Volume 5 Number 1
January, 1998

We will be awarding the fourth annual Distinguished Career Award in Pediatric Critical Care this Fall at the AAP meeting. Please email Drs. Brahm Goldstein (goldsteb@ohsu.edu) or Tim Yeh timbobyeh@aol.com with your nominations. Remember that the criteria should be based on the following - A distinguished history of contribution to pediatric critical care medicine with significant achievements in the areas of clinical care, education, and research.

This award carries with it a plaque honoring the recipient and an honorarium of $1,000. Past recipients were Drs. I. David Todres, John Downes, and Peter Holbrook.


Dr. Holbrook (center) receiving the Distinguished Career Award in Pediatric Critical Care from Drs. Goldstein (left) and Yeh at the 1997 AAP Critical Care Section meeting in New Orleans

This is the third year that the Section on Critical Care will fund a New Investigator Research Award. This year's award will be for $10,000. The award is available to individuals during their critical care fellowship through their second year postfellowship. The award, which is competitive, will provide support to an individual who has demonstrated aptitude for clinical or basic science research and who presents a sound plan of investigation. Dan Notterman, MD, FAAP, FCCM will be chair of the subcommittee reviewing grant applications.

The award will be judged on the following criteria: scientific merit, clarity of the presentation, likelihood of productivity by the investigator, sponsor's evidence of appropriate academic environment, and relevance to critical care.

Grant applications are available from:

Jacqueline Burke
AAP Sections Manager
Div. Of Sections
Elk Grove Village, IL 6009-0927
Tel: 1-800-433-9016 ext. 6759
Fax: 847-228-5097
email: jburke@aap.org

Grant Timetable
Jan. 1, 1998 Grant applications available
May 1, 1998 Deadline for receipt of application
June 1, 1998 Notification to Investigator and Institution
July 1, 1998 Initiation of the Award
June 30, 1999 Termination of the Award
Sept. 1, 1999 Scientific Progress Report due

The following is the annual report of the Section on Critical Care. The Critical Care Section Business Meeting was called to order at 12 noon, Saturday, Nov. 1.

1. Membership
Section membership has remained relatively stable with nine new member applications approved.

2. Council on Sections issues
Important issues from the February 1997 COS meeting included the recognition of the importance of Sections in review of Academy statements (mechanisms for insuring appropriate review to be put in place), opening Academy membership to International members, Osteopaths, and Dentists) and a resolution passed by the COS that addresses the problems associated with pediatricians not being able to refer to subspecialists that they feel appropriate due to managed care constraints. The Academy has established a time limited work group to address these needs.

3. Section CME Course
The course on Managed Care for Pediatric Intensivists held in April in Chicago was positively received by those who attended with strong evaluations for all of the speakers. However due to a late start in pulling the course together and publicizing the attendance was low and the course lost $13,500. Half the loss was covered by the Section and the remainder by the Academy.

4. RBRVS
The Academy is continuing its involvement with RBRVS/coding. Staff has agreed to forward new coding to appropriate sections for review and comment. The Critical Care Section's RBRVS Work Group has been chaired by Jeff Rubenstein.

The Perinatal Section was presenting a coding workshop at the Annual Meeting. The Critical Care Section Executive Committee also discussed the possibility of putting together a similar workshop for Section members.

5. Newsletter
We will be instituting a Guest Editor format for some of the upcoming editions of Critical Care News. Tex Kissoon, MD has agreed to be the first Guest Editor. Brahm Goldstein will be stepping down as the Co-Editor of the newsletter. If any members are interested in either becoming a Guest or Co-Editor, please contact either myself of Tim Timmons.

6. Liaison reports
Curt Steinhart presented a liaison report from the Hospital Care Committee including an update on the PICU Admission and Discharge Criteria Statement. Tim Yeh noted that the joint statement (with the American College of Critical Care Medicine/SCCM) on Regionalization of Care for Critically Ill and Injured Children was provisionally approved by the Committee on Pediatric Emergency Medicine.

