Creation of Three-dimensional Anatomic Models in Pediatric Surgical Patients Using Cross-sectional Imaging: A Demonstration of Low-cost Methods and Applications

BACKGROUND

Pediatric surgery patients often present with complex congenital anomalies or other conditions requiring deep understanding of their intricate anatomy. Commercial applications and services exist for the conversion of cross-sectional imaging data into three-dimensional (3D) models for education and preoperative planning. However, the associated costs and lack of familiarity may discourage their use in centers with limited resources. The purpose of this report is to present a low-cost, reproducible method for generating 3D images to visualize patient anatomy.

METHODS

De-identified DICOM files were obtained from the hospital PACS system in preparation for assorted pediatric surgical procedures. Using open-source visualization software, variations in anatomic structures were examined using volume rendering and segmentation techniques. Images were further refined using available editing tools or artificial intelligence-assisted software extensions.

RESULTS

Using the described techniques we were able to obtain excellent visualization of desired structures and associated anatomic variations. Once structures were selected and modeled in 3D (segmentation), they could be exported as one of several 3D object file formats. These could then be retained for 3D printing, visualization in virtual reality, or as an anatomic reference during the perioperative period. Models may also be imported into commercial gaming engines for rendering under optimal lighting conditions and with enhanced detail.

CONCLUSION

Pediatric surgeons are frequently tasked with the treatment of patients with complex and rare anomalies. Visualization and preoperative planning can be assisted by advanced imaging software at minimal to no cost, thereby facilitating enhanced understanding of these conditions in resource-limited environments.

LEVEL OF EVIDENCE

V, Case Series, Description of Technique.

Outcomes of Extracorporeal Life Support Utilization for Pediatric Patients With COVID-19 Infections

Outcomes of pediatric patients who received extracorporeal life support (ECLS) for COVID-19 remain poorly described. The aim of this multi-institutional retrospective observational study was to evaluate these outcomes and assess for prognostic factors associated with in-hospital mortality. Seventy-nine patients at 14 pediatric centers across the United States who received ECLS support for COVID-19 infections between January 2020 and July 2022 were included for analysis. Data were extracted from the electronic medical record. The median age was 14.5 years (interquartile range [IQR]: 2-17 years). Most patients were female (54.4%) and had at least one pre-existing comorbidity (84.8%), such as obesity (44.3%, median body mass index percentile: 97% [IQR: 67.5-99.0%]). Venovenous (VV) ECLS was initiated in 50.6% of patients. Median duration of ECLS was 12 days (IQR: 6.0-22.5 days) with a mean duration from admission to ECLS initiation of 5.2 ± 6.3 days. Survival to hospital discharge was 54.4%. Neurological deficits were reported in 16.3% of survivors. Nonsurvivors were of older age (13.3 ± 6.2 years vs. 9.3 ± 7.7 years, p  = 0.012), more likely to receive renal replacement therapy (63.9% vs. 30.2%, p  = 0.003), demonstrated longer durations from admission to ECLS initiation (7.0 ± 8.1 days vs. 3.7 ± 3.8 days, p  = 0.030), and had higher rates of ECLS-related complications (91.7% vs. 69.8%, p  = 0.016) than survivors. Pediatric patients with COVID-19 who received ECLS demonstrated substantial morbidity and further investigation is warranted to optimize management strategies.

Utility of continuous pulse CO-oximetry for hemoglobin monitoring in pediatric patients with solid organ injuries at level 1 trauma centers: A pilot study

INTRODUCTION

Hemorrhage is a major cause of preventable death in injured children. Monitoring after admission often requires multiple blood draws, which have been shown to be stressful in pediatric patients. The Rainbow-7 device is a continuous pulse CO-oximeter that measures multiple wavelengths of light, permitting continuous estimation of the total hemoglobin (Hb) level. The purpose of this study was to evaluate the utility of the noninvasive Hb measurement for monitoring pediatric trauma patients admitted with solid organ injury.

METHODS

This is a prospective, dual-center, observational trial for patients younger than age 18 years admitted to a Level I pediatric trauma center. Following admission, blood was routinely measured as per current solid organ injury protocols. Noninvasive Hb monitoring was initiated after admission. Time-synced data for Hb levels were compared with that taken using blood draws. Data were evaluated using bivariate correlation, linear regression, and Bland-Altman analysis.

RESULTS

Over a 1-year period, 39 patients were enrolled. The mean ± SD age was 11 ± 3.8 years. Forty-six percent (n = 18) of patients were male. The mean ± SD Injury Severity Score was 19 ± 13. The average change in Hb levels between laboratory measurements was -0.34 ± 0.95 g/dL, and the average change in noninvasive Hb was -0.12 ± 1.0 g/dL per measurement. Noninvasive Hb values were significantly correlated with laboratory measurements ( p < 0.001). Trends in laboratory Hb measurements were highly correlated with changes in noninvasive levels ( p < 0.001). Bland-Altman analysis demonstrated similar deviation from the mean throughout the range of Hb values, but the differences between measurements were increased by anemia, African American race, and elevated shock index, pediatric age-adjusted score and Injury Severity Score.

CONCLUSION

Noninvasive Hb values demonstrated correlation with measured Hb concentration as isolated measurements and trends, although results were affected by skin pigmentation, shock, and injury severity. Given the rapid availability of results and the lack of requirement of venipuncture, noninvasive Hb monitoring may be a valuable adjunct for pediatric solid organ injury protocols. Further study is required to determine its role in management.

LEVEL OF EVIDENCE

Dianostic Test or Criteria; Level III.

Investigating CT head diagnostic reference levels based on indication-based protocols - a single site study

INTRODUCTION

This study aimed to provide clinically-relevant insights into establishing CT DRLs based on indication-based protocols in Ireland, focusing on CT head examinations performed at a neurology centre of excellence hospital.

METHODS

Dose data were collected retrospectively. Typical values for six CT head indication-based protocols were established using a sample size of 50 patients for each protocol. Typical values for each protocol were set as the median of the distribution curve. Dose distributions for each protocol were calculated and compared using non-parametric median test (k-samples) to ascertain significant dose differences between the typical values.

RESULTS

Most typical values pairings showed significant differences (p < 0.001) except between stroke/non-vascular brain, stroke/acute brain, and acute brain/non-vascular brain pairings. This was expected due to similar scan parameters. The typical value for stroke (3-phases angiogram) was 52% lower than the typical value for stroke. Dose levels of the male populations recorded were higher than female populations for all protocols. Statistical comparison showed significant differences for dose quantities and/or scan length between both genders in five protocols.

CONCLUSION

Proposed values for DLP were up to 63% and 69% lower than the EU and Irish national DRLs respectively. Establishment of CT stroke DRLs should be based on the scan performed instead of number of scan acquisitions. Lastly, gender-based CT DRLs for specific protocols within the head region require further investigation.

IMPLICATIONS FOR PRACTICE

With increasing CT examinations worldwide, radiation dose optimisation is key. The value of indication based DRLs is to enhance the required patient protection so image quality can be maintained, however with relevant DRLs for varying protocols. Establishment of CT typical values and site specific DRLs for procedures beyond the national DRLs can drive dose optimisation locally.

