Sodium bicarbonate in acidosis

nahco3
metabolic acidosis

1. NaHCO3 in Acidosis Abdalmohsen Ababtain

2. Objectives What’s Bicarbonate How it works Dose ? How can we give it Contraindications and Safety Who do you want to give it? When shall we use it Bicarbonate Disadvantages Bicarbonate Alternatives

3. What’s Sodium Bicarbonate

4. What’s Sodium Biacarbonate ? IV fluid with pH of 8.0  8.4% solution contains 1 mEq / mL of NaHCO3 and is very hypertonic (2,000mOsm/kg) 7.5% solution contains 0.9 mEq / mL of NaHCO3 4.2% solution contains 0.5 mEq / mL of NaHCO3

5. How It works

6. Bicarbonate binds to H then breaks down into CO2 and water in the blood.

7. One Ampule of bicarbonate fully reacted will generate over 11 of CO2 and 1.5  meq /L of Hco3 Resp Acidosis, So what ? Current Opinion in Critical Care 2008, 14:379–383

8. Respiratory Acidosis Decreases left ventricular contractility but increased overall CO by 23% due to decrease SVR and increase HR Circultion Research 1990;67:628-635

9. Dose ?

10. Dose Based on the calculated Deficit : HCO 3 - ( mEq ) = 0.5 x weight (kg) x [24 - serum HCO 3 - ( mEq /L)] Administer  1 / 2  dose over 3-4 hrs, then remaining  1 / 2  dose over the next 24 hours;

11. If acid-base status is not available: 2-5 mEq /kg I.V. infusion over 4-8 hours ; subsequent doses should be based on patient's acid-base status initial goal of therapy is to target a pH of ~7.2 and a HCO 3 - of ~10 mEq /L to prevent overalkalinization .

12. How can we give it ?

13. 100 meq of NaHco 3  in 400 mL sterile water at rate 200ml/hr 150 meq of NaHco 3 in 1 liter or D5% or ½ NS at rate 150-200cc/hr

14. Bolus !!

15. No Hco3 Bolus  IV-push administration should be reserved for cardiac life support whenever indicated and not metabolic acidosis Koda -Kimble M, Young LY, et al. Handbook of Applied Therapeutics. Lippincott Williams & Wilkins, 2006. P10.3(1104)

16. Is Sodium Bicarbonate Safe ?

17. Safety Pregnancy Risk Factor  C Breast-Feeding Considerations  Sodium is found in breast milk Still No Enough Data !! Do you Really Care ?

18. Extravasation management Stop infusion immediately and disconnect (leave cannula in place); gently aspirate extravasated solution ( do NOT flush the line ); initiate hyaluronidase antidote; remove cannula ; apply dry cold compresses elevate extremity. Hyaluronidase :   SubQ : Inject four to five separate 0.2 mL injections of 15 units/ mL around area of extravasation (Hurst, 2004). Dimens Crit Care Nurs . 2004 May-Jun;23(3):125-8

19. Potential harms of bicarbonate therapy Increased PCO2 Hypernatremia Extracellular fluid (ECF) volume expansion Intracellular and CSF Acidosis (CO2) Hypokalemia severe tissue necrosis if extravasation takes place rebound alkalosis Ann Intern Med. 1986;105(6):836 Diabetes 1974, 23:405-411 N Engl J Med 1971, 284:283-290

20. bicarbonate increases lactate production by: increasing the activity of the rate limiting enzyme phosphofructokinase and removal of acidotic inhibition of glycolysis shifts Hb-O2 dissociation curve, increased oxygen affinity of haemoglobin and thereby decreases oxygen delivery to tissues hyperosmolality (cause arterial vasodilation and hypotension)

21. Reduced ionized calcium by 10% (10% drop may decrease cardiac and vascular contractility and responsiveness to catecholamines ) Ann Intern Med. 1990;112(7):492-498

22. Before you Give Bicarb : Correct the underlying cause of acidosis and give supportive care Ensure adequate ventilation to eliminate CO2 Correct hypoxia Think twice before you give it in high anion gap acidosis

23. Contraindications Alkalosis Hypernatremia severe pulmonary edema hypocalcemia

24. Why do you want to give bicarb ? What are the deleterious effects of acidemia , and when are they manifest? When is acidemia severe enough to warrant therapy?

