Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Intraoperative Period”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed1982

[Urea and potassium losses and changes in amino acid concentration after aortocoronary bypass operations].

Changes in urea nitrogen excretion, renal potassium losses, and changes of amino acid concentrations in plasma following aortocoronary bypass operations were observed in 10 patients. The observation time included the preoperative day, the day of operation, and 4 postoperative days. The patients were treated with a 5% glucose solution (800-1000 ml/m2). The additional spontaneous oral intake was estimated and reached approximately 600-800 kcal and 25-30 g protein on the 3rd and 4th postoperative day. The calculated urea nitrogen loss was between -8.2 g (operation day) and -11.2 g (4th postoperative day). The concentrations of serum amino acids in plasma were below normal preoperatively. It seems possible that this is due to longer preoperative fasting because only patients with normal body weight were admitted to operation. The amino acid concentrations fell significantly to lower than normal values during the postoperative period. There were massive renal losses of potassium of about 140 mEq/day on the day of operation and on the 1st postoperative day. High parenteral substitution was necessary to avoid severe falls in serum potassium levels and possible cardiac arrythmias.

Amino Acids↗
PubMed1995

Predicting perioperative stroke.

The purpose of this review is to examine the incidence and mechanisms of perioperative stroke and to identify possible associated risk factors. The perioperative period can be subdivided into preoperative, intraoperative, and postoperative periods; we focus here on assessment in the preoperative period, as this is the time when risk prediction usually occurs. Surgical technique itself will not be considered, nor will intraoperative monitoring to detect cerebral ischemia be considered. This review will examine perioperative stroke in relation to general surgical procedures, including peripheral vascular reconstruction, orthopedic, gynecologic, and head and neck surgery.

Anesthesia↗
PubMed1985

Prevention of postoperative facial edema with steroids after facial surgery.

A one-bolus (dose) of 1 g of methylprednisolone was administered intravenously to patients undergoing facial surgery or craniofacial surgery, before the termination of the operative procedure. The degree of facial edema noted was reduced, and when it occurred, it was mild and of shorter duration. These observations were made on the experimental design first, and later in the clinical setting. No adverse effects were noted, and patients given this treatment required less pain medication in the immediate postoperative period. The mechanism of action of the steroids is multifactorial, related to decrease in the accumulation of fluid at the capillary level, and reduction of flow at the venoarterial sphincters. The use of steroids is safe when used with caution in selected patients, and by experienced surgeons.

Edema↗
PubMed1989

The effects of anesthesia and surgery on lymphocyte populations and function in infants and children.

A study was designed to test the hypothesis that the lymphopenia caused by surgical stress in children may arise through selective depletion of one or more lymphocyte subsets. Blood samples from 22 children were taken pre- and postoperatively and 6, 12, 24, and 48 hours after surgery. Lymphocyte subsets were identified and counted using monoclonal antibodies and indirect immunofluorescence. By six hours postoperatively, the mean total lymphocyte count had fallen by 1.87 x 10(9)/L (P less than .01); this was largely due to the fall in helper T cells (1.53 x 10(9)/L, P less than .01) and both counts remained depressed for at least 48 hours. The helper:suppressor ratio also fell, from 3.42 to 1.92 (P less than .01), but had recovered by 48 hours. Lymphocyte function as measured by the response to pokeweed mitogen and concanavalin A was also reduced six hours postoperatively. These changes were independent of age. Major surgery in infants and children causes a selective reduction in helper T lymphocyte numbers, helper:suppressor ratio, and lymphocyte function. This suggests that immune competence in the immediate postoperative period in children is reduced, as it is in adults. The duration of this and its relationship to infection are not yet known.

Age Factors↗
PubMed1996

Reduced oxygen tension during cardiopulmonary bypass limits myocardial damage in acute hypoxic immature piglet hearts.

