-
defined as any condition in which there is inadequate delivery of oxygen and nutrients to the tissues to meet metabolic demands
Shock
-
General signs/symptoms of shock
- mental status changes,
- acidosis,
- oliguria,
- poor cutaneous perfusion (cool, pale skin).
-
a function of the cardiac output and the oxygen carrying capacity of the blood
Oxygen delivery
-
divisions of shock
- failures of the heart,
- failures of the blood,
- failure the vessels
-
hemodynamic responses to compressive cardiac shock
- decreased cardiac output,
- increased heart rate,
- large increase in LV filling pressures
-
hemodynamic responses to cardiogenic shock
- large decrease in cardiac output,
- increase in filling pressures
-
hemodynamic responses to hypovolemic shock
- decreased cardiac output,
- increased heart rate,
- large decrease in LV filling pressure,
- increased systemic resistance
-
hemodynamic responses to septic shock
- increased cardiac output,
- increased heart rate,
- large decrease in systemic resistance
-
shock due to pump failure can be due to
extrinsic compression of the heart, or intrinsic heart failure
-
results when compression of the great veins or heart itself retards blood return to the heart
cardiac compressive shock
-
examples of cardiac compressive shock
- pericardial tamponade,
- tension pneumo,
- diaphragmatic rupture,
- positive pressure ventilation
-
With cardiac compressive shock, in addition to general signs of shock, physical exam reveals
- hypotension,
- distended neck veins,
- pulmonary rales,
- Kussmaul's sign,
- pulsus paradoxus
-
rise in JVP with inspiration
Kussmaul's sign
-
exaggerated decrease in systolic pressure with inspiration
pulsus paradoxus
-
definitive treatment for cardiac compressive shock
correction of the mechanical abnormality
-
can result from failure of the heart muscle, arrhythmia, valvular or septal defects, or excessive afterload
cardiogenic shock
-
Physical exam of a patient in cardiogenic shock may reveal
signs of compensatory volume overload: distended neck veins, pulmonary rales, extra heart sounds, peripheral edema
-
in cardiogenic shock due to inadequate pumping, improve pump function with
inotrope (dopamine, dobutamine), intra-aortic balloon pump
-
in cardiogenic shock due to excessive afterload, reduce afterload with
vasodilators (ACEI's and nitrates)
-
in cardiogenic shock due to arrhythmias, optimize heart rate and rhythm with
- beta-blockers,
- anti-arrhythmics,
- pacemakers
-
in cardiogenic shock optimize volume status by
being cautious with fluid administration, and use diuretics if in CHF
-
one of the most common causes of shock encountered in the practice of surgery
hypovolemic shock
-
Hypovolemic shock may be due to blood loss as well as from
- third spacing,
- protracted vomiting,
- diarrhea,
- sweat
-
the sequestration of fluid into injured soft tissues or bowel
third spacing
-
hypovolemia leads to
decreased venous return to the heart and decreased cardiac output
-
decreased venous return to the heart
preload
-
mild hypovolemia
- <20% blood volume loss-
- decreased pulse pressure,
- postural hypotension,
- cutaneous vasoconstriction,
- collapsed neck veins,
- concentrated urine,
- hemoconcentration
-
moderate hypovolemia
- 20-40% blood volume loss-
- thirst,
- tachycardia,
- moderate hypotension,
- oliguria
-
severe hypovolemia
- >40% blood volume loss-
- mental status changes,
- arrhythmias,
- ischemic EKG changes,
- profound hypotension
-
systolic pressure - diastolic pressure = __
pulse pressure
-
treatment for hypovolemic shock
- Large-bore IV.
- Resuscitation should always begin with crystalloid infusion—30 cc/kg (2 liters for most adults) as fast as possible then titrate against signs of clinical improvement.
- Blood products may be appropriate in situations of blood loss.
-
loss of venous tone results in
venous pooling with decreased blood return to the heart (preload) and decreased cardiac output
-
loss of arterial tone results in
decreased systemic vascular resistance (SVR) and hypotension.
-
neurogenic shock
is a failure of the autonomic nervous system due to spinal cord injury or regional anesthetics
-
injury above the level of __ results in a loss of sympathetic tone and adrenergic stimulation
T4
-
physical signs of neurogenic shock may include
warm, flushed skin, and bradycardia
-
in neurogenic shock the loss of venous tone is exacerbated by
the loss of muscle tone
-
treatment of neurogenic shock
- IV fluids are the initial therapeutic agent since loss of venous tone results in relative hypovolemia.
