Prevention of thrombosis in microvascular surgery by the use of magnesium sulphate

Prevention of thrombosis in microvascular surgery by the use of magnesium sulphate

557 ABSTRACTS GENERAL CONSiDERATlONS Thermal Regulation in the Newborn. Edmund N. Hey. Br J Hosp Med 8:51-64 (July), 1972. The author gives a comp...

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557

ABSTRACTS

GENERAL

CONSiDERATlONS

Thermal Regulation in the Newborn. Edmund N. Hey. Br J Hosp Med 8:51-64 (July), 1972. The author gives a comprehensive account of thermoregulation in the newborn. The neonate is less capable than the adult of maintaining deep body temperature. Premature babies have an especially low resting heat production per unit surface area. Heat loss is by conduction, evaporation, radiation, and convection. Conduction loss is very small if the child is nursed on a warm mattress. About a quarter of the heat produced is lost by evaporation. Loss of heat by radiation and convection varies with environmental temperature. The response to cold is by increased heat production, but this response is muted in premature babies. Heat production is mostly from brown fat, Muscle activity plays a small part. The response to warmth is by increased Skin blood flow. Ability to sweat is limited, especially in premature babies, although sweat glands are numerous at term and their response to acetylcholine is good. The “set point” of thermoregulatiori is much the same as for adults but there is no diurnal rhythm. The air temperature most likely to provide neutral conditions can be calculated for any one infant of given age and weight. The range is narrow. This provision of optimal warmth leads to faster growth and avoidance of effects of adverse conditions on brain development. There is, however, a failure to develop the ability to withstand cold stress with time. The problems of delivery room, nursery, and incubator are discussed. The baby is very vulnerable to cold stress in the delivery room. The advantages of cot nursing are stressed. Nursing the baby naked in an incubator necessitates precise control of environment and heat loss by radiation must not be forgotten. Special problems of illness are also discussed. Finally, speed of rewarming the hypothermic baby is dealt with: hypothermia of rapid onset may be reversed quickly; that of slow onset is better reversed slowly.--H. M. Adair

Infection

in Embryo,

Foetus,

and Newborn.

Pamela A. Davies. Br J Hosp Med 8:13-26

(July), 1972. This account of infection in the embryo, fetus, and newborn begins by discussing the incidence and host immunity. Routes of infection and clinical aspects are considered, followed by

treatment, preventive measures, and, finally, prognosis. Small amounts of the immunoglobulins IgG, IgM, and IgE are synthesized in the spleen before birth. Most of the IgG is maternally derived in the last trimester. IgA and IgD synthesis occurs after birth. Complement levels at birih are comparatively low. Bacterial immunity is de: ficient in the newborn due to poor phagocytosis and low levels of antitoxin. Viral immunity is similarly limited with regard to antibody production, although interferon can be produced in fetal cultures. Neonatal mortality is higher in males than females, probably due to a genetic factor 8, there being a gene locus for immundglobulins on the X chromosome. Breast milk contains immunoglobulins and immundlogically competent cells. It has a bacteriocidal effect on Escherichia cob’, and promotes growth of Lacrobacillus bifdus in the gut Routes of infection vary accbrding to whether it occurs before, at the time of, or after birth. Normal bacterial colonization occurs in the first few days of life. Nonbacterial colonization is rare. Clinical illnesses produced after birth by bacteria are usually ill-defined with nonspecific symptoms and signs. They are more common in premature infants and in those with congenital abnormalities. Viral infections after birth are usually slight or subclinical. Diagnosis of bacterial infection rests on culture of the organism, usually from blood, cerebrospinal fluid, or urine. High or low white blood counts, the presence of circulating metamyelocytes, and IgM levels are other guides. Diagnosis of nonbacterial infection depends on recovery of the organism and serology. Specific IgM fluorescent antibody tests are useful. The dangers of overprescribing antibiotics is stressed. It is essential to obtain relevant specimens first. The initial choice of drugs will depend on the relevant flora. They are best given by the intramuscular route. Prevention depends on good maternal health and a clean environment after birth. There is no evidence for the value of the use of prophylactic antibiotics, except for umbilical spraying. From the point of view of prognosis, meningitis and osteomyelitis continue to have a high mortality and morbidity. A follow-up of 50 cases of rubella contracted in utero shows most of the patients to be of average intelligence but all but two to be deaf.-H. M. .4 dair Prevention of Thrombosis in Microvascular Surgery by the Use of Magnesium Sulphate. Robert Acland. Br J Plas Surg XXV:292-299 (July), 1972.

