Carbon dioxide, also known as CO2, is a compound made of one carbon atom and two oxygen atoms. Beverages are artificially carbonated when carbon dioxide is dissolved into the liquid under high pressure; when that pressure is released, small gas bubbles develop. Some of the carbon dioxide produces carbonic acid, which is acidic. A common concern with carbonated beverages is the acidity levels and the risk of calcium and magnesium loss from bones due to a change in the body’s pH levels. A study in the American Journal of Clinical Nutrition found no significant link between short-term consumption of carbonated beverages and urinary excretion of calcium, which is an indicator for calcium depletion.
Carbonated or sparkling water is made by dissolving carbon dioxide in water, creating carbonic acid. This process just adds bubbles — it does not add sugar, calories, or caffeine. Tonic water, club soda, and mineral water are all types of carbonated water, but these have added sodium, vitamins, or sweeteners, so it’s important to read the label.
On average, Americans consume more than 50 gallons of carbonated soft drinks each year, according to the 2005 USDA report, “Contributions of Nonalcoholic Beverages to the U.S. Diet.” Although the ingredients in carbonated drinks are deemed safe by the Food and Drug Administration, these beverages may cause side effects, especially if you consume them on a regular basis. Familiarizing yourself with the possible side effects of carbonated drinks can help you make informed nutrition choices.
Belching and Heartburn – Carbonated beverages contain dissolved carbon dioxide, which becomes a gas when it warms to body temperature in your stomach. Consuming carbonated soft drinks may cause repeated belching as your stomach stretches from the accumulation of carbon dioxide gas. Food and stomach acid may come up your food pipe as you belch, causing heartburn and a sour taste in your mouth.
Increased Risk of Obesity – Consuming sugar-sweetened, carbonated drinks adds calories to your diet, which may increase your risk of overweight and obesity. In an April 2007 article published in the “American Journal of Public Health,” Lenny Vartanian, Ph.D., and colleagues report that the risk of overweight and obesity associated with consumption of sugar-sweetened, carbonated beverages is greater for women than men and for adults compared to children and adolescents. Overweight and obesity are significant risk factors for the development of type 2 diabetes, heart disease and osteoarthritis. While plain carbonated water is a better choice than sugary beverages like soda, juice, or sweet tea, a small 2017 study revealed that plain carbonated water increased a hunger hormone called ghrelin in men. Even the beloved LaCroix may not be so perfect. Essentially, when your ghrelin levels are high, you’ll feel hungrier and are likely to eat more, which can lead to weight gain. But more research is needed to confirm this outcome on a larger scale and in women. It’s also important to note that not all carbonated water is created equal. While carbonated water is just water plus air, some bottled seltzers and flavor enhancers contain sodium, natural and artificial acids, flavors, sweeteners, and other additives.
Poor Nutrition – Consumption of carbonated soft drinks can adversely affect your overall nutrient intake. Drinking these beverages may reduce your consumption of proteins, starch, dietary fiber and vitamin B-2, also known as riboflavin. People who drink carbonated beverages also tend to eat less fruit and drink less fruit juice compared to those who do not drink sodas.
Tooth Decay – Regular and diet carbonated soft drinks can harm your teeth. Your mouth contains bacteria that feed on sugar, producing chemicals that can break down the hard enamel of your teeth. A cavity forms when erosion of the enamel exposes the soft, inner core of your tooth. When you drink sweetened, carbonated soda, the sugar remains in your mouth, promoting the processes that lead to tooth decay. The acid in these carbonated drinks further increase the likelihood of developing cavities, because these chemicals also slowly erode the enamel of your teeth.
Reduced Bone Strength – If you are a woman, consumption of cola-type, carbonated drinks may reduce your bone strength. In an October 2006 article published in “The American Journal of Clinical Nutrition,” nutrition scientist Katherine Tucker, Ph.D., and colleagues report that women who consume regular and diet cola tend to have weaker hipbones compared to those who do not drink these beverages. The authors note that the degree of bone weakness correlates to the amount of cola consumed.
