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Shock

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SHOCK & IV FLUIDS Dr. Ahmed Khan Sangrasi Associate Professor, Department of Surgery, LUMHS Jamshoro * * * * * * * * * * * * SmvO2 mixed venous oxygen saturation ... – PowerPoint PPT presentation

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Title: Shock


1
Shock IV Fluids
  • Dr. Ahmed Khan SangrasiAssociate Professor,
    Department of Surgery,
  • LUMHS Jamshoro

2
Shock
  • Shock is a life threatening medical condition
    that occurs due to inadequate substrate for
    aerobic cellular respiration.
  • Shock is a common end point of many medical
    conditions and one of the most common causes of
    death for critically ill people

3
Objectives
  • Definition
  • Approach to the hypotensive patient
  • Types
  • Specific treatments

4
Definition of Shock
  • Inadequate oxygen delivery to meet metabolic
    demands
  • Results in global tissue hypoperfusion and
    metabolic acidosis
  • Shock can occur with a normal blood pressure and
    hypotension can occur without shock

5
Understanding Shock
  • Inadequate systemic oxygen delivery activates
    autonomic responses to maintain systemic oxygen
    delivery
  • Sympathetic nervous system
  • NE, epinephrine, dopamine, and cortisol release
  • Causes vasoconstriction, increase in HR, and
    increase of cardiac contractility (cardiac
    output)
  • Renin-angiotensin axis
  • Water and sodium conservation and
    vasoconstriction
  • Increase in blood volume and blood pressure

6
Understanding Shock
  • Cellular responses to decreased systemic oxygen
    delivery
  • ATP depletion ? ion pump dysfunction
  • Cellular edema
  • Hydrolysis of cellular membranes and cellular
    death
  • Goal is to maintain cerebral and cardiac
    perfusion
  • Vasoconstriction of splanchnic, musculoskeletal,
    and renal blood flow
  • Leads to systemic metabolic lactic acidosis that
    overcomes the bodys compensatory mechanisms

7
Global Tissue Hypoxia
  • Endothelial inflammation and disruption
  • Inability of O2 delivery to meet demand
  • Result
  • Lactic acidosis
  • Cardiovascular insufficiency
  • Increased metabolic demands

8
Multiorgan DysfunctionSyndrome (MODS)
  • Progression of physiologic effects as shock
    ensues
  • Cardiac depression
  • Respiratory distress
  • Renal failure
  • DIC
  • Result is end organ failure

9
1. ANTICIPATION STAGE
10
2. PRE-SHOCK STAGE
11
3. COMENSATED SHOCK STAGE
12
4. DECOMPENSATED SHOCK STAGE (REVERSABLE)
13
5. DECOMPENSATED SHOCK STAGE (IRREVERSABLE)
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17
Approach to the Patient in Shock
  • ABCs
  • Cardiorespiratory monitor
  • Pulse oximetry
  • Supplemental oxygen
  • IV access
  • ABG, labs
  • Foley catheter
  • Vital signs including rectal temperature

18
Diagnosis
  • Physical exam (VS, mental status, skin color,
    temperature, pulses, etc)
  • Infectious source
  • Labs
  • CBC
  • Chemistries
  • Lactate
  • Coagulation studies
  • Cultures
  • ABG

19
Further Evaluation
  • CT of head/sinuses
  • Lumbar puncture
  • Wound cultures
  • Acute abdominal series
  • Abdominal/pelvic CT or US
  • Cortisol level
  • Fibrinogen, FDPs, D-dimer

20
Approach to the Patient in Shock
  • History
  • Recent illness
  • Fever
  • Chest pain, SOB
  • Abdominal pain
  • Comorbidities
  • Medications
  • Toxins/Ingestions
  • Recent hospitalization or surgery
  • Baseline mental status
  • Physical examination
  • Vital Signs
  • CNS mental status
  • Skin color, temp, rashes, sores
  • CV JVD, heart sounds
  • Resp lung sounds, RR, oxygen sat, ABG
  • GI abd pain, rigidity, guarding, rebound
  • Renal urine output

21
Is This Patient in Shock?
  • Patient looks ill
  • Altered mental status
  • Skin cool and mottled or hot and flushed
  • Weak or absent peripheral pulses
  • SBP lt110
  • Tachycardia

Yes! These are all signs and symptoms of shock
22
Shock
  • Do you remember how to quickly estimate blood
    pressure by pulse?

