short note

1. COMPLICATIONSOFMECHANICALVENTILATION
Patientssubjectedtomechanical ventilationcanface several complicationsindirectlyordirectlydue to
the machine.Complicationscanoccur at any stage of mechanical ventilationandare sometimeslife
threatening.
The complicationsare asfollows :-
 Short termcomplications:-
- Ventilator-inducedlunginjury:- Withventilator-inducedlunginjury,the alveolarepitheliumisatrisk
for both
I) barotrauma :- It referstorupture of the alveoluswith subsequententryof airintothe pleural space
(pneumothorax) and/orthe trackingorair alongthe vascularbundle tothe mediastinum
(pneumomediastinum).Barotraumamaybe associatedwithincreasedmortality,althoughitisoftennot
the directcause of death.Managementof barotraumaincludesaddressingspecificcomplications(eg,
chesttube for pneumothorax),loweringplateaupressure tolessthan30 by reducingtidal volume and
PEEP,and managingthe underlyingdisorder.
II) Volutrauma:- refersto the local overdistentionof normal alveoli.Whenamechanical ventilation
breathis forcedintothe patient,the positive pressure tendstofollow the pathof leastresistance tothe
normal or relatively normal alveoli, potentially causing overdistention . Since volutrauma was recognized,
lung-protective ventilationstrategyisrecommendedinall patientswithARDSoracute lunginjury. Both
volutraumaandbarotraumacan cause atelectrauma .Theyboth ina combinedfashionleadsto
ventilatorinducedlunginury
- Biotrauma:- Thiscan be due to the enormousamountof inflammatorycytokinesthatare
produced. Due to highpressure,the epithelialliningof the airwaymaybecome overdistended.
Thismay leadto an inflammatoryresponse whichresultsinenormousamountof releaseof
inflammatorycytokinesthatare produced. Thiscanleadto multiorganfailure
- DecreasedCO:- Prolongeduse of ventilationcausesincreaseinthe intrathoracicpressure.This
inturn compressedthe greatvessels,venacavasandthe the heart.Asthere isincrease inthe
pressure inside the rightheart,preloadbecomesless.Thisleadstolow stroke volumeandthus
a lowcardiac output.Thisleadsto hemodynamicinstability.
 Long termcomplications
- Oxygentoxicity:-Itisafunctionof increasedFIO2anditsdurationof use.The effectisas
follows:- Prolongedhighamountoxygendelivery reactive oxygenspeciesare produced 
damage of bronchial lining Pulmonary edema Impropergasexchange-V/Qmismatch
PaO2 decreased( hypoxaemia)therapistincreasesFiO2 toxicity.Itcausesinflammation in
the lungs,CNSimpairments(confusion,LOC),eyes(retinopathy,rarelyblindness).The clinician
isencouragedtouse the lowestFIO2thataccomplishessatisfactoryoxygenation.

2. - Ventilator-associatedpneumonia:- isa life-threateningcomplicationwithhighmortalityrate. Itis
definedasanewinfectionof the lungparenchymathatdevelopswithin48hours afterintubation. The
breathingtube that'sput inthe airwaycan allow bacteriato enteryourlungs.Asa result, maydevelop
ventilator-associatedpneumonia(VAP)
Foreignparticle maycome fromthe overcrowdedsecretionthroughETTand cause this. This can be
fatal.
- PNEUMOTHORAX - This isa conditioninwhichairleaksoutof the lungsand intothe space
betweenthe lungsandthe chestwall.Thiscancause painand shortnessof breath,andit may
cause one or bothlungsto collapse. Itiscausedwhenthere is overdistension of the alveoli and
finallyburstingthe airoutinthe interstitum .
- INJURIESTO FACE, LIPSANDOROPHARYNX - Trauma to the lip andchecksfrom the tube tie.
Injuriestothe tongue can occur particularlywhenentrappedbetweenthe endotracheal tube
and the lowerteeth
- LARYNGEAL INJURIES
Some degree of glottisinjuryisseenin94% of patientsintubatedfor 4 days. Erosive ulcersof
vocal cords may be seen. Swellingandedemaof the vocal cord. Granulomas(7% inpatients
intubatedfor4 days or more) occur.
- RENAL EFFECTS - The usual renal response toreductionof cardiacoutputandmean arterial
pressure. Reductioninurine outputsecondarytoa fall inthe transmural pressure of the right
atriumthat resultsinreductionof the secretionof atrial naturiticpeptide andthe activationof
renin-angiotensin-aldosterone systemandpituitaryvasopressinsecretion.
- Gi complications:-
Decreasedcardiacoutput
Splanchnichypoperfusion
GI mucosal injury AlteredGImotility
Loss of gut barrierfunction/increasedpermeability Malnutrition
Gi bleeding
- Anemia:- A significantpartisattributedtofrequentandexcessive blooddraws.
Gastrointestinal bleedingmayalsocause it. The conditionis aggravatedby coagulation
disorders that include platelet dysfunction,thrombocytopenia,lossof coagulationfactors,
and endo-theliumrelated coagulation disorders.