25. Why do you want to give bicarb ? metabolic acidosis leads to adverse cardiovascular effects: Reduced left ventricular contractility Arrhythmias Arterial vasodilation and venoconstriction Impaired responsiveness to catecholamine vasopressors

26. What Are we Treating ?

27. Bicarbonate in DKA Is it beneficial !

28. Does bicarbonate improve management of severe DKA ? Ann Pharmacother. 2013 Jul-Aug;47(7-8):970-5: Intravenous bicarbonate therapy did not decrease time to resolution of acidosis or time to hospital discharge for patients with DKA with an initial pH <7.0.

29. Crit  Care Med. 1999 Dec;27(12):2690-3:  Not in favor of the use of bicarbonate in the treatment of diabetic ketoacidosis with pH values between 6.90 and 7.10.

30. Ann Intern Med 1986;105:836–840: administration of bicarbonateto pt with pH (6.9 to 7.14) does not affect recovery outcome variables as compared with those in a control group.

31. In Pediatrics Ann Emerg Med. 1998. Jan;31 (1):41-8.: Prolonged hospitalizations were noted in the bicarbonate group No evidence that adjunctive bicarbonate improved clinical outcome in children with severe DKA (pH < 7.15). The rate of metabolic recovery and complications were similar in patients treated with and without bicarbonate

32. Systematic review of 44 studies : Ann Intensive Care. 2011 Jul 6;1(1):23 Showed increased risk for cerebral edema and prolonged hospitalization in children who received bicarbonate, and weak evidence of transient paradoxical worsening of ketosis , and increased need for potassium supplementation

33. Bicarb Increases Ketosis : Br Med J ( Clin Res Ed). 1984 October 20; 289(6451): 1035–1038. slower rate of lactate clearance, implying impaired tissue oxygenation J Clin Endocrinol Metab. 1996 Jan;81(1):314-20 The group receiving NaHCO3 showed a 6-h delay in the improvement of ketosis as compared with controls

34. Cerebral Edema in Pediatrics N Engl J Med 2001;344:264–269  cerebral edema occurs in approximately 1% of episodes of DKA in children with a mortality rate of 40-90% only treatment with bicarbonate was associated with cerebral edema

35. Cerebral Edema Risk Factors Use of bicarbonate Younger age newly diagnosed diabetes  hypocapnia   Severe acidosis higher serum glucose, urea nitrogen, and creatinine concentrations at the time of presentation N Engl J Med. 2001;344(4):264 J Pediatr. 1980;96(6):968

36. Conclusion Do not use NaHCO3 routinely in the management of DKA Despite the lack of evidence many intensivists have a personal cut-off pH at which they consider giving HCO3- in severe acidemia due to DKA (typically < pH 6.9 to 7.0) as a ‘last ditch’ measure

37. Ann Intern Med. 1987;106(4):615 To be used in collapsing pt. 1) patients with a pH <7.0, in whom decreased cardiac contractility and vasodilatation may be impairing tissue perfusion 2) patients with severe hyperkalemia 3) patients with coma

38. If you want to give it patients with a pH <6.9 , 100 meq of Hco3 in 400 mL sterile water at a rate of 200 ml/h. pH of 6.9–7.0 , 50 mmol sodium bicarbonate is diluted in 200 ml sterile water and infused at a rate of 200 ml/h. No bicarbonate is necessary if pH is >7.0 Diabetes Care January 2004 vol. 27 no. suppl 1 s94-s102

39. American Diabetic Association (ADA) Says bicarbonate “may be considered” in patients with pH < 6.9 in DKA High level evidence is lacking !!

40. Lactic Acidosis the most common cause of metabolic acidosis in hospitalized patients Type A :due to marked tissue hypoperfusion in shock Type B : toxin-induced impairment of cellular metabolism Metformin Alcoholism  Malignancy HIV infection

41. D-lactic acidosis rare form of lactic acidosis that can occur in patients with short bowel syndrome or other forms of gastrointestinal malabsorption who ingest large amount of carbohydrates Ingestion of propylene glycol Some DKA Patients

42. Lactic Acidosis Lactic Acidosis that is severe enough to warrants Bicarb therapy already has a high mortality to begin with Literature Review done : Chest. 2000 Jan;117(1):260-7 we do not give or advise bicarbonate infusion regardless of the pH.