- Peripheral vasoconstrictors are often required
-
Septic shock is a complex phenomenon most commonly due to overwhelming infection from __ but can be due to any type of infection
gram negative bacteria
-
In early septic shock, the response is __
hyperdynamic with tachycardia and increased cardiac output
-
In late septic shock __
the cardiovascular system decompensates and progresses to a hypodynamic state
-
Early clinical manifestations of septic shock include __
fever, chills, bounding pulses, and warm, flushed skin in the setting of hypotension
-
signs of progression to late septic shock are __
Hypothermia, coagulopathy, pulmonary failure (ARDS), and renal failure
-
definitive treatment of septic shock
clearance of the offending infection (surgical debridement or resection, appropriate antibiotic therapy)
-
Potential indications for the transfusion of blood products
- the restoration and maintenance of normal blood volume
- the correction of severe anemia
- the correction of bleeding and coagulation disorders
-
effect of administration of one unit of PRBC's
Hct increase by 3%
-
effect of administration of one unit of platelets increases platelets county by __
40000
-
effect of administration of one unit of cryoprecipitate
increase in fibrinogen by 3%
-
indication for administration of PRBC's
hypovolemia + anemia, symptomatic anemia
-
indication for administration of platelets in the presence of bleeding
plts <50,000 plts <15,000 (asymptomatic)
-
indication for administration of FFP
- bleeding + coagulopathy,
- coumadin reversal
-
indication for administration of Cryoprecipitate
fibrinogen <100 mg/dL
-
platelets are given for the correction of
thrombocytopenia
-
indication for administration of platelets for asymptomatic thrombocytopenia
plts <15,000
-
a pool of platelets from six donors
six_pack
-
FFP is given for the correction of the __
vitamin K dependant clotting factors
-
FFP contains
- serum clotting factors (except VIII, and V),
- antithrombin III,
- fibrinogen,
- proteins C and S
-
is a plasma component that is enriched for high-molecular-weight proteins
Cryoprecipitate
-
is a plasma component that is enriched for fibrinogen, factor VIII, factor XIII, and von Willebrand's factor
Cryoprecipitate
-
occur when the recipient possesses antibodies against the donor RBC’s major (A, B, and Rh) or minor (Kell, Kidd, Duffy, et al.) antigens.
Hemolytic reactions
-
acute (major) hemolytic reactions occur at the rate of 1/__ units
20000
-
delayed(minor) hemolytic reactions occur at the rate of 1/__ units
500
-
symptoms of hemolysis
- apprehension,
- headache,
- fever,
- chills,
- flank or chest pain,
- hematuria,
- and (in severe cases) hypotension
-
Febrile nonhemolytic reactions may occur against
donor WBC's
-
Disease transmission due to transfusion
is a rare but real phenomenon
-
rates of CMV transmission from blood products __% unless CMV-negative requested
50
-
rate of HIV transmission from blood products
1/400,000-1/600,000
-
rate of Hep C transmission from blood products
1/3000-1/6000
-
rate of Hep B transmission from blood products
1/50,000-1/200,000
-
__due to the chelating action of the preservative sodium citrate can contribute to coagulopathy and should be corrected
Hypocalcemia
-
__ can be associated with multiple transfusions of PRBC’s.
Dilutional coagulopathy
-
Some hemolysis of cells occurs during storage and administration, delivering an additional __ load to the recipient
potassium
-
A __ device can filter blood collected during clean procedures and return it to the patient
“cell-saver”
-
Autotransfusion is an option for elective operations where significant blood loss is expected. The patient should ideally donate more than __ week prior to operation
1
-
most common congenital abnormality of platelets
von Willebrand's disease
-
five causes of shock
- cardiogenic,
- hypovolemic,
- septic,
- neurogenic,
- anaphylactic
-
MI, cardiomyopathy, valvular disease, rhythm disturbances, Pulm HTN, cardiac tamponade, tension PNX, diaphragm rupture (heart is compresed), PPV
Cardiogenic shock
-
hemorrhage, severe dehydration, vomiting, diarrhea
Hypovolemic shock
-
infection due to GNRs causing SIR, MOF, arterial vasodilation
Septic shock
-
Spinal cord injury above T4 results in loss of sympathetic tone/adrenergic stimulation, regional anesthetics
Neurogenic shock
-
hypersensitivity reaction
Anaphylactic shock
-
initial treatment for cardiogenic shock
- optimized volume status without overloading lungs,
- decrease afterload (ACEI, Nitrates),
- Heart rate control (betablockers, anti-arrhythmics, pacemaker),
- Inotropy (dobutamine, dopamine, milrinone, IABP, VAD’s, revascularization)
-
initial treatment for hypovolemic shock
fluid resuscitation
-
initial treatment for neurogenic shock
- vasoactive agents may be needed,
- use fluid cautiously (watch for non-cardiac pulmonary edema)
-
initial treatment for septic shock
- treat underlying cause,
- try to identify organism,
- start broad spectrum empiric therapy, then narrow down when you find out the specific organism
