shorter procedure time compared with C-EUS using the water-filled method.

Morphine Suppresses Lung Cancer Cell Proliferation Through the Interaction with Opioid Growth Factor Receptor: An In Vitro and Human Lung Tissue Study

BACKGROUND

There have been inconsistent reports on whether opioids promote or inhibit lung cancer growth. In this study, we suggest that opioid growth factor receptor (OGFR), a negative regulator of cell proliferation, is a binding site of morphine and is involved in subsequent morphine-induced lung cancer growth suppression.

METHODS

The expression and distribution of OGFR in human lung cancer tissues and cell lines were assessed with immunohistochemistry and real-time reverse transcription polymerase chain reaction. The human lung cancer cell line, H1975 (adenocarcinoma), which overexpressed OGFR but not μ-opioid receptors, was selected for further analysis to verify the interaction between morphine and OGFR and the impact of morphine on cancer cell growth.

RESULTS

OGFR was expressed in lung cancer tissues and all cancer cell lines tested. Adenocarcinoma showed a higher OGFR expression than squamous cell carcinoma (reverse transcription polymerase chain reaction relative quantitation value: median [interquartile range], 13.1 [9.3-20.0] vs 4.3 [2.2-6.6]; P = 0.003). OGFR expression showed an inverse correlation with cell proliferation (r = -0.92, P = 0.0001). Morphine treatment reduced the median H1975 cell number by approximately 23% (P = 0.03). Growth suppression by morphine was attenuated when OGFR was knocked down. A confocal experiment demonstrated binding of morphine to OGFR. Growth suppression by morphine occurred in the S phase of the cell cycle.

CONCLUSIONS

Lung cancer tissues and cell lines express OGFR. Morphine interacts with OGFR and may suppress lung cancer progression.

Liver-Wrapping, Nitric Oxide-Releasing Nanofiber Downregulates Cleaved Caspase-3 and Bax Expression on Rat Hepatic Ischemia-Reperfusion Injury

BACKGROUND

Hepatic ischemia-reperfusion injury (IRI) is an important determinant of the outcome of hepatic surgery, including re-section and transplantation. Previous studies have shown that nitric oxide (NO) has a protective effect against IRI. Therefore, many studies have examined methods for supplying NO. In this study, we investigated the effect of NO-releasing nanofibers on hepatic IRI in a rat model.

METHODS

Male Sprague-Dawley rats were divided into 4 groups: control, IRI only (n = 3); group 1, hepatic IRI and liver-wrapping with nanofiber lacking NO (n = 4); group 2, hepatic IRI and liver-wrapping with NO rapid-releasing nanofiber (n = 4); and group 3, hepatic IRI and liver-wrapping with NO slow-releasing nanofiber (n = 5).

RESULTS

The levels of aspartate aminotransferase and alanine aminotransferase were not significantly different between groups. On the basis of Western blots, Bax/β-actin levels were significantly lower in group 2 than in group 3 (P < .01). Cleaved Caspase-3/β-actin levels were significantly lower in group 2 than in the control, group 1, and group 3 (P < .05, .01, and .01, respectively). However, there were no significant differences in Bcl-2/β-actin between groups.

CONCLUSIONS

The liver-wrapping NO rapid-releasing nanofiber downregulated cleaved Caspase-3 and Bax expression. It has a protective effect by reducing apoptosis in hepatic IRI in rats.

Remote Preconditioning on Rat Hepatic Ischemia-Reperfusion Injury Downregulated Bax and Cleaved Caspase-3 Expression

OBJECTIVE

Hepatic ischemia-reperfusion injury (IRI) is considered a major cause of hepatic damage in liver surgery. The aim of this study was to investigate the effect of the remote ischemic perconditioning method on hepatic IRI in a rat model.

METHODS

Seventeen rats underwent hepatic IRI for 30 minutes followed by reperfusion, and were divided into 3 groups: group I, only hepatic IRI (n = 5); group II, hepatic IRI with remote perconditioning (n = 7); and group III, hepatic IRI with remote postconditioning (n = 5).

RESULTS

For Bax/β-actin, mean values of the 3 groups (±standard deviation) were 1.29 ± 0.26 (group I), 0.89 ± 0.15 (group II), and 1.02 ± 0.23 (group III). The level of Bax/β-actin in group II was significantly lower than in group I (P < .01). The cleaved Caspase-3/β-actin ratio for groups I, II, and III was 0.93 ± 0.22, 0.46 ± 0.16, and 0.63 ± 0.22, respectively. The level of cleaved Caspase-3/β-actin in groups II and III were significantly lower than in group I (P < .01 and P < .05, respectively). The Bcl-2/β-actin ratio for groups I, II, and III was 1.01 ± 0.09, 1.19 ± 0.39, and 1.20 ± 0.12, respectively. However, there were no significant difference between groups II and III and group I.

