Local Anesthetic Drugs -Effects on the Baby

Local Anesthetic Drugs Used During Labor –Effects on the Baby

Conduction anesthesia has become the most commonly used in modern obstetric practice, both to provide analgesia for labor pain and anesthesia for surgical delivery. Epidural blocks give a versatile range of anesthesia from a mild sensory block for normal labor to a dense blockade of most of the nerve fibers required for cesarean section.

                The local anesthetics commonly used for obstetrics are bupivicaine and lignocaine. When injected, these drugs are absorbed from the epidural space into the maternal blood stream. This results in a significant level of circulating drug which will cross the placenta rapidly by passive diffusion. Many factors affect the placental transfer such as the total dose of drug injection, route of administration, presence of adrenalin, maternal metabolism and exertion, maternal protein binding and intervillous blood flow. These factors determine the fetal-to-maternal concentration ratio. Pathological conditions of the placenta such as eclampsia, diabetes, hyper-tension, and Rhesus disease may also affect this transfer but the extent to which they do so is unknown. The local anesthetic is taken up by the fetus and metabolized and excreted by the baby. Similar, though delayed, decay curves of drug activity are a seen in neonatal and maternal circulations.

                Local anesthetics act on all conduction tissue and toxicity in the fetus and neonate is seen in the central nervous system, peripheral blood vessels and the heart. No fetal heart rate changes occur at modest plasma levels of local anesthetic.

                Conduction anesthesia also has indirect effects on the fetus, which requires an adequate delivery of oxygenated maternal blood to the intervillous space. This can be affected by changes in the uterine blood flow, which varies directly with perfusion pressure across the uterine vascular bed, and in aversely with uterine vascular resistance. So, if hypotension results from an epidural block, a reduction in mean uterine pressure will reduce uterine blood flow and thereby impair fetal oxygenation and well-being. Hypotension is a common complication of epidural block, especially at term when pooling of blood in the lower limbs in encouraged not only by sympathetic blockade but by aortocaval compression.

                Uterine vascular resistance is maintained by the intrinsic vasomotor state of uterine vessels. These are fully dilated at term but ill constrict with high catecholamine levels, general anesthesia and toxic levels of local anesthetic drugs.

Antibiotics in Pregnancy

Antibiotics in Pregnancy

Antibiotics which are safe for pregnancy penicillin, erythromycin clindamycin cephalosporins.

Prophylactic Antibiotics

Ampocillin, amoxicillin, cefazolin, and erythromycin/sulbactam are the safest drug to treat the preterm premature rupture of membrane, prevention of bacterial endocarditis and during cesarean section, urinary tract infection, chorio-amnionitis and group B streptococci.

Antibiotics to be avoided

Following drugs to be avoided:

Ø  Amino glycosides = eight cranial nerve damage

Ø  Erythromycin estolate = hepatotoxic to mother

Ø  Fluoroquinolones = potentially mutagenic, cartilage damage, arthopathy, teratogenicity

Ø  Ribavarin = possibly fetotoxic

Ø  Tetracyclines = staining of deciduous teeth.

Drug Induced Acute Renal Failure in Pregnancy- Management

Drug Induced Acute Renal Failure in Pregnancy

Acute renal failure is a most challenging clinical problem when it occurs in pregnancy. It requires an understanding of the normal physiology of the kidney in pregnancy and the natural history of different underlying renal diseases when pregnancy occurs.

                Acute renal failure defined as the condition in which the urine volume falls below 400 ml in 24 hours. Anuria is the absence of excretion of urine in 12 hours whereas oliguria is the term given to clinical condition.

                Because patients with chronic renal disease may present with worsening proteinuria, hypertension, and renal function, these disorders must be excluded from those conditions that cause acute deterioration of renal failure in otherwise normal women during pregnancy. As in all patients who develop acute renal failure, perennial, renal and post renal obstructive causes must be excluded.

Causes of Renal Failure

Drugs

·         Hemodynamic affects

·         Acute allergic interstitial nephritis

·         Direct toxicity to tubule

Pathogenesis

Reversible prerenal acute Renal Failure

Homodynamic disturbances can initially produce acute renal dysfunction that has the potential to be rapidly reversed, prompt recognition and treatment is important.

                Prolonged under perfusion of kidney may lead to failure of the compensatory mechanisms and hence a acute decline in GRR. The renal tubules are intact and become hyper functional: that is, tubular reabsortion of sodium and water is increased, partly through physical factors associated with changes in blood and urine flow and partly through influence of angiotensins, aldosterone and vasopressin. This leads to formation of low volume urine which is concentrated but low in sodium. These urinary changes may be absent in patients with impaired tubular function, e.g. pre-existing renal impairment, or those who have received loop diuretics.

Established Acute Renal Failure

Established ARF may develop following severe or prolonged under perfusion of kidney. In such cases, the histological pattern of acute tubular necrosis is usually seen. In patients without an obvious cause of prerenal ARF, alternative ‘renal’ and ‘post renal’ causes must be considered.