-
indication for administration of platelets as prevention before surgery
plts <15,000
-
most common reason for ABO mismatch
clerical error
-
every unit of blood you give __ the patient
immunocompromises
-
hypocalcemia can lead to
decreased cardiac contractility, increased bleeding
-
hyperkalemia in a transfusion patient can be due to
hemolysis
-
be cautious in transfusing patients who are __
immunocompromised (HIV, on steroids, organ transplant)
-
signs and symptoms of anemia
- fatigue,
- tachycardia,
- hypotension,
- mental sluggishness/disorientation,
- shortness of breath
-
__ reverses warfarin
FFP or Vitamin K
-
__ may need platelet transfusions no matter what the platelet count
bleeding patients whose platelets have been impaired by aspirin or NSAIDs
-
bleeding after cardiopulmonary bypass may be due to inadequate neutralization of heparin. Giving __ in this setting may worsen the bleeding because __ provides antithrombin III
FFP
-
microvascular bleeding often indicates a
platelet defect
-
__ impairs platelet function and can prolong bleeding
hypothermia
-
blood should never __
be infused with medications or solutions other than saline
-
__ may result in significant blood loss without obvious bleeding
extensive tissue injury
-
the first BP change seen in hypovolemia. when present it means class II hemorrhagic shock
increase in diastolic pressure
-
systolic hypotension is a sign of
class III hemorrhagic shock
-
agitation is another sign of
shock
-
profound hypotension and apathy are signs of
class IV hypovolemic shock
-
a normal 70 kg man has about __L of blood volume
5
-
Humoral host defenses
antibody, complement
-
ACT AS THE FIRST LINE OF CELLULAR DEFENSE
macrophages
-
cellular host defenses
macrophages, t-cells
-
What do cytokines do in infection
recruit macrophages
-
phases of wound healing-inflammation days __
1-10
-
epithelialization, PMNs & macrophages
inflammation phase of wound healing
-
proliferation phase of wound healing days __
5-3 weeks
-
neovascularization, collagen production, granulation tissue, fibroblasts
proliferation phase of wound healing
-
remodeling phase of wound healing weeks __
3 weeks - 1 year
-
type III collagen replaced by type I, collagen cross-linking
remodeling phase of wound healing
-
order of arrival of cells to wound
PLTs, PMNs, macrophages, fibroblasts, lymphocytes
-
organism from dog bites
streptococcus viridans
-
organism from cat bites
pasteurella
-
with animal bites consider
tetanus, rabies, Augmentin, cephalexin
-
uninfected operative wound in which no inflammation is encountered the respiratory, alimentary, genital or infected urinary tract is not entered
clean wound
-
Respiratory, alimentary, genital or urinary tracts are entered under controlled conditions, no unusual complications
clean contaminated wound
-
open, fresh, accidental wounds; operations with major breaks in sterile technique or gross spillage from the gastrointestinal tracteg. Gunshot wound to colon
contaminated wound
-
old traumatic wounds with retained devitalized tissue, those that involve existing clinical infection or perforated visceraeg. Abscess
dirty
-
perioperative antibiotics are given
1 hour prior to skin incision
-
choice of antibiotics depends on
type of operation
-
surgical prophylaxis with first generation cephalosporin (Ancef) if
no anaerobes are expected
-
surgical prophylaxis with second generation cephalosporin (Cefotetan) if
anaerobic activity is likely
-
in a rapidly spreading infection think about
necrotizing fasciitis
-
necrotizing fasciitis can be caused by
clostridium perfringens, streptococcus (GABHS)
-
aka. Strep gangrene, Fournier's gangrene, flesh eating disease
necrotizing fasciitis
-
severe infection that leads to necrosis of the subcutaneous tissue and adjacent fascia
necrotizing fasciitis
-
mortality rate in patients with necrotizing fasciitis __%
40
-
treatment for __ includes broad-spectrum antibiotics, including Penicillin G,+ aggressive surgical debridement!
necrotizing fasciitis
-
Must have high index of suspicion for __ when Skin discoloration, necrosis, crepitus, drainage of thin Watery, grayish, foul-smelling fluid present.
necrotizing fasciitis
-
antibiotics usually not helpful with
Post-op Wound infection>48 hours 5-10 days post-op
-
local infection of the dermis and subcutaneous tissue characterized by spreading redness, swelling and pain
cellulitis
-
blanching erythema
cellulitis
-
#1 risk factor for development of pneumonia after surgery
bed rest
-
most common post-operative infection
UTI
-
four W's of fever
- wind,
- water,
- wound,
- wonder drugs
-
#1 cause of post op fever
atelectasis
-
atelectasis occurs < post operative day __
3
-
UTI occurs post operative day __
3
-
fever for wound infection occurs post operative day __
5
-
Abscess/pus collection in thorax
Empyema
-
diarrhea in the hospital is usually from infection due to overgrowth of
clostridium difficile
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