Postsurgical Recovery Period Research Articles

A technique for the venous cannulation of the mammary gland in the lactating sow.

The objective of this study was to develop a technique to cannulate the mammary venous system of the lactating sow in conjunction with the carotid artery. A total of 16 sows were subjected to surgery between d 3 and 6 of lactation. The dams were separated from their litter during the full surgical procedure and the post-surgical recovery period. The carotid artery was cannulated according to a previously described method. The mammary vein cannulation immediately followed the carotid artery cannulation. A small venous branch (approximately 4 mm in diameter) located on the lateral side of the thoracic region was used to obtain access to the mammary vein. It was isolated 4 to 5 cm above the plica lateralis, between the first and second anterior gland. The venous branch was exposed and a cannula inserted slowly for a distance of 16 cm or until the tip of the cannula would reach the most cranial point of the mammary vein. The cannula was allowed to follow the normal path of blood flow, running in a caudal to cranial direction. After recovery from surgery (1 to 2 h), the dams were returned to their respective litters and treated with antibiotics for a minimum of 6 d. All sows nursed and weaned normal litters. Cannulas were flushed with heparinized saline (20 U/mL) every 8 h and both arterial and venous blood samples (10 mL) were collected simultaneously at 0700, 1500, and 2300. Arterial and venous cannulas remained patent for a minimum of 15 d.(ABSTRACT TRUNCATED AT 250 WORDS)

Corticosterone-responsive and -unresponsive metabolic characteristics of adrenalectomized rats.

Glucocorticoids are important in influencing substrate flux through the metabolic pathways. This study was designed to answer the question "Does adrenalectomy (ADX) cause a shift toward fat metabolism as measured by a decrease in respiratory quotient (RQ)?" Male Sprague-Dawley rats were divided into four groups, ADX, ADX + 20% corticosterone (Cort) (ADX-20%), ADX + 40% Cort (ADX-40%), or sham-operated controls (Sham). ADX-20% received 50 mg and ADX-40% 100 mg Cort dissolved in 250-mg cholesterol pellets and placed subcutaneously. Each rat was monitored for 90 min four times both during a preoperative period and again after a 1-wk postsurgical recovery period in an indirect calorimeter. Cort prevented ADX-induced suppression of weight gain and food intake. ADX decreased motoric activity in both the light and dark periods. Cort restored activity to Sham levels. ADX decreased RQ only in the dark (0.858 ADX vs. 0.891 Sham) and was reversed only in the ADX-40% group. Energy expenditure (EE) was depressed in both the light and dark by ADX; Cort partially restored EE to Sham values in the light period.

Circadian rhythm of exocrine pancreatic secretion in rats: major and minor cycles

The circadian variations of exocrine pancreatic secretion were studied in conscious rats provided with pancreatic, biliary, duodenal, and peritoneal cannulas and kept in restraint cages under controlled conditions, with a regular 12-h light cycle. Rats were divided into fed and fasted groups, and experiments were performed separately. During a 4-day post-surgical recovery period, rats were fed ad libitum. During the experiment, fed rats had free access to food and water. Food, but not water, was denied fasted rats 10 h before the experiment and for its 48-h duration. During the experiment, pancreatic juice was continuously collected for 4 and 2 days from fed and fasted rats, respectively. Every 30 min, a 20-microliters aliquot of sampled pancreatic juice was removed for total protein, amylase, and chymotrypsinogen assays. The remainder was mixed with bile collected simultaneously, and the mixture was recirculated into the duodenum. Over the 4- and 2-day periods there was a clear circadian rhythm of 24-h duration; for all measured parameters, secretory rates increased in the dark period and decreased during the light period. This major circadian rhythm was unexpectedly found to be superimposed on by a remarkably constant neurosecretory-like minor cycle of 2-h duration present in both fed and fasted states. The amplitude of the minor cycle was diminished by fasting. The outputs of fluid, total protein, and amylase were found to be only modestly correlated with each other, whereas chymotrypsinogen output was virtually completely independent of the others. The results suggest that the spontaneous major increase of exocrine pancreatic secretion in the dark was at least partially independent of food intake.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of a surgical pre-operative assessment clinic on patient care.

Surgery makes many demands of both hospitals and patients. For the hospital, there are many procedural aspects: admission, health assessment, and patient education; the actual operation; and the post-surgical recovery period, a time when patients are susceptible to complications and nosocomial infections. For the patient, surgery means physical pain and emotional anxiety. A pre-operative assessment clinic (POAC), however, can assist both hospital and patients by streamlining their admission, assessment, and education, by decreasing the time they spend in the hospital recovering from surgery, and by easing their anxiety. In this article, the authors describe a study of a POAC at a Canadian hospital.

Perinatal exposure to anoxia alone does not alter the susceptibility to amygdaloid-kindled seizures in the adult rabbit

It is suggested that asphyxia on newborns increases the susceptibility to epileptic syndromes. The effect of perinatal and postnatal anoxia on subsequent seizure susceptibility was assessed by amygdaloid kindling in adult rabbits. Rabbits from 1 day pre-term to 53 days were exposed to 100% N 2 for an average of 7 min or until the heart rate was reduced by 70%. Non-anoxic littermates served as controls. At 2 months of age, animals were implanted with bilateral amygdalae electrodes. after a postsurgical recovery period, afterdischarge (AD) thresholds were determined for the electrodes sites and a kindling paradigm was performed. There were no significant differences in the rate of kindling in all groups studied (control, anoxic at 1 day pre-term or at term, anoxic at 44 and 53 days). These results demonstrate that perinatal anoxia did not alter the seizure susceptibility in the adult rabbit kindling model.

