Effect of extreme metabolic acidosis on oxygen delivery capacity of the blood-An in vitro investigation of changes in the oxyhemoglobin dissociation curve in blood with pH values of approximately 6.30

Refsum, H. E.; Opdahl, Helge; Leraand, S

doi:10.1097/00003246-199709000-00016

Cited by 18 publications

(13 citation statements)

References 13 publications

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“…The position of the HbO 2 curve at pH 6.30 calculated from these data was in agreement with that previously determined in a detailed investigation in our hospital [6] and served to verify the method for HbO 2 curve determination used in the present investigation. The choice of anticoagulant or the processing of blood to EC had no significant effect on the HbO 2 curve within the normal range of pH values.…”

Section: Methodssupporting

confidence: 89%

“…This routine was therefore utilized for determination of the position of the curve as defined by its P 50 value. The median P 50 value for heparinized blood at a pH of 6.30 calculated by this method (8.9 kPa) was very close to that previously determined in our institution (9.1 kPa) by multiple direct measurements in heparinized blood at the same pH [6], thus verifying our method for determining the position of the HbO 2 curve even in grave acidosis.…”

Section: Methodssupporting

confidence: 86%

“…Often used equations (Siggaard-Andersen, Severing-haus) for calculating changes in the HbO 2 curve induced by variations in pH overestimate the right-ward shift of the HbO 2 curve in grave acidosis [6]. A dedicated data program using LabView software was developed locally by one of the authors, a research data engineer (TAS).…”

Section: Methodsmentioning

confidence: 99%

“…Calculations of curve shifts based on standard pH-dependent correction factors do not correct for changes in 2,3-DPG; even in fresh blood such calculations become increasingly inaccurate with mounting acidosis [6]. We therefore measured the storage-induced effect on the HbO 2 curve shifts in EC at 2–5 day intervals of storage for up to 35 days; on each experimental day, the samples were examined at four different pH values.…”

Section: Introductionmentioning

confidence: 99%

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The acidosis-induced right shift of the HbO₂dissociation curve is maintained during erythrocyte storage

Opdahl¹,

Strømme

Jørgensen

et al. 2011

Scandinavian Journal of Clinical and Laboratory Investigation

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Background and objectives. In fresh blood, tissue hypoxia increases microcirculatory acidosis, which enhances erythrocyte O2 unloading and increases the amount of available O2. Storage of eryfhrocytes increases the HbO2 affinity and reduces O2 unloading. We examined the development of the affinity change during a period of 5 weeks of storage by present blood bank standards, and investigated to what extent acidosis offsets the affinity change. Materials and methods. Blood from volunteer donors was processed and stored as erythrocyte concentrates (EC). At 2–5 day intervals, EC were drawn from the bags and suspended in plasma and crystalloids to an Hb ≈ 10 g/dL. The suspensions were adjusted to give a pH of 7.40, 7.10, 6.80 or 6.30 and equilibrated with different gas mixtures to SO2 0, 25, 50, 75 and 100%. Measurements of the PO2/SO2 pairs at each pH were used to calculate the position of the HbO2 curve and its P50 value. Results. A significant leftward shift in the HbO2 curve was established after 1 week of storage; after 2.5 weeks only minor further changes were observed. Acidification right-shifted the HbO2 curve, after 2.5 weeks of storage the curve at pH 7.10 was similar to that for fresh blood at pH 7.40. Calculations of extractable O2 showed that the left-shifted HbO2 curve of stored EC could be advantageous at a low arterial PO2. Conclusions. The rightward shift of the HbO2 curve due to acidosis is well maintained in stored eryfhrocytes, a moderate pH decrease offsets the storage-induced increased HbO2 affinity.

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Section: Methodssupporting

confidence: 89%

Section: Methodssupporting

confidence: 86%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The acidosis-induced right shift of the HbO₂dissociation curve is maintained during erythrocyte storage

Opdahl¹,

Strømme

Jørgensen

et al. 2011

Scandinavian Journal of Clinical and Laboratory Investigation

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“…There may even be several benefi ts to the profound acidosis of heavy exercise, although it is generally thought to be a fatiguing factor. The fi rst is that acidosis, either hypercapnic or metabolic, shifts the Hb-O 2 dissociation curve to the right (Bohr effect) and aids in progressively more O 2 unloading down to a pH of 6.4 [ 119 ]. Muscle intracellular acidosis helps to preserve muscle excitability when muscles become more depolarized due to rising extracellular potassium with increasing work intensity by decreasing chloride ion permeability [ 111 ].…”

