Course VCSN630

Neonatology and Intensive Care Medicine

Clinical Problems 2017 

 

Instructions: Attached are clinical problems which should be completed by all students taking Course VCSN630. This is an open-book learning exercise. You are allowed to use any resource you can find, except other students. This should reflect your effort only. You may work together in groups studying the material but not in answering these questions. It is often evident when students work in groups to answer these questions since they all have the same incorrect reasoning even though they vary the wording of their answers.

Please type your answers and submit your problems as an attachments emailed to jepalmer@vet.upenn.edu.

Deadline: The deadline for emailing the completed exercise is

Friday, July 14th. The deadline for turning in the take-home clinical problems will be firm. Except under the most unusual circumstances, 1 point will be deducted for each day passed the deadline that the examination reaches Dr. Palmer. If you feel that your summer activities might prevent you from being able to email your completed problems by July 14 you must contact me by June 15 to request an extended deadline.

 

CASE 1You have been asked to consult on a case of a late term pregnant mare suffering from laminitis. She has had 5 foals previously without notable problems. Her gestational length has varied from 358 to 365 days. The cause of the laminitis is not clear, but on your examination and laboratory investigations, no other problems are identified.

As part of the analgesic therapy, she is placed on a constant intravenous lidocaine drip. Because of a mistake in mixing the solution, the mare receives an overdose which results in prolonged seizures. You realize that during such a seizure both the mare’s Pao2 may fall significantly.

 

How will the fetus be affected by the drop in maternal Pao2?

Seizures induced by lidocaine can be prolonged. How could the mare be treated during this seizure to minimize any adverse effect on the fetus?

 

After the mare stops seizing, name 2 ways you could try to determine the fetus’ health.

1.

2.

Another clinician on the case comments that since the mare is on day 336 of gestation, and is "now due," and labor should be induced so that the mare doesn’t have the extra weight of the pregnancy to compound her laminitis pain. Why don’t you believe that the foal is due and if delivered now may be very premature?

What physical examination finding(s) could help you determine if the mare is ready to foal soon?

 

You are writing orders for the nursing assistants (lay assistants) to watch for signs of foaling. Name 3 signs that you could include that would indicate that the mare is in stage I labor:

 

1.

2.

3.

 

It is decided that it is inhumane to continue with the mare because of the severity of the laminitis. A terminal Cesarean section is performed. The foal is delivered via Cesarean section at 10:17 a.m. The delivery is very rapid and occurs minutes after general anesthesia is induced in the mare. The foal is quickly transported to the neonatal intensive care unit (this takes less than one minute from the delivery time).

Once in the NICU you find that the foal is not breathing, has a heart rate of 36, has no body tone and is not responsive to stimulus as he is rubbed with towels to dry him. You establish an airway and ventilate with O2. Your treatment induces an increase in the foal’s heart rate to 90 and a positive response. An intravenous catheter is placed and drugs are given to help reverse effects of the anesthetics that had been given to the mare. The foal is also placed on intravenous fluids.

You do a blood pressure and find: systolic = 83; diastolic = 42; mean = 53; heart rate = 93. Are these pressures too low?

Soon after your manipulations the foal begins to breathe spontaneously and there is normal muscle tone. The foal is able to hold his head up when placed in a sternal position and was aware of his surroundings.

His birth blood work is as follows:

 

WBC 1600 Na 131 mEq/l

Segs 82% K 4.38 mEq/l

Bands 4% Cl 98 mEq/l

Lymphs 14% Cr 18.2 mg/dl

Fibrinogen 168 mg/dl Glucose 21 mg/dl

pH 7.174 O2 Saturation 66%

Paco2 66 torr O2 Content 12.7 ml/dl

Pao2 24 torr Lactate 5.9 mmol/l

HCO3 21

BE - 4.9

 

What is the significance of the creatinine level?

Based on the blood work, name 2 additional therapeutic interventions which should be initiated.

 

1.

2.

 

On physical examination you find the foal has a fine hair coat, scleral hemorrhages, aural petechia, excessive flexor tendon laxity, poorly developed ear cartilages, umbilical bleeding, hyperemic coronary bands, and loose joint ligaments. He is also somnolent, has poor body tone and does not stay sternal without a lot of help. He has no suckle and often holds his tongue out to one side of this mouth. You also note that he is much smaller than expected, weighing 66 lbs.

 

By 4:00 p.m. the foal developed seizure-like activity accompanied by uncontrolled marching type of behavior.

What could be given to immediately control the seizures?

What could be given if the seizures become consistent?

Why do the seizures need to be controlled?

