Septic neonates Flashcards
Normal gestation
- 320-360 days
- Average is 340 days
- Mare will typically foal close to the same date with each foal
What can cause gestation in mares to be longer?
- Mares carry colts
- Mares bred early
- Older mares
Last 48 hours of gestation
- Development is critical in foals in the last 48 hours
What signals readiness for birth?
- The HPA axis of the foal
- This is why you cannot induce the mare
What influences organ development in the foal?
- Steroid influence
- Another reason why induction of parturition not recommended
What are the three stages of fetal maturation development?
- Premature
- “Twilight”
- “Ready for birth”
Premature foals
- generally <310-320 days
- Immature adrenal axis
- Poor or no response to ACTH
- Low white cell count
“Twilight foals”
- 320-330 days
- Intermediate hormonal development
- Intermediate WBC counts
- Intermediate ACTH responsiveness
“Ready for birth” foal
- Mature
- Fully active and responsive adrenal axis
- Normal WBC count
How can you tell is a mare is close to parturition?
- Tail head relaxation
- Relaxation of the perineal area
- Relaxation of the pelvis
- Softening of cervix
- Development of mammary glands
- “waxing”
Milk electrolytes close to parturition
- Calcium >10mmol/L
- Potassium >35 mmol/L
- Sodium <30 mmol/L
Parturition stage 1 length of time
- 1-4 hours
Parturition Stage 1 neonatal position
- I think it rotates so that the head is down with both legs forward
Parturition Stage 1 “Pseudo colic”
- Flehman response
- Pawing
- Looking at flank
Stage 2 parturition
- Rupture of chorioallantois or breaking water
- Expulsion of the foal
How long should Stage 2 last?
- Up to 45 minutes, but average is 20 minutes
- NEED to set a timer; if it takes longer than this, there’s a problem
Stage 3 parturition
- Expulsion of fetal membranes
How long should stage 3 parturition take?
- No longer than 3 hours
What happens if stage 3 takes longer than 3 hours?
- Retained
What are risk factors for retained placenta or longer time?
- Dystocia or C-section
What can happen if fetal membranes stay in too long?
- Mare can get extremely toxic
- Probably put them on antibiotics
What’s normal in the first 5 minutes after birth?
- life head, alert, sternal, suckle, reflex
When should the foal be standing by?
- 1-2 hours
When should the foal be nursing by?
- 2-4 hours
When should a feeding pattern be established?
- 12 hours
- Usually nursing 7-10 times an hour
What is the HR of a foal at birth?
- 60-80 BPM
What is the HR of a foal 1 hour after birth?
- Increases to 100 at 1 hour
What is the HR of a foal by 12 hours after birth?
- 80-120 bpm by 12 hours
When should you do a physical exam of a foal?
- Between 12 and 14 hours of age
What should you assess on a physical exam of a foal? (3 very important factors)
- Mental status of the foal
- Attachment to the mare
- Nursing well
Neurologic status of a foal
- Awake
- Somnolent
- Stuporous
- Comatose
- Seizures
- Focal
- Generalized: interval, duration, status epilepticus
Mucous membranes on a foal
- Pale, cyanotic, icteric, petechiations, ecchymoses
What does it suggest if a newborn foal has icteric mucous membranes?
- Herpesvirus
Where can you assess mucous membranes of a foal for petechia and echymosis?***
- vulva
- Ears
- Gums
CHECK ALL OF THESE PLACES
Respiratory system exam on a foal
- Auscultation
- Palpation for rib fractures
- Ultrasound
- Radiographs
Cardiovascular system exam on a foal
- Mucous membrane color and refill
- Auscultation
- Heart rate
- Murmur (PDA up to 7 days)
- Arrhythmia
- Pulse quality
- MAP >60 mmHg
What should the 1 minute post foaling temp be?
- 99-100F
What should the 12 hour post foaling temperature be?
- 100-102F
When should you suspect a problem for foaling temperature at 12 hours post foaling?
