The past, present and future of ACS NSQIP-Pediatric: Evolution from a quality registry to a comparative quality performance platform

Quality and process improvement (QI/PI) in children's surgical care require reliable data across the care continuum. Since 2012, the American College of Surgeons' (ACS) National Surgical Quality Improvement Program-Pediatric (NSQIP-Pediatric) has supported QI/PI by providing participating hospitals with risk-adjusted, comparative data regarding postoperative outcomes for multiple surgical specialties. To advance this goal over the past decade, iterative changes have been introduced to case inclusion and data collection, analysis and reporting. New datasets for specific procedures, such as appendectomy, spinal fusion for scoliosis, vesicoureteral reflux procedures, and tracheostomy in children less than 2 years old, have incorporated additional risk factors and outcomes to enhance the clinical relevance of data, and resource utilization to consider healthcare value. Recently, process measures for urgent surgical diagnoses and surgical antibiotic prophylaxis variables have been developed to promote timely and appropriate care. While a mature program, NSQIP-Pediatric remains dynamic and responsive to meet the needs of the surgical community. Future directions include introduction of variables and analyses to address patient-centered care and healthcare equity.

Phenotyping right heart function for prognosticating heart failure

Funding Acknowledgements

Type of funding sources: None.

Background

Right heart failure has been shown to portend poor prognosis. The pathophysiology of right heart function is complex, as right ventricular (RV) function is easily affected by preload and afterload.

Purpose

To test the hypothesis that machine learning would detect heterogeneity in right heart function and improve risk stratifications in a heart failure population

Methods

This study included 403 heart failure patients who had a history of hospitalization for decompensation. Patients were excluded if they had primary heart valve disease or pericardial disease or a previous cardiac surgery. Hierarchical clustering was undertaken on right heart variables (RV strain, right ventricular systolic pressure (RVSP), vena contracta of tricuspid regurgitation (TR) and diameter of inferior vena cava) to identify homogenous groups of patients with similar profiles of the variables. Cox hazard analysis was used to elucidate the benefit of clustering over each variable for prognosticating heart failure. Endpoint was hospitalization for worsening heart failure.

Results

Cluster analysis identified three groups with distinct right heart function. Cluster 1 (n = 191) represented patients with preserved RV function and low RVSP (figure A).  On the other hand, cluster 2 (n = 144) had reduced RV function and low RVSP, while cluster 3 (n = 68) had preserved RV function and high RVSP, associated with severe TR and high central venous pressure. The latter 2 clusters carried worse outcome than cluster 1 (p < 0.001, figure B). Cox hazard analysis demonstrated that, although the addition of each right heart variable to baseline model constructed from left heart variables did not improve predictive power, clusters predicted events with a hazard ratio of 1.566, independent from and incremental to the left heart variables (Figure C).

Conclusion

Cluster analysis identified two distinct phenotypes of right heart failure that were associated with adverse outcomes. This data-driven phenotyping can help in categorizing right heart failure and better prognosticating heart failure.

Abstract Figure.

Pulmonary arterial wave reflection as a novel estimate of pulmonary vascular resistance

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): International Medical Research and Development Fund

Background

Measuring pulmonary vascular resistance (PVR) is essential for diagnosing pulmonary hypertension. PVR can be estimated from a simple ratio of tricuspid regurgitation velocity (TRV) to time-velocity integral of flow through right ventricular outflow tract (RVOT) (Abbas equation), but this relationship has been shown to be unreliable in patients with high PVR. Once PVR is elevated, there is an increased pressure wave reflected from the peripheral of pulmonary artery (PA). We tested the hypothesis that assessing PA wave reflection could be an alternative method for estimating PVR.

Methods

This study recruited 83 patients (69 ± 14 years old, 44 men), including 41 patients with left-sided heart disease, 23 patients with pulmonary arterial hypertension and 19 patients with chronic thromboembolic pulmonary hypertension. PA wave reflection was assessed by separating PA pressure waveform derived from a Doppler tracing of TRV into forward and backward pressure (Pf and Pb), using a velocity profile at RVOT. This separation was based on the concept of wave intensity. PVR was estimated using Abbas equation. Pb and PVR by Abbas equation were compared for the correlations with direct measurement of PVR by right heart catheterisation within 48 hours after echocardiography.

Results

Figure A illustrates Pb and Pf waveforms obtained from a patient with chronic thromboembolic pulmonary hypertension. Pb increased from mid systole and formed a late peak of PA pressure waveform. Pb correlated strongly with PVR by catheter (figure B), whereas PVR by Abbas equation underestimated PVR especially when PVR was high, resulting in a moderate correlation (figure C). Receiver-operator characteristic curves showed a higher accuracy of Pb for identifying PVR > 3WU as well as 6WU, compared with PVR by Abbas equation (figure D and E).

Conclusions

This novel echocardiographic method for assessing PA wave reflection helps diagnose the severity of pulmonary hypertension.

Abstract Figure.