7. FOPE II Survey
The Critical Care survey developed by Curt Steinhart, David Jardine and Sarah Brotherton for the Academy has been sent out. After the fourth mailing the return rate has been 59.9% out of a potential group of respondents of 1,584. Section members were encouraged to return their surveys if they have not already done so.

8. PCCM Web site
The Section Executive Committee met with Barry Markowitz to discuss the future direction of the PCCM Website. In the meantime, Dr. Markowitz encouraged Section members to actively participate in Web site activities such as the evidence based JC.

9. Distinguished Career Award
The Business meeting was adjourned at 1pm for the presentation of the 1997 Distinguished Career Award to Peter Holbrook, MD.

Respectfully submitted,

Tim Yeh, MD
Section Chair

The following is a brief summary of the research performed by Heidi V. Connolly, MD that was partially funded by the SectionÕs New Investigator Research Award.

SYSTEMIC HEMORRHAGE INCREASES HETEROGENEITY OF MICROVASCULAR OXYGEN EXTRACTION. Heidi V. Connolly, MD and Thomas E.J. Gayeski, MD, PhD. Departments of Pediatrics and Anesthesiology, University of Rochester Medical Center. Rochester, New York.

Background: With improvements in supportive care, intensive care unit no longer succumb to respiratory failure but more often to multiple systems organ failure. Occult tissue hypoxia occurs despite adequate levels of global oxygen supply during critical illness indicating an inability to utilize O2 efficiently. Failure of the microvascular system to efficiently distribute a limited supply of oxygen to tissue regions based on metabolic need may underlie the development of tissue hypoxia and subsequent organ failure. Sympathetic vasomotor tone is highly important for efficient tissue oxygen extraction during limited O2 supply. Proposed experiments tested the hypothesis that microvascular maldistribution of oxygen delivery contributes to impaired oxygen extraction and results in tissue hypoxia.

Methods: In a normovolemic group of anesthetized dogs (n=6), systemic blood volume was maintained by administration of normal saline and donor erythrocytes to minimize sympathetic tone while blood flow to a vascularly isolated gracilis muscle was reduced with an occlusive roller pump. In a hypovolemic group (n=5), blood volume was reduced in stages to augment sympathetic tone while blood flow to the muscle was similarly reduced. Systemic and muscle oxygen delivery, oxygen consumption and hemodynamics were measured in steady state. Muscles were then immediately frozen under a liquid-nitrogen cooled copper block. Frozen specimens were sectioned perpendicular to the length of the muscle and myoglobin saturation was measured in 50-100 myocytes per muscle. Hemoglobin saturation was measured in identifiable venules >30mm in diameter. Biochemical markers indicative of cellular hypoxia, including phosphocreatine, lactate and ATP were measured.

Results: Oxygen delivery to the muscle was similar in the hypovolemic (3.04 ± 0.84 ml/min/kg) and the normo-volemic group (4.06 ± 1.27 ml/kg/min, p=0.20). Muscle venous effluent PO2, a flow weighted average of end-capillary PO2, was significantly higher than myocyte PO2 both in the high sympathetic tone group (33.1 ± 13.5 torr vs. 4.7 ± 1.3 torr, p<0.05) and the low sympathetic tone group (37.3 ± 7.1 torr vs. 5.4 ± 2.0 torr, p<0.05). Venules represent a flow weighted average of only a few capillary modules. Those with high hemoglobin saturation are indicative of reduced extraction while those with low hemoglobin saturation are indicative of increased extraction. Augmentation of sympathetic tone tended to decrease average venular hemoglobin saturation (31.8 ± 8.8% vs. 47.0 ± 13.7%, p=0.08). Relative dispersion (S.D./mean), an index of heterogeneity, demonstrated significant variability of venular hemoglobin saturations with relative dispersions ranging from 42% to 157%. Relative dispersion of venular hemoglobin saturation was significantly increased in the hypovolemic group (relative dispersion 1.16 ± 0.27%) when compared to the normovolemic group (0.76 ± 0.20, p<0.05). Significant heterogeneity of myoglobin saturation was likewise evident, with relative dispersions ranging from 24% to 196% but was unchanged by alterations in sympathetic tone (p=0.31).