Ischemic tubular necrosis usually follows a period of shock, during which renal blood flow is greatly reduced. Even when systemic hemodynamic are restored, renal blood flow can remain as low as 20% of normal, due to swelling of endothelial cells of glomeruli and per tubular capillaries, and edema of the interstitium. Blood flow is further reduced by vasoconstrictors such as thromboxane, vasopressin, noradrenaline and angiotensin II, partly counterbalanced by release of intrarenal vasodilators prostaglandins. Thus in ischemic ATN there is reduced oxygen delivery to tubular cells. These cells are vulnerable to ischemia because they have high oxygen consumption in order to generate energy for solute reabsorption, particularly in thick ascending loop of henle.

The ischemic insult ultimately causes death of tubular cells, which may shed into the tubular lumen causing tubular obstruction. Focal breaks in the tubular basement membrane develop, allowing tubular contents to leak into the interstitial tissue and cause interstitial edema. In nephrotoxic ATN a similar sequence occours, but it is intitiated by direct toxicity of causative agent to tubular cells. Examples include aminoglycoside antibiotics such as gentamicin, cytotoxic agent cisplatin and the antifungal drug amphotericin B.

Clinical Presentation

The clinical presentation of both these conditions should be apparent, and appropriate diagnosis and treatment can then be promptly instituted. Renal cortical necrosis is another cause of renal failure that occurs more frequently in pregnancy and it must be differentiated from the many causes of acute tubular necrosis that may be associated with pregnancy. Those conditions that cause renal failure unique to pregnancy must always be considered when renal function deteriorates in the last trimester or the postpartum period. Severe pre-eclampsia, acute fatty liver of pregnancy and idiopathic postpartum acute renal failure may all present similar complications but the approach to each or these clinical disorders must be individualized. By understanding the causes of renal functional deterioration in pregnancy, a logical differential diagnosis can be established, allowing appropriate therapeutic decisions to preserve both maternal and fetal well-being.

Ayurvedic Drugs during Pregnancy

Ayurvedic Drugs during Pregnancy

In conventional medicine, the mother is given a pregnancy test and also the blood pressure, pulse rate, and weight are checked. Then she is advised to eat a generally healthy diet and to take prenatal vitamins. However, this prenatal diet does not give any specific recommendation for maintaining a happy and healthy pregnancy.

In Maharishi Vedic Medicine, it is understood that pregnancy is a time when everything the pregnant mother tastes, sees, touches, hears, and smells should be nourishing to the mother and child. There are very specific recommendations to bring about a state of balance in the consciousness, mind, boy, behavior, and environment of the pregnant woman.

Pregnant Woman’s Diet

The Vedic texts recommend a sattvic food, which means pure, easily digested foods that nourish the dhatus of mother and the unborn child. These include foods such as milk, rich, wheat, and ghee, fresh vegetables, fruits and grains. Sattvic foods do not cause constipation or indigestion, and they create a more settled state of mind. These foods help the mother enjoy ideal health and vitality, and also help with the growth of the baby. Maharishi Ayurveda Vata Churna is a convenient way to add Vata-balancing spices to your diet, and the Apple, Mango and Peach Chutneys can help balance cravings, Vata Tea or Worry Free Tea can be shipped through the day to help balance the mind and emotions.

Other Accessory Techniques applied to the mother and Unborn child

Techniques such as abhyanga, the Ayurvedic oil massage are recommended for the mother. Mothers who do this once a day, on arising, find that they feel more evenness, more balance, and more energy throughout the day. The massage and other techniques balance Vata dosha, so the mother feels steadier, more even, and less anxious. There is more happiness, even in the body itself, and more balance in the entire nervous system. Feelings of agitation, depression, or sorrow dissolve. I recommend the Rejuvenatio Massage oil for Women, cut 50% with base oil such as Almond Oil, or the Moisturizing Massage oil. In the summer, replace Moisturizing Massage oil with the Soothing Massage oil.

In Maharishi vedic Medicine it has been recognized for thousands of years that the mother must be very happy and feel harmony with nature during pregnancy. For this, various strategies have been recognized. One is the social environment, which means that the family tries to keep her happy, especially the husband. The ayurvedic tradition says, “Let her hear good news, let her hear harmonious music, let her eat sweet foods, let her attend monthly celebrations to always keep her uplifted and nourished. Aromatherapy with an uplifting aroma blend such as blissful Heart aroma can be helpful.

If the Mother is having Emotional Problems

Modern research shows that if there is grief, sorrow or depression, those negative emotions definitely affect the growth of the baby. The baby could be born with lower birth weight, the baby could be less happy. If the mother is much stressed this can also contribute to low-birth weight baby.

Ehen the mother is not as happy or settled during pregnancy, the newborn child experience more colic, more crying, more sleep problems. In extreme Vata imbalance, the child might develop dry skin, hyperactivity, or musculoskeletal problems while growing. The time to nip imbalances in the bud is during pregnancy, as it is much easier to correct it then. And most importantly, it is imperative to prevent so much suffering.

Techniques Recommended for bringing Balance in Pregnancy

The Transcendental Meditation technique is a profound way for pregnant mothers to reduce stress, experience deep rest, and bring balance to all the doshas. When there is balance in the nervous system of the mother, the baby spontaneously grows in a very happy and healthy way.