Prediction of atrial fibrillation by 12-lead electrocardiogram parameters in patients without structural heart disease

Background

Recently, the analysis of electrocardiogram (ECG) waveform by artificial intelligence has been reported to pick out those who have atrial fibrillation (AF) or have a high potential of developing AF, which, however, cannot explain the mechanisms or algorisms for the prediction from its nature.

Purpose

The purpose of this study is to conduct a comprehensive analysis to investigate the difference of weighting in predicting capability for AF among hundreds of automatically-measured ECG parameters using a single ECG at sinus rhythm.

Methods and results

Out of Shinken Database 2010–2017 (n=19170), 12825 patients were extracted, where those with ECG showing AF rhythm at the initial visit (including all persistent/permanent AF and a part of paroxysmal AF) and those with structural heart diseases were excluded. Out of 639 automatically-measured ECG parameters in MUSE data management system (GE Healthcare, USA), 438 were used. [Analysis 1] A predicting model for paroxysmal AF were determined by logistic regression analysis (Total, n=12825; paroxysmal AF, n=1138), showing a high predictive capability (AUC = 0.780, p<0.001). In this model, the relative contribution of ECG parameters (by coefficient of determination) according to the time phase were P:72.4%, QRS:32.7%, and ST-T:13.7%, respectively (Figure A). [Analysis 2] Excluding AF at baseline, a predicting model for new-developed AF were determined by Cox regression analysis (Total, n=11687; new-developed AF, n=87), showing a high predictive capability (AUC = 0.887, p<0.001). In this model, the relative contribution of parameters (by log likelihood) according to the time phase were P:40.8%, QRS:42.5%, and ST-T:24.9%, respectively (Figure B).

Conclusions

We determined ECG parameters that potentially contribute to picking up existing AF or predicting future development of AF, where the measurement of P wave strongly contributed in the former whereas all time phases were similarly important in the latter.

Weighting of parameters to predict AF

Funding Acknowledgement

Type of funding source: Private hospital(s). Main funding source(s): Self funding of the institute

Impact of pulmonary wave reflection in heart failure: right ventricular-arterial coupling

Background

Pulmonary wave reflection, an important loading component on RV, would help better describe right ventricular (RV) – arterial uncouplingin type II pulmonary hypertension (PH).

Methods

This study included 105patients with type II PH (age = 72±13 years old, ejection fraction = 47±21%). Pulmonary wave reflection was characterised by estimating pressure and velocity profiles from Doppler measurement and separating pressure waveform into forward (Pf) and backward pressure (Pb) waves based on the concept of wave intensity. The relationship of RV strain against Pb or pulmonary artery systolic pressure (PASP) was compared between patients with and without subsequent event of worsening heart failure, using discriminant analysis.

Results

Sample profiles of pressure waveforms illustrated Pb accounted for a significant proportion of total pressure (figure A). When RV strain was plotted against Pb, the distribution of both group were clearly separated, indicating significant uncoupling in patients with events, whereas when plotted against PASP, the both groups were overlapped (figure B and C).

Conclusions

Pulmonary wave reflection can better describe RV-arterial uncoupling in type II PH.

Funding Acknowledgement

Type of funding source: None

Heart rate recovery after exercise as a prognostic predictor in patients with atrial fibrillation

Background

A delayed heart rate recovery (HRR) after exercise is related to mortality in sinus rhythm. This study aimed to investigate this concept can be applied to patients with atrial fibrillation (AF).

Methods

We analyzed 483 patients with AF (mean 65 years, male 74%). HRR integral was calculated by integrating the difference in HR in every 3 second between the end of exercise and the specified time after the exercise (30, 60, 120 and 180 seconds). After evaluating the prognostic power of each HRR integral, we selected HRR integral of 180 seconds (180HRR-integral).

Results

We divided the patients into two groups using median value of 180HRR-integral. All-cause mortality, the incidence of cardiovascular events and heart failure events were higher in the poor 180HRR-integral. After adjustment for covariates, the impact of the high 180HRR-integral for all-cause mortality was 3.15 (p=0.057), 1.77 for cardiovascular events (p=0.067) and 1.28 for heart failure events (p=0.519).

Conclusion

Poor HRR was associated with worse prognosis in patients with AF.

Funding Acknowledgement

Type of funding source: None

General anesthesia risk across pediatric surgical specialties: Low in otolaryngology

PURPOSE

To determine the relevance of the Food and Drug Administration (FDA) warning regarding general anesthesia (GA) in children under 3 years of age for procedures lasting longer than 3 h, by surgical specialty and for otolaryngology specifically.

METHODS

A one-year retrospective review was conducted at a tertiary-care medical center for all children younger than 3 years undergoing surgical procedures with durations greater than 3 h. De-identified data related to age, surgical service, procedure types, American Society of Anesthesiologists (ASA) physical status classification, and general anesthesia time were collected and examined.