The Sinister Surgeon: Advanced Pediatric Minimally Invasive Surgery for Left-Handed Surgeons

Purpose: Left-handed (LH) surgeons face unique challenges in their training and practice. Contrary to the historical and unjust perception of technical inferiority, LH surgeons can thrive under appropriate mentorship and support. Here, we describe modifications to pediatric minimally invasive surgeries to benefit the LH surgeon. Methods: The surgical approaches to common and complex pediatric surgical operations were modified to facilitate training of an LH pediatric surgical fellow. Results: Preoperative preparation, including communication with the operating room team, patient positioning, and provision of appropriate equipment, allowed the procedures to be accomplished in a safe and efficient manner. Conclusions: Modifying complex minimally invasive surgery to allow for use of the dominant hand is feasible and safe.

Improving Billing and Collections in a High-Volume Pediatric Surgery Practice: Denials-Based Approach

BACKGROUND

Despite minimal coding and billing training, surgeons are frequently tasked with both in clinical practice. This often results in denials for reimbursement based on incorrect or insufficient documentation, and reduced collections for work performed. We sought to evaluate how to correct these deficits while improving reimbursement for the most frequently rejected procedures at a high-volume academic center.

STUDY DESIGN

Hospital billing data were analyzed for a 4-year period (2018 to 2021) to determine the CPT code denials with the largest overall cost. The denials were then stratified according to payor, reason for denial, and preventability. Assigned ICD-10 codes were categorized based on specificity as related to the procedure. The distribution of denials according to ICD-10 specificity was evaluated using the chi-square test.

RESULTS

A total of 8,833 denials representing $11,009,108 in billing were noted during the study period. The CPT code 44970 (laparoscopic appendectomy) was the code associated with the largest financial impact, representing 12.8% of the total denied amount ($1.41M). Of the 823 denials for CPT 44970, 93.3% were associated with nonspecific ICD-10 codes, whereas only 42.0% had been associated with procedure-specific ICD-10 codes. Of the patients with nonspecific codes, 80.7% of denials were due to criteria that could be remedied with supplemental information or timely filing, representing $1,059,968 in collections.

CONCLUSIONS

This is the first study to systematically evaluate a pathway for using denial data to improve collections for work performed at a high-volume academic pediatric surgery practice. Using this methodology, targets for improvement in coding and/or documentation can be identified to improve the financial performance of a surgical department. This study also provides evidence that association with nonspecific diagnostic codes is correlated with initial denial of payment by insurance companies.

2019 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 37th Annual Report

Introduction: This is the 37^th Annual Report of the American Association of Poison Control Centers' (AAPCC) National Poison Data System (NPDS). As of 1 January, 2019, all 55 of the nation's poison centers (PCs) uploaded case data automatically to NPDS. The upload interval was 6.52 [6.12, 8.68] (median [25%, 75%]) minutes, creating a near real-time national exposure and information database and surveillance system.Methods: We analyzed the case data tabulating specific indices from NPDS. The methodology was similar to that of previous years. Where changes were introduced, the differences are identified. Cases with medical outcomes of death were evaluated by a team of medical and clinical toxicologist reviewers using an ordinal scale of 1-6 to assess the Relative Contribution to Fatality (RCF) of the exposure.Results: In 2019, 2,573,180 closed encounters were logged by NPDS: 2,148,141 human exposures, 68,711 animal exposures, 351,163 information requests, 5,078 human confirmed nonexposures. Total encounters showed a 1.70% increase from 2018, while health care facility (HCF) human exposure cases remained nearly steady with a slight decrease of 0.495%. All information requests decreased by 4.58%, medication identification (Drug ID) requests decreased by 29.7%, and human exposure cases increased by 2.30%. Human exposures with less serious outcomes have decreased 2.08% per year since 2008, while those with more serious outcomes (moderate, major or death) have increased 4.61% per year since 2000.Consistent with the previous year, the top 5 substance classes most frequently involved in all human exposures were analgesics (11.0%), household cleaning substances (7.13%), cosmetics/personal care products (6.16%), antidepressants (5.32%), and sedatives/hypnotics/antipsychotics (5.21%). As a class, antidepressant exposures increased most rapidly, by 1,957 cases/year (3.90%/year) over the past 10 years for cases with more serious outcomes.The top 5 most common exposures in children age 5 years or less were cosmetics/personal care products (11.4%), household cleaning substances (10.5%), analgesics (8.97%), foreign bodies/toys/miscellaneous (7.17%), and dietary supplements/herbals/homeopathic (5.06%). Drug identification requests comprised 13.4% of all information contacts. NPDS documented 2,619 human exposures resulting in death; 2,048 (78.2%) of these were judged as related (RCF of 1-Undoubtedly responsible, 2-Probably responsible, or 3-Contributory).Conclusions: These data support the continued value of PC expertise and need for specialized medical toxicology information to manage more serious exposures. Unintentional and intentional exposures continue to be a significant cause of morbidity and mortality in the US. The near real-time status of NPDS represents a national public health resource to collect and monitor US exposure cases and information contacts. The continuing mission of NPDS is to provide a nationwide infrastructure for surveillance for all types of exposures (e.g., foreign body, infectious, venomous, chemical agent, or commercial product), and the identification and tracking of significant public health events. NPDS is a model system for the near real-time surveillance of national and global public health.

Change in Hematocrit during Trauma Assessment Predicts Bleeding Even with Ongoing Fluid Resuscitation

This study tests the hypothesis that a change in hematocrit (ΔHct) during initial trauma work-up is as reliable as conventional vital signs for detecting bleeding, even with ongoing fluid resuscitation. Consecutive trauma patients admitted to a Level I trauma center receiving two Hct measurements during initial resuscitation between January 2010 and January 2011 were stratified based on estimated blood loss greater than 250 mL (bleeding) or nonbleeding. Sensitivity, specificity, and receiver operating characteristic curves were calculated for systolic blood pressure (SBP), heart rate, base deficit, and ΔHct. In 168 (72%) nonbleeding versus 64 (28%) bleeding patients, age and gender were similar. Arrival SBP was highly specific (90 to 99%) but poorly sensitive (13 to 31%) for detecting bleeding. Combinations of vital signs increased specificity, albeit at the expense of sensitivity. For bleeding versus nonbleeding patients (all receiving resuscitation fluid), ΔHct was 9.0 versus 1.8, ΔHct/liter was 4.8 versus 1.5, and ΔHct/liter/hour was 2.8 vs 0.6 (all P < 0.001). Only SBP (area under the curve [AUC] 0.608 to 0.695) and ΔHct (AUC 0.731 to 0.921) were significant for identifying bleeding with ΔHct 6 or greater being the best predictor (sensitivity 89%, specificity 95%, AUC 0.921). During ongoing fluid resuscitation of a trauma victim, ΔHct is the single most reliable indicator of continuing blood loss. A ΔHct 6 or greater during initial resuscitation is highly suspicious for ongoing blood loss, but even lesser changes have predictive value. Altogether, these results support the idea that fluid shifts are rapid after hemorrhage and Hct can be valuable during initial trauma assessment.