11 reasons to renounce your fizzy drink habit (Telegraph.co.uk)
Earlier in the year, scientists issued a warning over fizzy drinks, claiming that they cause a death toll of 184,000 adults every year. Full of sugar, chemicals and (usually) with zero nutritional value, fizzy drinks are something that we have been warned against on countless occasions, even if they do look appealing when the sun comes out. And it’s not just the ‘full-fat’ versions. Diet fizzy drinks can also have extremely harmful effects.
- They can increase our risk of cancer – There have been many studies that have looked at the links between various types of cancer and fizzy drink consumption. They suggest:
- Drinking just two sugary soft drinks a week increases the amount of insulin the pancreas produces and can double the risk of developing pancreatic cancer.
- Drinking just one fizzy drink a day could increase a man’s chance of developing prostate cancer by around 40 per cent.
- Drinking just one-and-a-half cans a day can increase a girl’s breast cancer risk by 30 per cent.
- Some chemicals that are used to color soft drinks can cause cancer.
- They can raise our risk of heart disease – Scientists in America found a strong link between the proportion of daily calories from foods laden with added sugars (like fizzy drinks) and death rates from cardiovascular disease. They claimed that drinking three cans a day could triple our risk of heart disease.
- They can lead to diabetes – Sugar-laden drinks have been proven to increase cases of Type 2 diabetes. A study conducted between 1990 and 2000 estimated that the increased consumption of sugar-sweetened drinks contributed to 130,000 new cases of diabetes.
- They can cause liver damage – A study from 2009 found that sugary drinks can cause fatty liver disease and drinking just two cans per day could lead to liver damage.
- They can make us violent – A study carried out on teenagers found a link between drinking fizzy drinks, violence and the likelihood of them carrying a weapon. The researchers found that even teenagers who drank just two cans a week were more aggressive towards their friends and those who drank five or more cans a week were also more likely to have drunk alcohol or smoked at least once in the previous month.
- They can cause premature birth in pregnant women – Pregnant women were warned against drinking diet fizzy drinks after a study taken in Denmark on 60,000 women. Those who drank artificially sweetened soft drinks, whether fizzy or still, were found to be more likely to give birth prematurely. It was thought that the chemicals in the artificial sweetener changed the wombs of the women.
- They can change your brain – As well as affecting the body, fizzy drinks have been found to alter the protein levels in the brain, which could lead to hyperactivity.
- They can cause premature aging – Phosphates used in fizzy drinks, as well as many other processed foods, has been found to speed up the ageing process. This is not bad just in terms of wrinkles, but also health complications that some with age, such as chronic kidney disease and cardiovascular calcification.
- They can cause early puberty – A Harvard Medical School study of 5,583 girls aged nine to 14 found that those who drank just one-and-a-half cans of soft drink a day had their first periods earlier than those who did not. This consequently meant that their risk of cancer increased.
- They can make us fat – This one may seem obvious. However, what you may not know is that diet soft drinks can still affect our waistline dramatically. A study found that those who drank diet fizzy drinks saw their waistlines expand nearly three times as much as non-drinkers and even more so than those drinking non-diet versions.
- They can increase our risk of Alzheimer’s – Scientists in America found that mice fed the equivalent of five cans of sugary drinks a day had worse memories and twice the amount of brain deposits associated with the disease than mice without added sugar in their diet. This suggests that fizzy drinks could be linked with Alzheimer’s.
Harmful Effects of Carbonated Water By Paul Dohrman
Carbon dioxide (CO2) gas is expelled by the lungs, so some people expect that ingesting it is unhealthy. However, CO2 is absorbed very slowly through the gastrointestinal tract, at a much lower rate than it is produced in cells and expired out of the lungs. The gas expansion from release of dissolved CO2 in carbonation can lead to the distension of the stomach. Aside from the less serious case of triggering hiccups, irritable bowel syndrome (IBS) can also be aggravated. Furthermore, the stomach distension may reduce the effectiveness of stomach acid to digest food that requires sufficient acidity. Sufferers of IBS are advised to eliminate carbonated drinks from their diet (as well as many other items) to allow the GI lining to heal.