558 The mechanism of thrombus formation at the site of anastomoses in very small vessels is examined. In experimental rats it was found that magnesium sulfate solution could be used with benefit to irrigate the outside of the vessels for the first 20 min after the recommencement of blood flow. Leakage from the suture line had to be adequately stopped before irrigation was started because further thrombus formation is inhibited. This procedure gave a 90% chance of success in end-to-end anastomoses of arteries 0.5 mm in diameter.-,4. ioNeys Progressive Peripheral Fibromuscular Hyperplasia in an Infant: A Possible Manifestation of the Rubella Syndrome. David R. Srewarr, Robert A. Price, Robert Nebesar, and Samuel R. Schusrer. Surgery 73:374380 (March),

1973. This is a detailed case report of a child with progressive arterial insufficiency of the left lower extremity due to fibromuscular hyperplasia of the left femoral artery. Symptoms, first noted at 3 mo of age, were tempotarily improved by left lumbar sympathectomy but recurred, neccessitating amputation at age 3j/2 yr. Intimal and medial proliferation in the arteries was noted to be similar to those seen in congenital rubella syndrome. Common origin of the two conditions is suggested.- William K. Sieber Hydatid Cysts in Childhood. M. Carcassone, P. Aubrespy, V. Dor. and M. Chow Prog Pediatr Surg 5:1-35, 1973. Hydatid cysts may be seen outside the endemic areas, and 25% of cases occur in children. Forty-eight children presenting over a 6%yr period had cysts (often multiple) in the liver (27). lungs (14). brain (four), and other tissues (nine). Secondary echinococcus from rupture and operative spillage is especially likely with hepatic cysts and patients should be followed for 5 yr before a cure can be assumed. A raised eosinophil count is characteristic, the Casoni tests and Weinberg test are specific, but false negative results occur. The clinical effects depend on the location of the cysts but stunted growth is common. The mortality of the untreated condition is 27%. Children can become incidental hosts, interupting the usual dog/sheep sequence. The cysts in children are often surrounded by a very thin adventitia, which ruptures easily. It is only rarely calcified. The most useful investigation for hepatic cysts is splenoportog-

ABSTRACTS raphy. Treatment of all cysts (except cerebral) is best achieved by total pericystectomy. There was no mortality in this series.-R. C. M. Cook HEAD AND

NECK

A Study of the Elects of Early Bone-Grafting in Complete Clefts of the Lip and PalateFive Year Study. A. Jolleys and N. R. E. Roberrson. Br J Plas Surg XXV:229-237 (July), 1972. A prospective study of two groups of 14 patients is described. Each group was treated similarly, but in one group autogenous bone grafts were used to fill the bony defect in the alveolus at the age of 1 yr. The technique of matched pairs was used. Bony development of the face was studied by cephalometry, by measurements of plaster casts of the jaws, and by examination of the dental occlusion. The results in the grafted group at 5 yr of age were worse in all respects than in the control group.A. Jolleys

Laryngbtracheoesophageal Cleft Associated With Esophageal Atresia and Multiple Tracheoesophageal Fistulas in a Twin. G. H. Mahour, S. R. Cohen, and M. M. WooNey. J Thorac Cardiovasc Surg 65:223-226 (February), 1973. A neonate with laryngotracheoesophageal cleft, esophageal atresia with distal tracheoesop hageal Astula, and two proximal tracheoe,sophageal fistulas is presented with a favorable outcome. It is the seventh reported successful repair of laryngotracheoesophageal cleft and the first with associated major anomaiies. There are 12 references.-Thomas M. Holder THORAX

Surgical Respiratory Emergencies in the Newborn. S. Cywes. South Afr h&d J 46:15381544 (October), 1972. Respiratoty emergencies confronting the surgeon can be divided into two main groups: the preoperative congenital anomalies and the postoperative complications. The preoperative group can be further subdivided into intrinsic thoracic and lung lesions and extrinsic obstructive lesions. The intrinsic group includes congenital diaphragmatic hernia, congenital lobar emphysema, congenital cystic lung, and esophageal atresia. The author describes his plan of manaaement and