2018 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 36th Annual Report

Introduction: This is the 36^th Annual Report of the American Association of Poison Control Centers' (AAPCC) National Poison Data System (NPDS). As of 1 January, 2018, 55 of the nation's poison centers (PCs) uploaded case data automatically to NPDS. The upload interval was 7.72 [6.90, 12.0] (median [25%, 75%]) minutes, creating a near real-time national exposure and information database and surveillance system.Methods: We analyzed the case data tabulating specific indices from NPDS. The methodology was similar to that of previous years. Where changes were introduced, the differences are identified. Cases with medical outcomes of death were evaluated by a team of medical and clinical toxicologist reviewers using an ordinal scale of 1-6 to assess the Relative Contribution to Fatality (RCF) of the exposure.Results: In 2018, 2,530,238 closed encounters were logged by NPDS: 2,099,751 human exposures, 57,017 animal exposures, 368,025 information requests, 5,346 human confirmed nonexposures, and 99 animal confirmed nonexposures. United States PCs also made 2,621,242 follow-up calls in 2018. Total encounters showed a 2.96% decline from 2017, while health care facility (HCF) human exposure cases remained nearly steady with a slight decrease of 0.261%. All information requests decreased by 15.5%, medication identification (Drug ID) requests decreased by 30.2%, and human exposure cases decreased by 0.729%. Human exposures with less serious outcomes have decreased 2.33% per year since 2008, while those with more serious outcomes (moderate, major or death) have increased 4.45% per year since 2000.Consistent with the previous year, the top 5 substance classes most frequently involved in all human exposures were analgesics (10.8%), household cleaning substances (7.28%), cosmetics/personal care products (6.53%), sedatives/hypnotics/antipsychotics (5.53%), and antidepressants (5.22%). For cases with more serious outcomes, sedative/hypnotics/antipsychotics exposures were the class that increased most rapidly, by 1,828 cases/year (9.21%/year) over the past 18 years. Over just the past 10 years (for cases with the most serious outcomes) antidepressant exposures increased most rapidly, by 1,887 cases/year (7.02%/year).The top 5 most common exposures in children age 5 years or less were cosmetics/personal care products (12.1%), household cleaning substances (10.7%), analgesics (9.04%), foreign bodies/toys/miscellaneous (6.87%), and topical preparations (4.69%). Drug identification requests comprised 18.2% of all information requests. NPDS documented 3,111 human exposures resulting in death; 2,582 (83.0%) of these were judged as related (RCF of 1-Undoubtedly responsible, 2-Probably responsible, or 3-Contributory).Conclusions: These data support the continued value of PC expertise and need for specialized medical toxicology information to manage more serious exposures. Unintentional and intentional exposures continue to be a significant cause of morbidity and mortality in the US. The near real-time status of NPDS represents a national public health resource to collect and monitor US exposure cases and information requests. The continuing mission of NPDS is to provide a nationwide infrastructure for surveillance for all types of exposures (e.g., foreign body, infectious, venomous, chemical agent, or commercial product), and the identification and tracking of significant public health events. NPDS is a model system for the near real-time surveillance of national and global public health.

SURVEY OF KEY RADIATION SAFETY PRACTICES IN INTERVENTIONAL RADIOLOGY: AN IRISH AND ENGLISH STUDY

Interventional radiology is a rapidly evolving speciality with potential to deliver high patient radiation doses, as a result high standards of radiation safety practice are imperative. IR radiation safety practice must be considered before during and after procedures through appropriate patient consent, dose monitoring and patient follow-up. This questionnaire-based study surveyed fixed IR departments across Ireland and England to establish clinical practice in relation to radiation safety. Pre-procedure IR patient consent includes all radiation effects in 11% of cases. The patient skin dose surrogate parameter of Kerma to air at a reference point (Kar) is under-reported. Only 39% of respondents use a substantial radiation dose level and inform patients after these have been reached. Poor compliance with unambiguous, readily available best practice guidance was observed throughout highlighting patient communication, patient dose quantification and subsequent patient dose management concerns.

An Observational Study of the Factor Xa Inhibitors Rivaroxaban and Apixaban as Reported to Eight Poison Centers

STUDY OBJECTIVE

Rivaroxaban and apixaban are part of a new group of oral anticoagulants targeting factor Xa and approved by the Food and Drug Administration in 2011 and 2012. These oral anticoagulants are administered at fixed daily doses, without the need for laboratory-guided adjustments. There are limited data available on supratherapeutic doses or overdose of the oral Xa inhibitors. This study characterizes the clinical effect in patients exposed to rivaroxaban and apixaban.

METHODS

A retrospective study collected data from 8 regional poison centers covering 9 states. Cases were initially identified by a search of the poison centers' databases for case mentions involving a human exposure to Xarelto, rivaroxaban, Eliquis, or apixaban. Inclusion criteria included single-substance exposure. Exclusion criteria were animal exposure, polysubstance exposure, or information call. Data for the study were collected by individual chart review, including case narratives, and compiled into a single data set.

RESULTS

There were 223 patients: 124 (56%) were female patients, mean age was 60 years, and 20 were children younger than 12 years (9%). One hundred ninety-eight patients ingested rivaroxaban (89%) and 25 ingested apixaban (11%). Dose was reported in 182 rivaroxaban patients, with a mean dose of 64.5 mg (range 15 to 1,200 mg), and in 21 apixaban patients, with a mean dose of 9.6 mg (range 2.5 to 20 mg). For rivaroxaban, prothrombin time was measured in 49 patients (25%) and elevated in 7; partial thromboplastin time, measured in 49 (25%) and elevated in 5; and international normalized ratio, measured in 61 (31%) and elevated in 13. For apixaban, prothrombin time was measured in 6 patients (24%) and elevated in none; partial thromboplastin time, measure in 6 (24%) and elevated in none; and international normalized ratio, measured in 5 patients (20%) and elevated in none. Bleeding was reported in 15 patients (7%): 11 rivaroxaban and 4 apixaban. The site of bleeding was gastrointestinal (8), oral (2), nose (1), bruising (1), urine (1), and subdural (1). The subdural bleeding occurred after fall and head injury. All cases with bleeding involved long-term ingestions. Coagulation test results were normal in most patients with bleeding: prothrombin time 5 of 6 (83%), partial thromboplastin time 5 of 6 (83%), and international normalized ratio 5 of 9 (55%). Blood products were used in 7 rivaroxaban patients (1 suicide) and 3 apixaban patients. No bleeding or altered coagulation test results occurred in children, which all involved a one-time ingestion. All 12 suicide attempts involved rivaroxaban: altered coagulation test results occurred for 5 patients (42%), no bleeding occurred in any suicide attempt patient, 1 patient was treated with fresh frozen plasma (international normalized ratio 12.47), and dose by patient history did not predict risk of altered coagulation or bleeding. Two rivaroxaban patients experienced elevation of hepatic transaminase levels greater than 1,000 U/L.

CONCLUSION

Bleeding after Xa inhibitor ingestion as a single agent is uncommon. Prothrombin time, partial thromboplastin time, or international normalized ratio may be elevated in a minority of cases but appears unreliable to measure risk of bleeding. Massive acute ingestion in suicide attempt may result in significant anticoagulation. Single exploratory ingestion by children was not associated with toxicity.