Acidity – CO2 reacts with water to become carbonic acid (H2CO3). Some have argued that this excess acid in carbonation is dangerous. The stomach, however, is much more acidic (pH~1-2), and overwhelms the acidity of any carbonated drinks. To be concerned about ingesting acids that would make the stomach too acidic is misguided. It is a common misconception that digestive problems originate from too much acid in the stomach. Actually, antacids are oftentimes the opposite of what is healthy, since inadequate acidity can lead to insufficient digestion, which in turn leads to increased activity of intestinal bacteria, which causes increased bloating and reduced nutrient absorption. Furthermore, testament to the safety of carbonic acid in the body is that it exists in the blood as a natural step toward the expiration of CO2. The blood level of carbonic acid (of metabolic origin, not ingested) is tightly regulated by the body. Therefore, the introduction of carbonic acid by ingesting carbonated water is not likely to cause harm to the blood system.
Calcium Loss – It has been claimed that acidic ingestion from carbonated water can lead to leaching of calcium from other parts of the body. This would be of concern because bones are made of calcium. Calcium deficiency leads to osteoporosis. This claim has not been upheld in studies–not even when the stronger acids in soda have been tested in addition to carbonic acid. A study at Creighton University found no significant link between carbonated drinks and urinary excretion of calcium, a useful indicator of calcium depletion. Another study followed women in Spain during two months of drinking carbonated water; their bones were found to be normal at the end of the study.
Teeth – Is the carbonic acid of carbonated water harmful before reaching the stomach? Below a pH of 5.2, the enamel of teeth is dissolved. Therefore, there is a mechanism by which carbonated water can have an unhealthy effect — theoretically. However, in practice, one would have to drink a great deal of carbonated water in order to wear the enamel faster than it is renewed. A study at the University of Birmingham found that carbonation had measurable, but small erosive characteristics, much smaller than the more acidic levels found in sodas, whose pH is driven lower (made more acidic) by the addition of phosphoric acid. (Soda manufacturers add phosphoric and citric acid to their product.)
Carbonated Ocean Water – CO2 absorbed into the world’s oceans (effectively a carbonation process) may be far more harmful than drinking carbonated water. It has been estimated that half of the anthropogenic CO2 produced between 1850 and 1994 from fossil fuels and cement production has been dissolved into the oceans, increasing their acidity with the carbonic acid that the CO2 produced. The resulting carbonic acid dissociates, adding a hydrogen ion to the seawater, which can then leach carbonate ions (CO3(2-)) out of seawater before shellfish can use it to build their shells.
8 Negative Effects Of Soda On Your Brain (ThatDiary.com)
- Memory Loss – In a 2002 study conducted, researchers revealed that drinking or consuming high amounts of sugar in soda each day could lead to less production of brain-derived nuerotrophic factor or BDNF. This brain chemical plays a significant role in forming new memories. Without it, you can’t learn or remember about anything.
- Depression – In addition to memory loss, lower BDNF caused by too much consumption of sugar from drinking soda could lead to depression and dementia. This is according to a study conducted at the University of Copenhagen. What’s more frightening is the fact that your body may become resistant to insulin as a result of lower levels of said chemical. This will then cause other health problems.
- Restlessness – Regardless of the brand, soda contains high amount of caffeine. This chemical affects your brain by increasing your mental alertness. It inhibits neurotransmitter adenosine activity. In normal situation, this brain chemical increases your feeling of tiredness while decreases arousal stage. With the presence of caffeine from drinking soda, your alertness will be heightened causing you to become restless even at night. This will then disrupt your sleep causing your brain to trigger other responses, such as high blood pressure, reduce blood flow to your digestive system and increase heart rate. If you couldn’t control your cravings for soda, you could be addicted to caffeine that could lead to several health problems.
- Making Wrong Decision – The artificial sweeteners (aspartame, sucralose, and saccharin) of soda could affect the way you think. In a 2010 study, researchers concluded that the artificial sweeteners of soda could increase your chances of choosing short-term reward over a longer term reward. This might affect how you make decision and might prevent you from resisting the temptation in favor of short-term result.
