learn how to convert lab values to words

LECTURE 1

ACID BASES

•learn how to convert lab values to words •the rule of the B’s
 = if the pH and the BiCarb are both in the same 
 direction -> metabolic


Hint: draw arrows beside each to see directions


• down = acidosis

• up = alkalosis

• respiratory -> has no b in it; if in other directions 


(or if bicarb is normal value)


• KNOW NORMAL pH, BiCarb, CO2 


•Hint: DON’T MEMORIZE LISTS…know principles

(they test knowledge of principles by having you generate lists..) - for “select all” questions


• ex. in general/principle what do opioids/pain 


meds do? = sedate you, CNS depressors


• ex. what does dilaudid do? don’t memorize specifics 


or a list of dilaudid, know principles of opioids (such 
 as sedation, CNS depression -> lethargy, flaccidity, 
 reflex +1, hypo-reflexia, obtunded)


• boards don’t test by lists because all books/


classes have different lists


•principles of S&S acid bases: as the pH goes so

goes my patient (except K+)


• pH up = PT up -> body system gets more 


irritable, hyper-excitable (EXCEPT K+)
 -> alkalosis - think of a body system and go 


high: hyper-reflexive (+3, +4 [2 is normal]), 


tachypnea, tachycardia, borborygmi, seizure


• pH down = PT down -> body systems shut 


down (EXCEPT K+)


-> acidosis - think of a system and go low: 


hypo-reflexive (+1, 0), bradycardia, lethargy, 
 obtunded, paralytic illeus, respiratory arrest •ex. which acid-base disorders need an ambu-bag at the bedside? = acidosis (resp. arrest) •ex. which acid-base disorders need suction at the bedside? = alkalosis (seize and aspirate) •Mac Kussmaul - Kussmaul’s (compensatory respiratory mechanism) is only present in only 1 of the 4 metabolic (acid-base) disorders


• M = metabolic AC = acidosis


•most common mistake with select all questions = selecting one more than you should (stop when you select the ones you know! don’t get caught up on the “could be’s”)

•Hint: don’t select none or all on select all that apply

questions (never only one and never all)

•Causes of Acid-Base Imbalance:


• scenarios and what acid-base disorder would 


result (what would cause an imbalance)
 ** DON’T MIX UP S&S and CAUSATION


• often what causes something is the opposite of the S&S

• ex. diarrhea will cause a metabolic acidosis but once 


you are acidotic your bowel shuts down and you get a 
 paralytic illeus

•when you get scenarios: 


-> if it’s a lung scenario = respiratory


• then check if the client is over-ventilating 


(alkalosis) or under-ventilating (acidosis)


• remember to look at the words (ex. over, under, 


ventilating) -> “as the pH goes so goes my PT”
 -> VENTILATING DOESN’T MEAN RESPIRATORY 
 RATE; resp. rate is irrelevant w/ acid-base, 
 ventilation has to do with gas exchange not resp. 
 rate (look at the SaO2 -> if your resp. rate is fast 
 but SaO2 is low you are under-ventilating)
 -> ex. PCA pump - What acid-base disorder 
 indicates they need to come off of it? = respiratory 
 acidosis (resp. depression -> resp. arrest)
 —> if it’s not lung, it’s metabolic •metabolic alkalosis - really only one scenario = if the PT has prolonged gastric vomiting/suctioning


• because you are losing ACID

• ex. GI surgery w/ NG tube with suctioning for 

• days; hyperemesis graviderum

• otherwise everything else that isn’t lung you 


pick metabolic acidosis (DEFAULT)


• ex. hyperemesis graviderum w/ dehydration 


acute renal failure, infantile diarrhea

•remember, you only have 4 to pick from:


• respiratory alkalosis - respiratory acidosis

• metabolic alkalosis - metabolic acidosis

•pay more attention to the modifying phrases than the original noun


• ex. person w/ OCD who is now psychotic (psychotic 


trumps OCD); hyperemesis with dehydration (pay 
 attention to dehydration)

VENTILATION

•ventilators -> know alarm systems (you set it up so that the machine doesn’t use less than or more than specific amounts of pressure)


• high pressure alarm = increased resistance 


to airflow (the machine has to push too hard to 
 get air into lungs)


- from obstructions: 


• kinks in tubing (unkink it)


ii. water condensation in tube (empty it!)
 iii. mucous secretions in the airway (change 
 positions/turn, C&DB, and THEN suction)
 *** suction is only PRN!!!
 -> priority questions = you would check 
 kinks first, suction is not first
 


• low pressure alarm = decreased resistance 


to airflow (the machine had to work too little 
 to push air into lungs)


- from disconnections:


• main tubing (reconnect it duh!)


ii. O2 sensor tubing (which senses FiO2 at 
 the airway/trach area; black coated wire 
 coming from machine right along the 
 tubing - reconnect!) •ventilators -> know blood gases


• resp. alkalosis = ventilation settings might be 


set too high (OVER-VENTILATING)


• resp. acidosis = ventilation settings might be set 


too low (UNDER-VENTILATING) •ex. weaning a PT off ventilator -> should not be under-ventilated, they need the ventilator; if they are over-ventilating then they can be weaned •never pick an answer where you don’t do something and someone else has to do something I11 .Iftube disconnects From pt → wrap with3Sided occu bluetape Lorpetroleumdressing)