Yusuke Sasabuchi

Utility of the Penn Classification in Predicting Outcomes of Surgery for Acute Type A Aortic Dissection

The Penn classification, a risk assessment system for acute type A aortic dissection (AAAD), is based on preoperative ischemic conditions. We investigated whether Penn classes predict outcomes after surgery for AAAD. Three hundred fifty-one patients with DeBakey type I AAAD treated surgically, January 1997 to January 2011, were divided into 4 groups per Penn class: Aa (no ischemia, n = 187), Ab (localized ischemia with branch malperfusion, n = 67), Ac (generalized ischemia with circulatory collapse, n = 46), and Abc (localized and generalized ischemia, n = 51). Early and late outcomes were compared between groups. In-hospital mortality was 3% (6 of 187) for Penn Aa, 6% (4 of 67) for Penn Ab, 17% (8 of 46) for Penn Ac, and 22% (11 of 51) for Penn Abc. Multivariate logistic regression analysis showed Penn classes Ac and Abc, operation time >6 hours, and entry in the descending thoracic aorta to be risk factors for in-hospital mortality. Incidences of neurologic, respiratory, and hepatic complications differed between groups. Five-year cumulative survival was 85% in the Penn Aa group, 74% in the Penn Ab group (p = 0.027 vs Penn Aa), 78% in the Penn Ac group, and 67% in the Penn Abc group (p <0.001 vs Penn Aa). In conclusion, morbidity and mortality are high in patients with generalized ischemia. The Penn classification appears to be a useful risk assessment system for AAAD, predictive of outcomes.

The Dose-Response Relationship Between Body Mass Index and Mortality in Subjects Admitted to the ICU With and Without Mechanical Ventilation

BACKGROUND: Obesity has been associated with increased mortality in the general population, whereas a paradoxical relationship between higher body mass index and lower mortality has been referred to as the obesity paradox in critically ill patients. However, it remains unknown whether a particular subgroup is most affected. The aim of the present study is to elucidate whether obesity is associated with lower mortality in the ICU population by comparing subjects with and without mechanical ventilation. METHODS: A total of 334,238 subjects from a nationwide database who were discharged between July 2010 and March 2012 and who were admitted to general ICUs during their hospitalization were included in this study. The primary outcome was in-hospital mortality. RESULTS: Of all subjects evaluated, 23.3% were started on mechanical ventilation within the first 2 d after ICU admission. Compared with the non-ventilated group, the ventilated group was more likely to have sepsis, pneumonia, or coma. The ventilated group underwent more procedures within the first 2 d after ICU admission compared with the non-ventilated group. A restricted cubic spline function showed lower mortality in subjects with a higher body mass index among the ventilated group, whereas mortality was increased with increasing body mass index in the non-ventilated group. CONCLUSIONS: This study shows that a high body mass index is associated with low mortality in the mechanically ventilated group, whereas the non-ventilated group showed a reverse J-shaped association. There was a higher mortality rate in underweight subjects in both groups.

The Volume-Outcome Relationship in Critically Ill Patients in Relation to the ICU-to-Hospital Bed Ratio.

Objectives:A volume-outcome relationship in ICU patients has been suggested in recent studies. However, it is unclear whether the ICU-to-hospital bed ratio affects the volume-outcome relationship. The aim of this study is to investigate the relationship between hospital volume and in-hospital mortality of adult ICU patients in relation to the ratio of ICU beds to regular hospital beds. Design:Retrospective cohort study. Setting:Four hundred seventy-seven Japanese hospitals from 2007 to 2012 in the Japanese Diagnosis Procedure Combination database. Patients:A total of 596,143 patients discharged from acute care hospitals. Interventions:None. Measurements and Main Results:We analyzed data from 596,143 ICU patients from 2007 through 2012 using a nationwide administrative database. Patients were categorized into nine subgroups (the tertiles of hospital volume of ICU patients combined with the tertiles of ICU-to-hospital bed ratio). Multivariable logistic regression analyses were performed to examine the concurrent effects of hospital volume of ICU patients and ICU-to-hospital bed ratio on in-hospital mortality, with adjustment for patient and hospital characteristics. Higher hospital volume of ICU patients and a higher ICU-to-hospital bed ratio were independently associated with lower mortality. When patients were stratified by ICU-to-hospital bed ratio categories, in-hospital mortality was significantly lower in the high-volume subgroup (odds ratio, 0.74; 95% CI, 0.58–0.93) compared with the low-volume subgroup in hospitals with a high ICU-to-hospital bed ratio. However, these relationships were not significant in hospitals with low ICU-to-hospital bed ratios (odds ratio, 0.94; 95% CI, 0.59–1.50) or in hospitals with intermediate ICU-to-hospital bed ratios (odds ratio, 0.80; 95% CI, 0.71–1.08). Conclusions:An inverse relationship between hospital volume of ICU patients and mortality was seen only when the ICU-to-hospital bed ratio was sufficiently high. Regionalization and increasing the number of ICU beds in referral centers may improve patient outcomes.