60
  • If you palpate a pulse,
  • you know SBP is at
  • least this number

70
80
90
23
Goals of Treatment
  • ABCDE
  • Airway
  • control work of Breathing
  • optimize Circulation
  • assure adequate oxygen Delivery
  • achieve End points of resuscitation

24
Airway
  • Determine need for intubation but remember
    intubation can worsen hypotension
  • Sedatives can lower blood pressure
  • Positive pressure ventilation decreases preload
  • May need volume resuscitation prior to intubation
    to avoid hemodynamic collapse

25
Control Work of Breathing
  • Respiratory muscles consume a significant amount
    of oxygen
  • Tachypnea can contribute to lactic acidosis
  • Mechanical ventilation and sedation decrease WOB
    and improves survival

26
Optimizing Circulation
  • Isotonic crystalloids
  • Titrated to
  • CVP 8-12 mm Hg
  • Urine output 0.5 ml/kg/hr (30 ml/hr)
  • Improving heart rate
  • May require 4-6 L of fluids
  • No outcome benefit from colloids

27
Maintaining Oxygen Delivery
  • Decrease oxygen demands
  • Provide analgesia and anxiolytics to relax
    muscles and avoid shivering
  • Maintain arterial oxygen saturation/content
  • Give supplemental oxygen
  • Maintain Hemoglobin gt 10 g/dL
  • Serial lactate levels or central venous oxygen
    saturations to assess tissue oxygen extraction

28
End Points of Resuscitation
  • Goal of resuscitation is to maximize survival and
    minimize morbidity
  • Use objective hemodynamic and physiologic values
    to guide therapy
  • Goal directed approach
  • Urine output gt 0.5 mL/kg/hr
  • CVP 8-12 mmHg
  • MAP 65 to 90 mmHg
  • Central venous oxygen concentration gt 70

29
Persistent Hypotension
  • Inadequate volume resuscitation
  • Pneumothorax
  • Cardiac tamponade
  • Hidden bleeding
  • Adrenal insufficiency
  • Medication allergy

30
Practically Speaking.
  • Keep one eye on these patients
  • Frequent vitals signs
  • Monitor success of therapies
  • Watch for decompensated shock
  • Let your nurses know that these patients are sick!

31
Types of Shock
  • Hypovolemic
  • Cardiogenic
  • Septic
  • Anaphylactic
  • Neurogenic
  • Endocrine
  • Obstructive

32
What Type of Shock is This?
  • Types of Shock
  • Hypovolemic
  • Septic
  • Cardiogenic
  • Anaphylactic
  • Neurogenic
  • Obstructive
  • 68 yo M with hx of HTN and DM presents to the ER
    with abrupt onset of diffuse abdominal pain with
    radiation to his low back. The pt is
    hypotensive, tachycardic, afebrile, with cool but
    dry skin

Hypovolemic Shock
33
Hypovolemic Shock
34
Hypovolemic Shock
  • Non-hemorrhagic
  • Vomiting
  • Diarrhea
  • Bowel obstruction, pancreatitis
  • Burns
  • Neglect, environmental (dehydration)
  • Hemorrhagic
  • GI bleed
  • Trauma
  • Massive hemoptysis
  • AAA rupture
  • Ectopic pregnancy, post-partum bleeding

35
Hypovolemic Shock
  • ABCs
  • Establish 2 large bore IVs or a central line
  • Crystalloids
  • Normal Saline or Lactate Ringers
  • Up to 3 liters
  • PRBCs
  • O negative or cross matched
  • Control any bleeding
  • Arrange definitive treatment