RESULTS

During 2017, 430 of 11,757 patients (3.7%) met the age and duration of anesthesia criteria. Procedures performed by the cardiothoracic surgery service were mostly likely to result in duration of surgery greater than 3 h (46.6%), followed by neurosurgery (12.9%), cardiology (9.3%), plastic surgery (7.1%), general surgery (6.6%), and urology (5.1%). Less than 2% of patients undergoing ophthalmology (1.9%), orthopedic surgery (1.7%), and otolaryngology (0.5%) procedures required anesthesia greater than 3 h.

CONCLUSION

Less than 4% of patients younger than 3 years undergoing surgery required general anesthesia for longer than 3 h. The theoretical risks of general anesthesia per the FDA warning are discussed and must be balanced against the known functional and neurodevelopmental consequences of not performing critical and time-sensitive surgery on children in this age group. A strategy for addressing parental and provider concerns is discussed.

153 Multiparametric assessment of diastolic function in heart failure

Background

The assessment of diastolic function is still challenging in the setting of heart failure (HF). We tested the hypothesis that applying a machine learning algorithm would detect heterogeneity in diastolic function and improve risk stratification in HF population.

Methods

This study included consecutive 279 patients with clinically stable HF referred for echocardiographic assessment, for whom diastolic function variables were measured according to the current guidelines. Cluster analysis, an unsupervised machine learning algorithm, was undertaken on these variables to form homogeneous groups of patients with similar profiles of the variables. Sequential Cox models paralleling the clinical sequence of HF assessment were used to elucidate the benefit of cluster-based classification over guidelines-based classification. The primary endpoint was a hospitalization for worsening HF.

Results

Cluster analysis identified 3 clusters with distinct properties of diastolic function that shared similarities with guidelines-based classification. The clusters were associated with brain natriuretic peptide level (p < 0.001, figure A). During follow-up period of 2.6 ± 2.0 years, 62 patients (22%) experienced the primary endpoint. Cluster-based classification exhibited a significant prognostic value (c2 = 20.3, p < 0.001, figure B), independent from and incremental to an established clinical risk score for HF (MAGGIC score) and left ventricular end-diastolic volume (hazard ratio = 1.677, p = 0.017, model c2: from 47.5 to 54.1, p = 0.015, figure D). Although guideline-based classification showed a significant prognostic value (c2 = 13.1, p = 0.001, figure C), it did not significantly improve overall prognostication from the baseline (model c2: from 47.5 to 49.9, p = 0.199, figure D).

Conclusion

Machine learning techniques help grading diastolic function and stratifying the risk for decompensation in HF.

Abstract 153 Figure.

P1528 Prognostic impact of pulmonary arterial wave reflection in heart failure

Background

Pulmonary hypertension (PH) is prevalent and is associated with adverse outcomes in heart failure. The pathophysiology of PH is heterogeneous, including pre-capillary PH and combined pre- and post-capillary PH. The latter PH has been reported in experimental studies to cause wave reflection in pulmonary circulation, putting additional burden on right ventricle. This study tested the hypothesis that separating wave reflection would enhance risk stratification in heart failure.

Methods

This study included 152 patients with clinical stable heart failure associated with PH who were referred to echocardiography for hemodynamic assessment (age = 72 ± 13 years old, ejection fraction = 49 ± 21%). Pulmonary arterial wave reflection was characterised by separating PA pressure waveform into forward (Pf) and backward pressure (Pb) waves, based on the concept of wave intensity. PA pressure waveform was estimated from continuous Doppler tracing of tricuspid regurgitation. Flow velocity was measured by pulse Doppler at right ventricular outflow tract. Outcome data was obtained by reviewing medical charts. The endpoint was hospitalization for worsening heart failure (WHF).

Results

Figure A compares PA pressure waveforms (total and separated waves) obtained from 2 patients with and without WHF event. The patient with event had higher total pressure associated with late peak than the patient without event. Pb appeared later than Pf; it was markedly higher in the patient with event than the patient without event, although Pf was similar between both patients. Kaplan-Meier analysis demonstrated a significant separation of survival curves stratified by Pb (chi-square = 25.1, p < 0.001, figure B). During follow-up period of 1.5 ± 1.8 years, 65 patients (43%) experienced the endpoint. Sequential Cox analysis revealed that PASP remained significant after adjusted for left ventricular ejection fraction and E/e’ (hazard ratio = 1.017, p = 0.019). Pb also remained significant after the same adjustment (hazard ratio = 1.066, p = 0.003); the addition of Pb to a baseline model resulted in greater increase in predictive power than the addition of PASP (model chi-square: from 27.4 (baseline), to 37.6 (p = 0.004) for Pb, to 31.6 (p = 0.027) for PASP, figure C)

Conclusions

Pressure wave reflection in pulmonary artery is associated with early decompensation in heart failure.

Abstract P1528 Figure.

