debcpa28 Posted December 18, 2004 Share Posted December 18, 2004 Hi everyone! Just finished my first week at my new job as a PA hospitalist. BIG change for me!! Outpatient med is SO different from inpatient med! I'm having trouble with IV fluids- how and when and how much, etc. Any tips or good books to recommend? Thanks!! Debi :confused: Quote Link to comment Share on other sites More sharing options...
JustaPA Posted December 18, 2004 Share Posted December 18, 2004 Congratulation on your new job sounds like a very exciting opportunity. I know what you mean about inpatient being so different from outpatient. Sorry I don't have any advise for you. Quote Link to comment Share on other sites More sharing options...
Marlene G Posted December 18, 2004 Share Posted December 18, 2004 You will get the hang of it in no time. You will see. I just finished a rotation in internal med. The first 2 weeks, I hated it until the right people started teaching me a few things - and now - I could see myself working as a hospitalist. The best part was that, as I caught on, it was a great feeling. :) Quote Link to comment Share on other sites More sharing options...
SurgPA05 Posted December 18, 2004 Share Posted December 18, 2004 Calculation #1: Weight Conversion: If weight isn't in kg, convert it. Weight In Pounds / 2.2 = Weight In Kilograms -------------------------------------------------------------------------------- Calculation #2: Calculate Maintenance Fluids: Dependent on weight, not a linear relationship at low weights. Weight 0-10kg: Maintenance Fluids (cc) = 100cc/kg × Weight(kg) Weight 11-20kg: Maintenance Fluids (cc) = 1000cc + (( Weight(kg) - 10kg ) × 50cc/kg ) Weight >20kg: Maintenance Fluids (cc) = 1500cc + (( Weight(kg) - 20kg ) × 20cc/kg ) -------------------------------------------------------------------------------- Calculation #3: Calculate Maintenance Sodium and Potassium: This assumes that the daily requirements of Sodium (Na) and Potassium (K) are: 3mEq Na/100Kcal or 3mEq Na/100cc and 2mEq K/100Kcal or 2mEq K/100cc. Maintenance Sodium (mEq/24hour) = Maintenance Fluids(cc) × 3mEq Na /100cc/24hour Maintenance Potassium (mEq/24hour) = Maintenance Fluids(cc) × 2mEq K /100cc/24hour -------------------------------------------------------------------------------- Calculation #4: Calculate Fluid Deficit: Assumes that 1% dehydration = 10cc/kg Fluid Deficit (cc) = Weight(kg) × Percent Dehydration (%) × 10cc/kg Type Percent Dehydration Physical Exam Findings Mild Adult:2-4% Peds:5% Thirsty Dry Membranes No Tears Moderate Adult:5-7% Peds:10% Soft Eyes Soft Fontanelle Severe Adult:8-10% Peds:15% Elevated Heart Rate Skin Tenting Oliguric -------------------------------------------------------------------------------- Calculation #5: Calculate Sodium and Potassium Deficit: Must first determine how quickly and from where the deficit was lost. Type Duration of Loss From Where Normal Losses 3-5 days 60% Extracellular /40% Intracellular Rapid Losses < 24 hours 80% Extracellular /20% Intracellular Chronic Losses > 5 days 50% Extracellular /50% Intracellular Sodium Deficit (mEq) = Fluid Deficit (cc) × Percent Extracellular*(%) × 3mEq Na /100cc Potassium Deficit (mEq) = Fluid Deficit (cc) × Percent Intracellular*(%) × 2mEq Na /100cc *Recall that the major extracellular cation is Sodium and the major intracellular cation is Potassium. If the patient is hypertonic (i.e. Serum Sodium > 155mg/dl) then calculate the free water deficit. Free Water Deficit (cc) = [Observed Sodium - Ideal Sodium] × 4ml/kg × Weight (kg) Then, calculate the Sodium and Potassium Deficit based on the true fluid deficit. Sodium Deficit (mEq) = [ Fluid Deficit (cc) - Free Water Deficit (cc)] × Percent Extracellular*(%) × 3mEq Na /100cc Potassium Deficit (mEq) = [ Fluid Deficit (cc) - Free Water Deficit (cc)] × Percent Intracellular*(%) × 2mEq K /100cc If the patient is hypotonic (i.e. Serum Sodium < 130mg/dl) then calculate the extra sodium needed to raise the serum sodium to 135mg/dl. Extra Sodium (mEq) = [135mg/dl - Serum Sodium (mg/dl)] × Weight (kg) × 0.6 -------------------------------------------------------------------------------- Calculation #6: If a bolus is given, calculate the effect on fluid deficit and sodium deficit. New Fluid Deficit = Calculated Fluid Deficit (cc)(from Calculation #4) - Amount of Fluid Bolus (cc) New Sodium Deficit = Calculated Sodium Deficit (mEq)(from Calculation #5) - Amount of Sodium In Bolus (mEq) Amount of Sodium in Bolus = Concentration of Sodium in Bolus† (mEq/L) × Amount of Fluid Bolus (L) † In a bag of Normal Saline there are 155mEq/L Quote Link to comment Share on other sites More sharing options...