36
Evaluation of Hypovolemic Shock
  • As indicated
  • CXR
  • Pelvic x-ray
  • Abd/pelvis CT
  • Chest CT
  • GI endoscopy
  • Bronchoscopy
  • Vascular radiology
  • CBC
  • ABG/lactate
  • Electrolytes
  • BUN, Creatinine
  • Coagulation studies
  • Type and cross-match

37
Infusion Rates
  • Access Gravity Pressure
  • 18 g peripheral IV 50 mL/min 150 mL/min
  • 16 g peripheral IV 100 mL/min 225 mL/min
  • 14 g peripheral IV 150 mL/min 275 mL/min
  • 8.5 Fr CV cordis 200 mL/min 450
    mL/min

38
What Type of Shock is This?
  • Types of Shock
  • Hypovolemic
  • Septic
  • Cardiogenic
  • Anaphylactic
  • Neurogenic
  • Obstructive
  • An 81 yo F resident of a nursing home presents to
    the ED with altered mental status. She is
    febrile to 39.4, hypotensive with a widened pulse
    pressure, tachycardic, with warm extremities

Septic
39
Septic Shock
40
Sepsis
  • Two or more of SIRS criteria
  • Temp gt 38 or lt 36 C
  • HR gt 90
  • RR gt 20
  • WBC gt 12,000 or lt 4,000
  • Plus the presumed existence of infection
  • Blood pressure can be normal!

41
Septic Shock
  • Sepsis (remember definition?)
  • Plus refractory hypotension
  • After bolus of 20-40 mL/Kg patient still has one
    of the following
  • SBP lt 90 mm Hg
  • MAP lt 65 mm Hg
  • Decrease of 40 mm Hg from baseline

42
Sepsis
43
Pathogenesis of Sepsis
Nguyen H et al. Severe Sepsis and Septic-Shock
Review of the Literature and Emergency Department
Management Guidelines. Ann Emerg Med.
20064228-54.
44
Septic Shock
  • Clinical signs
  • Hyperthermia or hypothermia
  • Tachycardia
  • Wide pulse pressure
  • Low blood pressure (SBPlt90)
  • Mental status changes
  • Beware of compensated shock!
  • Blood pressure may be normal

45
Ancillary Studies
  • Cardiac monitor
  • Pulse oximetry
  • CBC, Chem 7, coags, LFTs, lipase, UA
  • ABG with lactate
  • Blood culture x 2, urine culture
  • CXR
  • Foley catheter (why do you need this?)

46
Treatment of Septic Shock
  • 2 large bore IVs
  • NS IVF bolus- 1-2 L wide open (if no
    contraindications)
  • Supplemental oxygen
  • Empiric antibiotics, based on suspected source,
    as soon as possible

47
Treatment of Sepsis
  • Antibiotics- Survival correlates with how quickly
    the correct drug was given
  • Cover gram positive and gram negative bacteria
  • Zosyn 3.375 grams IV and ceftriaxone 1 gram IV or
  • Imipenem 1 gram IV
  • Add additional coverage as indicated
  • Pseudomonas- Gentamicin or Cefepime
  • MRSA- Vancomycin
  • Intra-abdominal or head/neck anaerobic
    infections- Clindamycin or Metronidazole
  • Asplenic- Ceftriaxone for N. meningitidis, H.
    infuenzae
  • Neutropenic Cefepime or Imipenem

48
Persistent Hypotension
  • If no response after 2-3 L IVF, start a
    vasopressor (norepinephrine, dopamine, etc) and
    titrate to effect
  • Goal MAP gt 60
  • Consider adrenal insufficiency hydrocortisone
    100 mg IV

49
Treatment Algorithm
  • Rivers E et al. Early goal-directed therapy in
    the treatment of severe sepsis and septic shock N
    Engl J Med. 20013451368-1377.

