Chapter 6 - Medical Conditions Influencing Anesthetic Management Flashcards
T/F
Children with an UNcomplicated upper respiratory tract infection who are Otherwise Healthy have a Greater incidence of intraop desaturation, brochospasm, and laryngospasm
T
The following with a concommitant URTI may have MORE SERIOUS airway problems during and after anesthesia:
- Infants < 1 year
- Infants who were premature
- Children exposed to second hand smoke
- Children with reactive airway disease
Postop desaturation is MORE COMMON in children with a history of URTI
Airway irritabilty after a URTI may last for how many weeks?
6 to 8 weeks
T/F
Anticholinergics affect the incidence of perioperative airway complications in a negative way, in children with URTI
F
Do NOT Affect
help
T/F
Preoperative bronchodilators and a vital capacity cough may resolve bronchospasm and airways plugged with mucus
T
What can be done intraop to deliver most of the content of each puff of albuterol to the tip of the ETT?
A long narrow guague (19g) catheter may be inserted to the distal third of the ETT
- This allows the majority of the aresol to reach the tracheal mucosa
Children who present for elective surgery with which 4 signs and symptoms should be rescheduled after 4 weeks?
- Pyrexia > 38.5 C
- Change in behavior, diet, or activity
- Prulent secretions
- Signs of lower respiratory tract involvement (wheezing) that do not clear with forced cough
Child comes in for an elective hernia repair and has a URTI and a history of asthma. The surgeon insist that the case would be less than 1 hour, should you delay the case? If so, for how long?
Delay procedure 4 weeks
T/F
In an emergency surgery, when suitable, the LMA should be used as an alteratenative to tracheal intubation, it may result in fewer airway complications
T
Postop, the child should be carefully observed
In a child with asthma, if oral steroids are prescribed, it suggest what?
A recent exacerbation
During which time frame is a child’s airway reactivity increased and residual mucosal edema and secretions impair pulmonary function?
1 month (4 weeks) after the last acute attack
If the child with asthma is taking theophylline, and is presenting for elective surgery, what should be done preoperatively?
The blood level of theophylline should be measured
In the preoperative anesthesia managment, a stress dose of steroids should be administered at induction of anesthesia to who?
What is the drug and dose used for the stress dose?
IV hydrocortisone 1 to 1.5 mg/kg
Stress dose given to:
- >5 mg perdnisone per day
- Oral steroids within 3 months
- High-dose inhaled steroids
T/F
Atropine is contraindicated in children who present with asthma due to its bronchoconstrictive effects.
F
Decreases secretion and bronchodilates
What is the preferred IV induction agent for children with asthma?
Propofol
Which IV induction agent may cause bronchoconstriction in an asthmatic child due to the release of histamine?
Thiopental
Can ketamine be used for IV induction for a child with asthma?
Yes.
Use atropine to limit secretions
Which inhaled anesthetic may precipitate arrhythmias in children also receiving theophylline?
Halothane
Which inhaled anesthetic increases airway resistance in asthmatic children?
Desflurane
Intraoperative wheezing should be treated by…?
- Deepening anesthesia
- Give bronchodilaor via ETT
What are some nonasthmatic causes of wheezing intraoperatively?
- Partially obstructed ETT
- Endobronchial intubation
- Pneumothorax
T/F
At the end of surgery, in a child with asthma, muscle relaxants can be reversed using atropin and neostigmine.
T
Extubation in a child with asthma is prefferby performed with the child deeply anesthetized and breathing spontaneously. However, if awak extubation is planned, what may be given to reduce laryngeal reflexes?
IV lidocaine
or
IV Propofol
Cystic fibrosis is an inherited disorder that results from a genetic defect on which chromosome?
Defect on chromosome 9
What causes the incrased viscosity of secretions and increased electrolyte content in a patient with cystic fibrosis?
Abnorml Chloride and Sodium transport
What can occur in a child with cystic fibrosis in the second decade of life concerning malabsorption and pulmonary issues?