43. Uptodate suggest that patients with lactic acidosis and severe acidemia (pH <7.1 and Hco3 below or equal to 6  meq /L ) receive bicarbonate therapy (tube the pt. if PCo2 >20 for Inadequate ventilation)

44. Review Article In view of the paucity of data, we are not able to agree or disagree with Bicarb treatment we do not think that bicarbonate administration is indicated for LA due to shock if pH > 7.0 Current Opinion in Critical Care 2008, 14:379–383

45. in hemorrhegic lactic acidosis on animal study Bicarbonate treatment  along with hyperventilation and calcium administration increases pH and improves cardiovascular function Anesthesiology. 2013 Nov 20

46. Bicarb and Mortality Sodium bicarbonate administration was an independent factor associated with higher mortality PLoS One. 2013 Jun 5;8(6):e65283

47. Sodium bicarbonate elevated blood lactate concentrations to a greater extent than did either sodium chloride or no treatment. Science 15 February 1985

48. prospective randomized, double-blind, controlled clinical trial I: in first stage sodium bicarbonate was given by venous drip until pH≥7.15, and in second stage sodium bicarbonate was given by intravenous drip till pH≥7.25 after 6 hours C: intravenous drip of sodium bicarbonate was used till pH≥7.15 Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2013 Jan;25(1):24-7

49. Their conclusion !! The use of sodium bicarbonate in stages in treating hypoperfusion induced lactic acidemia as a result of septic shock can lower the occurrence rate of multiple organ dysfunction syndrome , time of mechanical ventilation , durations of stay in ICU and in hospital , and mortality Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2013 Jan;25(1):24-7

50. Surviving Sepsis Campaign 2012 We recommend against the use of sodium bicarbonate therapy for the purpose of improving hemodynamics or reducing vasopressor requirements in patients with hypoperfusion -induced lactic acidemia with pH ≥ 7.15 (grade 2B). No good Evidence on pH< 7.15

51. PH>7.1 Two randomized trials failed to find a benefit of bicarbonate therapy in critically ill patients with lactic acidosis and pH values > 7.1

52. Prospective, randomized, blinded, crossover study Correction of acidemia using sodium bicarbonate does not improve hemodynamics in critically ill patients who have metabolic acidosis and increased blood lactate pH (from 7.22 to 7.36) and serum bicarbonate (from 12 to 18  mmol /L) Ann Intern Med. 1990 Apr 1;112(7):492-8.

53. Prospective, randomized, blinded, crossover study Bicarbonate therapy significantly increased the arterial pH (from 7.16 to 7.21) and serum bicarbonate (from 16 to 19  mmol /L) The infusion of sodium bicarbonate and sodium chloride produced similar changes in cardiac output, mean arterial pressure, and pulmonary artery pressure Improving Numbers not M&M Ann Intern Med. 1990 Apr 1;112(7):492-8.

54. Prospective, randomized, blinded, crossover study Administration of sodium bicarbonate did not improve hemodynamic variables in patients with lactic acidosis, but did not worsen tissue oxygenation. Crit Care Med. 1991 Nov;19(11):1352-6

55. Case Report 43-year-old woman K/c HTN on atenolol and Anxiety on Mirtazipine and lorazepam was brought to the hospital with chest pain for 20 hours radiating to her Back Temp 32.5C BP 66/45 mmHg HR 57 Denied Hx of Ingestion Tx as Septic Shock due to pneumonia 4 hrs later her condition deteriorated, Got tubed Case Reports in Nephrology Volume 2012 (2012), Article ID 671595

56. pH 6.56 , bicarbonate 3  mmol /L, and lactate 18.4  mmol /L AG 31 serum creatinine of 162  μmol /L with a serum potassium of 5.3  mmol /L Hco3 Infusion Started NE, Dobutamine , phenylephrine and Vassopressin Started Case Reports in Nephrology Volume 2012 (2012), Article ID 671595

57. PAN CT and TEE was Done INCONCLUSIVE for aortic disease A Nurse Calling you for K+ 7.8 and GC 1.2mmol/l AG 43 Urine Tox Positive for Benzo and opioid Serum tox Acetaminophen level 81µmol/L Chart Arrived and shows a suicidal attempt 15 years ago by overdose Case Reports in Nephrology Volume 2012 (2012), Article ID 671595

58. A member of the family revealed that she have DM and on metformin Metformin Level 170µg/ mL (therapeutic range 1-2µg/ mL ) CRRT Started THAM, 0.3 mmol /L, 36 mg/ mL , 1600 mg administered by infusion at 300 mL /hr for 5 hours Case Reports in Nephrology Volume 2012 (2012), Article ID 671595