Trauma induced hypercoagulablity in pediatric patients

PURPOSE

Coagulation changes in pediatric trauma patients are not well defined. To fill this gap, we tested the hypothesis that trauma evokes a hypercoagulable response.

METHODS

A prospective observational study was conducted in hospitalized patients (age 8months to 14years) admitted for trauma or elective surgery. Informed consent was obtained from the parents and informed assent was obtained in patients 7years of age or older. Coagulation changes were evaluated on fresh whole blood using thromboelastography (TEG) and on stored plasma using assays for special clotting factors.

RESULTS

Forty three patients (22 trauma, median injury severity score =9; and 21 uninjured controls) were evaluated. For trauma vs control, prothrombin time (PT) was higher by about 10% (p<0.001), but activated partial thromboplastin time was not altered. TEG clotting time (R;p=0.005) and fibrin cross-linking were markedly accelerated (K time, alpha angle; p<0.001) relative to the control patients. d-Dimer, Prothrombin Fragment 1+2, and Plasminogen Activator Inhibitor-1 were all elevated, whereas Protein S activity was reduced (all p<0.01). Importantly, a large fraction of TEG values and clotting factor assays in the pediatric control group were outside the published reference ranges for adults.

CONCLUSION

A hypercoagulable state is associated with minor trauma in children. More work is needed to determine the functional significance of these changes and to establish normal pediatric reference ranges.

Pre-existing hypercoagulability in patients undergoing potentially curative cancer resection

BACKGROUND

Rotational thromboelastometry (ROTEM) is a new point-of-care test that allows a rapid and comprehensive evaluation of coagulation. We were among the first to show that ROTEM identifies baseline hypercoagulability in 40% of patients with intra-abdominal malignancies and that hypercoagulability persists for ≥1 month after resection. The purpose of this follow-up study was to confirm and extend these observations to a larger population in outpatient preoperative clinics. The hypothesis is that pre-existing hypercoagulability is present in patients undergoing surgery for malignant disease and that coagulation status varies by tumor type.

METHODS

After informed consent, preoperative blood samples were drawn from patients undergoing exploratory laparotomies for intra-abdominal malignancies and analyzed with ROTEM.

RESULTS

Eighty-two patients were enrolled, including 72 with a confirmed pathologic diagnosis and 10 age-matched controls with benign disease. The most common cancers involved the pancreas (n = 23; 32%), esophagus (n = 19; 26%), liver (n = 12; 17%), stomach (n = 7; 10%), and bile ducts (n = 5; 7%). Preoperative hypercoagulability was detected in 31% (n = 22); these patients were more likely to have lymphovascular invasion (88% vs 50%; P = .011), perineural invasion (77% vs 36%; P = .007), and stage III/IV disease (80% vs 62%; P = .039). More patients with pancreatic tumors (9/23, 39%) were hypercoagulable than with esophageal (3/19, 16%) or liver (2/13, 15%, P = .034) tumors. When only resectable malignancies were considered, clot formation was more rapid (low clot formation time, high alpha) with enhanced maximum clot strength (high maximum clot firmness) in pancreatic versus esophageal or liver cancers and in all cancers versus those with benign disease.

CONCLUSION

Preoperative hypercoagulability can be identified with ROTEM and is associated with lymphovascular/perineural invasion and advanced-staged disease in cancer. Compared with other tumor types, pancreatic adenocarcinomas have the greatest risk for hypercoagulability.

Change in hematocrit during trauma assessment predicts bleeding even with ongoing fluid resuscitation

This study tests the hypothesis that a change in hematocrit (ΔHct) during initial trauma work-up is as reliable as conventional vital signs for detecting bleeding, even with ongoing fluid resuscitation. Consecutive trauma patients admitted to a Level I trauma center receiving two Hct measurements during initial resuscitation between January 2010 and January 2011 were stratified based on estimated blood loss greater than 250 mL (bleeding) or nonbleeding. Sensitivity, specificity, and receiver operating characteristic curves were calculated for systolic blood pressure (SBP), heart rate, base deficit, and ΔHct. In 168 (72%) nonbleeding versus 64 (28%) bleeding patients, age and gender were similar. Arrival SBP was highly specific (90 to 99%) but poorly sensitive (13 to 31%) for detecting bleeding. Combinations of vital signs increased specificity, albeit at the expense of sensitivity. For bleeding versus nonbleeding patients (all receiving resuscitation fluid), ΔHct was 9.0 versus 1.8, ΔHct/liter was 4.8 versus 1.5, and ΔHct/liter/hour was 2.8 vs 0.6 (all P < 0.001). Only SBP (area under the curve [AUC] 0.608 to 0.695) and ΔHct (AUC 0.731 to 0.921) were significant for identifying bleeding with ΔHct 6 or greater being the best predictor (sensitivity 89%, specificity 95%, AUC 0.921). During ongoing fluid resuscitation of a trauma victim, ΔHct is the single most reliable indicator of continuing blood loss. A ΔHct 6 or greater during initial resuscitation is highly suspicious for ongoing blood loss, but even lesser changes have predictive value. Altogether, these results support the idea that fluid shifts are rapid after hemorrhage and Hct can be valuable during initial trauma assessment.

Use of CT enterography for the diagnosis of lower gastrointestinal bleeding in pediatric patients

Diagnosis of lower gastrointestinal bleeding (LGIB) represents a significant diagnostic and therapeutic challenge for any physician. While CT enterography (CTE) has been applied in adults with occult LGIB, its use in children has been limited to evaluation of Crohn's disease. We reviewed 6 patients ages 4-15 who underwent CTE for LGIB at a tertiary pediatric institution. In sum, CTE appears to be a valuable tool for localizing the source of LGIB prior to surgical or endoscopic intervention. However, rapid lesion identification must be weighed against the increased radiation exposure and patient discomfort due to bowel distention associated with this diagnostic technique.

Admission hematocrit and transfusion requirements after trauma

BACKGROUND

The decision to transfuse packed RBCs (PRBC) during initial resuscitation of trauma patients is based on physiologic state, evidence for blood loss, and potential for ongoing hemorrhage. Initial hematocrit (Hct) is not considered an accurate marker of blood loss. This study tests the hypothesis that admission Hct is associated with transfusion requirements after trauma.

METHODS

From June to December 2008, data from 1,492 consecutive admissions at a Level I trauma center were retrospectively reviewed to determine whether initial Hct was associated with PRBC transfusions. From October 2009 through October 2011, data from 463 consecutive transfused patients were retrospectively reviewed to determine whether Hct correlated with number of PRBC units received.

RESULTS

Packed RBC transfusion was not correlated with heart rate and was more highly correlated with Hct (r = -0.45) than with systolic blood pressure or base deficit (r = -0.32 or r = -0.26). Hematocrit was a better overall predictor than systolic blood pressure (sensitivity 45% vs 29%, specificity 94% vs 98%, area under receiver operator characteristic curve 0.71 vs 0.64). Lower Hct was associated with hypotension, more advanced shock, higher blood loss, and increased transfusion of PRBC, plasma, platelets, or cryoprecipitate (all, p < 0.01).