jwk Posted December 19, 2004 Share Posted December 19, 2004 This are the calculations we use for patients who are NPO and coming to surgery: 1st 10 kg = 20cc/kg/hr next 10 kg = 10cc/kg/hr So far, you have 60cc/kg/hr for weights up to 20kg. For weights >20kg, add 1.5cc/kg/hr for the amount of weight over 20kg. So for a 70kg patient 60cc/hr + ((70kg-20kg) x 1.5cc/kg/hr) 60cc/hr + (50kg x 1.5cc/kg/hr) 60cc/hr + 75cc/hr 135 cc/hr for maintenance IV fluids. Then simply take the hours of NPO time and multiply by the maintenance rate. Replace 1/2 the deficit the first hour, then 1/4 of the deficit each of the next two hours, then the maintenance rate after that. In addition to that, we would add in the 3rd space loss (as much as 10cc/kg/hr or more on an open abdominal case), as well as replace estimated blood loss at a rate 3cc of IV fluid per cc of blood loss, unless significant blood loss is anticipated, in which case we would replace blood loss with colloid (such as Hespan) or PRBC's. We follow urine output constantly, and adjust our fluid replacement to maintain a urine output of at least 1cc/kg/hr. Obviously these calculations don't take electrolytes into consideration. We run our fluids in too quickly to use potassium. If we're concerned, we'll run KCl as a background infusion. Again, these are the calculations we would commonly use in the OR, and are different than what you might use on a general medicine floor. Quote Link to comment Share on other sites More sharing options...
Guest PA_in_Jax Posted December 19, 2004 Share Posted December 19, 2004 Hey Debi, I know how ya feel. I just finished my first week working in Urology at a major teaching hospital. The majority of my experience has been in Emergency Medicine. I just relocated to Florida and got this Urology position. It's really interesting but mannnnnn... am I learning how little I know. Because of my experience as a PA, I kind of got thrown into the fire.... scorched a little but I THINK all my patients survived. Spent the weekend doing consults and rounding..... I coulda used your Hospitalist expertise a NUMBER of times :eek: !! It's an adventure and as exhausted as I am... I'm enjoying the hell out of it.. Hope you're in the same boat :D ! Good luck and have fun ;) Ed (aka PA in Jax) Quote Link to comment Share on other sites More sharing options...
Teasip Posted December 20, 2004 Share Posted December 20, 2004 Easy way to convert weights if you can subtract and divide in your head. Take any three digit weight in lbs., subtract the first two digits of the weight from the total then divide by two (ex. 128-12/2). You will be within a half kilogram each time. For a two digit weight subtract the first digit from the total and divide by two (ex. 91-9/2). Try it. Quote Link to comment Share on other sites More sharing options...
rcdavis Posted December 21, 2004 Share Posted December 21, 2004 "the ICU book" marino "drugs for the heart" opie. good starting places. the comments above are excellant good luck. you are a trailblazer Quote Link to comment Share on other sites More sharing options...
parc8 Posted January 18, 2006 Share Posted January 18, 2006 Just some tips I'ev picked up when trying to decide which IVF to use for resussitation- post op If you think they need more resuscitation, or significant on going losses- crystalloid is usually the choice. Normal saline is usually good resuscitation – especially in situations where k, mg is high, or if they have borderline K,MG and may be going into renal failure/insufficiency – (because it has no additional lytes besides NA,CL) However it may be a bad choice if they are going to require large amounts of fluid or are acidotic because it may lead to hyperchloremic acidosis. LR or plasmalyte are more physiologic fluids, both offering some K, (and other lytes remember if using plasmalyte there are different formulations so check the bag for its contents) and a bicarbonate precursor. So they are if the patient is slightly acidotic or has normal pH these are good. But if they have rising K or declining renal function you may change to another IVF to avoid hyperkalemia. Differences between the 2 (LR plasmalyte) LR has lactate as bicarb precursor and needs the liver to convert it to bicarb- so if patient has liver failure may choose another Plasmalyte uses acetate and gluconate, which are metabolized by skeletal muscle to bicarb so can use this independent of liver func. Quote Link to comment Share on other sites More sharing options...
andersenpa Posted January 18, 2006 Share Posted January 18, 2006 If you think they need more resuscitation, or significant on going losses- crystalloid is usually the choice. On going losses- if blood is the loss, give blood. Don't rely on a hematocrit in pt with significant bleeding- if they act dry or shocky in the face of blood loss, transfuse. Elderly pts with unknown CAD, renal insufficiency, or cerebrovascular disease may not tolerate the lack of perfusion. Trauma reasearch supports the use of Albumin for volume resuscitation. It may maintain higher oncotic pressure (except in the case of SIRS/capillary leak), and may prevent flooding a an 80 yr old with COPD and an EF 20%. Quote Link to comment Share on other sites More sharing options...
themadmedic Posted January 19, 2006 Share Posted January 19, 2006 These equations are in Maxwell's also- a decent pocket guide you may wish to consider... Agree with Anderson about the use of blood products... Quote Link to comment Share on other sites More sharing options...
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