OBJECTIVES: Cardiopulmonary bypass (CPB) is usually instituted in a hyperoxic fashion (oxygen tension (pO2) 300-500 mm Hg), which may expose cyanotic infants to potential reoxygenation damage. Oxygen free radicals play an important role in this injury. The rate of production of this highly reactive toxic oxygen species is dependent on the oxygen level during reoxygenation. This study tested the hypothesis that reduction of the oxygen in the bypass prime and in blood cardioplegia (BCP) to normoxic levels can reduce reoxygenation injury and will result in improved contractility. METHODS: We operated on 19 Duroc-Yorkshire piglets (2-3 weeks, 3-5 kg). Five underwent 30 min of BCP arrest during 1 h of CPB without hypoxia (control). Fourteen underwent 120 min of hypoxia (arterial pO2 20-30 mmHg) on ventilator before reoxygenation on CPB. Reflecting the clinical routine procedure, nine of them were reoxygenated on CPB for 5 min with high pO2 (350-450 mm Hg) followed by 30 min of BCP arrest (high pO2) and 25 min of reoxygenation/reperfusion on CPB with high pO2 levels (NoRx). Five others were put on CPB with pO2 reduced to normoxic levels (pO2 100 mm Hg) in CPB and BCP (Rx). Functional and biochemical measurements were made before hypoxia, as well as during and after reoxygenation. RESULTS: In contrast to controls, NoRx resulted in a 40% decrease in antioxidant reserve capacity (P<0.01) at 4 mM t-butyl hydroperoxide (t-BHP), a 1212% increase in myocardial conjugated diene production during BCP induction (P<0.0003), a 1000% during reperfusion (P<0.002), a 36.1% and a 37.0% increase in coronary sinus blood conjugated dienes at 35 min (P<0.05) and 60 min (P<0.05) of reoxygenation. These biochemical changes were accompanied by a 79% reduction of left ventricular contractility (P<0.0003). Conversely, Rx led to an improvement in antioxidant reserve capacity (939+/-212 vs. 1342+/-177 nmol/g protein; P<0.003), less conjugated diene production during BCP induction (15.5+/-6.1 vs. 42.1+/-8.8 A233 nm/min per 100 g; P<0.003) and reperfusion (1.8+/-3.9 vs 22.0+/-5.5 A233 nm/min per 100 g; P<0.005), and to a significantly improved post bypass LV contractility (58+/-25 vs. 21+/-5; P<0.0003). CONCLUSIONS: These data document that hypoxemic/reoxygenation injury occurs in acute hypoxic immature piglet hearts when reoxygenated on CPB with hyperoxic pO2 (normal clinical practice). By lowering the antioxidant reserve capacity, hypoxemia seems to render the developing heart susceptible to reoxygenation damage, which occurs with the reintroduction of molecular oxygen, and is associated with free radical production, subsequent lipid peroxida tion, and depressed post bypass LV function. Reduction of pO2 during the initial reoxygenation period and during BCP arrest to normoxic levels resulted in a significant reduction of this oxygen-related damage and in much improved myocardial performance.

Acute Disease↗
PubMed1991

[Perioperative myocardial infarct].

Retrospective analysis has been carried out with the surgical material of 9 years in the wards of surgical character of a county hospital to determine the incidence and main clinical characteristics of perioperative myocardial infarction. Data of 61 patients were processed in order to answer the questions. Age, arteriosclerosis causing disturbance of organ perfusion and the change of blood pressure in the perioperative period play the main role in the development of this complication of high mortality. Detailed clarification of the coronary state before the elective operation, a possible aortocoronary bypass operation appear to prevent most effectively the pathological picture.

Adult↗
PubMed1986

Ventilation and ventilatory CO2 response in children during halothane anaesthesia after non-opioid (midazolam) and opioid (papaveretum) premedication.

The influence of non-opioid (NO) and opioid (O) premedication on ventilation and ventilatory CO2 response was studied in 18 spontaneously breathing children during halothane anaesthesia. Eight patients in Group NO and 10 in Group O were comparable in age, body weight and type of surgery performed. The sedative effect was evaluated and measurements by pneumotachography and in-line capnography were made immediately after induction of sleep, just before the start of surgery, during surgery and after surgery both before and after 3 min of about 2% CO2 inhalation. Immediately after induction the mean value (+/- s.e. mean) of end-tidal CO2 concentration (ETCO2) was 4.86 +/- 0.21% in Group NO and 5.28 +/- 0.22% in Group O. Before and during surgery, minute ventilation (VE) was higher in Group NO (P less than 0.05) mainly due to higher respiratory rates. ETCO2 was similar in the two groups before, during and after surgery. The ratio of VE to CO2 elimination (VCO2) and of dead space (VD) to tidal volume (VT) was higher in Group NO, but ventilatory response to CO2 inhalation immediately before the postoperative period was similar in both groups. It was concluded that opioid premedication resulted in more efficient ventilation during anaesthesia and surgery, and that CO2 response at the end of surgery was maintained in both groups.

Analgesics↗
PubMed1992

Direct epidural morphine injection during lumbar discectomy for postoperative analgesia.