CONCLUSIONS

The remote perconditioning on rat hepatic IRI downregulated the Bax and cleaved Caspase-3 expression.

Potentially modifiable risk factors for atrial fibrillation following lung resection surgery: a retrospective cohort study

Atrial fibrillation is the most frequent arrhythmia after thoracic surgery and is associated with increased hospital costs, morbidity and mortality. In this study, we aimed to identify potentially modifiable risk factors for postoperative atrial fibrillation following lung resection surgery and to suggest possible measures to reduce risk. We retrospectively reviewed the medical records of 4731 patients who underwent lobectomy or more major lung resection over a 6-year period. Patients who developed atrial fibrillation postoperatively and required treatment were included in the postoperative atrial fibrillation group, while the remaining patients were assigned to the non-postoperative atrial fibrillation group. Risk factors for postoperative atrial fibrillation were analysed by multivariate analysis and propensity score matching. Overall, 12% of patients developed postoperative atrial fibrillation. Potentially modifiable risk factors for postoperative atrial fibrillation were excessive alcohol consumption (odds ratio (OR) = 1.48, 95% CI 1.08-2.02, p = 0.0140), red cell transfusion (2.70(2.13-3.43), p < 0.0001), use of inotropes (1.81(1.42-2.31), p < 0.0001) and open (vs. thoracoscopic) surgery (1.59(1.23-2.05), p < 0.0001). Compared with inotrope use, vasopressor administration was not related to postoperative atrial fibrillation. Use of steroids or thoracic epidural anaesthesia did not reduce the incidence of postoperative atrial fibrillation. We conclude that high alcohol consumption, red cell transfusion, use of inotropes and open surgery are potentially modifiable risk factors for postoperative atrial fibrillation. Pre-operative alcohol consumption needs to be addressed. Avoiding red cell transfusion and performing lung resection via video-assisted thoracoscopic surgery may reduce the incidence of postoperative atrial fibrillation and the administration of vasopressors rather than inotropes is preferred.

Synergistic Effect of Intravenous Ibuprofen and Hydromorphone for Postoperative Pain: Prospective Randomized Controlled Trial

Background: An intravenous form of ibuprofen has recently been approved by the Food and Drug Administration (FDA) and reports are rare on its co-administration with opioids. Objectives: We researched whether an intravenous ibuprofen-hydromorphone combination is synergistic, additive, or infra-additive on postoperative pain. Study Design: A parallel-group, 1:1:1 allocation, randomized, double-blind controlled trial. Setting: University teaching hospital in Korea. Methods: Ninety patients, undergoing breast surgery, were divided into one of the 3 groups (I, H, IH groups). Positive analgesic efficacy was defined as a numeric rating scale (NRS) ≤ 3 on a 0 – 10 NRS, 30 minutes after the drug administration. Drugs were administered by the Dixon’s upand-down method. Starting doses were ibuprofen (I) 50 mg, hydromorphone (H) 0.25 mg, or ibuprofen 25 mg + hydromorphone 0.125 mg (IH). The maximum doses were ibuprofen 800 mg, hydromorphone 2 mg, or ibuprofen 400 mg + hydromorphone 1 mg. Combination index (CI) (additive: 0.9 – 1.1, synergism: < 0.9, antagonism: > 1.1), dose reduction index (DRI, a measure of how much the dose of each drug in a combination can be reduced), and isobologram were used to define the nature of their interaction. Statistics: One way ANOVA, Kruskal Wallis test, and Chi square test, significance level P < 0.05. Results: The median effective doses (ED50) of ibuprofen and hydromorphone were 1,447 mg and 1.5 mg, respectively. The median ED50 of the combination was ibuprofen 71 mg and hydromorphone 0.3 mg. Ibuprofen and hydromorphone showed a strong synergy (CI 0.2, DRI 20 and 5 for ibuprofen and hydromorphone at ED50). Limitation: Analgesic efficacy was observed during post-anesthesia care unit (PACU) period only. Conclusions: The combination of intravenous ibuprofen and hydromorphone produces a strong synergistic analgesia on postoperative pain. Key words: Median effective dose, hydromorphone, pain, ibuprofen, postoperative