Comparison of the fat elimination between long-chain triglycerides and medium-chain triglycerides in rats with ischemic acute renal failure

To guide the administration of fat emulsion in the nutritional support of acute renal failure (ARF), pharmacokinetic analysis with an one-compartment open model after bolus intravenous injection was performed to compare the elimination kinetics of long-chain triglycerides (LCT) and medium-chain triglycerides (MCT) in ischemic acute renal failure rats. Sprague-Dawley rats were randomized into four groups, namely LCT normal group, LCT ARF group, MCT normal group and MCT ARF group. The model of ischemic acute renal failure was induced by clamping the left renal artery for 60 min and contralateral nephrectomy. All the rats were fasted with water ad libitum for 10 h before 0.3 g/kg body weight of 10% Intralipid (LCT) or 10% Lipofundin (MCT: LCT = 50:50) was injected as a bolus to them via the tail vein. The serum triglyceride concentration was determined at 2, 10, 40, 70, 100, 130 and 160 min after intravenous injection for kinetic analysis. The results showed that the elimination rate constant (ke) of LCT ARF group was significantly decreased, while the half life period (t1/2) of it was significantly longer than those of LCT normal group. The ke and t1/2 of MCT showed no statistical difference between normal and ARF groups. In the normal group the ke of LCT was significantly decreased compared with MCT whereas the t1/2 was significantly prolonged. In the ARF group the ke of LCT was much less than that of MCT while the t1/2 was much longer. The serum insulin levels of both MCT groups were significantly higher than those of LCT groups. These results indicate that MCT will be eliminated more rapidly than LCT in ARF rats. MCT may also increase the secretion of insulin. In conclusion, MCT may be more favorable than LCT in the nutritional management of ARF.     

Carnitine supplementation vs. medium-chain triglycerides in postburn nutritional support

The effect of dietary supplementation of carnitine on protein metabolism was studied in a burned guinea-pig model. Animals bearing a 30 per cent total body surface area burn were enterally infused with three isocaloric and isonitrogenous diets via gastrostomy feeding tubes for 14 days. Two diets contained safflower oil (long-chain triglycerides, LCT) and another diet contained medium-chain triglycerides (MCT) as their lipid sources (30 per cent of total calories as lipid). L-Carnitine was added to one of the two diets containing safflower oil. There were no significant differences in nitrogen balance, urinary excretion, serum albumin or transferrin among the three groups. However, the use of MCT in place of LCT appeared to increase liver weight and liver nitrogen. In this model, carnitine supplementation did not enhance the nitrogensparing effect of fat following burn injury.     

Experimental hyperosmolar diabetic syndrome. Ketogenic response to medium-chain triglycerides.

The clinical features of the experimental hyperosmolar diabetic (EHD) rat model resemble those seen in the human syndrome--extreme hyperglycemia without ketoacidosis is common to both. The absence of ketoacidosis in the syndrome has been ascribed to both substrate (free fatty acid) deficiency and to interference with hepatic ketone body synthesis. The potential for hepatic ketone body synthesis in the experimental model has been directly assessed by challenging the EHD animals with medium-chain triglycerides (MCT) administered intragastrically. This neutral lipid, largely consisting of C8 and C10 fatty acids, leads to a dose- and thime-related increase in the plasma concentration of acetoacetate and beta-hydroxybutyrate. The EHD rats respond to MCT with an increase in plasma ketone bodies that rises to levels that are twice as high as those observed in normal rats receiving MCT and are equivalent to the levels seen in untreated ketoacidotic animals. These data indicate that hepatic medium-chain fatty acid oxidation and ketogenesis are unimparied in the EHD animal. An analysis of the factors responsible for the greater ketogenic response in the EHD rat reveals that moderate diabetes and dehydration enhance MCT-induced ketone body accumulation, while cortisol is without effect. The plasma free fatty acid concentration in EHD animals does not differ from normal rats, but is significantly lower than that seen in diabetic ketoacidosis. These data support the concept that a principal reason for the absence of ketoacidosis in the EHD syndrome is the limitation in availiability of substrate, free fatty acids, for ketone body synthesis.     

Dietary substitution of medium-chain triglycerides improves insulin-mediated glucose metabolism in NIDDM subjects.