P289 Aortic valve resistance risk-stratifies low-gradient aortic stenosis

Background

Grading the severity of aortic stenosis (AS) is challenging, since there is a discrepancy between aortic valve area (AVA) and mean pressure gradient (mPG). Arotic valve resistance (RES) has been proposed as a usuful descriptor of AS severity, but it is not commonly used for clinical decision-making, because its robust validation of clinical-outcome efficacy is lacking. This study aimed to investigate whether RES holds an incremental value for risk-stratifying AS.

Methods

This study recuited 565 AS patients (AVA < 1.5cm²) referred to echocardiography for valve assessment. The patients were divided into three different groups, according to the guidelines: high-gradient AS (HG-AS, mPG≥40mmHg, n = 157), low-gradient AS (LG-AS, mPG < 40mmHg + AVA ≤ 1.0cm², n = 155) and moderate AS (Mod-AS, mPG < 40mmHg + AVA > 1.0cm², n = 253). RES was calculated from Doppler measurement of mPG and stoke volume. The diagnositic cutoff point for RES was determined at 190 dynes × s×cm-5 by substituting AVA = 1.0cm² and mPG = 40mmHg into the definition formula of RES and Gorlin formula. The patients were followed up for 2 years. The endpoint was a composite of cardiac death, hospitalization for heart failure and aortic valve replacement necessitated by the development of AS-related symptoms.

Result

Kaplan-Meier analyses showed that LG-AS exhibited an intermediate outcome between HG-AS and Mod-AS (event-free survival at 2 years = 20.9% for HG-AS, 59.7% for LG-AS, 89.9% for Mod-AS, p < 0.001, figure A). When LG-AS was stratified by RES, the survival curves showed a significant separation (event-free survival at 2 years = 35.3% for high RES, 70.7% for low RES, p < 0.001, figure B). This trend persisted even when analysed separately for norml (stroke volume index > 35ml/m²) and low (stroke volume index ≤ 35ml/m²) flow state ((normal flow) event-free survival at 2 years = 38.7% for high RES, 70.4% for low RES, p = 0.023, figure C; (low flow) event-free survival at 2 years = 26.7% for high RES, 74.6% for low RES, p < 0.001, figure D).

Conclusion

This study confirmed the clinical efficacy of RES for risk-stratifying LG-AS patients.

Abstract P289 Figure.

P893 Left ventricular flow energetics predicts worsening heart failure in dilated cardiomyopathy

Background

Blood flows through healthy hearts form optimal flow structures; they store flow kinetic energy (KE) that can be used for ejection. In contrast, in failing hearts, intracardiac flows become disorganized so that they may be energetically inefficient. However, it remained unknown whether left ventricular (LV) flow energetics prognosticates in heart failure.

Methods

This study included 61 patients with dilated cardiomyopathy (DCM). The temporal change in KE during early diastole (ED), atrial contraction (AC) and isovolumic contraction (IVC) was measured using Vector Flow Mapping particle tracking (Hitachi, figure top). LV inflow (total flow) were divided, based on whether they were ejected (direct flow, DF) or stayed in LV (retained flow, RF) in the following systole. KE of DF can be made use of for ejection, whereas KE of RF is supposed to be wasted. Diastolic function was graded, according to current EACVI/ASE guidelines. The patients were followed up for three years. Primary endpoint was hospitalization for worsening heart failure (WHF).

Results

12 patients had hospitalizations for WHF in the follow-up period. KE of total flow did not show any significant difference through the cardiac cycle between patients with and without WHF. KE of DF was slightly, but not significantly, smaller (ED: p = 0.252, AC: p = 0.119, IVC: p = 0.122), and KE of RF was slightly, but not significantly, larger (ED: p = 0.971, AC: p = 0.085, IVC: p = 0.134) in patients with WHF than those without events. The ratio of DF and RF (DF/RF ratio) showed significant differences between these two groups, especially from AC through IVC (figure, bottom-left). Cox proportional hazard analyses demonstrated that DF/RF ratio during IVC showed a significant correlation with clinical outcomes (p = 0.033, hazard ratio = 0.067). It remained significant even after adjusted for diastolic function grade (p = 0.046, hazard ratio = 0.074). Kaplan-Meier analysis confirmed the above results (figure, bottom-right). Conclusion: Efficiency of KE recruitment for LV ejection during IVC is associated with clinical outcomes in DCM.

Abstract P893 Figure. LISA

Metatropic dysplasia-a skeletal dysplasia with challenging airway and other anesthetic concerns

BACKGROUND

Metatropic dysplasia is a rare form of skeletal dysplasia requiring multiple anesthetics for surgical and imaging procedures, most of which are orthopedic procedures. We provide centralized care to patients with skeletal dysplasia at our tertiary care pediatric hospital, and we were able to collect the largest number of metatropic dysplasia patients reported to date.

AIM

The aim of this retrospective study was to describe and characterize the anesthetic difficulties in this high-risk population.

METHODS

Medical charts of all patients with metatropic dysplasia were reviewed to collect data, including anesthetics performed, difficulties, and complications related to the anesthetic care, co-morbid conditions, and related events.