Categorized diagnoses and procedure records in an administrative database improved mortality prediction

OBJECTIVES Comorbidity measures are widely used in administrative databases to predict mortality. The Japanese Diagnosis Procedure Combination database is unique in that secondary diagnoses are recorded into subcategories, and procedures are precisely recorded. We investigated the influence of these features on the performance of mortality prediction models. STUDY DESIGN AND SETTING We obtained data of adult patients with main diagnosis of acute myocardial infarction, congestive heart failure, acute cerebrovascular disease, gastrointestinal hemorrhage, pneumonia, or septicemia during a 1-year period. Multiple models were constructed representing different subcategories from which Charlson and Elixhauser comorbidities were extracted. Prevalence of comorbidities and C statistics of logistic regression models predicting in-hospital mortality was compared. Associations between four procedures (computed tomography, oxygen administration, urinary catheter, and vasopressors) and mortality were also evaluated. RESULTS C statistics of the model using all secondary diagnoses (Charlson: 0.717; Elixhauser: 0.762) were greater than those using a limited subcategory to strictly specify comorbidities (Charlson: 0.708; Elixhauser: 0.744). However, misidentification of complications and main diagnoses as comorbidities was observed in the all-diagnosis model. The four procedures were associated with mortality. CONCLUSION Subcategorized diagnoses allowed correct identification of comorbidities and procedures predicted mortality. Incorporation of these two features should be considered for other administrative databases.

Risks and Benefits of Stress Ulcer Prophylaxis for Patients With Severe Sepsis.

Objectives: The Surviving Sepsis Campaign Guidelines recommend stress ulcer prophylaxis for patients with severe sepsis who have bleeding risks. Although sepsis has been considered as a risk factor for gastrointestinal bleeding, the effect of stress ulcer prophylaxis has not been studied in patients with severe sepsis. Furthermore, stress ulcer prophylaxis may be associated with an increased risk of hospital-acquired pneumonia or Clostridium difficile infection. The aim of this study was to investigate the risks and benefits of stress ulcer prophylaxis for patients with severe sepsis. Design: Retrospective cohort study. Setting: Five hundred twenty-six acute care hospitals in Japan. Patients: A total of 70,862 patients with severe sepsis. Interventions: None. Measurements and Main Results: One-to-one propensity score matching created 15,651 pairs of patients who received stress ulcer prophylaxis within 2 days of admission and those who did not. Patient characteristics were well balanced between the two groups. No significant differences were seen between the stress ulcer prophylaxis group and the control group with regard to gastrointestinal bleeding requiring endoscopic hemostasis (0.6% vs 0.5%; p = 0.208), 30-day mortality (16.4% vs 16.9%; p = 0.249), and Clostridium difficile infection (1.4% vs 1.3%; p = 0.588). The stress ulcer prophylaxis group had a significantly higher proportion of hospital-acquired pneumonia (3.9% vs 3.3%; p = 0.012) compared with the control group. Conclusions: Since the rate of gastrointestinal bleeding requiring endoscopic hemostasis is not different comparing patients with and without stress ulcer prophylaxis, and the increase in hospital-acquired pneumonia is significant, routine stress ulcer prophylaxis for patients with severe sepsis may be unnecessary.

Outcomes after early or late timing of surgery for infective endocarditis with ischaemic stroke: a retrospective cohort study

OBJECTIVES The timing of cardiac surgery for infective endocarditis with ischaemic stroke remains controversial. METHODS Using a nationwide inpatient database in Japan, we conducted a retrospective observational study. We identified patients aged 20 years or older with ischaemic stroke on admission who were diagnosed with infective endocarditis and underwent cardiac surgery during the initial hospitalization between July 2010 and March 2013. In-hospital mortality and perioperative complications were compared between the early (≤7 days) and late (>7 days) surgery groups using logistic regression analyses with adjustment for propensity scores and inverse probability of treatment weighting. RESULTS We identified 253 patients who underwent cardiac valve surgery for infective endocarditis with ischaemic stroke on admission. In-hospital mortality rates were 8.6 and 9.5% in the early (n = 105) and late (n = 148) surgery groups, respectively. There were no significant differences in the in-hospital mortality between the early and late surgery groups in the propensity score-adjusted model [odds ratio (OR), 0.95; 95% confidence interval (CI), 0.35-2.54] and inverse probability-weighted model (risk difference, -0.82%; 95% CI, -6.43 to 4.84%). The perioperative complication rates were 42.9 and 37.8% in the early and late surgery groups, respectively, and showed no significant differences in the propensity score-adjusted model (OR, 1.11; 95% CI, 0.63-1.97) and inverse probability-weighted model (risk difference, 1.54%; 95% CI, -7.13 to 10.2%). CONCLUSIONS Early timing of surgery for infective endocarditis patients with ischaemic stroke was not associated with higher in-hospital mortality or complications after admission. Early timing of surgery may not be contraindicated for infective endocarditis patients with ischaemic stroke.

