Critical Care
Overview
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Damage Control
Resuscitation from Shock
Traumatic Brain Injury
Pulmonary System and Ventilators
Cardiovascular System
Renal System and Electrolytes
Hematologic System
Gastrointestinal System and Nutrition
Immune System and Infections
Endocrine System
Musculoskeletal System
Preparation for Evacuation
Damage Control
• Damage Control is the initial control of
hemorrhage and contamination followed by
intraperitoneal packing and rapid closure.
• Definitive re-exploration is then done only after
resuscitation to normal physiology in the ICU
• May include
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Rewarming
Large volume resuscitation
Blood products
Vasoactive drugs
Mechanical ventilation
Resuscitation from Shock
• Shock: acute state of cardiovascular insufficiency
leading to hypoperfusion
• Hemorrhagic shock is the most common cause of
shock in the trauma patient
• Hypoperfusion implies inadequate tissue delivery
to the tissues. Oxygen delivery depends on (and
resuscitation attempts should address):
– Cardiac function
– Arterial hemoglobin content
– Arterial oxygen saturation
Resuscitation from Shock
• Resuscitation Goals:
– Mean arterial pressure >60mmHg
– Urine output >0.5cc/kg/hr
– O2 saturation >92%
• Achieve these goals with crystalloid (preferred over colloid)
at a rate of 500-1000cc every 15-20 minutes as needed
• After 3L crystalloid, blood products should be given
• Vasoactive agents should be considered only after fluid
resuscitation and confirmation of adequate intravascular
volume
– Prefer dopamine, phenylephrine, norepinephrine
– Dobutamine should be used only for cardiac dysfunction
Traumatic Brain Injury
• Hypoxemia or hypotension can lead to death or
poor neurologic damage in the traumatic brain
injury patient
– Maintain O2 sat >92%, PaO2 > 100, intubate if GCS <8
– Maintain SBP > 100 mmHg, MAP >80
• Need to maintain cerebral perfusion pressure
(CPP) between 70-90mmHg
• Need to maintain intracranial pressure (ICP)
between 5-15mmHg
• CPP = MAP - ICP
Traumatic Brain Injury
• Hypoxemia or hypotension can lead to death or
poor neurologic damage in the traumatic brain
injury patient
– Maintain O2 sat >92%, PaO2 > 100, intubate if GCS <8
– Maintain SBP > 100 mmHg, MAP >80
• Need to maintain cerebral perfusion pressure
(CPP) between 70-90mmHg
• CPP = MAP - ICP
• Need to avoid intracranial hypertension.
Maintain intracranial pressure (ICP) between 515mmHg
Traumatic Brain Injury
• Measures to avoid intracranial hypertension
– Elevate head of bed to 30◦
– Check serum sodium twice per day and maintain between
145-150 mEq/dL
– IV mannitol 0.25-1.0 g/kg every 6-8 hours to keep serum
osmolarity optimal (but not in anuric patients)
– Control PaCO2 (avoid hypercarbia by therapeutic
hyperventilation to keep PaCO2 30-35mmHg)
– Avoid hyperthermia
– Intraventricular catheter to remove cerebrospinal fluid
– May consider barbiturates in extreme cases (benefit
unproven)
– Craniotomy as a last resort
Traumatic Brain I jury
• General Considerations
– Prophylaxis (H2 blocker, heparin) to prevent stress ulcers
and venous thrombosis
– Oral care to prevent aspiration
– Blood products as needed to correct elevated prothrombin
time
– Aggressively treat pain, agitation, fever, and shivering to
avoid increased cerebral metabolism and oxygen
consumption
– Hyperglycemia has an adverse effect. Maintain serum
glucose betwee 100-150 mg/dL
– Seizure prophylaxis with phenytoin or phosphenytoin