50
What Type of Shock is This?
  • Types of Shock
  • Hypovolemic
  • Septic
  • Cardiogenic
  • Anaphylactic
  • Neurogenic
  • Obstructive
  • A 55 yo M with hx of HTN, DM presents with
    crushing substernal CP, diaphoresis,
    hypotension, tachycardia and cool, clammy
    extremities

Cardiogenic
51
Cardiogenic Shock
52
Cardiogenic Shock
  • Signs
  • Cool, mottled skin
  • Tachypnea
  • Hypotension
  • Altered mental status
  • Narrowed pulse pressure
  • Rales, murmur
  • Defined as
  • SBP lt 90 mmHg
  • CI lt 2.2 L/m/m2
  • PCWP gt 18 mmHg

53
Etiologies
  • What are some causes of cardiogenic shock?
  • AMI
  • Sepsis
  • Myocarditis
  • Myocardial contusion
  • Aortic or mitral stenosis, HCM
  • Acute aortic insufficiency

54
Pathophysiology of Cardiogenic Shock
  • Often after ischemia, loss of LV function
  • Lose 40 of LV clinical shock ensues
  • CO reduction lactic acidosis, hypoxia
  • Stroke volume is reduced
  • Tachycardia develops as compensation
  • Ischemia and infarction worsens

55
Ancillary Tests
  • EKG
  • CXR
  • CBC, Chem 10, cardiac enzymes, coagulation
    studies
  • Echocardiogram

56
Treatment of Cardiogenic Shock
  • Goals- Airway stability and improving myocardial
    pump function
  • Cardiac monitor, pulse oximetry
  • Supplemental oxygen, IV access
  • Intubation will decrease preload and result in
    hypotension
  • Be prepared to give fluid bolus

57
Treatment of Cardiogenic Shock
  • AMI
  • Aspirin, beta blocker, morphine, heparin
  • If no pulmonary edema, IV fluid challenge
  • If pulmonary edema
  • Dopamine will ? HR and thus cardiac work
  • Dobutamine May drop blood pressure
  • Combination therapy may be more effective
  • PCI or thrombolytics
  • RV infarct
  • Fluids and Dobutamine (no NTG)
  • Acute mitral regurgitation or VSD
  • Pressors (Dobutamine and Nitroprusside)

58
What Type of Shock is This?
  • Types of Shock
  • Hypovolemic
  • Septic
  • Cardiogenic
  • Anaphylactic
  • Neurogenic
  • Obstructive
  • A 34 yo F presents to the ER after dining at a
    restaurant where shortly after eating the first
    few bites of her meal, became anxious,
    diaphoretic, began wheezing, noted diffuse
    pruritic rash, nausea, and a sensation of her
    throat closing off. She is currently
    hypotensive, tachycardic and ill appearing.

Anaphalactic
59
Anaphalactic Shock
60
Anaphylactic Shock
  • Anaphylaxis a severe systemic hypersensitivity
    reaction characterized by multisystem involvement
  • IgE mediated
  • Anaphylactoid reaction clinically
    indistinguishable from anaphylaxis, do not
    require a sensitizing exposure
  • Not IgE mediated

61
Anaphylactic Shock
  • What are some symptoms of anaphylaxis?
  • First- Pruritus, flushing, urticaria appear
  • Next- Throat fullness, anxiety, chest tightness,
    shortness of breath and lightheadedness
  • Finally- Altered mental status, respiratory
    distress and circulatory collapse

62
Anaphylactic Shock
  • Risk factors for fatal anaphylaxis
  • Poorly controlled asthma
  • Previous anaphylaxis
  • Reoccurrence rates
  • 40-60 for insect stings
  • 20-40 for radiocontrast agents
  • 10-20 for penicillin
  • Most common causes
  • Antibiotics
  • Insects
  • Food