Dietary medium-chain triglycerides (MCT) may improve insulin-mediated glucose metabolism. To examine this possibility, 10 non-insulin-dependent diabetes mellitus (NIDDM) patients, 4 hypertriglyceridemic, and 6 normotriglyceridemic nondiabetic control subjects were examined with a 5-day cross-over design, in which the short-term metabolic effects of a 40% fat diet containing 77.5% of fat calories as MCT were compared with an isocaloric long-chain triglyceride-containing diet. In diabetic patients, MCT failed to alter fasting serum glucose concentrations but reduced preprandial glycemic excursions by 45% (F = 7.9, P less than 0.01). On MCT, the amount of glucose needed to maintain euglycemia during an intravenous insulin infusion was increased in diabetic subjects by 30%, in hypertriglyceridemic subjects by 30%, and in normotriglyceridemic control subjects by 17%. MCT increased mean +/- SE insulin-mediated glucose disposal (4.52 +/- 0.56 vs. 2.89 +/- 0.21 mg.kg-1.min-1; n = 3, P less than 0.05) but failed to alter basal glucose metabolism or insulin-mediated suppression of hepatic glucose output. Metabolic responses to MCT were observed independent of sulfonylurea therapy or severity of fasting hyperglycemia. No change in fasting serum insulin or triglyceride concentrations were seen with MCT administration. Although MCT increased mean fasting serum beta-hydroxybutyrate levels from 0.10 +/- 0.03 to 0.26 +/- 0.06 mM (P less than 0.05) in normotriglyceridemic nondiabetic subjects, no change was seen in diabetic patients. Thus, MCT-containing diets increased insulin-mediated glucose metabolism in both diabetic patients and nondiabetic subjects. In diabetic subjects, this effect appears to be mediated by increases in insulin-mediated glucose disposal.(ABSTRACT TRUNCATED AT 250 WORDS)     

中链甘油三酯对手术后接受肠外营养患者代谢的影响

目的比较长链甘油三酯(LCT)和中链甘油三酯(MCT)2种脂肪乳的代谢效应差异.方法24例胃、结肠手术患者和6例志愿者参加本研究,均有知情同意.患者随机分为2组,分别接受含50%MCT或单纯LCT的肠外营养.测定前臂动静脉血中甘油三酯的浓度差及氮平衡.结果MCT组肌肉利用脂肪乳的能力明显提高,氮平衡也有所改善,且术后体重减轻较少.在脂肪乳廓清试验中发现,血清酮体浓度MCT组[(0.063±0.004)mmol/L]明显高于LCT组[(0.039±0.002)mmol/L].氮储存的增加与酮体和胰岛素水平的增加相关.结论含50%MCT的脂肪乳用于肠外营养是安全的,可作为又一种能改善机体蛋白代谢的能量物质.     

Pain on injection: a double-blind comparison of propofol with lidocaine pretreatment versus propofol formulated with long- and medium-chain triglycerides

The incidence of pain on injection of propofol has been reported to be 70%. A new propofol formulation with a 10% emulsion of long- and medium-chain triglycerides (LCT/MCT) is associated with less pain on injection. Our goal was to compare the effect of propofol-LCT/MCT on the incidence of pain versus propofol with lidocaine 40 mg IV pretreatment injected as a Bier's block. Two hundred healthy women scheduled for ambulatory gynecological procedures were allocated to 1 of 2 groups in a randomized double-blind fashion. Group LIDO received lidocaine 2% 2 mL injected with a tourniquet 1 min before propofol 1% 2 mg/kg IV; group LCT/MCT received NaCl 0.9% 2 mL with tourniquet 1 min before propofol-LCT/MCT 1% 2 mg/kg IV. Spontaneous verbal expressions of pain, movement of hand, frowning, and moaning during the injection were recorded. The incidence and severity of pain were assessed 30 min and 6 h after surgery. Recall of pain was considered with a visual analog scale (VAS) score >1, and pain was graded as VAS 0-10. More women reported spontaneous verbal expression of pain with propofol-LCT/MCT (47% versus 24%; P = 0.0014; relative risk 1.61 [95% confidence interval, 1.22-2.13]). Among women with a painful injection, there was no difference after surgery regarding the intensity of pain or recall of pain. In contrast to previous reports, we found that propofol-LCT/MCT resulted in a more frequent incidence of pain than propofol 1% with IV lidocaine pretreatment. This may be due to the diversity of pain definitions used in studies or to the lack of premedication in our study.     