should be given to patients with penetrating head injuries
Pulmonary System and Ventilators
• Indications for intubation
– Airway obstruction due to trauma, edema, excess
secretions
– Apnea
– Increased work of breathing
– Glasgow coma scale <8
– Hypoxia despite supplemental oxygen: SaO2< 90%,
PaO2 < 60mmHg
– Hypercarbia: PaCO2 >60mmHg
– Shock
Pulmonary System and Ventilators
• Ventilator
– Most patients well ventilated by SIMV mode
(synchronized intermittent mandatory ventilation)
– Oxygenation
• Set FiO2 to 1.0 initially and wean down to 0.4 as able
• Set PEEP to 5 cm H2O for most patients or can increase if
needed (max 15 cm H2O)
– Ventilation (controls PaCO2)
• Set tidal volume between 6-10 mL/kg (increase if need to
lower PaCO2, decrease if need to raise PaCO2)
• Set rate between 10-14 breaths (increase if need to lower
PaCO2, decrease if need to raise PaCO2)
Pulmonary System and Ventilators
• ARDS (adult respiratory distress syndrome) defined by:
– PaO2/FiO2 ratio <200
– Decline in pulmonary compliance (“stiff lungs”)
– Bilateral alveolar infiltrates on chest X-ray withouth clinical evidence
of hypervolemia
• Ventilation priorities in ARDS
– Maintain sedation to prevent agitation and patient/ventilator
asynchrony
– Keep SaO2 > 90% by increasing FiO2 or PEEP (max 15-18 cm H2O)
– Avoid prolonged FiO2 > 60% (oxygen toxicity)
– Avoid respiratory acidosis (keep pH > 7.25)
– Keep peak inspiratory pressure < 40 cm H2O (decrease tidal volume to
6-8 cc/kg)
Cardiovascular System
• Causes of cardiovascular instability (the H’s and T’s)
– H’s:
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Hypoxia
Hemorrhage
Hypovolemia
Hyper- or Hypo- kalemia
H+ (acidosis)
– T’s
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Tension pneumothorax
Tachyarrhythmia
Thromboembolism
Tamponade
Toxins
Cardiovascular System
• Four measures of hemodynamic performance
– Preload: Best measured by pulmonary capillary
wedge pressure (PCWP) but can be estimated by
central venous pressure (CVP)
– Afterload: Systemic Vascular Resitance (SVR) =
[MAP – CVP]/CO*80
– Heart rate: Stroke Volume (SV = CO/HR)
– Contractility
Cardiovascular System
• Myocardial Infarction: uncommon on the battlefield
• Suspect if soldier complains of anginal chest pain
• Diagnose by ST elevation or depression on EKG,
elevation in cardiac enzymes (troponin, CK-MB)
• Treatment:
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Morphine
Oxygen
Nitroglycerin
Aspirin
B-blocker
Transfer for definitive treatment (revascularization by
thrombolytic or catheterization)
Renal System and Electrolytes
• Manifestations of renal injury/failure: low urine
output, electrolyte abnormalities, elevations in
BUN or creatinine
• Acute renal failure (ARF) defined as oliguria ( <
0.5 cc/kg/hr) and rise in BUN and creatinine
• Common causes of ARF:
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Hypovolemia
Acute tubular necrosis (ATN)
Crush injury resulting in rhabdomyolysis
Renal or ureteral trauma
Renal System and Electrolytes
• Treatment algorithm for oliguria or anuria in
hemodynamically stable patient
– Irrigate or replace Foley catheter
– If no signs of fluid overload, give 1-2L saline bolus
– Review medication list and discontinue any potential
nephrotoxins
– Check fractional excretion of sodium (FeNa)
• FeNa =(urine sodium * plasma creatinine)/(plasma sodium * urine
creatinine)
• FeNa < 1.0 indicates hypovolemia, > 2 indicates renal or postrenal
insult (ATN, obstructive uropathy, etc)
– Consider renal U/S
• If ineffective, consider dialysis.