63
Anaphylactic Shock
  • Mild, localized urticaria can progress to full
    anaphylaxis
  • Symptoms usually begin within 60 minutes of
    exposure
  • Faster the onset of symptoms more severe
    reaction
  • Biphasic phenomenon occurs in up to 20 of
    patients
  • Symptoms return 3-4 hours after initial reaction
    has cleared
  • A lump in my throat and hoarseness heralds
    life-threatening laryngeal edema

64
Anaphylactic Shock- Diagnosis
  • Clinical diagnosis
  • Defined by airway compromise, hypotension, or
    involvement of cutaneous, respiratory, or GI
    systems
  • Look for exposure to drug, food, or insect
  • Labs have no role

65
Anaphylactic Shock- Treatment
  • ABCs
  • Angioedema and respiratory compromise require
    immediate intubation
  • IV, cardiac monitor, pulse oximetry
  • IVFs, oxygen
  • Epinephrine
  • Second line
  • Corticosteriods
  • H1 and H2 blockers

66
Anaphylactic Shock- Treatment
  • Epinephrine
  • 0.3 mg IM of 11000 (epi-pen)
  • Repeat every 5-10 min as needed
  • Caution with patients taking beta blockers- can
    cause severe hypertension due to unopposed alpha
    stimulation
  • For CV collapse, 1 mg IV of 110,000
  • If refractory, start IV drip

67
Anaphylactic Shock - Treatment
  • Corticosteroids
  • Methylprednisolone 125 mg IV
  • Prednisone 60 mg PO
  • Antihistamines
  • H1 blocker- Diphenhydramine 25-50 mg IV
  • H2 blocker- Ranitidine 50 mg IV
  • Bronchodilators
  • Albuterol nebulizer
  • Atrovent nebulizer
  • Magnesium sulfate 2 g IV over 20 minutes
  • Glucagon
  • For patients taking beta blockers and with
    refractory hypotension
  • 1 mg IV q5 minutes until hypotension resolves

68
Anaphylactic Shock - Disposition
  • All patients who receive epinephrine should be
    observed for 4-6 hours
  • If symptom free, discharge home
  • If on beta blockers or h/o severe reaction in
    past, consider admission

69
What Type of Shock is This?
  • Types of Shock
  • Hypovolemic
  • Septic
  • Cardiogenic
  • Anaphylactic
  • Neurogenic
  • Obstructive
  • A 41 yo M presents to the ER after an MVC
    complaining of decreased sensation below his
    waist and is now hypotensive, bradycardic, with
    warm extremities

Neurogenic
70
Neurogenic Shock
71
Neurogenic Shock
  • Occurs after acute spinal cord injury
  • Sympathetic outflow is disrupted leaving
    unopposed vagal tone
  • Results in hypotension and bradycardia
  • Spinal shock- temporary loss of spinal reflex
    activity below a total or near total spinal cord
    injury (not the same as neurogenic shock, the
    terms are not interchangeable)

72
Neurogenic Shock
  • Loss of sympathetic tone results in warm and dry
    skin
  • Shock usually lasts from 1 to 3 weeks
  • Any injury above T1 can disrupt the entire
    sympathetic system
  • Higher injuries worse paralysis

73
Neurogenic Shock- Treatment
  • A,B,Cs
  • Remember c-spine precautions
  • Fluid resuscitation
  • Keep MAP at 85-90 mm Hg for first 7 days
  • Thought to minimize secondary cord injury
  • If crystalloid is insufficient use vasopressors
  • Search for other causes of hypotension
  • For bradycardia
  • Atropine
  • Pacemaker

74
Neurogenic Shock- Treatment
  • Methylprednisolone
  • Used only for blunt spinal cord injury
  • High dose therapy for 23 hours
  • Must be started within 8 hours
  • Controversial- Risk for infection, GI bleed