RESULTS

Twenty-three patients with metatropic dysplasia underwent 188 anesthetics with 61% of the anesthetics having been administered for orthopedic procedures. Fourteen of 23 (60.8%) progressively became difficult to intubate over the course of their care, with 12 out of 14 having undergone cervical spine fusion. These 14 patients had a total of 133 procedures. Sixty procedures (45.1%) had an airway described as difficult. Glidescope was the difficult airway tool most commonly used (68%) with flexible fiberoptic scope used 12% and Miller or Macintosh blade used 18% of the time. In addition to the airway difficulties, spinal canal narrowing or stenosis was widely prevalent, and no neuraxial anesthetic was performed in any of our patients.

CONCLUSION

Difficult airway is the most common co-morbid condition present in patients with metatropic dysplasia, especially if their cervical spine has been fused. Familiarity with the difficulties involving the airway and its management is critical in safe and successful management of anesthesia in this high-risk population.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Wake Up Safe and root cause analysis: quality improvement in pediatric anesthesia

In 2006, the Quality and Safety Committee of the Society for Pediatric Anesthesia initiated a quality improvement project for the specialty of pediatric anesthesiology that ultimately resulted in the development of Wake Up Safe (WUS), a patient safety organization that maintains a registry of de-identified, serious adverse events. The ultimate goal of WUS is to implement change in processes of care that improve the quality and safety of anesthetic care provided to pediatric patients nationwide. Member institutions of WUS submit data regarding the types and numbers of anesthetics performed and information pertaining to serious adverse events. Before a member institution submits data for any serious adverse event, 3 anesthesiologists who were not involved in the event must analyze the event with a root cause analysis (RCA) to identify the causal factor(s). Because institutions across the country use many different RCA methods, WUS educated its members on RCA methods in an effort to standardize the analysis and evaluate each serious adverse event that is submitted. In this review, we summarize the background and development of this patient safety initiative, describe the standardized RCA method used by its members, demonstrate the use of this RCA method to analyze a serious event that was reported, and discuss the ways WUS plans to use the data to promote safer anesthetic practices for children.

Safety and efficacy of a drug regimen to control heart rate during 64-slice ECG-gated coronary CTA in children

BACKGROUND

The adult practice for ECG-gated single-source 64-slice coronary CTA (CCTA) includes administering beta-blockers to reduce heart rate. There are limited data on this process in children.

OBJECTIVE

To evaluate the safety and efficacy of a drug regimen to decrease heart rate before performing CCTA in children.

MATERIALS & METHODS

IV remifentanil and esmolol infusion were chosen to decrease heart rate in 41 children (mean age 6.5 years) while they were under general anesthesia (GA) for CCTA. Drug doses, changes in heart rate and procedural complications were recorded. CCTA image quality was graded on a scale of 1 to 5. The relationships between image quality and heart rate and image quality and age were evaluated. Patient effective radiation doses were calculated.

RESULTS

Heart rates were lowered utilizing esmolol (4 children), remifentanil (2 children) or both (35 children); 26 children received nitroglycerin for coronary vasodilation. The mean decrease in heart rate was 26%. There were no major complications. The average image-quality score was 4.4. Higher heart rates were associated with worse image quality (r = 0.67, P < 0.0001). Older age was associated with better image quality (r = 0.66, P < 0.0001). Effective radiation doses were 0.7 to 7.0 mSv.

CONCLUSION

Heart rate reduction for pediatric CCTA can be safely and effectively achieved while yielding high-quality images.

Anesthetic management of the pediatric patient undergoing solid organ transplantation

Solid organ transplantation is now routinely performed at many institutions. Pediatric organ recipients present difficult challenges to pediatric anesthesiologists. Physiologic, anatomic, and pharmacologic derangements in this population may make both the surgical procedure and the anesthetic management complicated. This article presents an overview of the unique problems and the strategies to solve them in this population.

General pediatric emergencies. Acute pulmonary edema

This article focuses on three types of acute pulmonary edema in children: negative-pressure pulmonary edema, neurogenic pulmonary edema, and cardiogenic pulmonary edema.

Intramuscular rapacuronium in infants and children: a comparative multicenter study to confirm the efficacy and safety of the age-related tracheal intubating doses of intramuscular rapacuronium (ORG 9487) in two groups of pediatric subjects

BACKGROUND

This multicenter, assessor, blinded, randomized study was conducted to confirm and extend a pilot study in which intramuscular rapacuronium was given to infants and children to confirm efficacy and to evaluate tracheal intubating conditions.

METHODS

Ninety-six pediatric patients were studied in two groups: infants aged 1 to 12 months (n = 46) and children aged 1 to 3 yr (n = 50). Infants received 2.8 mg/kg and children 4.8 mg/kg of intramuscular rapacuronium during 1 minimum alveolar concentration halothane anesthesia. These two groups were studied in three subgroups, depending on the time (1.5, 3, or 4 min) at which tracheal intubation was attempted after the administration of intramuscular rapacuronium into the deltoid muscle. Neuromuscular data collected included onset time, duration of action, and recovery data during train-of-four stimulation at 0.1 Hz. Data were analyzed by the Cochran-Mantel-Haenszel procedure.