CONCLUSION

Admission Hct is more strongly associated with the PRBC transfusion than either tachycardia, hypotension, or acidosis. Admission Hct is also correlated with 24-hour blood product requirements in those receiving early transfusions. These findings challenge current thinking and suggest that fluid shifts are rapid after trauma and that Hct can be important in initial trauma assessment.

Insertion of central venous catheters induces a hypercoagulable state

BACKGROUND

Central venous catheters (CVCs) increase the risk of venous thromboembolism. We have previously demonstrated that pulmonary artery catheters are associated with a hypercoagulable state in an animal model and in patients. The purpose of this study is to determine whether the insertion of a CVC is associated with a similar response.

METHODS

ANIMAL

7F femoral artery catheters were placed in healthy anesthetized swine (N = 16). Serial arterial blood samples were drawn immediately before and after an 8.5F jugular vein CVC and then for 3 hours after CVC removal. Samples were analyzed using kaolin-activated thromboelastography (TEG) at precisely 2 minutes. Human: An institutional review board-approved prospective observational trial was conducted, with informed consent, in patients with critical illness (N = 8) at a Level I trauma center. Blood was drawn from indwelling arterial catheters immediately before and 60 minutes after CVC insertion. Samples were stored in sodium citrate for 15 minutes before TEG. Routine and special coagulation tests were performed on stored samples in the hospital pathology laboratory.

RESULTS

Insertion of a CVC decreased TEG clotting time (R) by 55% in swine and by 29% in humans (p < 0.001 and 0.019, respectively). Initial clot formation time (K) was reduced by 41% in swine and by 36% in humans (p = 0.003 and 0.019). Fibrin cross-linking (α) was accelerated by 28% in swine and by 17% in humans (p = 0.007 and 0.896), but overall clot strength (maximum amplitude) was not affected. There was no change in routine or special coagulation factors, including von Willebrand factor, antithrombin III, prothrombin time, international normalized ratio, or activated partial thromboplastin time. In animals, the hypercoagulable TEG response was persistent for 3 hours after CVC removal and was prevented by pretreatment with enoxaparin (n = 4) but not heparin (n = 2).

CONCLUSION

In healthy swine and patients with critical illness, a systemic hypercoagulable state occurred after CVC insertion, and this may partially account for an increased risk of venous thromboembolism. However, because the sample size was small and not powered to detect changes in coagulation proteins, no inferences can be made about the mechanism for the hypercoagulable response.

Segmental absence of intestinal musculature: an increasingly reported pathology

BACKGROUND

Segmental absence of the intestinal musculature (SAIM) is a known but clinically rare entity involving partial or complete absence of the intestinal muscularis propria. Clinical presentation is consistent with peritonitis, and treatment involves an emergent laparotomy, bowel resection, and reanastamosis or possible ostomy creation. Diagnosis results from histopathologic evaluation of the resected intestinal specimen. Most of the publications are case reports.

METHODS

We retrospectively reviewed all surgical pathology files at a tertiary pediatric hospital from 2003 to 2010, identifying children who were noted to have absence of intestinal musculature on pathology. Patients meeting criteria were reviewed in detail, and data regarding clinical presentation, diagnostic testing, radiologic findings, treatment, and outcome were recorded.

RESULTS

Five patients were identified between 2003 and 2010 who received the diagnosis of SAIM. Patient age ranged from 1 to 99 days of life. All children were born preterm by cesarean section, had a mean birth weight of 828 ± 338 g, and were intubated after birth.

CONCLUSIONS

The 5 patients presented are reviewed and contrasted with previous cases presented in the literature. Theories of pathogenesis and classification are discussed, and the cases are labeled as primary versus secondary SAIM.

Effect of hetastarch bolus in trauma patients requiring emergency surgery

If blood products are not available, current military guidelines recommend a hetastarch bolus (HEX, Hextend 6% hetastarch in lactated electrolyte buffer, www. hospira.com) for initial treatment of hypovolemic shock in the field. We previously reported that a HEX bolus plus standard of care (SOC = crystalloid plus blood products) was safe during initial resuscitation in 1714 trauma patients. This study tests the hypothesis that HEX+SOC is more effective than SOC alone for volume expansion in trauma patients requiring urgent operation.

METHODS

From July 2009 to August 2010, the records from all adults who required emergency surgery within 4 hours of admission were screened for a retrospective cohort observational study. Burns, and those with primary neurosurgical or orthopedic indications, were excluded. The study population was comprised of 281 patients with blunt (n = 72) or penetrating (n = 209) trauma; 141 received SOC and 140 received SOC+HEX in the emergency room only (ER, n = 81) or the ER and operating room (OR, n = 59). Each case was reviewed with waiver of consent.

RESULTS

After penetrating injury, with SOC, the injury severity score was 17 and mortality was 12%; the corresponding values in the HEX(ER) and HEX(OR) groups were 19?21 and 8%, but these apparent differences did not reach significance. However, in patients receiving HEX, initial heart rate was higher, base deficit was lower, and hematocrit was lower (consistent with relative hypovolemia), even though blood product requirements were reduced, and urine output was greater (all p < 0.05). These effects were absent in patients with blunt trauma. Platelet consumption was higher with HEX after either penetrating (p = 0.004) or blunt trauma (p = 0.045), but coagulation tests were unchanged.

CONCLUSION

HEX is safe for initial resuscitation in young patients who required urgent operation after penetrating trauma, but there was no apparent effect after blunt trauma. A bolus of HEX reduced transfusion requirements without inducing coagulopathy or causing renal dysfunction, but a randomized controlled trial is necessary to eliminate the possibility of selection bias.

Portal venous gas and cardiopulmonary arrest during pneumatic reduction of an ileocolic intussusception

We present the case of an 8-month-old infant with a small bowel obstruction secondary to an ileocolic intussusception without a pathologic lead point. During pneumatic reduction, the patient went into cardiopulmonary arrest, at which point portal venous gas (PVG) was visualized on radiography. Here we present-to our knowledge-the first reported case of PVG secondary to pneumatic reduction of an intussusception along with a review of the literature regarding known complications of pneumatic reduction and the etiologies of PVG.

Unintentional therapeutic errors involving insulin in the ambulatory setting reported to poison centers

BACKGROUND

Adverse drug events in the ambulatory care setting are not uncommon and can cause significant morbidity. Little research has been published on the management of adverse drug events involving insulin in the outpatient setting.

OBJECTIVE

To analyze data on patients with unintentional therapeutic errors involving insulin managed by 9 regional poison control centers.

METHODS

A retrospective search was performed for all records involving insulin at 9 poison centers, covering the population of 4 states for the years 2000-2009. A subgroup of the study population was selected with a reason for exposure of "unintentional-therapeutic error."

RESULTS

There were 3819 insulin exposures reported, with an increase in the annual incidence of insulin exposures of 279% (from 170 to 645 patients/year) and a mean annual increase of 18%. Of the insulin exposures, 2584 were unintentional therapeutic errors (68%). The percentage of all insulin exposures that were unintentional therapeutic errors increased progressively, from 41% to 78%. There was a 495% increase in annual incidence of unintentional therapeutic errors involving insulin, with a mean annual increase of 28%. Unintentional therapeutic errors involving insulin occurred primarily in adults >40 years (73%), with 63% occurring in women. There was a pronounced increase in unintentional therapeutic errors involving insulin in the later evening hours, with 71% occurring between 1800 and 2400 and reaching a peak at 2200. The majority (n = 1803; 70%) of patients were managed in a non-health-care facility location, primarily their own residence.