Annual trends in knee arthroplasty and tibial osteotomy: Analysis of a national database in Japan

BACKGROUND Various nationwide studies have reported differing annual trends in utilization of knee arthroplasty and tibial osteotomy. Using the Diagnosis Procedure Combination database in Japan, the present series examined annual trends and demographics in total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA) and tibial osteotomy. METHODS All patients were identified who underwent TKA, UKA or tibial osteotomy for osteoarthritis, osteonecrosis or rheumatoid arthritis of the knee between July 2007 and March 2015. RESULTS A total of 170,433 cases of TKA, 13,209 cases of UKA and 8760 cases of tibial osteotomy were identified. The proportion of patients undergoing UKA rose from 4.0% in 2007 to 8.1% in 2014 (P<0.001), and that of tibial osteotomy from 2.6% in 2007 to 5.5% in 2014 (P<0.001); the proportion undergoing TKA fell from 93.4% in 2007 to 86.3% in 2014 (P<0.001). Between 2007 and 2014 the proportions of patients with osteonecrosis who underwent UKA and tibial osteotomy increased from 34.7% and 11.6% to 38.6% and 16.2%, respectively (P=0.001 for UKA and P=0.004 for tibial osteotomy). The proportions of patients with osteonecrosis undergoing UKA or tibial osteotomy were significantly greater than those with other diagnoses (P<0.001 for both). CONCLUSIONS The popularity of UKA and tibial osteotomy in Japan increased during the period 2007-2014 at the expense of TKA. The proportions of UKA and tibial osteotomy in patients with osteonecrosis also increased, and were larger than those in patients with other causative diseases.

Safety of Tranexamic Acid in Pediatric Cardiac Surgery: A Nationwide Database Study.

OBJECTIVES The present study aimed to examine the association between tranexamic acid (TXA) use and adverse effects (seizures, thromboembolism, and renal dysfunction) in a pediatric cardiac surgery population using a national inpatient database in Japan. The authors also assessed the association between TXA use and other clinical outcomes (length of hospital stay and in-hospital mortality). DESIGN A nationwide, retrospective cohort study using propensity score analyses. SETTING Japanese Diagnosis Procedure Combination inpatient database. PARTICIPANTS Pediatric patients who underwent cardiac surgery using cardiopulmonary bypass between July 2010 and March 2014 (N = 11,275). INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Propensity-score matching created 3,739 pairs of patients with and without TXA administration. Propensity-matched analysis showed that the proportion of seizures was significantly higher in the TXA group than in the non-TXA group (1.6% v 0.2%, difference, 1.4%; 95% confidence interval, 1.0-1.9; p<0.001). However, none of the other outcomes was significantly different between the groups. CONCLUSIONS TXA use is associated with a significantly increased risk of seizures. However, there is no difference in any other outcomes between the TXA and non-TXA groups.

Prolonged propofol infusion for mechanically ventilated children

We retrospectively analysed 30‐day mortality and duration of intubation for 8016 children ventilated for three or more days, sedated with midazolam (n = 7716) or propofol (n = 300). We matched the propensity scores of 263 pairs of children. The propensity‐matched 30‐day mortality (95% CI) was similar: 17/263 (6.5%) with midazolam vs. 24/263 (9.1%) with propofol, p = 0.26. Weaning from mechanical ventilation of children sedated with midazolam was slower than weaning of children sedated with propofol, subhazard ratio (95% CI) 1.43 (1.18–1.73), p < 0.001.

Carperitide Increases the Need for Renal Replacement Therapy After Cardiovascular Surgery.

OBJECTIVES Acute kidney injury is a common complication after aortic surgery. Carperitide, a human atrial natriuretic peptide, was reported to be effective for preventing acute kidney injury after cardiac surgery. However, most studies were from single centers, and results of meta-analyses are subject to publication bias. The aim of the present study was to investigate whether carperitide preserved renal function in patients undergoing cardiovascular surgery. DESIGN Retrospective cohort study. SETTING Participating hospitals (N = 281) in a national database from 2010 to 2013. PARTICIPANTS Adult patients (N = 47,032) who underwent cardiovascular surgery. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS The main intervention variable investigated was the use of carperitide on the day of surgery. Assessed outcomes included receiving renal replacement therapy within 21 days of surgery and in-hospital mortality. Data were available for 47,032 patients, of whom 2,186 (4.6%) received carperitide on the day of surgery. Multivariate logistic regression analysis revealed that carperitide was significantly associated with a greater likelihood of receiving renal replacement therapy within 21 days of surgery, but not with in-hospital mortality. CONCLUSIONS In patients undergoing cardiovascular surgery, carperitide significantly increased the odds of receiving renal replacement therapy within 21 days after surgery.