75
What Type of Shock is This?
  • Types of Shock
  • Hypovolemic
  • Septic
  • Cardiogenic
  • Anaphylactic
  • Neurogenic
  • Obstructive
  • A 24 yo M presents to the ED after an MVC c/o
    chest pain and difficulty breathing. On PE, you
    note the pt to be tachycardic, hypotensive,
    hypoxic, and with decreased breath sounds on left

Obstructive
76
Obstructive Shock
77
Obstructive Shock
  • Tension pneumothorax
  • Air trapped in pleural space with 1 way valve,
    air/pressure builds up
  • Mediastinum shifted impeding venous return
  • Chest pain, SOB, decreased breath sounds
  • No tests needed!
  • Rx Needle decompression, chest tube

78
Obstructive Shock
  • Cardiac tamponade
  • Blood in pericardial sac prevents venous return
    to and contraction of heart
  • Related to trauma, pericarditis, MI
  • Becks triad hypotension, muffled heart sounds,
    JVD
  • Diagnosis large heart CXR, echo
  • Rx Pericardiocentisis

79
Obstructive Shock
  • Pulmonary embolism
  • Virscow triad hypercoaguable, venous injury,
    venostasis
  • Signs Tachypnea, tachycardia, hypoxia
  • Low risk D-dimer
  • Higher risk CT chest or VQ scan
  • Rx Heparin, consider thrombolytics

80
Obstructive Shock
  • Aortic stenosis
  • Resistance to systolic ejection causes decreased
    cardiac function
  • Chest pain with syncope
  • Systolic ejection murmur
  • Diagnosed with echo
  • Vasodilators (NTG) will drop pressure!
  • Rx Valve surgery

81
FLUID Therapy
82
Fluid and electrolyte balance is an extremely
complicated thing.
83
Importance
  • Need to make a decision regarding fluids in
    pretty much every hospitalized patient.
  • Aggressive IV fluids are recommended in most
    types of shock eg. 1-2 litres of NS bolus over
    10mins or 20ml/kg in a child
  • Can be life-saving in certain conditions
  • Choice of IV fluid whether crystalloid or colloid
    is superior remains undetermined
  • For persistent shock after initial resuscitation,
    packed RBCs should be given to keep Hb gt 100gms

84
  • loss of body water, whether acute or chronic, can
    cause a range of problems from mild
    lightheadedness to convulsions, coma, and in some
    cases, death.
  • Though fluid therapy can be a lifesaver, it's
    never innocuous, and can be very harmful.
  • Permissive hypotension For haemorrhagic shock
    current evidence supports that, limiting the use
    of fluids for penetrating thorax and abdominal
    injuries allowing mild hypotension. (Target MAP
    of 60mmHg, SBP 70-90 mmHg

85
Kinds of IV Fluid solutions
  • Hypotonic - 1/2NS
  • Isotonic - NS, LR, albumen
  • Hypertonic Hypertonic saline.
  • Crystalloid
  • Colloid

86
Crystalloid vs ColloidType of particles (large
or small)
  • Fluids with small crystalizable particles like
    NaCl are called crystalloids
  • Fluids with large particles like albumin are
    called colloids, these dont (quickly) fit
    through vascular pores, so they stay in the
    circulation and much smaller amounts can be used
    for same volume expansion. (250ml Albumin 4 L
    NS)
  • Edema resulting from these also tends to stick
    around longer for same reason.
  • Albumin can also trigger anaphylaxis.

87
  • There are two components to fluid therapy
  • Maintenance therapy replaces normal ongoing
    losses, and
  • Replacement therapy corrects any existing water
    and electrolyte deficits.

88
Maintenance therapy
  • Maintenance therapy is usually undertaken when
    the individual is not expected to eat or drink
    normally for a longer time (eg, perioperatively
    or on a ventilator).
  • Big picture Most people are NPO for 12 hours
    each day.
  • Patients who wont eat for one to two weeks
    should be considered for parenteral or
    enteralnutrition.