Malabsorption is superseded by increasing pulmonary problems because of abnormally viscious secretions
In an individual with cystic fibrosis, when does respiratory failure usually develop?
Respiratory failure is secondary to what?
Respiratory failure usually develpos by second or third decade of life, secondary to reatined secreions and chronic infection.
T/F
When considering anesthesi problems in a patent with cystic fibrosis, because of the V/Q disturbance, Hypoxia may quickly develop and induction with inhalational agents is prolonged
T
- Prolong induction with inhaled agent exacerbated with less soluble anesthics such as sevoflurane
What can ou say about the lung compliance in a patient with cystic fibrosis?
Lung compliance is reduced
- Cuffed ETT used
- High peak pressures required to adequately ventilate the lungs and prevent hypoxemia
What time of the day is pulmonary function in a patient with cystic fibrosis usually at its worst?
Usually at its worst early in the morning
- If possible, schedule surgery that allows for chest physiotherapy and clearing of secretions preoperatively
The child with cystic fibrosis should be offered clear fluids until how many hours preoperatively?
Cystic fibrosis - clear fluids up to 2 hours before surgery
In a child with cysic fibrosis, and requires general anesthesia, how long should they my preoxygenated for?
100% O2 for 5 min. with pulmonary involvement
T/F
Postoperative treatment for anagesia can be provided with the use of regional anesthesia and NSAIDs whenever possible
T
What is the Hb concentration at birth?
Hb by 3 months?
Hb by 6 years?
At birth: Hb is 18 to 20 g/dl
3 months: 10 to 11 g/dl
6 years: 12 to 14 g/dl
What are the three reasons that in the preterm infant, the Hb often decreases to lower concentrations?
- Reduced RBC mass at birth
- Brief survial time of the fetal RBC
- Poor erythropoietin
In children with anemia, the major compensating mechanism to transport the oxygen to the tissues is?
Increased cardiac output
- Hb-02 curve (caused by increase 2,3 DPG) contributes very little
- Hb (<8 g / dl) the cardiac output must increase to compensate
At what Hb level is the myocardium compromised to meet its own needs?
<5 g/dl
- Results in subendocardial ischemia
- High-output congestive cardiac failure may occur
In children with significant cardiac or respiratory disease, what Hb level is considered the acceptable minimum?
14 g/dl
How long does it take for Hb levels to increase for iron-deficiency anemic children after oral iron therapy?
3 to 4 weeks
Infarction of the lungs is also known as?
Acute chest syndrome
Why does performing the Sickledex test in the first 6 months have a chance of NOT detecting the presence of HbS?
HbS replaces fetal Hb (HbF) after 6 months of age
Tell me about Sickle cell trait
- Mild form
- HB AS heterozygous
- < 50% HbS
- Sickling unlikely without VERY SEVERE hypoxemia
- Sickling under anesthesia possible during cardiopulmonary bypass
Telll me about Sickle cell disease
- Severe form
- HbSS homozygous
- >75% HbS
- Serious complications
What is the second most common abnormal Hb diseae?
HbC
T/F
Infants with Sickle cell trait should recieve pneumococcal vaccine and PCN prophylaxis up to 6 years of age
F
Sickle cell disease (Hb SS)
T/F
The difference between Sickledex and Sickleprep, is that Sickledex can differentiate sickle disease from sickle trait
F
Neither DO NOT differentiate between disease and trait
In infants < 6 months, what provides an acurate diagnosis to Sickle cell?
Hb electrophoresis
T/F
Children with HbC may have a NORMAL Hb concentration but are still at risk of sickiling
T
In the child with sickle cell disease, tell me about the traditional approach to preoperative transfusions.
Traditional approach
- Packed RBC infused over several days
- Supresses erythropoiesis
- HbS reduces to <40% which is considered safe for MOST surgeries
In the child with sickle cell disease, tell me about the conservative approach to preoperative transfusions.
Conservative approach
- blood transfusion as necessary to increase Hb to _>_10 g/dl
- As effective as traditional approach
Children with Sickle cell disease who require cardiopulmonary bypass and hypothermia should have packed cell infusions or exchange transfusion to reduce the HbS levels to less than ___%
Hb S < 5%
The diagnosis of Factor VIII deficiency can be performed by what test?