Conclusions: These findings demonstrate significant heterogeneity of oxygen extraction at the microvascular level which is increased during augmentation of sympathetic vasomotor tone. Because post-capillary red blood cell PO2 is significantly higher than tissue PO2 and quite similar to venous PO2, resistance to oxygen flux exists. Enhancement of sympathetic vasomotor tone decreased the average post-capillary red blood cell PO2 and thereby decreased the resistance to convective oxygen transport implying that sympathetic activation increased capillary recruitment. Theoretically, this should allow the tissue to extract to a lower end-capillary PO2. Both the average myocyte PO2 and the heterogeneity of myocyte PO2 is unaffected by an increase in sympathetic tone. These findings suggest that diffusion of oxygen between cells by myoglobin facilitated O2 flux prevents cellular dysoxia and maintains homogeneity of myocyte PO2 during periods of limited O2 supply. Because myocyte PO2 is maintained, use of glycolysis, depletion of phospho-creatine, and alteration of the redox state are not required to maintain tissue concentrations of ATP.

Ongoing Research: Preliminary data obtained from the above research funded by the American Academy of Pediatrics has been the basis of funded applications to the American Lung Association (Edward Livingston Trudeau Research Scholar) and to the Parker B. Francis Foundation (Fellowship in Pulmonary Research). Experiments proposed in these grants will attempt to identify the spatial scale of blood flow and oxygen extraction heterogeneity using in-vivo video-microscopy of flourescently labeled erythrocytes in the Golden hamster microvasculature studied during critical supply dependency.

Please address all suggestions for future articles and/or comments to any of the following editors:

Timothy S. Yeh, MD, FAAP, FCCM (Chairperson)
PICU, Children's Hospital of Oakland
747 52nd St.
Oakland, CA 94609
Tel 510-428-3714 Fax 510-601-3923
timbobyeh@aol.com

Otwell Timmons, MD, FAAP
PO Box 32861
Charlotte, NC 28232-2861
Tel 704-355-7815 Fax 704-355-3116
otimmons@carolinas.org

The success and utility of this newsletter is dependent upon input from Section members. Ideas for articles, job listings, and notices of upcoming events related to Pediatric Critical Care are welcome.

In order to coordinate activities and efforts and make the best use of resources, Dr. Burris Duncan, Chairperson for Section on International Child Health, has put together a questionnaire aimed toward creating a central repository of information regarding ongoing international child health activities by Fellows of the Academy. Dr. Duncan has asked those section members involved in international child health issues to please fill out the following form and return to Dr. Duncan at the address listed below.

[PedsCCM ed.note: You may print this out directly or download a Word 6.0 for Macintosh or Windows version instead.]

INTERNATIONAL CHILD HEALTH ACTIVITIES ALERT

NAME:
ADDRESS:


PHONE:
FAX:

INSTITUTION AND COUNTRY YOU WILL BE WORKING IN:

DATES OF YOUR VISIT:

TYPE OF ACTIVITIES:

INSTITUTION(S) TO WHICH YOU ARE SENDING EDUCATIONAL MATERIALS, SUPPLIES AND EQUIPMENT:

EDUCATIONAL MATERIALS:

TYPE OF SUPPLIES:

TYPE OF EQUIPMENT:

CAN THE AAP'S INTERNATIONAL CHILD HEALTH SECTION BE OF ANY ASSISTANCE TO YOU AND YOUR EFFORTS?

IF SO, HOW?

Thanks for any help you can give us in this initiative.

Sincerely yours,

Burris Duncan, MD
Chairperson for Section on International Child Health
Department of Pediatrics
University Medical Center
1501 N. Campbell Ave.
Tucson, AZ 85724
Fax: 520-626-3636

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Document created February 10, 1998; last modified (links only) September 3, 1999
http://PedsCCM.wustl.edu/ORG-MEET/AAP/AAP_Jan98.html