CONCLUSIONS

This is the first report of an increasing trend of insulin-related unintentional therapeutic errors in the ambulatory setting. Our study highlights a number of striking features, including: (1) a consistent and dramatic increase of unintentional therapeutic errors involving insulin over the 10-year period, (2) a high incidence of unintentional therapeutic errors involving insulin in the late evening hours, and (3) a high incidence of unintentional therapeutic errors involving insulin involving adults >40 years and females. With their 24/7 availability, poison centers appear to be an increasingly important resource for patients experiencing unintentional therapeutic errors involving insulin.

Use of antivenom for snakebites reported to United States poison centers

In 2001, a new antivenin was introduced to the United States and became widely available in the snakebite season of 2002. We investigated what impact this may have had on snakebite treatment and medical outcome.

METHOD

The study used a retrospective review of all snakebites to humans reported to the National Poison Center Database System from 2000 to 2007.

RESULTS

During the 8 years, there were 37,760 snakebites, with a mean of 4720 bites per year. There was a 27% increase in bites reported to a Poison center for the 8-year period and an overall 13.5% increase in the use of antivenin. The 2 categories primarily responsible for the increased use of antivenin were copperhead and crotaline-unknown. Rattlesnake bites remained the category most frequently treated with antivenin with a mean 52.5% treatment rate and only moderate increase for the 8 years. There was no change in the percentage or number of patients with a major outcome (mean, 3.8%) or death (mean, 0.5%). There was a decrease in patients with a minor outcome and an increase in patients with a moderate outcome.

DISCUSSION

The new antivenin is reported to have a reduced potential for adverse reactions. This may have had a role in the decision of which snakebite victims received antivenin.

CONCLUSION

With the introduction of a new antivenin, there has been a dramatic increase in the number of snakebite patients treated with antivenin. This has been most noticeable in snake bite categories that were less frequently treated with antivenin in the past.

A review of ureteral injuries after external trauma

INTRODUCTION

Ureteral trauma is rare, accounting for less than 1% of all urologic traumas. However, a missed ureteral injury can result in significant morbidity and mortality. The purpose of this article is to review the literature since 1961 with the primary objective to present the largest medical literature review, to date, regarding ureteral trauma. Several anatomic and physiologic considerations are paramount regarding ureteral injuries management.

LITERATURE REVIEW

Eighty-one articles pertaining to traumatic ureteral injuries were reviewed. Data from these studies were compiled and analyzed. The majority of the study population was young males. The proximal ureter was the most frequently injured portion. Associated injuries were present in 90.4% of patients. Admission urinalysis demonstrated hematuria in only 44.4% patients. Intravenous ureterogram (IVU) failed to diagnose ureteral injuries either upon admission or in the operating room in 42.8% of cases. Ureteroureterostomy, with or without indwelling stent, was the surgical procedure of choice for both trauma surgeons and urologists (59%). Complications occurred in 36.2% of cases. The mortality rate was 17%.

CONCLUSION

The mechanism for ureteral injuries in adults is more commonly penetrating than blunt. The upper third of the ureter is more often injured than the middle and lower thirds. Associated injuries are frequently present. CT scan and retrograde pyelography accurately identify ureteral injuries when performed together. Ureteroureterostomy, with or without indwelling stent, is the surgical procedure of choice of both trauma surgeons and urologists alike. Delay in diagnosis is correlated with a poor prognosis.

Skin breakdown and blisters from senna-containing laxatives in young children

BACKGROUND

At the direction of the Food and Drug Administration, phenolphthalein was removed from all over-the-counter laxatives in 1999. Phenolphthalein was then replaced in most laxative products with the natural product senna from Cassia acutifolia Delile, which contains various anthraquinones. No data are available on the safety of senna use in children <6 years of age.

OBJECTIVE

To describe the clinical outcomes of exposure to unintentional ingestion of senna-containing laxatives in young children.

METHODS

All ingestion exposures of senna-containing laxatives in children <5 years of age from 6 poison centers over a 9-month period were evaluated. Inclusion criteria required 24-hour follow-up and the presence of diarrhea to confirm ingestion. Parents were told routinely that severe diaper rash was possible and to protect the perianal area with frequent cleansing and a barrier ointment if the child was wearing diapers.

RESULTS

During the study period, 111 cases were reported: 19 children experienced no diarrhea, 4 were lost to follow-up, and 88 exposures were evaluated. Fifty-two children (59%) were </=2 years old. Fifty children remained in diapers, 28 children were fully toilet trained, and 10 wore diapers (pull-up pants) overnight. Twenty-nine children (33%) experienced severe diaper rash. The mean +/- SD time to recognition of the diaper rash was 15.6 +/- 8.6 hours. Ten children (11%) had blisters and skin sloughing. There was a significant increase in severe diaper rash (p < 0.05) and onset of blisters and skin breakdown (p < 0.05) in children wearing diapers versus those who were fully toilet trained. The mean time to onset of blisters was 14.5 +/- 6.8 hours. Skin burns and loss were seen primarily on the buttocks and perineum, loosely following the diaper area.

CONCLUSIONS

Unintentional ingestion of senna-containing laxatives in young children may potentially cause severe diaper rash, blisters, and skin sloughing.

Changing physician prescribing behavior: the community-acquired pneumonia intervention trial

The Notes section welcomes the following types of contributions: (1) practical innovations or solutions to everyday practice problems, (2) substantial updates or elaborations on work previously published by the same authors, (3) important confirmations of research findings previously published by others, and (4) short research reports, including practice surveys, of modest scope or interest. Notes should be submitted with AJHP's manuscript checklist. The text should be concise, and the number of references, tables, and figures should be limited.

Fetal response to maternally administered morphine

OBJECTIVE

We sought to determine the effects of maternally administered morphine on fetal response.

STUDY DESIGN

Singleton pregnancies requiring fetal blood sampling were enrolled. Only study patients were given morphine intramuscularly. Maternal vital signs, fetal heart rate, biophysical profile score, and umbilical artery Doppler indices (systolic/diastolic ratio, resistance index, and pulsatility index) were completed before and after fetal blood sampling. Maternal and cord blood morphine concentrations were measured.

RESULTS

Ten study and 6 control patients were enrolled. A significantly lower biophysical profile score was observed in study patients (P =.001) as a result of absent fetal breathing movements and nonreactive nonstress tests. Gross and fine fetal movements were unaffected. A significant correlation was measured between the biophase morphine concentration and each of the Doppler indices.

CONCLUSION

Morphine administered to the mother causes a significant decrease in the biophysical profile score. Correlation between the biophase morphine concentration and the Doppler indices was calculated. These results suggest that morphine acts as a vasoconstrictor of the placental vasculature but do not support the use of intramuscular morphine to suppress fetal movement.

Pharmacoeconomic evaluation of flumazenil for routine outpatient EGD

BACKGROUND

Flumazenil is a benzodiazepine antagonist indicated for reversal of the sedative effects of benzodiazepines. Previous studies suggest that flumazenil may shorten recovery time after endoscopy, but there are few data on actual recovery room times and charges.