Renal System and Electrolytes
• Indications for dialysis (Nemonic = AEIOU)
– A: acidosis
– E: electrolytes
– I: ingestions
– O: overload (Hypervolemia)
– U: uremia
Renal System and Electrolytes
• Hyperkalemia
– Give calcium carbonate to stabilize the cardiac
membrane
– Agents that lower serum potassium
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Sodium bicarbonate
Dextrose
Albuterol
Sodium polystyrene sulfonate
• Hypokalemia
– Check for hypomagnesemia and correct if present
– Give potassium chloride
Renal System and Electrolytes
• Hypernatremia: Need to replace free water deficit
– Free water deficit = 0.6 * weight in kg * [(measured
sodium/normal sodium of 140) – 1]
– Replace half of the deficit in the first 24 hours, the other
half over the next 1-2 days
• Hyponatremia: caused by excess of free water or SIADH
(syndrome of inappropriate anti-diuretic hormone)
– Treatment with either free water restriction if suspect
SIADH, otherwise treat by administration of saline
– Do not correct faster than 15mEq/L in 24 hours
Renal System and Electrolytes
• Hypophosphatemia: replete with sodium
phosphate or potassium phosphate
• Hyperphosphatemia: Usually associated with
acute renal failure. Treat with phosphate
binders such as sucralfate
• Hypomagnesemia: Give magnesium sulfate to
achieve serum level of 2.0 mEq/dL
Renal System and Electrolytes
• Metabolic acidosis: Usually due to lactic
acidosis (hypovolemia) or ketoacidosis
(diabetic). Do not give sodium bicarbonate for
these conditions, treat the underlying cause.
• Metabolic alkalosis: Caused by gastric losses
(vomiting or NG suction) or excessive diuresis
with furosemide. Usually treated with
crystalloid.
Hematologic System
• Coagulopathy
– Causes: dilutional, heparin induced
thrombocytopenia, disseminated intravascular
coagulation, hypothermia, liver failure,
thrombocytopenia
– Treatment: blood products
• Deep venous thrombosis and pulmonary
embolism: Prophylaxis important in trauma
patients (subcutaneous heparin and/or
sequential compression devices)
Gastrointestinal System and Nutrition
• Stress gastritis: give prophylaxis with H2 blocker or proton pump inhibitor
for the following conditions
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Burns
Mechanical ventilation
Head injury
Sepsis
Systemic anticoagulation
• Acalculous cholecystitis
– Suspect if right upper quadrant pain, fever, leukocytosis, liver function test
abnormalities, and ultrasound with thickened gallbladder wall and/or
pericholecystic fluid
– Treatment = IV antibiotics and percutaneous drainage or surgery
• Hepatic failure
– Suspect if hyperbilirubinemia, hypoalbuminemia, increased prothrombin time,
hypoglycemia, obtundation (hepatic encephalopathy)
– Give fresh frozen plasma to correct coagulopathy
Gastrointestinal System and Nutrition
• Early nutritional support important due to catabolism and
protein wasting associated with trauma
• Enteral feeding superior to parenteral
• Caloric requirements = 25-30 kcal/kg/day
• Protein requirement 1.0-1.5 g/kg/day
• 30-40% of daily caloric intake should come from fat
• Problems associated with enteral feedings include
aspiration and diarrhea. Prevent by:
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Increasing head of bed
Feed into jejunum or duodenum instead of stomach
Check residuals every 4 hours and stop feedings if >200cc
Add fiber and/or give anti-diarrheal medications such as
loperamide
Immune System and Infections
• Differential diagnosis of ICU infection:
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Pneumonia
Central venous catheter infection
UTI
Wound or soft tissue infection
Intra-abdominal abscess
Systemic fungal infection
Sinusitis
Acalculous cholecystitis
Pancreatitis
• Prophylactic antibiotics:
– Should be given for 24-48 hours after penetrating battlefield injury
– Should be discontinued after this unless documented infection present
Endocrine System
• Hyperglycemia:
– Must control to prevent hypovolemia due to
osmotic diuresis, increased risk of infection, etc.
– This is best done with IV infusion of insulin as
subcutaneous injections are less reliable in ICU
patients
– Do not correct faster than 100 mg/dL/hr to avoid
to avoid hypokalemia (insulin causes potassium to
shift intracellularly). Check K+ frequently and
replete as needed
Musculoskeletal System
• In patients with musculoskeletal injuries,
monitor for the following:
– Rhabdomyolysis
– Compartment syndrome
– Vascular ischemia
• Regular neurovascular checks essential. Check
for:
– Pulse, sensation, motor function, warmth, skin
color
Preparation for Evacuation
• Stabilize patient before transport
– Secure airway
– Ensure blood pressure has been stable for 8 hours
– Complete primary and secondary phases of shock
resuscitation
– Stop bleeding
– Ensure definitive surgery not required for next 24
hours