- Alzheimer’s Disease – In an animal study conducted, it showed that mice that drank soda have higher plaque deposits than those mice that didn’t consume such drink. These plaque deposits are said to result in the development of Alzheimer’s disease and other diseases related to the brain. In another study, it showed that humans who consumed soda with high glycemic level have higher beta-amyloid levels in their brain. These levels could lead to Alzheimer’s disease.
- Stroke – High amount of sugar in soda could restrict proper blood flow in your brain. This may result in paralysis, stroke or loss of motor function. If it’s not treated immediately, then it could lead to permanent brain damage.
- Violence – Those who drink soda are more likely to act violently and get involved in fights than those who don’t consume such carbonated drink. According to researchers, soda drinkers act more aggressively. This could be caused by the excess sugar of soda that might affect the brain leading to violent acts of these individuals. This isn’t a surprising news considering soda’s ability to influence mood and behavior. However, these findings aren’t conclusive and more studies are needed to validate the results.
- Overeating – The sweeteners of soda could greatly affect your ability to lose weight as they could disturb one of the areas of your brain called caudate head. Soda consumption could diminish said area’s activity that’s involved in reward system and food motivation. Decreased activity is associated with the risk of obesity. Your brain couldn’t provide a gauge of how much energy you need from sugar causing you to eat more.
Although studies are still needed to gather more pieces of evidence as to how soda affects the brain, avoiding soda entirely could help you achieve good health. Unfortunately, the prevalence of this carbonated drink could be hard for some individuals to make the right choice. Thankfully, there are other healthier options for soda. For instance, you could mix water with low-sugar fruit juice. With this beverage, you won’t be adding calories to your diet. Instead, you’re drinking refreshment that has similar taste to soda.
Why fizzy drinks (and even sparkling water) are WORSE than you thought
- They speed up ageing – People who drink the equivalent of two cans of full-sugar cola daily may age more quickly than people who never drink it, say U.S. researchers. Last year, scientists at the University of California found these people had DNA changes that made their cells 4.6 years older – their telomeres, the tiny ‘caps’ that protect the ends of our chains of DNA, were shorter. ‘Telomere length has an impact on cell repair and regeneration and that is linked to the ageing process,’ says Dr Sajjad Rajpar, a consultant dermatologist at Queen Elizabeth Hospital in Birmingham.’ ‘A great deal of research is looking at how telomere length can affect that process.’
- They trigger sugar cravings – Drinking just two cans of sugary fizzy drinks a day dulls people’s perceptions of sweet tastes and makes them crave sugar even more, says Dr Hans-Peter Kubis, a physiologist at the University of Bangor who led a study into the effects of fizzy drinks on the body. ‘Because sweetness is strongly connected to the reward system in the brain, people may increase the frequency of their use of sugar as a result.’ The bubbles, too, could make you want more sugar. Carbon dioxide acts as an acid which enhances our responses to other tastes, such as sugar, says Dr Kubis. ‘Though the sugar may create the craving responses, the acidity or fizz of the drink makes the pleasantness of the taste even stronger. This could explain why people prefer carbonated water over still.’
- They have been linked to cancer – Women who have more than three sugary drinks – fizzy or otherwise – a week may have an increased risk of developing breast cancer. Last year, researchers from Laval University in Quebec found that the more sugary and fizzy drinks consumed by women, the greater the density of their breasts – a known risk factor for cancer. It is not clear how the two might be linked and more research is needed. ‘Women with dense breasts have a higher risk of developing cancer because there are more cells that can become cancerous,’ explains Dr Anne Trigg, a medical oncologist at the London Bridge Hospital. ‘It can increase the risk factor four-fold. It may be linked to higher levels of oestrogen, which is associated with breast cancer.’