Respiration Rate, Heart Rate, and Body Temperature Values in Cynomolgus Monkeys (Macaca fascicularis) During Barbiturate Anesthesia

Respiration rate, heart rate, and body temperature values were obtained from 14 cynomolgus monkeys (Macaca fascicularis) during neurosurgery under barbiturate anesthesia. Vital sign values markedly declined below baseline during the early stages of surgery, steadily increased as surgery progressed and neared completion, and finally returned to baseline by the end of the postsurgical recovery period. There was considerable variability among the 14 monkeys, but the ranking of each monkey relative to the others remained constant across the period of observation. The findings suggested that the cynomolgus monkey may be more sensitive to barbiturates than the rhesus monkey, and cynomolgus monkeys may exhibit considerable individual differences in their sensitivity to barbiturates.

Rapid adaptation of pancreatic enzyme secretion in the conscious rat. II. Effects of fasting and dietary modulation.

The influence of fasting and dietary modulation on basal and stimulated pancreatic enzyme secretion was studied in conscious rats with cannulated pancreatic ducts. Two days' fasting decreased pancreatic secretion by about 30%. After stimulation of the secretion rate by acute derivation of pancreatic juice or by intravenous infusion of cerulein (0.2 micrograms/kg/h) no rapid change of enzyme composition was found. In further experiments, two groups of rats were fed with carbohydrate-rich and carbohydrate-poor diets, respectively. After pancreatic duct cannulation and a postsurgical recovery period, the diets were interchanged. An adaptation of pancreatic enzyme secretion to the new diet was observed in pancreatic juice. Stimulation of the secretion rate during the adaptation process by acute derivation of the juice or by intravenous infusion of either cerulein, secretin, carbachol or cerulein plus secretin did not further modify the composition of pancreatic proteins. 'Nonparallel' secretion of enzymes was never found when sufficient time for recovery from pancreatic duct surgery was allowed.

Deficits in conditioned avoidance responding following adrenalectomy and central norepinephrine depletion are dependent on postsurgical recovery period and phase of the diurnal cycle.

Deficits in conditioned avoidance responding following adrenalectomy and central norepinephrine depletion are dependent on postsurgical recovery period and phase of the diurnal cycle.

Deficits in conditioned avoidance responding following adrenalectomy and central norepinephrine depletion are dependent on postsurgical recovery period and phase of the diurnal cycle.

Rats that had undergone combined dorsal noradrenergic bundle lesion (DNBL) and bilateral adrenalectomy were impaired in acquiring a conditioned avoidance response when tested 1 week following surgery. Normal acquisition was observed, however, when testing occurred 3 weeks or more after surgery despite low levels of both plasma corticosterone and brain norepinephrine at that time. Furthermore, neither neonatal systemic administration of 6-hydroxy-dopamine to deplete forebrain norepinephrine, combined with the corticosterone inhibitor metyrapone, nor the pharmacological blockade of noradrenergic receptors, combined with adrenalectomy, disrupted acquisition of the avoidance response. Thus, the combination of forebrain norepinephrine loss and low plasma corticosterone does not inevitably impair avoidance acquisition. Rather, the determining factor for such impairment seems to be the interval between surgery and testing. The impairment at 1 week following DNBL and adrenalectomy occurred only for rats tested during the dark phase of their light cycle. In addition, the DNBL abolished the effect of the light/dark cycle on posttraining plasma corticosterone. These results demonstrate the importance of the phase of the rat's diurnal rhythm on both the hormonal and the behavioral effects of altering the pituitary-adrenal axis and/or forebrain norepinephrine. Because adrenocorticotropin, corticosterone, and vasopressin all show diurnal patterns of release, it cannot be determined at this time which, if any, of these hormones is most important for the behavioral results reported here.

Effects of amphetamine and illumination on activity following frontal ablation

Hyperactivity in the rat resulting from the removal of the frontal lobe, including the head of the caudate-putamen nucleus, in combination with d-amphetamine administration was studied in the light and dark over a 30 day postsurgical recovery period. Both d-amphetamine administration and frontal ablation increased activity level. In addition, d-amphetamine administration reversed the normal relationship of illumination with activity level. The postoperative hyperactivity following frontal ablation was dependent on the illumination level during testing. Potentiation of frontal induced hyperactivity by d-amphetamine was observed but the potentiation was not independent of the ambient illumination.

Perioperative management of the infant with congenital heart disease

The essential prerequisite for a successful outcome following surgery for infants with congenital heart disease, is an operation that achieves anatomic correction or palliation of the basic hemodynamic abnormality. In addition, however, careful perioperative medical management is required to prepare the critically ill infant for surgery, and to allow him to benefit from its technical accomplishment. The goals during the preoperative period are twofold: to attain optimal cardiorespiratory status and to obtain an accurate diagnosis. Following surgery, physiologic data is meticulously monitored, and intensive supportive care is instituted. This paper has presented an overall approach to perioperative care of the infant from the time that a congenital heart defect is suspected until the late post-surgical recovery period. The important aspects of management are outlined, and therapeutic problems during all phases of the pre- and postoperative period are discussed.