The blood pressure drops (S69/ D33 Mean 41) and glucose remains low (54 mg/dl). The foal also remains hypothermic (Temp 97.3 F)

 

 Name 4 signs seen in this case which indicate that the foal could be premature.

 

1.

2.

3.

4.

Name 4 signs seen in this case which indicate that the foal could be suffering from Neonatal Encephalopathy.

 

1.

2.

3.

4.

Name 4 signs seen in this case which indicate that the foal could be septic.

 

1.

2.

3.

4.

What could you do to try to prove that the foal has bacterial sepsis?

 Name 3 problems the foal has which make it contraindicated to tube feed with colostrum.

1.

2.

3.

What might happen if the foal is tube fed with a large quantity of colostrum?

You decide to place the foal on TPN. You choose to start him on 10 gm/kg glucose + 2 gm/kg amino acids + 1 gm/kg lipids. In the pharmacy you find 50% glucose solution, 10% amino acid solution, 10% lipid solution and a large (3 liter) empty IV bag. How much of each solution should you place in the bag for a 24 hour supply?

 

50% glucose: mls

10% amino acids:

mls

10% lipids: mls

 

This mix should run at _____ ml/hr. It will deliver ______kcal/kg. The normal growing foal should receive ____ kcal/kg/hr.

By 8:00 p.m. that evening the foal’s lung sounds have become moist and the foal has not passed any urine since birth which, considering the fluids being given, suggested a problem with renal function.  

By 10:45 p.m. the foal’s respiratory efforts had become labored and there were more moist lung sounds. The foal is on an intranasal O2 flow of 6 lpm. An arterial blood gas sample shows:

 pH 7.073

Paco2 92.4 torr

Pao2 87.8 torr

HCO3 28.4

BE - 1.6

O2 Saturation 92%

O2 Content 13.4 ml/dl

 

Characterize the acid/base abnormality:

.

You decide to ventilate the foal. Is there any other option which might be effective?

The foal is placed on a volume-cycled ventilator. The initial parameters are as follows: Tidal volume 210 ml; respiratory rate 22; FIO2 0.40; PEEP 4. After 20 minutes another arterial blood gas shows:

 pH 7.151

Paco2 84 torr

Pao2 135.8 torr

HCO3 29.2

BE - 0.3

O2 Saturation 99.2%

O2 Content 14.4 ml/dl

Capnograph 70

Peak inspiratory pressure

32

Plateau pressure 28

 

Why did the O2 content only rise 1 ml/dl despite the fact that the Pao2

rose from 87.8 to 135.8 torr?

 

What is the alveolar dead space ventilation?

What does this value mean?

 

What is the dynamic compliance (calculated value)?

What is the static compliance (calculated value)?

What does having a difference between the 2 compliance values mean?

 

Name 2 adjustments to the ventilator which can be done to treat the persistent hypercapnia:

1.

2.

After making your adjustments to correct the hypercapnia, you run another arterial blood gas and find:

 

pH 7.191

Paco2 57.2 torr

Pao2 123.8 torr

HCO3 22.1

BE - 5.9

O2 Saturation 97.6%

Capnograph 55

 What new abnormality is evident from the arterial blood gas?

At approximately 4:30 a.m., the foal develops more profound hypotension with a drop of his blood pressure (S59/D32 M38). You initiate industrial strength pressor therapy (dobutamine + norepinephrine) but this only increases blood pressure modestly. Two hours later you run another arterial blood gas and find:

PH 6.915

Paco2 121 torr

Pao2 228 torr

HCO3 24.9

BE - 7.1

O2 Saturation 99%

O2 Content 13.6

Capnograph 43

What is the alveolar dead space ventilation now?

Why did it change so much?

Why would it be a bad idea to treat the metabolic acidosis with NaHCO3?

The foal had been on an FIO2 = 1.0 for a half-hour before the last blood gas was taken. The other NICU resident says that this foal must have a congenital cardiac abnormality and a large right to left shunt with almost no blood passing through the lungs. Do you think the other resident is correct?

Yes/No

During the next 8 hours we tried a variety of therapies to increase his blood perfusion of his lungs and other tissues. He became more difficult to ventilate and his lungs began to fail because of retention of fluids. He developed pulmonary edema and he was intolerant of the intravenous feedings with very high blood sugar levels and lipid levels despite the constant infusion of insulin. Despite all of our efforts the situation was hopeless. The foal was euthanized.