Protective effects of medium-chain triglycerides on the liver and gut in rats administered endotoxin

OBJECTIVE: To determine if medium-chain triglycerides (MCTs) prevent organ injuries and mortality in rats administered endotoxin and to investigate effects of MCT on the gut. SUMMARY BACKGROUND DATA: Since dietary MCTs prevent alcohol-induced liver injury by inhibiting activation of Kupffer cells in the enteral feeding model, the authors hypothesized that MCT could prevent deleterious conditions in endotoxemia. METHODS: After a preliminary experiment determined the optimal dose of MCT, rats were given MCT (5 g/kg per day) or the same dose of corn oil by gavage daily for 1 week. Then, lipopolysaccharide (LPS) was administered intravenously and survival was assessed for the next 24 hours. For analysis of mechanisms, rats were killed 9 hours after LPS injection and serum and liver sections were collected. To investigate effects of MCT on the gut, pathologic change, permeability, and microflora were assessed. Kupffer cells isolated by collagenase digestion and differential centrifugation were used for endotoxin receptor CD14 immunoblotting, phagocytic index, and TNF-alpha production assay. RESULTS: All rats given corn oil died after LPS administration; however, this mortality was prevented by MCT in a dose-dependent manner. Rats given corn oil showed liver injury after LPS administration. In contrast, MCT prevented this pathologic change nearly completely. MCT blunted CD14 expression on the Kupffer cells and TNF-alpha production by isolated Kupffer cells; however, there were no differences in phagocytic index between the two groups. The length of the intestinal epithelium was increased in the MCT group compared to the corn oil group. Further, after LPS administration, increases in gut permeability and injury were prevented by MCT. Importantly, MCT also prevented hepatic energy charge and gut injuries in this condition. CONCLUSIONS: Enteral feeding using MCT could be a practical way of protecting the liver and intestine during endotoxemia.     

Propofol in an emulsion of long- and medium-chain triglycerides: the effect on pain

IMPLICATIONS: In a test of two formulations of propofol for induction, patients experienced less pain with the formulation in Intralipid (Propofol-Lipuro 1%) than with Diprivan 1%.     

Protein sparing during general anesthesia with a propofol solution containing medium-chain triglycerides for gastrectomy: comparison with sevoflurane anesthesia

Purpose

Despite the importance of the inhibition of catabolic response to surgery, the effects of different anesthetic techniques on the catabolic response in surgical patients are controversial. This study compared the endocrine-metabolic responses and protein catabolism during gastrectomy in patients who received either sevoflurane or propofol anesthesia with remifentanil.

Methods

Thirty-seven patients (American Society of Anesthesiologists status I–III) aged 20–79 years undergoing elective gastrectomy were randomly assigned to receive sevoflurane anesthesia with remifentanil (n = 19) or intravenous propofol anesthesia (Propofol-Lipuro^® 1 %; B. Braun, Melshungen AG, Germany) with remifentanil (n = 18). Urine samples were collected every 1 h after skin incision (0 h) and the urinary 3-methylhistidine:creatinine ratio (3-MH/Cr ratio) was used as a marker of protein catabolism. Respiratory quotient was measured during a 1 h period following skin incision.

Results

The 3-MH/Cr ratio significantly increased at 1–2 and 2–3 h compared to 0 and 0–1 h in both groups, but the propofol group exhibited a lower 3-MH/Cr ratio (nmol/μmol) than the sevoflurane group at 1–2 h (15.7 vs. 18.2, P = 0.012) and 2–3 h (15.9 vs. 18.1, P = 0.025). A difference was observed in the respiratory quotient between the sevoflurane and propofol groups (0.726 vs. 0.707, P = 0.003).

Conclusion

A lower 3-MH/Cr ratio and a lower respiratory quotient during propofol anesthesia, compared to those exhibited during sevoflurane anesthesia, suggest that protein sparing probably occurs through the utilization of medium-chain triglycerides contained in the fat emulsion of propofol solution as a fuel source.     

A comparison of intensive care unit care of surgical patients in teaching and nonteaching hospitals.