- Below 100 or above 102
Umbilicus examination
- Palpate for abnormalities
- Dip with dilute chlorhexidine
- Ultrasound
Ultrasound findings of the umbilicus
- Stump <2 cm
- Vessels <0.5 cm
- Urachus (don’t want to see it patent)
Potential problems with umbilicus
- Infection
- Hernia
- Patent urachus
- Urachal rupture
Urinary tract exam in foals
- intact bladder
- Can rupture during parturition
- Colts more likely than filly
Why are colts more likely to have a bladder rupture during parturition?
- Narrow pelvis
- Often have a full bladder when born, and colts have a big bladder going through their narrower pelvis
When should colts typically urinate by?
- 6-8 hours of age
When should fillies typically urinate by?
- 12-14 hours of age
- Often expelled as it was born
GI tract exam in a foal
- Meconium (do they have tiny black feces?)
- Diarrhea
- Abdominal distension
When should meconium pass by?
- 12-14 hours after parturition
Reproductive tract exam in a foal
- Scrotal hernia
- Inguinal hernia
- Congenital vs ruptured tunic
Ophthalmology exam on a foal - why important?
- Septic foals often have a problem with the eyes
Ophthalmology exam on a foal possible findings
- Entropion (dehydration)
- Corneal ulcers
- Periocular trauma
- Uveitis
- Congenital
- Cataracts**
Musculoskeletal exam findings on a foal
- Flexural deformities
- Joint effusion - always palpate
- Angular limb deformities
Immaturity/dysmaturity signs
- Floppy ears
- Tendon laxity
- SIlky hair coat (if immature, premature, or dysmature)
- Carpal and tarsal bones lack of ossification
What does prognosis depend on carpal and tarsal bone ossification?
- How well ossified they are
- She will often take an x-ray pretty quickly to get a sense of prognosis
Dysmature foal
- Dysmature if it’s 340 days or older and has characteristics of floppy ears
Normal PCV for a foal
- 34-44% at birth
What happens to the PCV of a foal over the first week?
- Decreases over the first week
What is suggested if the PCV of a foal is >45% when born?
- May indicate in utero hypoxia
What are two differentials if a foal is anemic?
- Neonatal isoerythrolysis
- blood loss (when foals are born, they can bleed for awhile from the umbilical site)
Normal TP at birth
- Less than 5.0g/dL
What should happen to TP after birth?
- Increases with passive immunity
What is suggested if TP and globulins are high at birth?
- In utero infection
What is suggested if the TP is low at 12-14 hrs after birth?
- Failure of passive transfer
- Protein loss through GI or kidney
Hematology of a foal with in utero infection?
- Leukocytosis
- Neutrophilia/neutropenia
- Band neutrophils
- Lymphopenia
- Fibrinogen should normally be less than 200g/dL
What is suggested if fibrinogen is greater than 200g/dL?
- In utero infection
Biochemistry panel “normal” elevations
- Alkaline phosphatase can be normal up to 2835 for a few weeks
- Bilirubin may go as high as 5.5mg/dL due to lysis of foal erythrocytes in first week of life
- Phosphorus elevation (growing)
Biochemistry panel “abnormal” elevations
- Creatinine
- Elevated BUN
- Lactate
What is suggested if the foal has an elevation in creatinine?
- Consider placental insufficiency
What is suggested if the foal has an elevation in BUN?
- Consider protein catabolism from starvation in utero
- Mare had colitis or something
What is suggested if the foal has an elevation in lactate?
- Watch trend
- Problems with perfusion and utilization
- Not too concerned if high at birth but goes down
What is the most common problem in neonates?
- Neonatal septicemia
Morbidity rate of neonatal septicemia
- High
What factors are key to success of treating neonatal septicemia?