Factor VIII assay
In a child with classic hemophilia Type A, an emergency surgery is necessay, but facilities of a hematology department are not available, what should be administered?
Fresh-Frozen Plasma (20 ml/kg)
- In a child with classic hemophilia type A, one hour before surgery an infusion of Factor VIII concentrate of what dose should be given?
- Followed by what test?
- 25 U/kg to 50 U/kg
- Assay for plasma factor VIII activity
1 U/kg factor VIII increases plasma level by what %?
1 U/kg increases factor VIII plasma level by 2%
What is the half-life of factor VIII concentrate?
Half-life is 12 hours
After a patient has been given factor VIII concentrate, what level of factor VIII activity is recommended before proceeding with surgery?
> 50%
For major surgery, an infusion of factor VIII at what rate is advisable?
Factor VIII 3 to 4 u/kg/hr
What is the most common congenital bleeding disorder?
Vo Willebrand disease
Von Willebrand’s disease may occur secondary to what two other diseases?
Congenital heart disease
&
Wilms tumor
What is the basic defect in Von Willebrand’s disease?
Lack of plasma cofactor that is a carrier protein for Factor VIII
How many types of the Von Willebrand’s disease are there?
3 types
Tell me about Von Willebrand’s disease Type 1.
Type 1
- Common (90%)
- Mild
- Bleeding time prolonged
- PT & PTT are often normal
*DDAVP is effective
Tell me about Von Willebrand’s disease Type 2a
Type 2a
- Common (90%)
- Mild
- Bleeding time prolonged
- PT & PTT are often normal
PLUS
- Normal platelet count
*DDAVP is effective
Tell me about Von Willebrand’s disease Type 2b
Type 2b
- Common (90%)
- Mild
- Bleeding time prolonged
- PT & PTT are often normal
- Normal platelet count
PLUS
- Thrombocytopenia
*DDAVP may exacerbate Type 2b
*MUST be treated with crypprecipitate or FFP
Tell me about Von Willebrand’s disease Type 3
Type 3
- Most severe form
- von Willebrand factor and factor VIII undetectable
*DDAVP is ineffective
*MUST be treated with crypprecipitate or FFP
T/F
Abnormal cholinesterase may result in prolonged apnea after administration of muscle relaxants?
T
What are the 5 aleles of pseudocholinesterase found on chromosome 3 that comprise the majority of the phenotypes?
- Normal
- Silent gene
- Atypical
- Fluopride rsistant
- E Cynthiana (Neitlich or C5 variant)
Homozygous Atypical can delay recovery of muscle strength for how long?
5 to 6 hours
Heterozygous Atypical can delay recovery of muscle strength for how long?
5 to 25 min.
May be unrecognizable
What are the normal ranges for the following?:
- Cholinesterase activity?
- Dibucaine number?
- Fluoride number?
Normal levels:
- Cholinesterase activity
- 60 to 200 units
- Dibucaine number
- 75 to 85
- Fluoride number
- 55 to 65
What is the presenting sign for Factor VIII Deficiency in neonates?
What about in infants?
Neonates: Bleeding from umbilical cord
Infants: Bleeding after circumcision
What is the most common endocrine disorder of childhood?
DM
Symptomatic hyperglycemia (ketoacidosis) may have an abrupt onset and mimic what condition?
Appendicitis
- Abdominal pain
- Leukocytosis
T/F
Hyperglycemia is associated with increased wound infection.
T
In a child with DM, and coming in for a brief procedure, when should the surgery be scheduled?
As early as possible in the morning
Before surgery, in a pt with DM, how much insulin should be administered?
1/2 to 2/3 the usual dose of insulin.
Intermediate only.
NOT Short-Acting
For brief procedures (<1 hour), in a DM patient, start an infusion of 5% glucose containing solution and infuse at (3 to 4 ml/kg/hr) a maintenance rate unless the blood glucose is less then?