89
  • Maintenance Requirements can be broken
  • into water and electrolyte requirements

90
Water
  • Two liters of water per day are generally
    sufficient for adults
  • Most of this minimum intake is usually derived
    from the water contentof food and the water of
    oxidation, therefore
  • it has been estimated that only 500ml of water
    needs be imbibed given normal diet and no
    increased losses.
  • These sources of water are markedly reduced in
    patients who are not eating and so must be
    replaced by maintenance fluids.

91
  • water requirements increase with fever,
    sweating, burns, tachypnea, surgical drains,
    polyuria, or ongoing significant
    gastrointestinal losses.
  • For example, water requirements increase by 100
    to 150 mL/day for each C degree of body
    temperature elevation.

92
Several formulas can be used to calculate
maintenance fluid rates.
93
4/2/1 rule a.k.a Weight40
  • I prefer the 4/2/1 rule (with a 120 mL/h limit)
    because it is the same as for pediatrics.

94
  • 4/2/1 rule4 ml/kg/hr for first 10 kg
    (40ml/hr)then 2 ml/kg/hr for next 10 kg
    (20ml/hr)then 1 ml/kg/hr for any kgs over
    thatThis always gives 60ml/hr for first 20
    kgthen you add 1 ml/kg/hr for each kg over 20
    kg
  • This boils down to Weight in kg 40
    Maintenance IV rate/hour.For any person weighing
    more than 20kg

95
What to put in the fluids

96
Start D5 1/2NS20 meq K _at_ Wt40/hr
  • a reasonable approach is to start 1/2 normal
    saline to which 20 meq of potassium chloride is
    added per liter. (1/2NS20 K _at_ Wt40/hr)
  • Glucose in the form of dextrose (D5) can be added
    to provide some calories while the patient is
    NPO.
  • The normal kidney can maintain sodium and
    potassium balance over a wide range of intakes.
  • So,start
  • D5 1/2NS20 meq K
  • at a rate equal to their weight 40ml/hr, but
    no greater than 120ml/hr.
  • then adjust as needed, see next page.

97
Start D5 1/2NS20 meq K, then adjust
  • If sodium falls, increase the concentration (eg,
    to NS)
  • If sodium rises, decrease the concentration (eg,
    1/4NS)
  • If the plasma potassium starts to fall, add more
    potassium.
  • If things are good, leave things alone.

98
Usually kidneys regulate well, butAltered
homeostasis in the hospital
  • In the hospital, stress, pain, surgery can alter
    the normal mechanisms.
  • Increased aldosterone, Increased ADH
  • They generally make patients retain more water
    and salt, increase tendency for edema, and become
    hypokalemic.

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  • Now onto Part 2 of the presentation

104
Hypovolemia
  • Hypovolemia or FVD is result of water
    electrolyte loss
  • Compensatory mechanisms include
    Increased sympathetic nervous system stimulation
    with an increase in heart rate cardiac
    contraction thirst plus release of ADH
    aldosterone
  • Severe case may result in hypovolemic shock or
    prolonged case may cause renal failure

105
Causes of FVDhypovolemia
  • Gastrointestinal losses N/V/D
  • Renal losses diuretics
  • Skin or respiratory losses burns
  • Third-spacing intestinal obstruction,
    pancreatitis

106
Replacement therapy.
107
  • A variety of disorders lead to fluid losses that
    deplete the extracellular fluid .
  • This can lead to a potentially fatal decrease in
    tissue perfusion.
  • Fortunately, early diagnosis and treatment can
    restore normovolemia in almost all cases.

108
  • There is no easy formula for assessing the degree
    of hypovolemia.
  • Hypovolemic Shock, the most severe form of
    hypolemia, is characterized by tachycardia, cold,
    clammy extremities, cyanosis, a low urine output
    (usually less than 15 mL/h), and agitation and
    confusion due to reduced cerebral blood flow.
  • This needs rapid treatment with isotonic fluid
    boluses (1-2L NS), and assessment and treatment
    of the underlying cause.
  • But hypovolemia that is less severe and therefore
    well compensated is more difficult to accurately
    assess.