- Early ID and management
Risk factors for neonatal septicemia
- FPT or partial FPT
- Perinatal stress
- In utero hypoxia
- Prematurity
- Poor management: unsanitary conditions, poor ventilation, exposure to primary pathogens
Neonatal risk factors for septicemia
- Stress
- Prematurity/dysmaturity
- Prolonged gestation
- Twin gestation
- Meconium staining
- FPT
- Perinatal asphyxia syndrome
Maternal risk factors for septicemia
- Old age (colostrum not good)
- Illness
- Colic
- Loss of colostrum
- Stress
- Prolonged gestation
- Dystocia
- Poor nutritional status
In utero infection CBC findings
- Leukocytosis and high fibrinogen at <24 hours
- Some foals born from dams with placentitis may not be septic but will have elevated WBC count for 2-4 days
In utero infection signs
- +/- uveitis
- changes on CBC
- May be slightly premature or thin as a result of inflammatory cytokines (IL-1, IL-6, TNF)
What is usually the etiology of in utero infections?
- Bacterial placentitis usually the etiology
Treatment of SIRS of Sepsis in the fetus
- Influence development of SIRS in the fetus by treatment of the mare and placental inflammation
- Antimicrobials
- Pentoxyfylline
- NSAIDs (flunixin meglumine or Firocoxib)
- Altenogest
- Antioxidants (Vitamin E)
Pentoxyfylline
- Drug used for laminitis
- Makes red cells more flexible
- Decrease production of IL6, IL1, TNF
Altenogest function
- Decrease myometrial response
- Progesterone
What two events must have occurred for a postpartum infection to have occurred?
- Exposure to microbes
- Defense response inadequate
Environmental risk factors for postpartum infections
- Nosocomial infections
- influence of antimicrobial agents altering flora
- Stall vs pasture - less incidence of diarrhea, same incidence of septicemia
immune risk factors for postpartum infections
- Failure of passive transfer
Organ dysfunction risk factors for postpartum infection
- Usually effect of perinatal asphyxia
- Weakness
- Abnormal intestinal motility
- Inadequate or abnormal nutrition
- Red bag (??)
Prevention of exposure to environmental pathogens
- Good management is most important
- Clean stalls
- Hygiene around foaling time
- Cleaning mare’s udder and perineal regions
- Umbilical care
Colostral management
- Checking mare to determine if adequate mammary development
- Testing colostrum
- IgG evaluation in foal
What should specific gravity of colostrum be?
- > 1.060
When should you perform IgG eval in a foal?
12-14 hours of age
What is considered adequate transfer of immunity?
- > 800 or >400
- Everyone agrees that <400 is inadequate
What influences production of colostrum?
- Produced under hormonal influence last 2-4 weeks of gestation
What does colostrum contain?
- Contains immunoglobulins (primarily IgG type) concentrated from mare’s blood as well as other factors important in immunity
Characteristics of colostrum
- thick, yellow sticky
When is colostrum replaced by milk?
- 12-24 hours after foaling
Special cells to absorb IgG in the neonate
- Neonate has specialized cells in the small intestine to absorb large molecules
How do neonates absorb antibodies?
- pinocytosis
- Not specific
When are the specialized cells replaced?
- by 36 hours of life
When is the peak of colostrum absorption?
- Shortly after initial ingestion
- Usually around 2 hours of age
When is the ability to absorb colostrum decreased?
- 6-8 hours of age
When is the ability to absorb colostrum gone?
- 18 hours
What is optimum amount of colostrum to absorb?
2-4 L
Colostrum replacement
- No replacement better than good quality, tsted colostrum
Colostrum banks:
Which antibodies does colostrum from a bank usually test negative for?
Which viral disease is screened out as well?
- Tested negative for Aa and Qa antibodies against a bank of RBCs
- From EIA negative donors
Oral supplements as substitute for oral colostrum
- Rarely achieve sufficient plasma levels of IgG
When does neonatal sepsis usually occur?
- Usually <7 days of age
- Can be later
Pathogenesis of sepsis
- Bacterial infection
- Can progress to Systemic Inflammatory Response Syndrome –> sepsis –> septic shock –> MODS –> DEATH
What do older foals tend to get instead of systemic sepsis?
- Localized infections
Onset of sepsis
- Variable but typically <7 days
When does acquired post natal sepsis usually occur?
- Typically 3-4 days of age
- Can see as early as 24 hours of age
What gram stain are most common pathogens in neonatal sepsis?