RESULTS

The tracheal intubating conditions were deemed acceptable in 17, 36, and 64% of infants and 20, 47, and 71% of children at 1.5, 3, or 4 min, respectively. The mean values for % of control twitch height (T1) 2 min after rapacuronium in both groups were similar. The mean (SD) time required to achieve more than or equal to 95% twitch depression in infants was 6.0 (3.7) versus 5.5 (3.8) min in children.

CONCLUSIONS

Only 27% of patients achieved clinically acceptable tracheal intubating conditions at 1.5 or 3 min after administration of 2.8 mg/kg and 4.8 mg/kg rapacuronium during 1 minimum alveolar concentration halothane anesthesia. Tracheal intubation conditions at 4 min were acceptable in 69% of subjects. The duration of action of 4.8 mg/kg of rapacuronium in children was longer than 2.8 mg/kg of rapacuronium in infants.

Intramuscular rocuronium in infants and children: a multicenter study to evaluate tracheal intubating conditions, onset, and duration of action

BACKGROUND

This multicenter, assessor-blinded, randomized study was done to confirm and extend a pilot study showing that intramuscular rocuronium can provide adequate tracheal intubating conditions in infants (2.5 min) and children (3 min) during halothane anesthesia.

METHODS

Thirty-eight infants (age range, 3-12 months) and 38 children (age range, 1 to 5 yr) classified as American Society of Anesthesiologists physical status 1 and 2 were evaluated at four investigational sites. Anesthesia was maintained with halothane and oxygen (1% end-tidal concentration if <2.5 yr; 0.80% end-tidal concentration if >2.5 yr) for 5 min. One half of the patients received 0.45 mg/kg intravenous rocuronium. The others received 1 mg/kg (infants) or 1.8 mg/kg (children) of intramuscular rocuronium into the deltoid muscle. Intubating conditions and mechanomyographic responses to ulnar nerve stimulation were assessed.

RESULTS

The conditions for tracheal intubation at 2.5 and 3 min in infants and children, respectively, were inadequate in a high percentage of patients in the intramuscular group. Nine of 16 infants and 10 of 17 children had adequate or better intubating conditions at 3.5 and 4 min, respectively, after intramuscular rocuronium. Better-than-adequate intubating conditions were achieved in 14 of 15 infants and 16 of 17 children given intravenous rocuronium. Intramuscular rocuronium provided > or =98% blockade in 7.4+/-3.4 min (in infants) and 8+/-6.3 min (in children). Twenty-five percent recovery occurred in 79+/-26 min (in infants) and in 86+/-22 min (in children).

CONCLUSIONS

Intramuscular rocuronium, in the doses and conditions tested, does not consistently provide satisfactory tracheal intubating conditions in infants and children and is not an adequate alternative to intramuscular succinylcholine when rapid intubation is necessary.

Characteristics of bath-related burns in Japan

A retrospective study of bath-related burn injuries was carried out at our institution. A total of 216 patients with burns were admitted between 1982 and 1996. Bath-related burns were identified in 58 patients (26.9%). The number of patients with bath-related burns increased throughout the study period. The percentage body surface area burned was 43.8 +/- 25.7% in the bath-related burn group and 27.3 +/- 28.3% in the bath-unrelated burn group. This difference was significant. There was no significant difference between the two groups with respect to mortality rate. The mechanism by which the patients sustained a bath-related burn clearly differed according to age. The percentage of burns which are bath-related and the severity of bath-related burns are higher in Japan than in any other country. This can be attributed to lifestyle, bathing systems, bathroom architecture, housing conditions and an increase in the elderly population. These burns can be prevented. Education based on this study will play a critical role in the prevention of the bath-related burn injuries.

Evaluation of a new operating room ventilator with volume-controlled ventilation: the Ohmeda 7900

Changes in fresh gas flow (FGF) during volume-controlled ventilation with the circle system have clinically important effects on the ventilatory variables of children. Current operating room ventilators allow a portion of the FGF to be added to the delivered tidal volume. The Ohmeda 7900 (Madison, WI) ventilator was designed to compensate for changes in FGF. We compared this ventilator with a standard ventilator, the Ohmeda 7000. Twenty patients (13-56 kg) undergoing dental or lower extremity surgery were studied. A side-by-side comparison of the two ventilators was performed using each patient as his or her own control. Beginning with the 7900 ventilator, FGF was set at 3.0 L/min, and the inspiratory to expiratory ratio was set at 1:2. Respiratory rate and tidal volume were adjusted to achieve an ETCO2 of 30-40 mm Hg. After a 10-min period of stabilization, inspired minute ventilation (VI), expired minute ventilation (VE), and ETCO2 were measured. FGF was then increased to 6.0 L/min, and the measurements were repeated after 10 min; FGF was then decreased to 1.5 L/min, and measurements were repeated after 10 min. The patient was then ventilated with an Ohmeda 7000 ventilator, and the sequence was repeated. The Ohmeda 7000 ventilator demonstrated significant changes in VI, VE, plateau pressure, and ETCO2, with changes in FGF (P = 0.0039-0.0001). The Ohmeda 7900 ventilator demonstrated compensation for changes in FGF; there were no significant changes in VI, VE, and ETCO2. We conclude that the Ohmeda 7900 ventilator provides stable ventilatory variables regardless of alterations in FGF (1.5-6.0 L/min).

