Workshop on Electrolyteand Acid-BaseDisturbances Organisers AKAgarwal,RKSingal Editor PraveenAggarwal Governing Body of Association of Physicians of India PresidentElect President PastPresident AKAgarwal, NewDelhi(2009) SKBichile,(Mumbai 2009) RKSingal,(NewDelhi 2009) Vice Presidents BRBansode,(Mumbai 2009) PritamGupta,(NewDelhi 2010) AlakaDeshpande,(Mumbai 2011) Hon.General Secretary Sandhya Kamath,(Mumbai 2010) Hon.Treasurer Milind Y Nadkar,(Mumbai 2009) Members ShyamSundar,(Varanasi 2009) RohiniHanda,(NewDelhi 2010) NarinderPalSingh,(NewDelhi 2011) YSatyanarayanRaju,(Hyderabad 2009) AmalKumarBanerjee,(Howrah 2010) MadhukarRai,(Varanasi 2011) JMukhopadhyay,(Howrah 2009) RSajithkumar,(Kottayam 2010) SurendraDaga,(Kolkata 2011) NKSingh,(Dhanbad 2009) AbhayNRai,(Gaya 2010) SArulrhaj,(Tuticorin 2011) Zonal Members NorthZone–RajeshUpadhyay,(NewDelhi 2011) MidSouthZone–GNarsimulu,(Hyderabad 2011) NorthWestZone–GurpreetSWander,(Ludhiana 2011) SouthZone–AMuruganathan,(Tirupur 2011) CentralZone–SanjivMaheshwari,(Ajmer 2011) MidEastZone–KamleshTewary, Muzaffarpur( 2011) WestZone–AshitBhagwati,(Mumbai 2011) EastZone–SamarKumarBanerjee,(Kolkata 2011) Ex Officio Member Dean ICP AK Das, Pondicherry Invited Members Hon.Editor,JAPI APIHouseChairman Editor-in-chief,APITextBook ShashankRJoshi, Mumbai SiddharthNShah, Mumbai YPMunjal, NewDelhi Co-opted Members Jt.Secretary, President’sPlace ArmedForces, MedicalServices Jt.Secretary(HQ) JMPhadtare, Mumbai(2009) Lt.Gen.SRMehta,(NewDelhi 2007-2008) FalguniParikh, Mumbai OrganisingSecretary, APICON2008 OrganisingSecretary, APICON2008 NNAsokan, Muvattupuzha NKSoni, Ghaziabad APICON 2009 Workshop on Electrolyte and Acid-Base Disturbances Date: January 30, 2009 Time: 2.00 pm – 6.00 pm Convener Praveen Aggarwal, All India Institute of Medical Sciences New Delhi Faculty l Praveen Aggarwal, New Delhi l Chhavi Sawhney, New Delhi l Sanjeev Bhoi, New Delhi Electrolyte and Acid-Base Disturbances l APICON 2009 l Jan. 29 - Feb. 1, 2009 1 SCIENTIFIC COMMITTEE, APICON – 2009 A. K. Agarwal Chairman, Scientific Committee S. K. Bichile President, Association of Physicians of India (API) A. K. Das Dean, Indian College of Physicians (ICP) B. B. Thakur Dean-Elect, ICP Sandhya Kamath Hony. General Secretary, API and ICP Shashank R. Joshi Hony. Editor, Journal of Association of Physicians of India (JAPI) N. K. Soni Organising Secretary, APICON - 2009 Members – Scientific Committee R. K. Singal Surendra K. Sharma Samar Banerjee Shyam Sundar Principal Advisors Y. P. Munjal B. K. Sahay Siddharth N. Shah Members – Advisory Board S. Arulrhaj T. Kadhiravan J. M. Phadtare Amal Kumar Banerjee O. P. Kalra Prashant Prakash B. R. Bansode Ulka Kamble A. N. Rai Subhash Chandra Umesh Kansra Y. Satyanarayan Raju Anil Chaturvedi Ram Kapoor B. B. Rewari S. Chugh V. N. Kaushal Anita Sharma Naveen Garg Navin Kumar N. K. Singh P. S. Ghalaut Rajat Kumar N. P. Singh Anil Gomber Sanjiv Maheshwari Rita Sood Vinay Gulati Lt. Gen. S. R. Mehta Dinesh Srivastava B. Gupta Vipin Mendiratta B. K. Tripathi B. B. Gupta Adhip Mitra Rajesh Upadhyay Pritam Gupta Alladi Mohan A. K. Vaish Rohini Handa Ashutosh Mohan A. K. Varshney 2 Electrolyte and Acid-Base Disturbances l APICON 2009 l Jan. 29 - Feb. 1, 2009 Contents 1. Fluid and Electrolyte Disturbances 4 Sanjeev Bhoi, Chhavi Sawhney 2. Acid-Base Disturbances 19 Praveen Aggarwal Electrolyte and Acid-Base Disturbances l APICON 2009 l Jan. 29 - Feb. 1, 2009 3 1. Fluid and Electrolyte Disturbances Sanjeev Bhoi, Chhavi Sawhney The Body Water sweat, exudates, and transudates can also be considered as specialized portions of the extracellular water, because About a billion years ago, life began-in the sea. The sea when these are lost a severe loss of extracellular water possessed unique properties for the maintenance of life. occurs. For example, the water of the sea is a solvent for the electrolytes and the oxygen that are necessary for life. The relation of the body water to the body weight are as The sea is also a solvent for the carbon dioxide that follows: accumulates during life’s processes. Since the carbon Water Compartment Percentage Volume in dioxide is volatile, it can be easily dissipated from the of Body Liters surface of the sea. In addition, the volume of the sea is Weight (man, 70 kg) so great that it can absorb large amounts of heat, or lose large amounts of heat, with only relatively small changes Plasma water (plus) 4 2.8 in temperature. The volume of the sea is also so great Interstitial water 16 11.2 that significant changes in its composition occur only over a period of hundreds of thousands of years. Finally, Total extracellular its dielectric constant, its surface tension, and other water (plus) = 20 = 14 physical properties are all important in maintaining and Intracellular