- Gram negative
- Can be mixed
When do Actinobacillus sepsis infections usually occur?
- 24-48 hours old
Most common Gram negative pathogens
- E. coli
- Klebsiella
Most common Gram positive pathogens
- Streptococcus
- Staphylococcus
- Less common overall
Recognition of sepsis in neonate early signs
- Septic until proven otherwise
- Early signs are weakness, somnolence, lethargy, decreased suckle
- Petechiae and microvascular injury
- Discolored mucous membranes due to poor microvascular flow
- Icterus as endotoxin impairs bile flow in the liver
- Hypotension/poor arterial pulses/cold peripheral skin
What is one of the most important signs of sepsis?
- DECREASED SUCKLE
What are five quick things to indicate of a foal isn’t suckling or dehydrated?
- Udder distension/streaming milk
- CRT
- Entropion
- Urine specific gravity (mare’s milk and colostrom often have low USG so should be <1.008 in the first 48-72 hours)
- Hypoglycemia
History of mare that would suggest neonatal sepsis
- Placentitis
- Vulvar discharge
- Dystocia
- Prematurity
CBC results in neonatal sepsis
- Leukopenia/neutropenia
- Left shift
- Toxic changes
Chemistry results in neonatal sepsis
- Hypoglycemia
- Elevated lactate
Blood culture results
- Isolation of microorganisms
- 26-28% in some NICU’s
- New study showed healthy foals can be bacteremic in the first 24-48 hours of life
Interpretation of positive blood culture?
- Iffy
- If they’re showing signs of sepsis, they are probably septic
Clinical findings of neonatal sepsis
- Fever/hypothermia
- Petechiae
- Scleral injection
- Obtundation/coma/seizures
- Anterior uveitis
- Diarrhea
- Pneumonia
- Swollen joints
Diagnosis of neonatal sepsis
- history
- Clinical signs
- Blood culture
- Radiographs
- Ultrasound
- Sepsis score
- Joint tap
Sepsis score categories
- History (peripartum events)
- Physical exam (signs of infection; foal’s condition)
- CBC (markers of sepsis)
- Chemistry panel
- Indicative of organ or systemic disease
- Helps understand parameters that indicate sepsis
- Helps predict likelihood of sepsis
What score on the sepsis score usually correctly predicts sepsis?
- Score of 12 or more
- not 100% by any means
Initial stabilization of septic neonates
- Heat (prevent hypothermia)
- Respiratory support: nasal oxygen, caffeine
- Eye care: correct entropion
- Fluid therapy: over the wire catheter (blood culture, give glucose, administer plasma)
- Control seizures with diazepam
Antimicrobial selection in septic neonates
- Broad spectrum combo
- Penicillin (Gram positive) + aminoglycoside (gram negative)
- Do not use nephrotoxic drugs if birth asphyxia suspected
- Ceftiofur alone or in combination
- Reserve advanced antimicrobial drugs (e.g. iminpenim) for severe sepsis and susceptibility known
Monitoring for nephrotoxic abx
- If creatinine is WNL you can use, but make sure you monitor it over time
- Pay attention to hydration and albumin concentrations
Adverse effects of antimicrobials
- Avoid nephrotoxic drugs
- Long term can alter normal microbiome
- Predispose to fungal overgrowth (Candida)
- Usually seen in very sick weak foals, not on normal nutrition
Nutrition of septic foals
- Enteral if possible
- If possible birth asphyxia consider parenteral nutrition
- Pass small bore nasogastric tube to be left in place
What % of body weight to healthy foals eat?
- up to 25%
What % of body weight should be given to septic foal initially?
- 10% of amount initially or less
Other nursing care considerations when feeding a septic foal
- Make sure in sternal
- Frequent feedings q2 hours
- Sick foals have a decreased RER
Treatment summary for septic foal
- Supportive care
- Fluid therapy
- +/- pressor
- +/- physiologic doses of corticosteroids
- Plasma
- Oxygen insufflation
- Antimicrobials
- Nutritional support