                If the mother is not calm and rested, there could be discomfort as the baby grows, or the child could be overly active in the womb. Or other complications could develop, such as fluid retention, high blood pressure, or spotting during pregnancy.

Effects on the Baby

Drugs Used for Medical Disorders in Pregnancy 

Sex Hormones –in Pregnancy

There is good evidence that stilbestrol given during pregnancy predisposes to minor histological changes in the vagina, to minor developmental distortions of the vagina and uterus and to instances of vaginal adenocarcinoma in teenage female offspring. Abnormalities of the genital tract of male offspring may also occur.

                Porgestagens of the 19-nor-groups, such as ethisterone, norethisterone and norethynodrel, given in pregnancy have a small change of causing clitoral enlargement in female babies, which resolves without treatment, and rare cases of labioscrotal fold fusion, which require incision. The 17α-hydroxy compounds such as progesterone, hydroxyprogesterone and medroxyprogeserone do not have this effect.

                There seems to be a very small risk, between 1 in 500 and 1 in 5000, of drug-associated anomalies in the babies of women taking full-dose combined estrogen-progestagen oral contraceptives or given hormone pregnancy tests risk in early pregnancy. The babies affected are mostly male. Whether or not any risk persists with the low doses of synthetic steroids now in oral contraceptives is not clear.

Ovulation Stimulants –in pregnancy

Clomiphene induction of ovulation gives rise to 6% of multiple conceptions very nearly all twin pregnancies, but not to congenital anomalies. The abnormality rate is slightly increased if use of the drug is continued through the first trimester. Menotrophin gives a higher proportion of multiple pregnancies. Some of these ate due to failure to monitor administration with frequent estrogen estimations, resulting in overdose and multiple ovulations. Bromocriptine is not teratogenic, even if continued through the first trimester.

Sedatives and tranquillizers in Pregnancy

Attempts have made to incriminate the use of sedative doses of both barbitutates and benzondiazepines but there is clear evidence that either group of drugs is teratogenic in humans. The babies of women taking regular doses of these groups of drugs before delivery are liable to a newborn withdrawal syndrome. Barbiturates may be more likely to depress the baby, but they are enzyme inducers, which may help if there is a risk of neonatal jaundice, and they are more rapidly eliminated by the newborn than benzodiazepines.

                There is not clear evidence that phenothiazines, monoamine oxidase inhibitors or tricyclic antidepressants, have teratogenic affects on the fetus, though transient neonatal effects such as extra pyramidal reactions after large doses of phenothiazines given to the mother have been recorded.

                Lithuim given in the first trimester may cause small proportion of fetal abnormalities, mainly of the cardiovascular system. If plasma levels are not strictly controlled at the end of pregnancy there is a risk of neonatal lithium toxicity with hypotonia and cyanosis.

Hypotensive Drugs –in Pregnancy

Ganglion-blockers were associated with a 50% fetal loss, mainly from neonatal ileus. Reserpine depresses the baby and causes nasal congestion. The most widely used hypotensive drugs in pregnancy, methyldopa and hydralazine, do not cause congenital anomalis in humans. Methyldopa occasionally gives rise to a positive Coombs test in the baby; neonatal hemolysis has not been reported. Unusually large doses of methyladopa can cause neonatal ileus. Propranolol and other beta-sympaholytics seem to be harmless if treatment with moderate doses for mild hypertension or arrhythmias is initiated before pregnancy, but large doses used to trate severe hypertension developing in mid- or late pregnancy have been associated with a high perinatal lose. It is possible this may be due to impairment of sympathetic vasodilatation in the placental blood supply or of autonomic reflexes in the fetus. Thiazide diuretics can rarely cause neonatal thrombocytopenia.

Hypoglycemic Drugs –in Pregnancy

Women with diabetes mellitus have an increased risk or producing a baby with a congenital abnormality, particularly if this disease is ill-controlled during pregnancy. Insulin or oral hypoglycemic agents do not appear to increase the risk, and the former drug, used to control the diabetes may protect the fetus.

Corticosteroids –in Pregnancy

There is evidence that these drugs cause abortion, intrauterine growth retardation or perinatal death and with some medical disorders the risks these problems may be reduced with adequate steroid treatment. The incidence of fetal cleft palate is less than 1%; the spontaneous incidence of this abnormality is between 0.1 and 0.5%. It has been suggested that this complication is related to the use of large doses in the first trimester, but this has not been clearly differentiated from the effects of the diseases for which the steroids are given. Steroids given o induce pulmonary maturation of the fetus before premature deliveries have been found not to affect the newborn adversely or to impair mental or physical development of the resulting infants.

Cardiotonic Drugs –in Pregnancy

Digitalis is harmless to the fetus unless the mother receives a toxic dose. If heart disease in pregnancy istreated with large doses of frusemide hem concentration may predispose to placental insufficiency.

Antiemetics –in Pregnancy

With the exception pormethazine, each of these drugs has in turn been accused of low level tertogenic effects and subsequently exonerated.