- They may damage bones – Drinking large quantities of cola could affect your bones, U.S. researchers have suggested. This is because they often contain high levels of phosphoric acid – added to cola-type drinks to give them a tangy taste, and tingle when swallowed. A 2006 study by nutritional epidemiologists at Tufts University in Boston found that women who drank cola daily had lower bone mineral density in their hips than those who drank it once a week, regardless of their age, total calcium intake or use of cigarettes and alcohol. The body naturally strives to maintain balanced levels of calcium and phosphorus – so when there is excess phosphorus, calcium is released from the bones to correct the balance. Researchers didn’t find this effect when women drank other fizzy drinks. It’s possible that the caffeine in the cola had an impact, since caffeine has been associated with risk of lower bone density. The National Osteoporosis Society says that while there is ‘no clear evidence’ of fizzy drinks having a detrimental effect on bone health, women may want to moderate their intake. The other problem is that people prefer fizzy drinks to calcium-rich milk, adds Dr Peter Selby, an osteoporosis expert based at Manchester Royal Infirmary.
- They cause bloating – When we have a fizzy drink, the gas – namely carbonic acid – fills the stomach with air, creating pressure which pushes the air back up the gullet (or esophagus) causing a belch. And if you suffer from bloating, the extra gas will make it worse, says Dr Steven Mann, a consultant gastroenterologist at the Royal Free Hospital in London, as the air will simply sit in the stomach. These bubbles eventually burst and get reabsorbed into the blood, he adds. Fizzy drinks can also aggravate irritable bowel syndrome, a disorder linked to digestive system problems.
- They attack your teeth – Sugar reacts with the bacteria in plaque (the sticky coating on your teeth) and produces harmful acids that can cause decay, making sugary fruit juices a threat to oral health. But fizzy drinks may cause even greater damage. A study by the University of Birmingham found that full-sugar cola is ten times as corrosive as fruit juices in the first three minutes of drinking, even though they contain similar amounts of sugar. It’s thought citric acid added to give drinks their tangy taste might be to blame. ‘Even diet colas, though low in sugar, can be bad for teeth, because of the citric acid in diet and sweetened fizzy drinks,’ said Professor Damian Walmsley, scientific adviser to the British Dental Association. Fizzy water can also damage teeth because it contains carbonic acid, formed when carbon dioxide is dissolved in water, which erodes tooth enamel. The more sugary and fizzy drinks consumed by women, the greater the density of their breasts – a known risk factor for cancer. ‘Even one glass can cause microscopic levels of the outer surface of the enamel to dissolve, and when we consume something acidic, the mouth stays acidic for 45 minutes before returning to a normal pH level,’ says Professor Andrew Eder of University College London’s Eastman Dental Institute. However, you’d need to drink sparkling water on a daily basis for years to suffer the effect – one or two glasses a week won’t hurt.
- They bombard your liver – Fizzy drinks with high levels of fruit juice have been linked to fatty liver disease. A 2009 Israeli study found that people who have two cans of fizzy fruit drinks a day were five times more likely to develop the condition, a precursor to cirrhosis (scarring of the liver) and liver cancer. The drinks have high levels of fruit sugar, readily absorbed by the liver and converted into fat. And upmarket fizzy drinks are no healthier as sparkling elderflower and sports drinks can contain up to 13tsp of sugar, compared with around 9tsp in supermarket cola, campaign group Action on Sugar said last year. Although the evidence is inconclusive the study suggests diet drinks have a similar effect by tricking the body into thinking it has had sugar.
Something to Consider
No matter what the research says about carbonated water safety you must still consider what you are putting in your body. Carbonation is literally Carbon Dioxide (CO2) shoved into a liquid; which is chemical that your body tries to get rid of all day every day through respiration. If your body constantly tries to rid itself of this waste product made by cellular respiration (normal cell functions) why would you add more back in to the system? Scientific ‘research’ shows no long-term side effects of regular consumption of carbonation of any kind, yet they know what carbonic acid (the molecular derivative of CO2) does to all other living things. So please consider that science is not always on our side, we must learn and understand for our own protection. Most bodies are capable of removing the excess carbonic acid, but when the delicate balance is shifted to acidic due to the consumption of too many acids you begin to develop inflammation, arthritis, and bone loss because the body uses calcium to protect itself from acids in the blood stream.