IMPLICATIONS

In this study, we compared the effects of changing fresh gas flow on volume-controlled ventilation using two operating room ventilators (Ohmeda 7000 and Ohmeda 7900). The Ohmeda 7900, but not the Ohmeda 7000, provided stable ventilatory variables with fresh gas flows between 1.5 and 6.0 L/min.

Clinical characteristics of a newly developed ovarian tumour marker, galactosyltransferase associated with tumour (GAT)

In this study clinical studies were conducted on galactosyltransferase associated with tumour (GAT) as a newly developed marker of ovarian cancers. The positive rates of GAT with a cut-off value of 16 U/ml (which corresponds to the mean + 2 standard deviations (S.D.) for healthy females) were 4.7% for benign ovarian tumours, 4.5% for endometriosis and 45.9% for ovarian cancers. GAT showed a positive rate comparable to that of CA546 or CA72-4 among other tumour markers (CA602, CA125, CA546, CA72-4, STN and SLX) examined in ovarian cancers. However, it showed lower positive rates for benign ovarian diseases and, in particular, it gave the lowest positive rate for endometriosis among the aforementioned tumour markers. Furthermore, the receiver operating characteristic (ROC) analysis for discriminating between ovarian cancer and endometriosis showed a significantly high area under the curve (AUC) for GAT compared with that of the other markers. GAT showed the lowest correlation coefficients with other markers, and the positive rate and the diagnostic efficiency were increased by its combination assay with CA602 and/or CA546. Furthermore, the accuracy of the diagnosis of ovarian cancer improved by examining GAT after screening with CA602 or ultrasonography. These results suggest that GAT is a suitable marker for distinguishing ovarian cancers from benign gynaecological diseases, particularly endometriosis, and is useful for combination assay or secondary screening for ovarian cancers.

Efficacy of ketamine hydrochloride sedation in children for interventional radiologic procedures

OBJECTIVE

The purpose of this study was to evaluate the efficacy of ketamine hydrochloride sedation in children younger than 11 years old who underwent short interventional radiologic procedures.

SUBJECTS AND METHODS

Two hundred eleven children, 3 days to 10 years old, were given Ketalar (ketamine hydrochloride; Parke-Davis, Morris Plains, NJ), either 2 mg/kg i.v. (114 patients) or 3 mg/kg intramuscularly (i.m.) (97 patients). Atropine sulfate (Fujisawa USA, Deerfield, IL) (0.01 mg/kg i.v. or 0.02 mg/kg i.m.) was added in all patients to control secretions. Patients were monitored with continuous pulse oximetry and with automatic blood pressure cuffs. Respiratory rate and heart rate were recorded every 5 min. Adequacy of sedation was graded by the radiologist. Induction time, procedure time, recovery time, and adverse effects were recorded.

RESULTS

Sedation was considered excellent and the procedures were completed in 191 patients (91%). The sedation was considered light but the procedures were completed in the remaining 20 patients (9%). No sedation failures were observed. Average induction time was 45 sec for the i.v. procedure and 4 min for the i.m. procedure. Average recovery time was 18 min for the i.v. procedure and 25 min for the i.m. procedure. Average procedure time for both methods was 25 min. Hemoglobin saturation remained at or greater than 95% in 200 patients (94%). Transient desaturation below 95% occurred in 11 patients (5%). The airway was manipulated to improve ventilation (head, neck, and jaw lifts) and supplemental oxygen was given via nasal cannula or mask. The episodes lasted only a few seconds and oxygen saturation promptly returned to a level greater than 95%. A 7-week-old male infant who had been born prematurely at 32 weeks' gestation experienced apnea. Ventilation was assisted for several breaths and the patient promptly recovered. We observed only minor cardiovascular changes in all patients.

CONCLUSION

Ketamine hydrochloride provides excellent sedation and analgesia in young children. The short induction time, rapid recovery, and minimal respiratory depression are features that make this sedative ideal for interventional radiology.

Traumatic laceration of the intracranial vertebral artery causing fatal subarachnoid hemorrhage: case report

A 36-year-old man who had been drinking alcohol had a fatal subarachnoid hemorrhage immediately after suffering a moderate craniofacial injury. Autopsy revealed a 3-mm longitudinal laceration of the left intracranial vertebral artery proximal to the posterior inferior cerebellar artery. There was no finding of arterial dissection. We discuss the mechanisms of the traumatic laceration of the vertebral artery in relation to traumatic dissection of the vertebral artery.