METHODS

Fifty patients undergoing routine upper endoscopy were sedated with midazolam alone in the usual titrated manner. Patients were randomized in a double-blind fashion to receive either flumazenil or saline immediately after procedure. Assessments of responsiveness, speech, facial expression, and ptosis (Observer's Assessment of Alertness/Sedation [OAA/S] scale) were made before procedure, immediately after procedure and every 15 minutes thereafter. The patient was discharged from the recovery room when vital signs and OAA/S scale reached preprocedure levels. Recovery room times and charges were recorded.

RESULTS

The flumazenil group demonstrated shorter recovery room times and recovery room charges than the placebo group (p < 0.001). The difference in recovery room charges was not statistically different when flumazenil charges were included (p = 0.09).

CONCLUSIONS

The routine use of flumazenil after midazolam sedation for upper endoscopy significantly shortened recovery time and charges but did not statistically reduce overall charges.

A patent ductus arteriosus is associated with reduced middle cerebral artery blood flow velocity

The study objective was to determine the effect of a patent ductus arteriosus (PDA) on cerebral blood flow velocity in ventilated, very low birth weight neonates, in the first 5 days of life. Sonography of the right middle cerebral artery and ductus arteriosus was performed using a colour Doppler technique. Statistical analysis was by stepwise regression. Thirty-one neonates without and 43 with a PDA, mean (SD) birth weight 1004 g +/- 192 and 1071 g +/- 227 respectively, were studied. The end diastolic and mean velocities were reduced (P = 0.008 and P = 0.129) and the resistive index was increased (P = 0.047) by a PDA. pH was inversely related to end diastolic and mean velocities (P = 0.015 and P = 0.003), suggesting that low pH may increase cerebral artery blood flow velocity.

CONCLUSION

A patent ductus arteriosus reduces middle cerebral artery blood flow velocity in very low birth weight neonates.

Activities, functions, and structure of pharmacy and therapeutics committees in large teaching hospitals

The results of a survey on the activities and functions of hospital-based pharmacy and therapeutics (P&T) committees are presented. Questionnaires were mailed to the pharmacy director or the person responsible for the pharmacy's drug information service at 267 teaching hospitals throughout the United States in 1994 and 1995. The survey questions covered P&T committee composition, functions, roles of members, policies and procedures, and formulary-maintenance activities. The overall response rate was 70%. The mean number of members on the P&T committees was 19.3, of whom 91% were allowed to vote. There was an average of 12.3 physicians on the committees. Each P&T committee had at least one pharmacist member, with an average of 3.2 pharmacist members; 69.5% of the institutions reported having a committee secretary, who was almost always a pharmacist. On almost all committees, pharmacists wrote the minutes, prepared the formulary review documents, and were responsible for monitoring formulary activities outside the meeting. The P&T committee functioned in a very formal manner. Most (87.7%) of the respondents reported that their institutions had a closed formulary. At all hospitals, the attending medical staff could request additions to the formulary, but at only 62.4% of the hospitals could pharmacy staff make a similar request. The committees were active in changing the formulary. P&T committees in large teaching hospitals are active in formulary management, are large and diverse, and consist mainly of physicians, although pharmacists play an important role in the meetings.

Doppler velocimetry of the fetal middle cerebral and renal arteries: interobserver reliability

Using color and pulsed Doppler ultrasonography, the interobserver reliability of measurements in the fetal circulation was evaluated in 41 pregnancies of 25 to 39 weeks' gestation. Two observers recorded flow velocity waveforms from the middle cerebral and renal arteries for measurement of peak systolic, minimum diastolic, and mean velocities, pulsatility index, and resistive index. Intraclass correlation coefficient of reliability was calculated by analysis of variance. Substantial interobserver agreement was found for pulsatility index and minimum diastolic velocity in both arteries. Therefore, these measurements have the greatest clinical applicability.

Aminophylline and Doppler time-averaged mean velocity in the middle cerebral artery in preterm neonates

OBJECTIVE

The purpose of this study was to assess the effect of an intravenous loading dose of aminophylline (6 mg/kg) on Doppler time-averaged mean velocity in the middle cerebral artery in ventilated preterm neonates.

METHODOLOGY

Twenty infants were studied by colour/duplex Doppler technique prior to and at 5, 10, 30 and 60 min after the administration of aminophylline.

RESULTS

Aminophylline treatment was associated with a statistically significant reduction in time-averaged mean velocity from baseline (P < 0.001) and an increase in heart rate (P < 0.001) at all timepoints. The largest reduction in time-averaged mean velocity of 19% (95% confidence interval -10 to -28%) occurred at 10 min post-dose. There were no statistically significant changes in transcutaneous PCO2 or mean arterial blood pressure.

CONCLUSIONS

The observed reduction of 19% from baseline in time-averaged mean velocity following treatment with aminophylline alone is unlikely to be of clinical importance. Whether aminophylline in combination with other drugs that decrease central blood flow velocity such as indomethacin and/or dexamethasone could result in a clinically significant reduction deserves further study.

Selecting a pharmacy computer system for the future

Major advances are occurring in the field of computer science that have placed us at the threshold of a significant revolution in the management and application of clinical data. These advances will have a profound effect on the practice of pharmacy and are occurring at a time when many hospital pharmacies are deciding whether to enhance or replace their current systems. To best position your department for the future, it is essential that you are knowledgeable of the advances being made, have a vision for how they will affect your practice, and undergo a well-organized and thorough selection process.

Recurrent laryngeal nerve activation by alpha 2 adrenergic agonists in goats

The purpose of this study was to test the hypothesis that respiratory and apneas induced by alpha 2 agonists in anesthetized goats are associated with an increase of upper airway expiratory-related activity, rather than a general depression of breathing. Activities of phrenic (Phr) and recurrent laryngeal nerves (RLN) were recorded in response to the alpha 2 agonists clonidine (0.5-3.0 microgram.kg-1 i.v.) or guanabenz (7.0-20.0 micrograms.kg-1 i.v.) in ten chloralose-anesthetized goats. Injection of either alpha 2 agonist resulted in respiratory arrhythmias with a greater than seven-fold increase in TE and a 30% reduction in TI. During apneas RLN expiratory-related activity remained tonic until the next Phr burst, consistent with our hypothesis. Cessation of Phr activity during hypocapnia also resulted in a tonic increase of RLN expiratory activity; and injection of NaCN (50 micrograms.kg-1 i.v.) increased Phr and RLN inspiratory activities, while attenuating RLN expiratory-related activity. Inspiratory and expiratory-related activity of RLN motoneurons appear to be reciprocally modulated by alpha 2 agonists or changes in central or peripheral chemoreceptor drive. The results indicate that central apneas and respiratory arrhythmias may be associated with alpha 2-adrenoceptor modulation of laryngeal expiratory-related activity.