The compound carbonic acid has the chemical formula H2CO3. It’s formed through the chemical reaction of carbon dioxide and water, and when it decomposes, it produces these as the products. Decomposition isn’t the only chemical reaction carbonic acid can undergo; it can also act as an acid, and break into a positively charged hydrogen particle and a negatively charged HCO3, or bicarbonate, particle, explain Drs. Reginald Garrett and Charles Grisham in their book “Biochemistry.” Circumstances help dictate which reaction carbonic acid undergoes.
Dangers of Sparkling Water (DrAxe.com)
According to Dr. Gene Romo, a Chicago dentist and consumer adviser for the American Dental Association, and Dr. André Ritter, chair of the Department of Operative Dentistry at the University of North Carolina School of Dentistry, the problem with the carbonic acid found in sparkling water is that it lowers the pH of water, making it more acidic, and one of the things that causes dental erosion is the acid in food and beverages.
However, these doctors do agree that sparkling water is still a much better choice than soda, which is a lot more acidic. They also note that sparkling mineral water contains minerals “that can actually offset some of the potential damage caused by the low pH.” In general, they recommend non-sparkling water over sparkling, but sparkling water definitely wins over high-sugar soda and juices.
Another issue with sparkling water is when companies add health-hazardous additives and sweeteners. Some sparkling water brands have made sparkling water even more popular these days. Flavored sparkling water provides soda drinkers with the fizz they love and comes in a range of fruit flavors. To look on the positive side, naturally flavored sparkling waters without any sweeteners may help break an unhealthy soda addiction. However, the bad news is that these flavorings, including citric and other fruit acids, have been linked to possible enamel teeth erosion.
Again, the pH of flavored sparkling waters is concerning. While tap water’s pH is typically between 6 and 8, the carbonating of water lowers its pH to around a 5. With flavor essences and other additions to sparkling water, the pH can go down even lower, and the lower the pH the more likely it is to be destructive to our teeth.
Sparkling Water vs. Coconut Water vs. Lemon Water (DrAxe.com)
How does sparkling water compare to other healthy hydrators like coconut water and lemon water? Let’s take a look:
- Sparkling mineral water naturally contains various minerals — most commonly calcium, magnesium, potassium and sodium.
- Coconut water also contains the same electrolyte minerals, including potassium, calcium, magnesium and sodium. It also contains manganese, iron, copper, selenium and some B vitamins.
- Lemon water contains significant amounts of vitamin C as well as potassium, folate, magnesium and other key nutrients.
- Sparkling water is calorie-free and sugar-free.
- Coconut water (with no sugar added) contains around 45 calories and just over six grams of sugar per cup.
- If you create lemon water by adding the juice of half of a lemon to water then you only add around five calories and less than one gram of sugar to the water.
- Coconut water and lemon water have no carbonation.
Depending on your personal preference, all three beverages can be great sources of hydration in moderation when you’re looking for a healthy alternative to plain water.
Normal Acid Base balance and Its Disorders BY ARUN PAL SINGH
Normal Acid Base Balance – In healthy state, the pH of the blood or , blood hydrogen ion concentration lies within the range pH 7.3 6—7.44.
Blood acidity increases when:
- Level of acidic compounds in the body rises. This could be due to increased intake or production, or decreased elimination
- Level of basic compounds in the body falls (through decreased intake or production, or increased elimination)
Blood alkalinity increases when the level of acid in the body decreases or when the level of base increases.
The terms acidosis and alkalosis in clinical practice indicate a change or a tendency to a change in the pH of the blood in a particular direction. In acidosis, there is an accumulation of acid or a loss of a base causing a fall or a tendency to a fall in the pH. The opposite occurs in alkalosis.
Regulation of Blood PH – The pH of the blood is regulated and controlled by lungs, kidneys and various buffering systems essentially consisting of weak acids and bases, of which the most important is the bicarbonate:carbonic acid ratio HCO3:H2C03.
