Download The ABC of Craniosynostosis Repair: A (air embolus), B (blood loss

Title:
The ABC of Craniosynostosis Repair: A (air embolus), B (blood loss), C (Cardiopulmonary
resuscitation)
Moderators:
M. Concetta Lupa, Assistant Professor of Anesthesiology and Pediatrics, University of
North Carolina
Karene Ricketts, Assistant Professor of Anesthesiology and Pediatrics, University of North
Carolina
Goals:
After completion of the PBLD, the participant should be able to discuss
the anesthetic management for craniosynostosis repair including
potential problems such as venous air embolism and blood loss / replacement
/ conservation
a.
b.
the revised 2010 Pediatric Basic and Advanced Life Support guidelines
Case history:
A 15-month old male with craniosynostosis scheduled for repair. His past medical history is significant for
prematurity at 29 weeks, shunted hydrocephalus, chronic lung disease and developmental delay.
Questions:
What is craniosynostosis?
What are the implications of syndromic vs. non-syndromic craniosynostosis?
What are the anesthetic implications of prematurity?
What is chronic lung disease? How can it affect your anesthetic plan? Would you obtain more
information based on his history of prematurity/chronic lung disease?
What other preoperative workup would you want in preparation for his craniosynostosis repair?
What do you include in your informed consent? What specific risks and possible complications should be
disclosed to the patient’s parents? Does your institution require a separate written anesthesia consent?
Case history and physical examination (continued):
Preoperative assessment includes Hgb 11.9 mg/dL and type / cross.
Parents wish to be directed donors for blood transfusion.
Questions:
What monitors would you want in proceeding with this case? Why? Would you place a central venous
line? If so, where? Does location matter?
What blood conservation techniques would you utilize? What pharmacological agents? Amicar?
Tranexamic Acid? What anesthetic techniques? Discuss risks/benefits of each. What does your
institution use? Do the surgeons at your institution employ preoperative therapies to help decrease the
impact of anticipated blood loss Are these evidence-based therapies?
What about directed donated blood from family members? Is it beneficial? What are the risks?
Preoperative studies/results:
The type and cross showed the presence of anti-kell antibodies. The surgeon is eager to start his case. A
senior colleague suggests that by the time your lines are set-up, a match is likely to be available.
Questions:
Would you start the case without identifying available blood products for the case? How much blood
would you want to be available before starting the procedure? Do you think it is necessary to have the
blood in the room prior to the induction of anesthesia?
What is involved in a type and cross? What are some common antibodies? Why would this child be likely
to have the presence of antibodies?
Intraoperative course:
Standard monitors, arterial line, and peripheral intravenous access established.
Amicar infusion 10 mg/kg/hr was initiated prior to incision.
Questions:
Is there evidence in pediatrics that Amicar (Aminocaproic acid) is useful in preventing blood loss in
craniosynostosis repair? In other procedures? How is it dosed?
Are there risks in giving pharmacologic agents (i.e. antifibrinolytics)? What are contraindications to using
these types of therapies?
At what point in the surgery is blood loss most likely to occur?
Intraoperative (continued)
Acute hypotension, oxygen desaturation, and decrease in ETCO2 during surgical exposure of the dural
sinuses raises concern for venous air embolism.
Questions:
What are some unique concerns to intracranial procedures….concern for venous air embolism? How
would you address/prepare for potential complications? What is a venous air embolism? How does it
develop? What other surgical procedures are high risk for venous air embolism? What are the signs of a
venous air embolism? How should it be managed? Role of PEEP? Role of anesthetic technique? Echo vs.
precordial Doppler for detection?
Intraoperative (continued):
After covering the surgical field, intravenous epinephrine, and fluid bolus the patient stabilizes and
surgery proceeds. During craniectomy, progressive hypotension secondary to profound blood loss, results
in pulseless electrical activity. Cardiopulmonary resuscitation initiated.
Questions:
What is pulseless electrical activity? What are the causes? What is the recommended therapy per
current PALS guidelines? How do these guidelines differ outside of the operating room in a non-intubated
patient?
Summarize the new PALS changes as they relate to airway, breathing, and circulation. Why were these
changes implemented? Is the data substantial enough for these new recommendations?