A double-blind controlled study was done on 42 patients to test the analgesic activity of epidural morphine after lumber laminectomy for single level disc herniation. Sixteen patients received 3 mg preservative-free morphine. Twenty-six patients received normal saline. The patients given epidural morphine had a longer postoperative pain-free period (6.28 vs 2.37 hours) and needed less postoperative analgesia (0.2 vs 0.9 times for paracetamol, and 0.16 vs 0.51 times for morphine). Epidural morphine injection under direct vision during discectomy operation is an effective and safe method for postoperative pain relief.

Adult↗
PubMed1999

Fast-track cardiac anesthesia in patients with sickle cell abnormalities.

UNLABELLED: We conducted a retrospective review of 10 patients with sickle cell trait (SCT) and 30 patients (cohort control) without SCT undergoing first-time coronary artery bypass graft surgery with cardiopulmonary bypass. Demographic, perioperative management, and outcome data were collected. Both groups were matched according to age, weight, duration of surgery, and preoperative hemoglobin (Hb) concentration. Distribution of gender, medical conditions, pharmacological treatment, and preoperative left ventricular function were similar between the groups. The comparisons were analyzed in respect to postoperative blood loss and transfusion rates, as well as duration of intubation, intensive care unit, and hospital length of stay (LOS). All patients underwent fast-track cardiac anesthesia. A combination of cold crystalloid and blood cardioplegia was used. The lowest nasopharyngeal temperature was 33 degrees C. There were no episodes of significant hypoxemia, hypercarbia, or acidosis. None of the patients had sickling crisis during the perioperative period. The postoperative blood loss was 687 +/- 135 vs 585 +/-220 mL in the SCT and control groups, respectively. The trigger for blood transfusion during cardiopulmonary bypass was hematocrit <20% and Hb <75 g/L postoperatively. Three SCT patients (30%) and 10 control patients (33%) received a blood transfusion. Median extubation time was 4.0 vs 3.9 h; intensive care unit LOS was 27 vs 28 h; and hospital LOS was 6.0 vs 5.5 days in the SCT and control groups, respectively. There were no intraoperative deaths. One patient in the SCT group died from multiorgan failure 2 mo after surgery. IMPLICATIONS: Fast-track cardiac anesthesia can be used safely in patients with sickle cell trait undergoing first-time coronary artery bypass graft surgery. Extubation time and intensive care unit and hospital length of stay are comparable to those of matched controls, and blood loss and transfusion requirements are not increased. A hematocrit of 20% seems to be a safe transfusion trigger during cardiopulmonary bypass in these patients.

Adult↗
PubMed1987

Reduced incidence of hepatic metastases by perioperative treatment with recombinant human interleukin-2.

Abdominal operations induce immunosuppression during the time when tumors are manipulated and tumor cells are released into the circulation. The authors tested the hypothesis that the combined effect of these factors may promote the development of metastatic tumor implants and that perioperative treatment with Human Recombinant Interleukin-2 (RIL-2), a known immunostimulant of t, natural killer (NK), and lymphokine activated killer (LAK) cells may reduce the incidence of liver metastases from transplantable rat colon cancers. Hepatic metastases were induced in male Fischer 344 (F344) rats by injecting 10(7) rat colon tumor cells into the portal venous system during laparotomy. Control rats developed tumors by four weeks and were dead by ten weeks. Eleven groups of rats underwent celiotomy with portal vein injection of tumor on day three. Rats received either no RIL-2, RIL-2, or excipient buffer at varying doses on days 1 through 5 or 3 through 7 of these experiments. Animals were assessed for the presence of tumor and the incidence of liver metastases at autopsy (sacrifice and autopsy performed at seven weeks). Eighty-five percent of the rats in the untreated group developed tumor. This compared with only 50 percent of animals receiving 10(3) u/dose (P less than .025) and 42 percent of animals receiving 10(4) u/dose (P less than .01) of Interleukin-2 on days 1 through 5. Animals receiving very high doses of RIL-2 (10(5) or 4 X 10(5) units per dose) had a greater chance of developing tumors than did control rats, or rats receiving lower doses of RIL-2 (P less than .05). It is concluded that the perioperative period may be critical for the implantation and growth of metastatic disease and that perioperative immunostimulation with RIL-2 can decrease the incidence of tumors in these animals. This model may have relevance to the treatment of human colon cancer.

Animals↗
PubMed1993

Management of an innominate artery aneurysm during an open heart operation.

A 76-year-old woman was found to have a 4 x 2.5-cm saccular aneurysm at the origin of the innominate artery at the time of a reoperative open heart operation. The operative procedure was modified to include repair of the aneurysm with a Dacron patch. During the period of innominate artery occlusion, the patient was cooled to 25 degrees C and the mean arterial pressure was maintained at 90 mm Hg to maximize cerebral protection.