59. 90 mg Metformin !! Afterward Pt improved, Extubated Admitted Taking 90 mg Metformin Case Reports in Nephrology Volume 2012 (2012), Article ID 671595

60. Metformin Toxicity Dtsch Med Wochenschr.  2000 Mar 3;125(9):249-51 Conventional management of the lactic acidosis neither corrected the acidosis nor stabilized the circulatory system. Continuous veno -venous haemodialysis with bicarbonate-buffered solutions succeeded in reducing the need for catecholamines

61. Metformin Toxicity Diabetes Care June 1999 vol. 22 no. 6 925-927 9 per 100,000 person-years Biguanides and NIDDM.Diabetes Care 15:755–772, 1992 Metformin. N Engl J Med 334:574–579, 1996 The lactic acidosis rate in metformin users has been reported to be much lower: 0–8.4 cases per 100,000 person-years

62. Risk factors age of >60 yr decreased cardiac Hepatic Disease renal function diabetic ketoacidosis surgery respiratory failure ethanol intoxication fasting

63. Severe acidosis in Trauma retrospective therapeutic cohort study of 225 severely acidotic (arterial pH ≤ 7.10) between 1989-2011 if dead space in the lungs increases due to shock with poor lung perfusion, the arterial-end tidal PCO 2 difference [P(a-ET)CO 2 ] increases J Trauma Acute Care Surg. 2013 Jan;74(1):45-50

64. 2-8 vials of HCO3 given HCO 3 10.5 (3.1) to 16.8 (4.0) mEq /L PaCO 2 44 (9) to 51 (11) mmHg end-tidal CO 2 stayed relatively constant 26 [6] to 25 [5] P(a-ET)CO 2 from 17 (9) to 24 (13) mmHg More Dead Space ! J Trauma Acute Care Surg. 2013 Jan;74(1):45-50

65. 75 patients who survived had P(a-ET)CO 2 10 (6) mm Hg 103 patients who died in the operating room or within 48 hours of surgery had a P(a-ET)CO 2 of 23 (10) mm Hg J Trauma Acute Care Surg. 2013 Jan;74(1):45-50

66. We have found that in severely injured patients, P(a-ET)CO 2 of less than 10 mm Hg is associated with survival and P(a-ET)CO 2 of greater than 16 mm Hg is usually fatal. Our initial studies suggested that intravenously administered bicarbonate increases P(a-ET)CO 2 J Trauma Acute Care Surg. 2013 Jan;74(1):45-50

67. Sodium bicarbonate supplements for treating acute kidney injury Cochrane Review was Done 2012 We did not find any randomized controlled trials (RCTs) that assessed the benefits or harms of giving sodium bicarbonate to people with acute kidney problems.

68. Bicarb is not that good !   Tromethamine  (THAM) Carbicarb Dichloroacetate (DCA) CRRT

69. Carbicarb is a mixture of Na2CO3/NaHCO3 that buffers similarly to NaHCO3, but without net generation of CO2 Same risks of hypertonicity and hypervolemia are similar to those of sodium bicarbonate

70. Comparing carbicarb Vs.bicarb in hypoxic LA 28 Dogs with HLA Given 2.5 meq /kg of either NaHCO3 or carbicarb over 1 hr. Lactate use by muscle, gut, and liver all improved with carbicarb and decreased with NaHCO3. Circulation 77, No. 1, 227-233, 1988 Carbicarb Bicarb PH (7.22 to 7.27 7.18 to 7.13 PCo2 No Change Lactate Stabilized

71. Twenty-one dogs were anesthetized, mechanically ventilated, and randomly allocated into: Carbicarb sodium bicarbonate sodium chloride Carbicarb administration in HLA improved hemodynamics compared with sodium bicarbonate or sodium chloride administration Chest. 1993;104(3):913-918

72. THAM A biologically inert amino alcohol of low toxicity, which buffers H+ and gets excreted in the urine without production of Co2 Administration of THAM in ALI cases was associated with significant improvements in arterial pH and base deficit, and a decrease in arterial carbon dioxide tension Toxicities of THAM include hyperkalemia , hypoglycemia, and respiratory depression Am J Respir Crit Care Med. 2000 Apr;161(4 Pt 1):1149-53