What is the recommended chest compression rate/depth in children of this age? If the patient was in the
prone position, would this change your management?
Postoperative Care:
A stable rhythm was obtained and the surgery proceeded uneventfully. The surgeon asks what your
plans are for extubation. The patient has had good urine output, is not requiring pressor support, and
ventilation is stable.
Questions:
Would you attempt extubation in this patient? What are your criteria for extubation? Does the amount of
blood transfused/IV fluids given play a role? What other factors play a role in your decision
How would you explain the intraoperative events to the parents?
Craniosynostosis is the result of premature closure of the cranial sutures during the
development of an infant’s skull growth. There are many different types of
craniosynostosis, depending on which and how many sutures are involved. Therefore,
presentation can be varied from patient to patient A common classification is between
syndromic and non-syndromic craniosynostosis, mostly because non-syndromic
craniosynostosis involves usually only one suture, and syndromic craniosynostosis may
present in a more complex fashion, thereby necessitating a more involved repair. The
reasoning behind surgical correction of craniosynostosis is not solely cosmetic. Operations
are performed early in life in an attempt to allow for normal brain growth and cognitive
development.
Preoperative assessment of the patient is generally the same as any basic pediatric
preoperative assessment, with consideration of the patient’s other medical conditions as
well as current state of health. There are a few points, however, that need to be addressed
specifically to the patient presenting for craniosynostosis repair. One should assess for the
presence of increased ICP, although it is fairly uncommon. In syndromic patients, it may be
common to see other abnormalities, such as congenital heart disease and/or difficult
airway, and therefore history and physical exam should be directed towards such. The
surgical procedure often results in major blood loss, and so a CBC and coagulation profile, as
well as a type and cross, should be obtained. Parents should be made aware of the
increased risk of transfusion. Another risk in this patient population is the risk of venous air
embolism, and therefore preparations should be made to detect and treat in case of
emergency.
Intraoperatively, standard monitoring, as per the American Society of Anesthesiologists
guidelines, and an arterial line for blood pressure measurement are indicated. A central
venous line is not routinely established for pressure monitoring, but should be strongly
considered if peripheral access is inadequate (2 large bore IVs is most common) or if there
is a great concern for venous air embolism. Venous air embolism is a complication seen in
craniosynostosis repair, with a reported incidence of 83%, although most are without
hemodynamic symptoms. Routine use of a precordial Doppler to increase the chance of
early diagnosis is recommended.
A balanced anesthetic of opioid and inhalation agents is most often utilized. Intraoperative
blood loss management is the most challenging part of the anesthetic management for
craniosynostosis repair. Elevation of the vascular periosteum is usually the most significant
source of bleeding and accurate assessment of the blood loss is difficult because a significant
percentage is lost on the surgical gowns and drapes. The dural sinuses are another potential
source of bleeding and generally require immediate fluid resuscitation or transfusion.
The usual strategies for decreasing homologous transfusion, such as preoperative
autologous donation, are generally not feasible in children (especially those less than 3
years of age) because of their small blood volume and the difficulty donation would pose
without sedation. There are also potential risks if parents wish to be directed donors
because transfusion of parental blood has raised concerns of chimerism and graft-versushost diseases (GVHD). Induced hypotension is not a widely accepted blood saving technique
for craniosynostosis repair because of the increased risk of venous air embolism and the
potential hemodynamic instability associated with blood loss. There is evidence to support
use of perioperative blood salvage, but there are associated risks to consider including
coagulopathy, hemolysis, bacterial contamination, and damage to platelets. Recently, several
investigators have shown that intraoperative tranexamic acid reduces blood loss and
transfusion requirements in children undergoing surgical correction of craniosynostosis.
Postoperative management varies by surgeon and institution. In most circumstances, the
patient can be extubated at the end of surgery and transported to the perioperative
anesthetic care unit or pediatric intensive care unit where the hemodynamic and volume
status, hematologic, and coagulation profiles are closely monitored. Patient outcome is
usually excellent with proper preoperative planning and careful attention to intravascular
volume status.
References:
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Perioperative management of pediatric patients with craniosynostosis.
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Intraoperative tranexamic acid reduces blood transfusion in children undergoing
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