water 40 28 protecting life. Total average body As a result, the water that surrounds the cells of water in a man = 60 = 42 vertebrates and of humans, namely, the extracellular Total average body water, still has an electrolyte composition similar to what water in a 70 kg woman 50 35 the sea had in pre-recorded times, in spite of all the countless changes in evolution that have occurred. Over These figures represent average values that we shall use the years, the rivers of the world have eroded land and in calculating water and electrolyte requirements in this washed elements into the sea. This has caused the book. electrolytes of the sea to become more concentrated. In The total body water varies. It is related principally to spite of this, there is still a remarkable similarity between the fat content of the body, and to sex. Fat has relatively the proportional composition of electrolytes in seawater less water associated with it; therefore a fat person will and in extracellular water. have relatively less water than a thin person. In addition, The total amount of water in the body can be determined a woman has a lower content of body water than a man. by introducing into the body a known quantity of a The water content of the body also decreases with age. substance that diffuses evenly throughout the The average water content of a man is approximately extracellular water and the cells, and then determining 60%. The average water content of a woman is its concentration. Antipyrine, urea, thiourea, and more approximately 50%. recently “heavy water” (deuterium oxide or tritium oxide) have been used for this purpose. Body water is also composed of inaccessible bone water and transcellular fluids. The Extracellular Water Transcellular fluids include the fluid of organs such as the kidneys, liver, pancreas, skin and the mucous The body water is usually divided into two main membranes of the gastrointestinal and respiratory, tracts; compartments: the extracellular water (extracellular and so on. It is difficult to measure the volume of the fluid) and the intracellular water (intracellular fluid). fluid in these compartments. The extracellular water includes the plasma water and the interstitial water (the fluid in the tissue spaces, lying Body water, including percentage of fat and of lean body between the cells). Gastrointestinal secretions, urine, tissue, can now be measured using a bioelectrical 4 Electrolyte and Acid-Base Disturbances l APICON 2009 l Jan. 29 - Feb. 1, 2009 impedance analyzer. This is due to the fact that the capillary walls prevent the outward movement of most of the protein from The Electrolytes in the Extracellular Water the plasma. As a result, the sodium concentration in plasma is slightly greater than the sodium Chemists are able to determine the nature and the concentration in the interstitial water. Conversely, the concentration of the electrolytes in both the extracellular chloride concentration in the plasma is slightly less water and the cells. However, the determination of than the chloride concentration in the interstitial water. electrolyte concentration in the cells requires special research techniques. Therefore, physicians must rely on The electrolyte concentrations are given in terms of the changes in electrolyte concentration in the milliequivalents per liter of serum or plasma (mEq/L). extracellular water, particularly in the plasma or serum, in treating patients. Milliequivalents The relative concentration of electrolytes in the The electrolytes of the body are in solution, mostly in extracellular water and in the cells is shown in Table 1. the form of ions. Their concentration can be described Notice that sodium (Na) and chloride (Cl) are the in terms of weight, such as milligrams (mg) per deciliter principal electrolytes in the extracellular water. However, (dL) of blood (mg/dL: a deciliter, or one tenth of a liter, potassium (K) and phosphates (PO4) are the principal is the same as 100 mL). Since the concentrations of the electrolytes in the cells. various electrolytes are small, they are expressed as milliequivalents per liter, mEq/L. Table 1: The Electrolyte concentration of body fluids (mEq/L)* These values are shown in Table 1. Notice that the concentration of the cations is the same as the Solution Extracellular Intracellular concentration of the anions in blood, serum or plasma Fluid Fluid when expressed in terms of milliequivalents. In other Cations words, each liter of blood has 153 mEq of cations (Na, K, Sodium 142 10 Ca, Mg) and 153 mEq of anions (bicarbonate, chloride, sulphate, phosphate, organic acids and protein anions). Potassium 4.5 150 Magnesium 2 40 The relationship between milliequivalents and Calcium 4.5 milligrams Total 153 200 The relationship between