[Long survival after removal of a huge brain tumor which had metastasized from a lung cancer: case report]

Patients with large metastatic brain tumors are considered to have poor prognosis. We report a case of a patient with more than 33 months survival after complete resection of a huge temporal tumor which had metastasized from a lung cancer. A 57-year-old woman presented left hemiparesis and disturbance of consciousness. Magnetic resonance images revealed a huge cystic mass lesion in the right temporal lobe. After a macroscopically complete excision of the tumor, she received radiation therapy (whole brain 50 Gray). She had received lung surgery for the primary lung cancer, 2 years prior to brain metastasis. Histological examination showed papillary tubular adenocarcinoma which was similar to the previously resected lung cancer. Thirty three months after the resection of the intracranial tumor, she has no neurological deficits and no signs of recurrence of either brain tumor or lung tumor. We discuss the size of metastatic brain tumor and the postoperative prognosis of patients with metastatic brain tumor.

Treatment of severe localized cerebral vasospasm following recurrent hemorrhage from middle cerebral artery aneurysm--case report

A 52-year-old female presented with localized but severe cerebral vasospasm induced by recurrent aneurysmal subarachnoid hemorrhage. The middle cerebral artery (MCA) aneurysm was clipped and the subarachnoid hematoma evacuated 1 day after recurrent hemorrhage. The cerebral vasospasm, localized in a region near the MCA aneurysm, was reduced by papaverine and nicardipine vasodilating agents delivered via an Ommaya cerebrospinal fluid reservoir placed at craniotomy.

Mouse monoclonal antibodies which recognize a human (beta 1-4)galactosyl-transferase associated with tumor in body fluids

Mouse monoclonal antibodies against human (beta 1-4)galactosyl-transferase (GalT) purified from human ovarian tumor effusion fluids were prepared and characterized. GalT purified from normal human plasma showed a single diffused band in nondenaturing polyacrylamide gel electrophoresis, but GalT purified from human ovarian tumor effusion fluids showed several oligomeric bands and a monomeric band in nondenaturing polyacrylamide gel electrophoresis. These oligomeric bands were dissociated into monomer by urea treatment and polymerized by a 2-mercaptoethanol treatment. Nine monoclonal antibodies (MAb) were prepared by immunization of purified GalT from human ovarian tumor effusion fluids and classified into three groups. Type I MAbs (MAb8611, MAb8913, and MAb8919) reacted only to the GalT monomer. Type II MAbs (MAb4880, MAb8507, and MAb8628) reacted to both the GalT monomer and the GalT polymer. Type III MAbs (MAb7907, MAb8513, and MAb8677) reacted only to the GalT polymer. These MAbs except MAb7907 could recover GalT enzyme activity from effusion fluids by immunoprecipitation. A fraction passed through MAb8513 affinity chromatography still showed reactivity to MAb8919, demonstrating that an epitope of MAb8513 resides on a minor part of GalT. A sandwich immunoassay (MAb8513-MAb8628HRP) was developed, and serum samples from ovarian cancer patients and benign ovarian patients were tested. The levels of sandwich immunoassay of serum samples from cancer were elevated significantly compared to those from benign and did not necessarily correlate to total GalT enzyme activity in serum samples. These results suggested that MAb8513 (Type III) might recognize a unique GalT associated with tumor (GAT).

Complementary DNA cloning for galactosyltransferase associated with tumor and determination of antigenic epitopes recognized by specific monoclonal antibodies

The galactosyltransferase associated with tumor (GAT) was the name given to the isoenzyme that tends to polymerize resulting in slower moving in a nondenaturing polyacrylamide gel electrophoresis than normal (beta 1-4)galactosyltransferase (normal GalT). A complementary DNA (cDNA) library was constructed from a human ovarian cancer cell line, RMG-I, which secreted an amount of GAT into the culture supernatant and screened with monoclonal antibodies (MAbs) against GAT and normal GalT. One of six cDNA clones, UG86-1, encoded an epitope recognized by a GAT-specific MAb, 8513. Recombinant proteins expressed by UG86-1 in Escherichia coli also had antigenic epitopes recognized by the other MAbs against normal GalT. The 229-base pair nucleotide sequence encoded by UG86-1 was identical to the stem region sequence of HGT832 which encodes a full-length cDNA of human GalT. Using recombinant proteins directed by deletion mutant cDNAs, the antigenic epitopes recognized by each MAb were determined. The epitope of MAb8628, which reacts to both the GAT and normal GalT, was localized to the COOH-terminal side of proteolytic cleavage site where the membrane-bound form enzyme is cleaved to be converted to soluble forms, while MAb8513 epitope was at the NH2-terminal side from this cleavage site between the COOH-terminal end of the membrane-binding domain and the cleavage site. These results demonstrate that GAT is produced by aberrant proteolytic cleavage at the different site, closer to the membrane-binding domain, from the normal GalT.