Lungs – Carbon dioxide is mildly acidic. The end product of the metabolism of oxygen. It is constantly produced by the cells and gets excreted into the blood. The blood carries carbon dioxide to the lungs, where it is exhaled. When concentration of carbon dioxide increases in the blood, the pH of the blood decreases (acidity increases). The brain regulates the amount of carbon dioxide that is exhaled by controlling the speed and depth of breathing. By adjusting the speed and depth of breathing, the brain and lungs are able to regulate the blood pH minute by minute.
Role of the kidneys – The kidneys are able to affect blood pH by excreting excess acids or bases. The kidneys are slower to respond and this compensation generally takes several days.
Buffer systems – The pH buffer systems are combinations of naturally occurring weak acids and weak bases which exist in pairs that are in balance under normal pH conditions. The pH buffer systems work chemically to minimize changes in the pH of a solution by adjusting the proportion of acid and base. The most important pH buffer system in the blood involves carbonic acid and bicarbonate ions.
The ratio of bicarbonate to carbonic acid is normally 20:1. Alteration in this ratio alters the pH regardless of the absolute values of the bicarbonate and carbonic acid. A decrease in the ratio leads to increased acidity and vice versa. The bicarbonate level can be altered by metabolic factors, while the carbonic acid level is subject to alteration by respiratory factors. The change in one is followed by a compensatory change in the other, so that the ratio (HCO3:H2C03) and therefore the pH of the blood remains constant.
Disorders of Acid Base Balance
The disturbances of pH leads to Alkalosis or acidosis. Depending on the causation, these are further classified as respiratory or metabolic. So we have following acid base balance disorders:
Metabolic alkalosis is a condition of base excess or a deficit of any acid other than H2C03. It can be caused by excessive ingestion of absorbable alkali, repeated vomiting or aspiration, cortisone excess. The body tries to compensate by:
- retention of carbon dioxide by the lungs.
- Excretion of bicarbonate base by the kidneys. This results in alkaline urine.
In severe alkalosis, the respiration pattern alters. The respiration becomes is Cheyne—Stokes respiration. The alkalosis accompanied by low potassium [due to loss in vomiting for example] is called hypokalemic alkalosis.
Metabolic alkalosis without hypokalaemia seldom requires direct treatment. The cause of the alkalosis should be removed where possible and a high urinary output encouraged. Hypokalaemic alkalosis required replacement of potassium.
Respiratory alkalosis is a condition where the arterial PCO2 is below the normal range of 31—42 mmHg (4.1—5.6 kPa). It is caused most commonly by excessive pulmonary ventilation as seen in high altitudes, hyperpyrexia, a lesion of the hypothalamus and hysteria. In an attempt to decrease blood pH, there is increased renal excretion of bicarbonate, usually is inadequate. Severe respiratory alkalosis may lead to suppression of respiration. Respiratory suppression due to alkalosis is rectified by insufflation of carbon dioxide.
Metabolic acidosis, a condition where there is a deficit of base or an excess of any acid other than H2C03, occurs as a result of increase in fixed acids [ketone bodies as in diabetes or starvation, renal insufficiency, anaerobic tissue metabolism] or loss of bases [diarrhea, ulcerative colitis, gastrocolic fistula, a high intestinal fistula or prolonged intestinal aspiration.] Hyperpnoea occurs due to over stimulation of the respiratory center by the reduction in pH of the blood [ an attempt to eliminate as much as possible of the acid substance H2C03]. Kidney excretes acids and the urine is strongly acidic. The standard bicarbonate level is lowered and there is a base deficit. Correction of tissue hypoxia by restoration of adequate tissue perfusion is the general treatment. Bicarbonate solutions will correct the measured metabolic acidosis but not treat the problem which should be addressed separately.
Respiratory acidosis, a condition where the PCO2 is above the normal range, is caused by impaired alveolar ventilation. This occurs when there is inadequate ventilation of the anaesthetised patient, or when the effects of muscle relaxants have not worn off or been fully reversed at the end of the anaesthetic. There is also a risk of respiratory acidosis when the patient undergoing surgery already has pre-existing pulmonary disease.