73. Bicarb + THAM Using a blood- perfused isolated heart preparation, left ventricular contractility and relaxation were measured The combination of THAM with NaHco3 is based on the ability of THAM to capture the CO2 produced by the sodium bicarbonate buffer. This combination achieves a perfect correction of metabolic acidosis and improves myocardial performance. Am J Respir Crit Care Med. 1997 Mar;155(3):957-63

74. CRRT Use bicarbonate-based replacement fluid over citrate as citrate may increase the strong ion gap Current Opinion in Critical Care 2008, 14:379–383

75. When shall we use it Accepted Hyperkalaemia Treatment of sodium channel blocker overdose (e.g. tricyclic overdose) Urinary alkalinisation ( salicylate poisoning) Metabolic acidosis (NAGMA) due to HCO3 loss (RTA, fistula losses)

76. Controversial Diabetic ketoacidosis (very rarely, perhaps if shocked and pH < 6.8) Severe pulmonary hypertension with RVF to optimize RV function Severe ischemic heart disease where lactic acidosis is thought to be an arrhythmogenic risk

77. Cardiac Arrest The empirical early administration of sodium bicarbonate (1 mEq /kg) has no effect on the overall outcome in prehospital cardiac arrest. However, a trend toward improvement in prolonged (>15 minutes) arrest outcome was noted. 2-fold increase in survival (32.8% vs 15.4%) ! Sodium bicarbonate improves outcome in prolonged prehospital cardiac arrest Am J Emerg Med. 2006;24(2):156

78. retrospective cohort The administration of sodium bicarbonate at around 36 Minutes of CPR did not significantly improve the rate of ROSC in out-of-hospital cardiac arrest American Journal of Emergency Medicine 31 (2013) 562–565

79. No Benifit Buffer therapy during out-of-hospital cardiopulmonary resuscitation. Resuscitation. 1995;29:89 –95 . (RCT) Sodium bicarbonate improves outcome in pro-longed prehospital cardiac arrest. Am J Emerg Med. 2006;24:156 –161 . Prehospital bicarbonate use in cardiac arrest: a 3-year experience. Am J Emerg Med. 1992;10:4 –7 .

80. Out-of-hospital buffer therapy in heart arrest Tidsskrift for den Norske Laegeforening : Tidsskrift for Praktisk Medicin , ny Raekke  [1996, 116(27):3212-3214

81. CRITICAL CARE CLINICS VOLUME 14 NUMBER 3 - JULY 1998

82. ACLS Guidelines 2010 Giving sodium bicarbonate during CPR is not helpful and may even be harmful! (Class III, LOE B).

83. Bicarbonate may compromise CPR by reducing SVR It can create extracellular alkalosis that will shift the oxyhemoglobin saturation curve and inhibit oxygen release. It can produce hypernatremia and therefore hypersmolarity . It produces excess CO2, which freely diffuses into myocardial and cerebral cells and may paradoxically contribute to intracellular acidosis. It can exacerbate central venuous acidosis and may inactivate simultaneously administered catecholamines .

84.  prospective, randomized, double-blind, controlled trial 36% receiving buffer were admitted to hospital ICU and (10%) were discharged from hospital alive, vs. (36%) and (14%) receiving saline Buffer therapy during out-of-hospital cardiopulmonary resuscitation Resuscitation . 1995;29(2):89

85. Hyperkalemia Though no studies demonstrate harm, the solo administration of bicarbonate does not acutely decrease potassium levels. But it may improve insulin/ albuterol action on potassium in acidotic patients. Don’t Give It Alone If you want to Give it Give as infusion (150mEq in 1 liter D5%) Miner Electrolyte Metab . 1991;17(5):297 Kidney Int. 1992;41(2):369

86. Rhabdomyolisis There is no evidence that bicarbonate is helpful or harmful in rhabdomyolysis An excellent  EBMedicine.net review  recommends bicarbonate if urine pH <6.5 with CK level > 5000 as class III evidence – indicating “it may be acceptable, possibly useful, considered optional or an alternative treatment

87. bicarbonate is still recommended in TCA overdose Salicylate toxicity Phenobarbarbital Chlorpropamide Chlorophenoxy herbicide poisoning Cocaine overdose Organophosphate poisoning Methanol and ethylene glycol Increased ICP

88. Home Message Bicarbonate has many complication you have to be aware of In NAGMA (Absolute bicarb loss) give it with no doubt aiming for Hco3 20 There are other options to Hco3 Its usually a last resort choice after treating the underlying disease

89. References Pubmed Uptodate Emcrit.org lifeinthefastlane.com