Intracarotid substance P infusion inhibits ventilation in the goat

Substance P (SP) has been proposed as an excitatory neuromodulator of the carotid body (CB) response to hypoxia based on data from the cat and rat. The role of SP as a CB neuromodulator in the goat is unknown. Awake (n = 14) and chloralose anesthetized goats (n = 6) were used to investigate the effects of intracarotid (IC) SP infusions (1-6 micrograms.kg-1.min-1) and bolus injections (6 micrograms kg-1) to the CB intact and denervated (CBX) sides (control) on mean ventilation (VE) and mean blood pressure (MBP). In awake goats VE was decreased by infusion or bolus SP injection at a dose of 6 micrograms.kg-1 (P < 0.05) and occurred with infusions to the intact or CBX sides. MBP was elevated with SP infusion to either the CB intact or CBX sides at all SP doses. The SP antagonist CP-96,345 (0.1 mg.kg-1, IV) blocked the decrease in VE induced by SP in normoxia and significantly increased the hypoxic ventilatory response (PaO2 = 40 torr). In anesthetized goats, IC injections of SP (1 to 6 micrograms.kg-1) reduced phrenic activity and MBP before and after CBX. In only one of five goats airway pressure was increased suggesting that bronchoconstriction was not a cause for the reduced ventilatory and phrenic activity induced by SP. Immunohistochemistry provided evidence of SP in CB nerve fibers and terminals, carotid sinus nerve axons and petrosal ganglion cells, but not in type I glomus cells. Our results do not support the view that SP is an excitatory neuromodulator of CB chemotransduction in the goat.

Effects of carotid body sympathetic denervation on ventilatory acclimatization to hypoxia in the goat

Our objective was to test the hypothesis that diminishing sympathetic input to the carotid body (CB) during prolonged exposure to hypoxia results in increased CB afferent activity and increased ventilatory drive. Six awake goats were studied prior to and following sectioning of the efferent sympathetic input to the CB from the superior cervical ganglion. Ventilatory responses to acute and prolonged isocapnic hypoxia (PaO2 40 Torr) and drugs (norepinephrine and dopamine, 0.5, 1.0 and 5.0 micrograms.kg-1 min-1) were collected prior to the denervation. One week and 3-4 weeks following the sympathetic denervation, the animals were restudied following the above protocol. Ventilation was significantly lower following sympathetic denervation in normoxia and during the hypoxic exposure. However, the response to acute hypoxia and the time-course of ventilatory acclimatization to hypoxia was not altered by sympathetic denervation. All doses of norepinephrine and dopamine significantly inhibited VE in a dose-dependent manner. Sympathetic denervation did not significantly alter the response to the drug infusions. The sympathetic innervation to the CB does not appear to play a role in either the acute or prolonged ventilatory responses to hypoxia in the awake goat, but may affect overall ventilation.

Superior mesenteric artery and renal artery blood flow velocity measurements in neonates: technique and interobserver reliability

The objective of this study was to establish the interobserver reliability for superior mesenteric artery (SMA) and renal artery (RA) Doppler blood flow velocity (BFV) measurements in neonates. Forty-two clinically stable infants were enrolled, mean (SD) gestational age 33 (2) weeks, birthweight 2.00 (0.54) kg, postnatal age 10 (11) days. Doppler recordings were made by two trained observers. The SMA and RA were studied with a 5.0-MHz phased array transducer. The optimal spectral trace from each artery containing a minimum of five consecutive waveforms was analysed. The peak systolic velocity (PS), end diastolic velocity (ED) and mean peak velocity (MV) were measured and the time-averaged mean velocity (TAV) and waveform indices were calculated. Using the intraclass correlation coefficient (ICC) the estimates of interobserver reliability for different measurements varied from 0.40 to 0.83. Substantial agreement was obtained between observers in the TAV, PS, ED and MV; the ICC varied from 0.72 to 0.83 demonstrating that Doppler BFV measurements of the SMA and RA are reliable in neonates.

Development of a continuous quality improvement/total quality management program for medication use monitoring

The design of institutional medication use programs that are effective and meet regulatory and accreditation standards is becoming increasingly dependent upon a thorough understanding of the principles and applications of continuous quality improvement (CQI) and total quality management (TQM). Both the Joint Commission on Accreditation of Healthcare Organizations and the federal government have recently begun to make significant attempts to transform our existing quality assurance programs into indicator-based quality improvement management systems that are based on the principles of CQI and TQM. The article outlines and illustrates an effective approach for developing and implementing a comprehensive CQI/TQM program for medication use monitoring.

Use of total quality management techniques to improve compliance with a medication use indicator

Total quality management techniques were used to lay the groundwork for and to implement procedural changes designed to improve compliance with the Joint Commission on Accreditation of Healthcare Organizations' medication use indicator for ordering and administering presurgical antibiotics. The effect of these procedural changes on patient outcomes (i.e., postsurgical infection rates and length of hospitalization) is described. In a study to assess compliance, 57 (30 percent) of 40 control patients received a presurgical antibiotic within 1 hour of incision compared with 65 (52 percent) of 126 study group patients, and 83 (44 percent) of the control group received a presurgical antibiotic within 2 hours of incision compared with 88 (70 percent) of 126 study group patients. Postsurgical infection rates and length of hospitalization were not significantly different (p = .407 and p = .885, respectively).

Modulation of respiratory rhythm by alpha 2-adrenoceptors in awake and anesthetized goats

The purpose of this study was to examine the effects of alpha 2-adrenoceptor agonists in the control of breathing with goats that were either awake (n = 7) or anesthetized and artificially ventilated (n = 11). Awake goats infused intravenously with either of the alpha 2-agonists clonidine (1.0-6.0 micrograms/kg) or guanabenz (15.0-63.0 micrograms/kg) exhibited two distinct ventilatory patterns. One pattern was characterized by tachypnea in which respiratory frequency and minute ventilation increased to approximately 50% above control values. A second ventilatory pattern consisted of slow breathing with reductions of respiratory frequency and minute ventilation and highly variable expiratory duration intervals. These two patterns were unaffected by bilateral carotid body denervation. In anesthetized goats, alpha 2-agonists also caused an arrhythmia in phrenic nerve activity that was similar to the slow breathing pattern seen in awake goats. Respiratory disturbances were abolished by the selective alpha 2-receptor antagonist SKF-86466 (100-500 micrograms/kg), indicating that the effects are mediated by alpha 2-receptors. The results suggest that stimulation of alpha 2-adrenoceptors generally has an inhibitory effect on breathing in goats. The disruption of ventilation with clonidine or guanabenz suggests that alpha 2-adrenoceptors may play an important role in the control of central respiratory rhythm.

The effect of dexamethasone on time averaged mean velocity in the middle cerebral artery in very low birth weight infants

The effect of repeated doses of dexamethasone (0.25 mg/kg/dose every 12 h) on time averaged mean velocity in the middle cerebral artery was assessed in ten ventilated very low birth weight infants requiring treatment with dexamethasone for bronchopulmonary dysplasia or airway obstruction. The infants were studied by colour/duplex Doppler technique prior to the administration of the first and the third dose of dexamethasone, and 10, 30, and 120 min after these doses. Dexamethasone treatment was associated with an improvement in infant lung condition, an increase in mean arterial blood pressure and a decrease in heart rate. The time averaged mean velocity was statistically significantly reduced at 120 min after the first dose. This was not associated with a decrease in PCO2. The observed reduction of 18% from baseline in the time averaged mean velocity is unlikely to be of clinical importance.