Section: Acidosis and Hypoxia With Exercisementioning

confidence: 99%

Hypoxia and Its Acid–Base Consequences: From Mountains to Malignancy

Swenson

2016

Advances in Experimental Medicine and Biology

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Hypoxia, depending upon its magnitude and circumstances, evokes a spectrum of mild to severe acid-base changes ranging from alkalosis to acidosis, which can alter many responses to hypoxia at both non-genomic and genomic levels, in part via altered hypoxia-inducible factor (HIF) metabolism. Healthy people at high altitude and persons hyperventilating to non-hypoxic stimuli can become alkalotic and alkalemic with arterial pH acutely rising as high as 7.7. Hypoxia-mediated respiratory alkalosis reduces sympathetic tone, blunts hypoxic pulmonary vasoconstriction and hypoxic cerebral vasodilation, and increases hemoglobin oxygen affinity. These effects and others can be salutary or counterproductive to tissue oxygen delivery and utilization, based upon magnitude of each effect and summation. With severe hypoxia either in the setting of profound arterial hemoglobin desaturation and reduced O2 content or poor perfusion (ischemia) at the global or local level, metabolic and hypercapnic acidosis develop along with considerable lactate formation and pH falling to below 6.8. Although conventionally considered to be injurious and deleterious to cell function and survival, both acidoses may be cytoprotective by various anti-inflammatory, antioxidant, and anti-apoptotic mechanisms which limit total hypoxic or ischemic-reperfusion injury. Attempts to correct acidosis by giving bicarbonate or other alkaline agents under these circumstances ahead of or concurrent with reoxygenation efforts may be ill advised. Better understanding of this so-called "pH paradox" or permissive acidosis may offer therapeutic possibilities. Rapidly growing cancers often outstrip their vascular supply compromising both oxygen and nutrient delivery and metabolic waste disposal, thus limiting their growth and metastatic potential. However, their excessive glycolysis and lactate formation may not necessarily represent oxygen insufficiency, but rather the Warburg effect-an attempt to provide a large amount of small carbon intermediates to supply the many synthetic pathways of proliferative cell growth. In either case, there is expression and upregulation of many genes involved in acid-base homeostasis, in part by HIF-1 signaling. These include a unique isoform of carbonic anhydrase (CA-IX) and numerous membrane acid-base transporters engaged to maintain an optimal intracellular and extracellular pH for maximal growth. Inhibition of these proteins or gene suppression may have important therapeutic application in cancer chemotherapy.

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Thrombolysis and mechanical cardiopulmonary resuscitation for pulmonary embolism complicated by hepatic and splenic lacerations resulting in major haemorrhage

Flower,

Extremera‐Navas,

Mackenney

2024

Anaesthesia Reports

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SummaryThrombolysis with prolonged cardiopulmonary resuscitation may be required for the successful resuscitation of patients presenting with massive pulmonary embolism leading to cardiac arrest. A rare, recognised complication of cardiopulmonary resuscitation is traumatic hepatic and splenic laceration. The incidence of complications is believed to be increased in those who receive automated mechanical cardiopulmonary resuscitation, compared to those who receive standard chest compressions. We present a case of a patient with massive pulmonary embolism leading to cardiac arrest which was successfully treated with thrombolysis and mechanical automated cardiopulmonary resuscitation. The patient suffered hepatic and splenic lacerations resulting in major haemorrhage. This required emergency resuscitation with blood products and splenic embolisation. This case highlights the importance of continual re‐assessment of patients, the early recognition of complications and an awareness of the potential complications of treatments we deliver.

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Effect of extreme metabolic acidosis on oxygen delivery capacity of the blood-An in vitro investigation of changes in the oxyhemoglobin dissociation curve in blood with pH values of approximately 6.30

Cited by 18 publications

References 13 publications

The acidosis-induced right shift of the HbO₂dissociation curve is maintained during erythrocyte storage

The acidosis-induced right shift of the HbO₂dissociation curve is maintained during erythrocyte storage

Hypoxia and Its Acid–Base Consequences: From Mountains to Malignancy

Thrombolysis and mechanical cardiopulmonary resuscitation for pulmonary embolism complicated by hepatic and splenic lacerations resulting in major haemorrhage

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Effect of extreme metabolic acidosis on oxygen delivery capacity of the blood-An in vitro investigation of changes in the oxyhemoglobin dissociation curve in blood with pH values of approximately 6.30

Cited by 18 publications

References 13 publications

The acidosis-induced right shift of the HbO2dissociation curve is maintained during erythrocyte storage

The acidosis-induced right shift of the HbO2dissociation curve is maintained during erythrocyte storage

Hypoxia and Its Acid–Base Consequences: From Mountains to Malignancy

Thrombolysis and mechanical cardiopulmonary resuscitation for pulmonary embolism complicated by hepatic and splenic lacerations resulting in major haemorrhage

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Product

Resources

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The acidosis-induced right shift of the HbO₂dissociation curve is maintained during erythrocyte storage

The acidosis-induced right shift of the HbO₂dissociation curve is maintained during erythrocyte storage