Shock | Shock- clinical features | Classification | Cardiogenic shock – |Hypovolemic shock – | Septic shock – | Neurogenic shock-| Anaphylactic shock-  | Pathogenesis of septic shock | Stages of shock | Non-progressive phase- | Progressive stage-  | Irreversible stage- | Morphology | Clinical features of shock |

-

 Shock 

Definition- Systemic hypoperfusion owing to reduction in either cardiac output or in the effective circulating blood volume.


Shock- clinical features


  • Hypotension
  • Tachycardia
  • Cold clammy skin
  • Rapid shallow respiration.
  • Drowsiness. 
  • confusion, irritability
  • Multi organ failure.


Classification 

Cardiogenic shock – 


  • myocardial pump failure –
  • Intrinsic myocardial damage (infarction), vent. Arrhythmias, 
  • extrinsic comopression (cardiac tamponade) or outflow obstruction (pulmonary embolism).


Hypovolemic shock – 


  • loss of blood or plasma volume- 
  • by h’hage, fluid loss from severe burns or trauma.

Septic shock –

  •  systemic microbial infection most commonly in gram negative infectns(endotoxic shock) ,can occur with gram +ve & fungal infectns


Neurogenic shock-


  • anaesthetic accident or spinal cord injury.

Anaphylactic shock- 


  • due to loss of vascular tone & peripheral pooling of blood-
  • IgE mediated response
  • -sys vasodilatation & increased vascular permeability.

Pathogenesis of septic shock


  • Results from spread & expansion of initially localised infection (eg. Abscess, peritonitis , pneumonia) into the blood stream.
  • Most cases are caused by endotoxin (ET) producing gram –ve bacilli . 
  • ET’s are bacterial wall lipopolysaccharides
  • Systemic vasodilatation(hypotension)
  • Decreased myocardial contractility
  • Widespread endothelial injury &activation  (ARDS)
  • Activation of coagulation sys (DIC).

   All this induces multiorgan system failure  affecting liver, kidneys & CNS .

Stages of shock


Non-progressive phase-


  •  reflex compensatory mech are activated & perfusion of vital organs is maintained. These include- 
  • Baroreceptors, 
  • Catecholamine release,
  • Activatn of renin-angiotensin axis,ADH release 
  • generalised Sympathetic stimulation.


Progressive stage- 


  • tissue hypoperfusion 
  • onset of worsening circulatory & metabolic imbalances including acidosis.
  • Clinically patient may become confused & urine output decreases.


Irreversible stage-


  • after the body has suffered cellular & tissue injury so severe that even if hemodynamic defects are corrected, survival is not possible. 
  • Here pt has complete renal shutdown due to acute tubular necrosis.


Morphology


  • Brain- ischemic encephelopathy
  • Heart- focal or widespread coagulation necrosis or subendocardial h’hage or contraction band necrosis.
  • Kidneys- tubular ischemic injury (ATN)-causes oliguria, anuria & electrolyte disturbances.
  • Lungs – less commonly affected ,resistant to hypoxic injury in hypovolemic shock. But in bacterial sepsis or trauma, changes of diffuse alveolar damage- shock lung.
  • Adrenals- cortical cell lipid depletion 

Clinical features of shock


  • Hypotension
  • Tachycardia
  • Cold clammy skin
  • Rapid shallow respiration.
  • Drowsiness, confusion, irritability
  • Multi organ failure.











Comments

Post a Comment

If you have any doubts, please let me know

Popular posts from this blog

Pulmonary tb | Classiffication of drugs used in tuberculosis  | first line drugs | second line drugs  | second line newer drugs  | isoniazide | rifampicin | Uses of rifampicin  |

-
Pulmonary tb is the bacterial infection of the lungs caused by mycobacterium tuberculosis... It can cause various symptoms like chest pain,difficulty in breadthing and severe coughing... Classiffication of drugs used in tuberculosis  1.first line drugs  -isoniazid(H)  -rifampicin(R)  -pyrazinimide(z)  -ethambutol(E)  -streptomycin(S)  2.second line drugs  -thiacetazone(tzn)  -para amino salicylic acide(pASA)  -ethionamide(etm)  -kanamycin(kmc)  -amikacin(am)  -capriyomycin(cpr)  3.second line newer drugs  -ciprofloxacin  -ofloxacin  -azithromycin  -clarithromycin  -rivabutn isoniazide  -first line anti tubercular drugs  -it is bacteriostatic for resting bacili and bactericidal for rapidlly diving organism -act on both extracelluar and intracellular tb bacilli  -MOA (inhibit the synthesis of mycolic acid which is present in the mycobacterial cel wall) -atypical mycobacteria are n...
Read more

Guidelines for treatment of asthma | medical energency condition Features | Acute management of COPD  | MBBS SIMPLIFIED HANDWRITTEN TO TEXT NOTES |

-
Contents [ hide ] Guidelines for treatment of asthma   1.mild episode asthma- step 1   2.seasonal astma- step 2  3.mild chronic asthma with occasional exacerbations -step 2   4.moderate asthma with frequent excerbations -step 3  5.severe asthma -step 4,5 Step1 - inhaled short acting b2 agonist  Step 2 - low dose glucocorticoids or sodium chromoglyacate +inhaled long acting b2 agonist  Step 3- add leukotrine antagonist  Step 4 - inhaled high dose glucocorticoid+ipratropium bromide  Step 5 -add oral prednisolone +omalizumab Status asthmaticus  -medical energency condition Features  - chest pain,cynosis,bradycardia, hypotension,pulsus paradoxus Management  - correct dehydration  -O2 adminstration  -nebulise salbutamol and ipratropium bromide  -oral glucocorticoides  -if poor response is seen after one hour then following treatmanets are required •hospitalized the patient  •marked ventilation  •c...
Read more