Aged↗
PubMed1986

Perioperative and long-term results after electrophysiologically directed ventricular surgery for recurrent ventricular tachycardia.

Thirty-six patients underwent ventricular aneurysmectomy and electrophysiologically directed endocardial resection for treatment of recurrent ventricular tachycardia refractory to antiarrhythmic drug therapy. The surgical mortality rate was 17% and all 30 patients discharged from the hospital were alive at the end of the follow-up period (range 6 to 54 months), yielding a cumulative projected survival rate of 83% by actuarial analysis. Poor systolic function of the nonaneurysmal ventricular segments was the strongest and the only independent predictor of operative mortality among the clinical, hemodynamic, angiographic and electrophysiologic variables analyzed by stepwise logistic regression. Ventricular tachycardia recurred early in four of the six patients in whom the endocardial resection was limited to a small area for technical reasons. Twelve patients, including 10 with sustained ventricular tachycardia still inducible by postsurgical programmed electrical stimulation, were discharged receiving antiarrhythmic drugs that had been tried unsuccessfully before surgery. During a mean follow-up period of 25 +/- 15 months, nonfatal sustained ventricular tachycardia recurred in two patients after discharge. Inadequate endocardial resection was a significant predictor of arrhythmia recurrence.

Actuarial Analysis↗
PubMed1981

Plasma propranolol before, during, and after cardiopulmonary bypass.

We evaluated changes in propranolol plasma levels before, during, and after cardiopulmonary bypass (CPB). Two groups of patients were studied, all of whom had been on long-term propranolol and had received their last oral dose 10 to 15 hr before surgery. Approximately 100 min before CPB began group 1 patients (n = 7) received 0.1 mg/kg propranolol intravenously while group II patients (n = 7) received a placebo. Before CPB the plasma propranolol levels fell in accordance with published descriptions for nonsurgical patients receiving oral and intravenous propranolol. Thereafter, the changes in the plasma levels were much the same in both groups. With the onset of CPB, the plasma levels decreased by approximately 50%. There was an insignificant fall in plasma levels during CPB, but the most interesting observation was made after : in each patient, the plasma levels obtained 5, 60, 120, and 240 min after CPB were higher than the last level during CPB. Mean plasma levels did not decline in either group during the 4-hr period. Although the reason for the sustained rise in the propranolol levels after CPB is not known, we suggest that it is due to the redistribution of propranolol from the lungs of the plasma coupled with reduction in hepatic elimination.

Administration, Oral↗
PubMed1992

[Cerebral complications and general anesthesia].

Postoperative cerebral dysfunction is usually assumed to be a consequence of anaesthesia. Temporary postoperative confusion is quite common. This review points out that the anaesthetic technique is clinically relevant for mental dysfunction only in the few hours immediately following operation. Of primary importance are the preoperative state of the patient, the drugs used in the perioperative period, the type and duration of the operation, the technique of postoperative analgesia and sedation and the postoperative clinical course of the patient. Cerebral infarction is a very severe but rather rare complication which occurs mainly after the operation. The incidence of perioperative cerebral infarction is about 1% in 65-year-old patients and increases with higher age. An asymptomatic preoperative carotid bruit is not a risk factor; therefore, invasive investigations are not warranted. The most frequent cause for cerebral insults are emboli. Intraoperative hypotensive periods are very rarely responsible for cerebral insults. Peripheral and central nervous lesions due to positioning of the patient for the operation occur not frequently and are certainly an avoidable neurologic complication. Hypoxic cerebral damages are usually the consequence of anaesthetic mismanagement. Today they are very rare, due to modern monitoring techniques.

Anesthesia, General↗
PubMed1988

Variation in T helper cell/T cytotoxic-suppressor cell index during cardiac operations.

After surgical procedures, humoral and cell-mediated immunity responses decrease. Both anesthesia and surgical trauma play an important role in this effect. Cardiac operations induce a greater decrease in immunologic response than other surgical operations. On the other hand, identification of functional lymphocyte subclasses by means of appropriate monoclonal antibodies appears to provide an accurate measurement of cellular immune competence. Employing these methods, we found a significant decrease of T helper cell/T cytotoxic-suppressor cell ratio in the periperal blood of 20 patients undergoing cardiac operations. This decrease during the period of anesthesia (before surgical incision) is due as much to a decrease of T helper cell percentage as to an increase of T cytotoxic cell percentage. However, during the surgical trauma period (surgical incision to the end of the operation) it is due to a greater increase of T cytotoxic-suppressor cell percentage without significant changes in the percentage of T helper cells.