109
History for assessing hypovolemia
  • The history can help to determine the presence
    and etiology of volume depletion.
  • Weight loss!
  • Early complaints include lassitude, easy
    fatiguability, thirst, muscle cramps, and
    postural dizziness.
  • More severe fluid loss can lead to abdominal
    pain, chest pain, or lethargy and confusion due
    to ischemia of the mesenteric, coronary, or
    cerebral vascular beds, respectively.
  • Nausea and malaise are the earliest findings of
    hyponatremia, and may be seen when the plasma
    sodium concentration falls below 125 to 130
    meq/L. This may be followed by headache,
    lethargy, and obtundation
  • Muscle weakness due to hypokalemia or
    hyperkalemia
  • Polyuria and polydipsia due to hyperglycemia or
    severe hypokalemia
  • Lethargy, confusion, seizures, and coma due to
    hyponatremia, hypernatremia, or hyperglycemia

110
Basic signs of hypovolemia
  • Urine output, less than 30ml/hr
  • Decreased BP, Increase pulse

111
Physical exam for assessing volume
  • physical exam in general is not sensitive or
    specific
  • acute weight loss however, obtaining an accurate
    weight over time may be difficult
  • decreased skin turgor - if you pinch it it stays
    put
  • dry skin, particularly axilla
  • dry mucus membranes
  • low arterial blood pressure (or relative to
    patient's usual BP)
  • orthostatic hypotension can occur with
    significant hypovolemia but it is also common in
    euvolemic elderly subjects.
  • decreased intensity of both the Korotkoff sounds
    (when the blood pressure is being measured with a
    sphygmomanometer) and the radial pulse
    ("thready") due to peripheral vasoconstriction.
  • decreased Jugular Venous Pressure
  • The normal venous pressure is 1 to 8 cmH2O, thus,
    a low value alone may be normal and does not
    establish the diagnosis of hypovolemia.

112
SIGNS SYMPTOMS OF Fluid Volume Excess
  • SOB orthopnea
  • Edema weight gain
  • Distended neck veins tachycardia
  • Increased blood pressure
  • Crackles wheezes
  • pleural effusion

113
Which brings us to Labnormalities seen with
hypovolemia
  • a variety of changes in urine and blood often
    accompany extracellular volume depletion.
  • In addition to confirming the presence of volume
    depletion, these changes may provide important
    clues to the etiology.

114
BUN/Cr
  • BUN/Cr ratio normally around 10
  • Increase above 20 suggestive of prerenal state
  • (rise in BUN without rise in Cr called prerenal
    azotemia.)
  • This happens because with a low pressure head
    proximal to kidney, because urea (BUN) is
    resorbed somewhat, and creatinine is secreted
    somewhat as well

115
Hgb/Hct
  • Acute loss of EC fluid volume causes
    hemoconcentration (if not due to blood loss)
  • Acute gain of fluid will cause hemodilution of
    about 1g of hemoglobin (this happens very often.)

116
Plasma Na
  • Decrease in Intravascular volume leads to greater
    avidity for Na (through aldosterone) AND water
    (through ADH),
  • So overall, Plasma Na concentration tends to
    decrease from 140 when hypovolemia present.

117
Urine Na
  • Urine Na goes down in prerenal states as body
    tries to hold onto water.
  • Getting a FENa helps correct for urine
    concentration.
  • Screwed up by lasix.
  • Calculator on PDA or medcalc.com

118
IV Modes of administration
  • Peripheral IV
  • PICC
  • Central Line
  • Intraosseous

119
IV ProblemExtravasation / Infiltrated
  • The most sensitive indicator of extravasated
    fluid or "infiltration" is to transilluminate the
    skin with a small penlight and look for the
    enhanced halo of light diffusion in the fluid
    filled area.
  • Checking flow of infusion does not tell you where
    the fluid is going

120
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