Less than 5 mmol/L (90 mg/dl)
- In which case, the rate should be increased
Prolonged procedures (> 1 hour) in a patient with DM, what is the preferred technique for maintence fluids?
Infusion of insulin
PLUS
Infusion of dextrose
How would you mix a bag for insulin infusion?
How much would you infuse per hour?
Add 50 u of reg insulin to 500 ml saline
(0.1 unit/ml)
- Saturate insulin binding sites in IV tubing with 50 to 100 mL
Infuse 1 ml/kg/hr
(Delivers 0.1/kg/hr)
When infusing a 5% glucose solution in a procedure lasting > 1 hour, the rate would be adjusted to maintain glucose level at…?
5 to 10 mmol/L (90 to 180 mg/dl)
In a pt with ketoacidosis and emergency surgery, which lines should be placed to assist in correcting hypovolemia and hyperglycemia?
CVP
A-line
In a patient with ketoacidosis, the goal is to reduce the gluce level how much per hour?
100 mg/dl each hour
T/F
In correcting ketoacidosis, hypokalemia is expected
In a patient with Ketoacidosis, sodium bicarb can be used when…?
Severe acidosis occurs
(pH < 7.0)
Subclinical brain swelling occurs during the treatment of ketoacidosis and total fluid administration be limited to…?
4 L/m2/24 hr
In a child with malignancy, What can occur if dexamethasone is administered?
Tumor lysis syndrome
- Metabolic disorder
Characterized by:
- hyperkalemia
- hypocalcemia
- acute renal failure
T/F
Respiratory infections, chronic sinus infections, and ear infections are common in Down syndrome.
T
T/F
With trisomy 21, Thyroid hypfunction and subglottic stenosis is common.
With Trisomy 21, what abnormalities are common with the radial arteries?
Single median artery is common
What is presently the “gold standard” for diagnostic test for MH?
Caffeine-Halothane test
T/F
An increase in temperature of more than 1 C, is an early sign of MH
F
It is a late sign
- Prognosis is much more favorable MH is recognized early and dantrolene is administered before significant increase in temp occurs
MH treatment?
- Discontinue all inhalationals, send for help!
- 100% O2
-
Dantrolene
- 2.5 mg/kg IV
- 1mg/kg Q5 min. as needed
- If DANTROLENE not available, or if arrythmias persist, give:
- Procainamide
- 1mg/kg/min up to 15 mg/kg
- Sodium Bicarb (7.5%) 4ml/kg IV
- Mannitol 0.5 g/kg
- Active coolong
- Insert A-line, CVP, foley
How to treat hyperkalemia in MH?
Give
0.15 u/kg of reg insulin
with
0.5 g/kg of glucos
During MH, why should you maintain urine output at 1 ml/kg/hr?
to prevent
rhabdomyolysis - induced renal failure
T/F
Calcium channel blocker agents are considered during MH
F
They interact with dantrolene and produce prfound myocardial depression
and
No therapeutic role
What is a disorder charcterized by:
- Fever
- Muscle rigidity
- Tachycardia
- Autonomic instability
in patients taking antipsychotic medication
Neuroleptic Malignant Syndrome
T/F
40% of children with spinal bifida have latex allergy
T
due to number of surgerie and exposure to latex
The signs of latex allergy, usually develop in how many minutes after the induction of anesthesia?
30 to 200 min.
T/F
Allergy to chestnuts, bananas, avocado, and kiwi places you at risk for latex allergy?
T/F
In patients with crebral palsy, GERD is common
T
T/F
Latex allergy is common in children with cerebral palsy
T
T/F
When providing anesthesia to a child with CP, careful administration of succinylcholine should be taken in order to prevent hyperkalemia
F
Succ does not induce hyperkalemia in children with CP
What happens to the MAC of inhaled anesthetic agents in a child with CP?
20% decrease
Are children with CP prone to hypothermia?
Yes
T/F
In a patient with a transplanted heart,
coronary artherosclerosis is accelerated and ischemia may occur without pain
T