 

 

Case 2The next case is a 15 hour old foal. The history includes that the mare has had at least 4 foals. Last year's foal was 2 weeks early but alright. Two weeks ago the mare began to make an udder. Her reported due date is 32 days away. The foal was found at about 7 AM this morning still wet (mare last checked 4:30 AM). The foal is reported to be large and strong but unable to stand except for seconds at a time. The foal was fed 24 ounces of colostrum via nasogastric tube at 9 AM, 1 PM and 5 PM. The foal had a suckle but it was not effective so the foal was tube fed. What suckle there was, he was losing. Has been hypothermic all day. He was referred for further evaluation and intensive care.

The foal arrived at approximately 9:50 p.m. in the front of a car after a 5 hour ride. The foal was very cold and only minimally responsive. He was transported to the NICU, and his body temperature was found to be 95.6 F. He had ice cold legs, no peripheral pulses, dry mucous membranes, and severe entropion with sunken eyes. His mucous membranes were pale and muddy with splotchy areas of hyperemia. He had no oral, aural, or scleral hemorrhages. Initially, his blood pressures were too weak to obtain an arterial blood gas or to record noninvasive blood pressures.  He had a short hair coat, poor ear cartilage development, aural petechia, icterus, mild dome to head, incisors erupted, was weak, had an intermittent suckle, abdominal distension, gassy borborygmi, gassy palpation to bowel, the presence of fetal diarrhea and on passing a nasogastric tube hemorrhagic reflux.

Admission blood work:

WBC 671 Na 133

Segs 70% K 3.54

Bands 15% Cl 86

Lymphs 15% Cr 3.11

Fibrinogen 198 Glucose Too low to measure

PCV 39% IgG 40 mg/dl

T.P. 4.9

What clinical sign makes the history of prematurity with a gestational age of 310 days questionable?

You decide the foal is in septic shock.

 Name 3 findings of your physical examination which support the diagnosis of shock:

1.

2.

3.

Name 2 laboratory findings which support the diagnosis of sepsis:

1.

2.

Name 3 things you would do to treat the shock:

 

1.

2.

3.

 After your initial treatment his legs began to warm. Now you would like to treat the suspected septic origin of the shock. Name 2 ways you could do this:

1.

2.

 

You decide to treat the hypoglycemia by placing the foal on a 10% dextrose solution. The foal weighs 132 lbs on admission. A reasonable initial fluid rate for the 10% dextrose which would deliver enough dextrose to equal what is usual delivered to the fetal foal through the placenta:

Would this result in enough fluids to meet maintenance fluid needs for this foal (after the foal is rehydrated)?

After you initiate your therapy, you are able to obtain an arterial blood gas. The results (on room air) are as follows:

 

pH 7.436

Paco2 54 torr

Pao2 37 torr

HCO3 36

BE +11.5

O2 Saturation 75%

O2 Content 10.0

What is the acid base abnormality?

  

Name 3 things you could do to correct the hypoxia:

1.

2.

3.

You place the foal on intranasal oxygen. If you begin using an oxygen flow rate of 10 lpm. After 10 minutes, you take another ABG and find:

pH 7.459

Paco2 54 torr

Pao2 268 torr

HCO3 38

BE +13.6

O2 Saturation 100.0

O2 Content 12.8

What does the Pao2 tell you about the pathophysiology going on in the foal?

During the night, the foal’s condition deteriorated markedly. The foal appeared to have severe sepsis. The foal was placed on a ventilator with an Fio2 = 1.0. After 20 minutes, the following arterial blood gas was obtained:

 

pH 7.096

Paco2 55 torr

Pao2 68 torr

HCO3 17.1

BE -12.1

O2 Saturation 85.8

O2 Content 13.1

Capnograph 39

What is the alveolar dead space ventilation?

 What does the Pao2 of 68 torr suggest about the pathophysiology of the hypoxia now?

 

The foal was placed on NO at 8 ppm in the inhaled gas. An arterial blood gas was repeated after 30 minutes and showed:

 

 

pH 7.101

Paco2 61 torr

Pao2 114 torr

HCO3 18.9

BE -10.1

O2 Saturation 96.3

O2 Content 13.8

Capnograph 60

 

Why did the Pao2 improve with the addition of NO?

What is the alveolar dead space ventilation now?

Why did the alveolar dead space ventilation decrease with the addition of NO?

The foal became hypotensive (S43/D22 M26 and HR = 80 bpm). His urine production has been less than 10% of that expected. His hypotension was treated through intravenous vasopressin and norepinephrine. This treatment resulted in a transient but dramatic increase in blood pressure (S96/D58 M74 and HR = 94). Despite this, the foal became anuric. Why did this happen?

The blood pressures began to fall again within 2 hours. The foal began to develop pulmonary edema and fluid began to appear in the endotracheal tube. It became difficult to measure his blood pressures with our indirect methods, and he had begun to develop progressive abdominal distention probably associated with necrotizing enterocolitis. Despite our intensive efforts the foal was not responding to therapy and was euthanized.

