sodium-bicarbonate and Hypertension--Pulmonary

Anesthesia for lung transplantation remains one of the highest risk surgeries in the domain of the cardiothoracic anesthesiologist. End-stage lung disease, pulmonary hypertension, and right heart dysfunction as well as other comorbid disease factors predispose the patient to cardiovascular, respiratory and metabolic dysfunction during general anesthesia. Perhaps the highest risk phase of surgery in the patient with severe pulmonary hypertension is during the induction of anesthesia when the removal of intrinsic sympathetic tone and onset of positive pressure ventilation can decompensate a severely compromised cardiovascular system. Severe hypotension, cardiac arrest, and death have been reported previously. Here we present 2 high-risk patients for lung transplantation, their anesthetic induction course, and outcomes. We offer suggestions for the safe management of anesthetic induction to mitigate against hemodynamic and respiratory complications.

Topics: Adrenergic alpha-Agonists; Anesthesia; Bronchodilator Agents; Calcium Chloride; Cardiopulmonary Resuscitation; Cardiotonic Agents; Epinephrine; Fatal Outcome; Female; Heart Arrest; Humans; Hypertension, Pulmonary; Lung Transplantation; Male; Middle Aged; Milrinone; Nitric Oxide; Norepinephrine; Sodium Bicarbonate; Vasoconstrictor Agents; Vasopressins

Amniotic fluid embolism (AFE) is a rare and potentially fatal complication of pregnancy. In this case report, we highlight the successful use of sodium bicarbonate in a patient with an AFE. We present a case of a 38-year-old mother admitted for an elective caesarean section. Following the delivery of her baby, the mother suffered a cardiac arrest. Following a protracted resuscitation, transoesophageal echocardiography demonstrated evidence of acute pulmonary hypertension, with an empty left ventricle and an over-distended right ventricle. In view of these findings and no improvement noted from on-going resuscitation, sodium bicarbonate was infused as a pulmonary vasodilator. Almost instantaneous return of spontaneous circulation was noted, with normalisation of cardiac parameters. We propose that in patients suspected with AFE and who have been unresponsive to advance cardiac life support measures, and where right ventricular failure is present with acidosis and/or hypercarbia, the use of sodium bicarbonate should be considered.

Topics: Adult; Embolism, Amniotic Fluid; Female; Heart Arrest; Humans; Hypertension, Pulmonary; Pregnancy; Sodium Bicarbonate; Vasodilator Agents

Sodium bicarbonate is used to treat metabolic acidosis or to induce metabolic alkalosis in sick neonates. The aim of this study was to quantify the decrease in serum concentration of ionized magnesium ([Mg(2+)]) when sodium bicarbonate is administered in vivo. We administered 1 mEq/kg body weight sodium bicarbonate 4.2% for correction of metabolic acidosis (n = 11) for management of persistent pulmonary hypertension (n = 3). After sodium bicarbonate treatment, serum pH increased by an average of 0.046 (P < 0.001), serum [Mg(2+)] decreased by an average of 0.07 mmol/L (P < 0.01), and serum [Ca(2+)] decreased by an average of 0.06 mmol/L (P = 0.04). There was a significant correlation between baseline [Mg(2+)] and baseline [Ca(2+)] (R(2) = 0.328, P = 0.032). Sodium bicarbonate therapy in infants causes a significant decrease in [Mg(2+)] and serum [Ca(2+)]. We suggest that infusion of sodium bicarbonate be effected while monitoring serum [Mg(2+)] and serum [Ca(2+)].

Topics: Acidosis; Calcium; Cations, Divalent; Female; Humans; Hydrogen-Ion Concentration; Hypertension, Pulmonary; Infant, Extremely Premature; Infant, Newborn; Infant, Premature; Magnesium; Male; Retrospective Studies; Serum; Sodium Bicarbonate

Sodium bicarbonate (NaHCO3) has been used successfully in mammals and birds to alleviate pulmonary hypertension. Experiment 1 was designed to provide measurements of arterial and venous blood-gas values from unanesthetized male broilers subjected to a cool temperature (16 degrees C) challenge and fed either a control diet or the same diet alkalinized by dilution with 1% NaHCO3. The incidences of pulmonary hypertension syndrome (PHS, ascites) for broilers fed the control or bicarbonate diets were 15.5 and 10.5%, respectively (P = 0.36, NS). Non-ascitic broilers fed the control diet were heavier than those fed the bicarbonate diet on d 49 (2,671 vs. 2,484 g, respectively); however, other comparisons failed to reveal diet-related differences in heart weight, pulse oximetry values, electrocardiogram amplitudes, or blood-gas values (P > 0.05). When the data were resorted into categories based on right:total ventricular weight ratios (RV:TV) indicative of normal (RV:TV < 0.28) or elevated (RV:TV > or = 0.28) pulmonary arterial pressures, broilers with elevated RV:TV ratios had poorly oxygenated arterial blood that was more acidic, had high partial pressure of CO2 (PCO2), and had higher HCO3 concentrations when compared with broilers with normal RV:TV ratios. Experiment 2 was conducted to determine if metabolic variations associated with differences in feed intake or environmental temperature potentially could mask an impact of diet composition on blood-gas values. Male broilers maintained at thermoneutral temperature (24 degrees C) either received feed ad libitum or had the feed withdrawn > or = 12 h prior to blood sampling. Broilers fed ad libitum had lower venous saturation of hemoglobin with O2, higher venous PCO2, and higher arterial HCO3 concentrations than broilers subjected to feed withdrawal. Broilers in experiment 2 fed ad libitum and exposed to cool temperatures (16 degrees C) had lower arterial partial pressure of O2 and higher venous PCO2 than broilers fed ad libitum and maintained at 24 degrees C. Overall, these results demonstrate that changes in diet composition (control vs. 1% NaHCO3 diets) had minimal impact on arterial and venous blood-gas variables when compared with the more dramatic differences associated with feed intake (ad libitum vs. > or = 12 h withdrawal), environmental temperature (24 vs. 16 degrees C), and the pathogenesis associated with PHS (RV:TV < 0.28 vs. > or = 0.28).

Topics: Acid-Base Equilibrium; Animals; Ascites; Blood Gas Analysis; Carbon Dioxide; Chickens; Cold Temperature; Food Deprivation; Hydrogen-Ion Concentration; Hypertension, Pulmonary; Incidence; Male; Oxygen; Partial Pressure; Poultry Diseases; Pulmonary Artery; Random Allocation; Sodium Bicarbonate; Syndrome