Adult↗
PubMed1995

Energy expenditure (EE) and substrate utilization (SU) in the perioperative period in orthotopic liver transplantation (OLTX).

12 patients were investigated with IC (Datex, Deltatrac) preoperatively and during the surgical procedure of OLTX, VO2, VCO2 were continuously measured and RQ, EE and SU were calculated considering the different periods of the procedure: preoperative resting EE: (PREE), anaesthesiological procedures (ANEE), liver preparation EE (LPEEE), liver removal EE (LREE), anhepatic phase EE (APEE), reperfusion, EE (RPEE) and end of operation EE (EOEE). EE were expressed as % respect value calculated with H.B. (Harris-Benedict) formula. Data were analyzed with Student T-test and p < 0.01** or < 0.05* PREE is typical in end stage liver disease with low RQ values and increased EE. Energy production depends on lipid utilization since liver gluconeogenesis and glycogen stores are impaired. Anesthesia reduces energy needs and production up to 50% of the preoperative values, reducing VO2 more than VCO2 and therefore an augmented RQ value over 1.0. SU analysis indicates an increased glucose and aminoacid utilization coupled with high nitrogen catabolism that continues in the postoperative period (from 0.08 0.01 gN/kg b.w. to 0.20 0.06 gN/kg b.w.). When the new liver is reperfused, VO2 increases more than VCO2 indicating the risk of reperfusion injury.

Calorimetry, Indirect↗
PubMed1988

[Automated monitoring of respiratory parameters in the anesthetized patient in mechanical respiration].

The constant monitoring of respiratory elastance and resistance can be of interest in patients who present a high risk of peroperative bronchospasm. The constant inspiratory flow method, proposed by Bates et al. (J Appl Physiol, 58: 1840, 1985) was chosen and automated. The inspiratory flow rate and pressure were measured respectively by a pneumotachograph linked to a differential pressure, and by a differential pressure transducer, both placed at the outlet of the inspiratory circuit. The pressure and flow signals were low-pass filtered, sampled, and then processed by an Apple II microcomputer, in order to obtain respiratory elastance and resistance. New results were displayed on the screen about every minute. The automated method was first tested in a series of 18 guinea-pigs; the respiratory parameters were compared with those obtained by the occlusion method proposed by Rossi et al. (J Appl Physiol, 58: 1849, 1985). They were found not significantly different and very strongly correlated (p less than 0.001). The ability of the constant flow method to detect changes in respiratory mechanics was then tested in a series of nine patients, after anaesthetic induction. The results obtained were in accordance with those previously published: a rise in both respiratory elastance and resistance. After giving 1 mg atropine intravenously, the respiratory resistance fell rapidly over a 5 min period, and then reached a plateau. The constant flow method, which avoids interruption in the mechanical ventilation and is sensitive to small changes in respiratory parameters, appears particularly convenient for the peroperative monitoring of patients.

Airway Resistance↗
PubMed1995

Enhanced polymer one-step staining (EPOS) for proliferating cell nuclear antigen (PCNA) and Ki-67 antigen: application to intra-operative frozen diagnosis.

Enhanced polymer one-step staining (EPOS) is a novel, highly sensitive one-step immunostaining method. This simple and rapid technique was applied to intra-operative frozen diagnosis. The markers of choice were proliferating cell nuclear antigen (PCNA) and Ki-67 antigen. These cell proliferation markers were both identifiable in fresh frozen sections of the human tonsil in approximately 7 min. The suitable staining sequences are as follows. Frozen sections prepared using 3-aminopropyltrimethoxysilane-coated glass slides are immediately fixed, without air drying, for 15 s in a mixture of 50% formalin and 50% methanol for PCNA, and in 10% formalin for Ki-67 antigen. After a brief rinse in phosphate-buffered saline (PBS), sections are incubated with the EPOS antibody for 3 min, followed by PBS rinse for 1 min. The peroxidase activity is visualized in diaminobenzidine-H2O2 solution containing 10 mmol/L imidazole for 2 min. After a light rinse in tap water, the nuclei are briefly counterstained with 5% methyl green. When necessary, endogenous peroxidase blockage in 1% periodic acid solution for 1 min is added before the EPOS antibody incubation. This procedure is applicable to frozen sections of gastric cancers, malignant lymphomas, and brain, liver and peritoneal lesions in which differential diagnosis between benignancy and malignancy was required.

Brain Neoplasms↗