 

 

Case 3The next case is a full-term foal born to a multiparas mare. The mare did not appear ready to foal and ended up foaling in the field at 11:30 AM yesterday. The foal was immediately brought into the barn. She nursed small amounts off the bottle but never found the teat and was never well coordinated. By eight this morning (20.5 hr old) it was noted that the foal would often lose her balance and cross her legs. She had been getting up on her own but she became weaker and not able to rise.

The foal arrives down in the van but is quite active. The foal's oral mucous membranes were splotchy and muddy. You decide to place the foal on intranasal O2 before completing your examination because of the appearance of the mucous membranes.

After beginning the intranasal oxygen the foal gained strength. On further examination you find that there are no oral, scleral or aural petechiae. But the foal has hypertonus, clonic/tonic seizures, muscle weakness and has become poorly responsive with somnolent periods during which she is not arousable. She also has abdominal distension with retained meconium.

She has somewhat labored breathing (respiratory rate 48), but only mild nostril flare. The foal is somewhat thin but has a normal hair coat and good ear cartilage development and no excessive joint laxity. Her left hind fetlock is moderately contracted with fetlock and P1-P2 involvement. She has good peripheral pulses, and her feet and ears are warm.

 

Initial laboratory analysis:

WBC 2,440 Na 133meq/l

Segs 55% K 3.8 meq/l

Bands 3% Cl 97 meq/l

Lymphs 41% Cr 1.34 mg/dl

Monos 1% Glucose 138 mg/dl

Fibrinogen 641 IgG 460 mg/dl

What does the WBC and differential tell you?

How can you tell that this problem began in utero?

What does the IgG level tell you?

Name 2 ways you could try to correct the problem indicated by the IgG level.

1.

2.

How can you tell if the treatment you chose worked?

By the next morning, the foal’s attitude had improved and she appeared to be doing well. You have been giving her intravenous dextrose overnight, but now want to begin oral feeding. However, the foal has no meaningful suckle. How can you feed her enterally?

You decide to begin by giving 10% of her body weight in milk per day. How much should you feed the foal every 2 hours to reach this goal?

How many kcal/kg/day will this provide?

Name 2 ways you could treat the hind leg fetlock contracture.

1.

2.

 

During the first few days of her hospital stay she had an improved attitude and strength with periods of more normal activity. She did search and was very responsive to her surroundings but had no suckle. Although she had a very active search reflex she only had a licking motion with her tongue and never meaningfully suckled.  

By Hospital Day 4 she was being fed 20% of her body weight because of lack of weight gain. How many kcal/kg/day is she being fed?

Healthy foals usually gain weight at this level of nutrition. But, there was no weight gain on this level of nutrition. Why not?

 

 On Hospital Day 6, she was noted to have gained weight and her contracture was improving, however, she still had no meaningful suckle response. On Hospital Day 11, the filly nursed off the mare several times and appeared to be suckling well enough to receive some milk. By the next day, the foal began to nurse off the mare and she was discharged on Hospital Day 15.

 

Many of this foal’s signs can be explained by diagnosing NE and sepsis. Name 2 signs consistent with a diagnosis of NE.

1.

2.

Name 2 signs that can be explained by sepsis:

1.

2.

 

Normal Laboratory Values

(only for the purpose of these clinical problems)

 

Normal Values at Birth

WBC 6-10,000 Na 130-142 meq/l

Segs 60-80% K 3.6 – 4.2 meq/l

Lymphs 40-20% Cl 98 – 104 meq/l

Monos 0-5% Cr 2.0-3.0 mg/dl

Fibrinogen 100-150 mg/dl Glucose 55-110 mg/dl

pH 7.35 – 7.45

Paco2 45 – 60 torr

Pao2 70 – 98 torr

HCO3 24 – 29

BE - 2.0 - +2.0

O2 Saturation 92-99%

O2 Content 12.5 – 15.5 ml/dl

 

Normal Values 48hrs to 1 week

WBC 6-10,000 Na 130-142 meq/l

Segs 60-80% K 3.6 – 4.2 meq/l

Lymphs 40-20% Cl 98 – 104 meq/l

Monos 0-5% Cr 0.80 – 1.1 mg/dl

Fibrinogen 250 – 360 mg/dl Glucose 80 - 110 mg/dl

pH 7.35 – 7.45

Paco2 45 – 50 torr

Pao2 80 – 98 torr

HCO3 24 – 29

BE -2.0 - +2.0

O2 Saturation 92-99%

O2 Content 12.5 – 15.5 ml/dl