Three hundred forty-eight teaching (TH) and 282 nonteaching (NTH) hospitals were surveyed to determine how intensive care unit (ICU) care is delivered to surgical patients and current views on surgical critical care. Teaching hospitals were more likely than NTHs to have a separate surgical ICU (92% versus 37%), a dedicated ICU service/physician (37% versus 7%), and a surgeon as director of the ICU (67% versus 29%). All THs and 33% of NTHs provided 24 hour in-house coverage for the ICU. A majority of respondents preferred a surgeon as ICU director (TH, 85%; NTH, 67%) and felt that critical care was an essential part of surgery (THs, 87%; NTHs, 74%). Most (THs, 58%; NTHs, 56%) thought that a cooperative effort between the primary service and an ICU service provided better patient care, but only 37% of THs and 22% of NTHs provided care with such a system. Many (THs, 45%; NTHs, 33%) thought that surgeons are willingly relinquishing ICU care. Surgeons continue to desire responsibility for their patients in the ICU and most prefer ICU service involvement provided by surgeons. This discrepancy between what is practiced and what is desired, along with proposed changes in reimbursement for surgery and the recent definition of critical care as an essential part of surgery, may stimulate greater involvement of surgeons in critical care.     

A comparison of surgical complications after appendicostomy and neoappendicostomy in pediatric patients

PurposeThere are limited data on neoappendicostomy complications owing to small patient populations. This study compares appendicostomy and neoappendicostomy procedures with an emphasis on major postoperative complications requiring either a surgical or interventional radiology procedure.MethodA single-institution retrospective review included all patients with complete medical charts in the Cincinnati Children's Colorectal Database who underwent either an appendicostomy or neoappendicostomy from August 2005 through December 2016. Demographics, details of the procedure, and major postoperative complications were evaluated.Results261 patients (appendicostomy n = 208, neoappendicostomy n = 53) with a median follow up time of 2.5 years resulted in 84 patients (appendicostomy n = 60, neoappendicostomy n = 24) experiencing a total of 118 complications requiring surgical or radiologic intervention with a significant difference between the groups (29% vs 45%, RR = 1.79 (95% CI: 1.24–2.60), p < 0.01). Skin level stricture was the most common complication (20% appendicostomies vs 30% neoappendicostomies, p = 0.13).ConclusionsAppendicostomies and neoappendicostomies can be an effective way to manage fecal incontinence; however, 32% of our patients experienced a complication that required either a surgical or interventional radiology procedure. Patients need to be informed of the possible complications that are associated with appendicostomy and neoappendicostomy construction.Type of studySingle institution retrospective review.Level of evidenceIV.     

Limited surgical discectomy and microdiscectomy. A clinical comparison

This study was performed in an attempt to determine if there was any clinical or cost benefit of microdiscectomy over surgical discectomy. Each patient was asked to rate his pain or neurologic deficit on a scale from 1 to 10 (1 = no pain or deficit and 10 = the most severe pain or deficit). Thirty patients underwent microdiscectomy. Average preoperative back pain was rated 8.03 and leg pain 8.53. Preoperative numbness was rated 5.29 and weakness 5.38. The median time off work preoperatively was 4 weeks. The mean hospitalization was 2 days, and a postoperative median of 8 weeks for returning to work. Average follow-up was 17.4 months. Mean back pain was 1.8, with 57% having no back pain at follow-up. Mean leg pain at follow-up was 1.3, with 67% having no leg pain. Numbness was rated 0.97, with 85% having none at follow-up. Weakness was rated 1.4, with 76% having none at follow-up. Thirty-four patients underwent surgical discectomy. Average preoperative back pain was rated 7.56 and leg pain 9.32. Preoperative numbness was rated 6.94 and weakness 5.88. The median time off work preoperatively was 6 weeks. The mean hospitalization was 7 days, and a median of 7 weeks postoperative before returning to work. Average follow-up was 18.5 months. The mean pain rating for back pain was 1.09, with 74% having no back pain at follow-up. The average leg pain was 1.09, with 74% having no leg pain at follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hemodynamic action profile of propofol in comparison with midazolam. A study in coronary surgical patients

Propofol, a rapid and short-acting i.v. anesthetic, was associated with the risk of anaphylactic reactions in its original cremophor-EL formulation. It has been reformulated in a soybean emulsion with satisfactory anesthetic properties. A former study of hemodynamic changes after i.v. induction with propofol, thiopental, methohexital, etomidate, and midazolam in patients with coronary artery disease demonstrated that in comparison to other induction agents propofol depressed systolic and diastolic arterial pressures more severely, compromising coronary perfusion. In the present investigation left ventricular parameters as well as hemodynamic effects during extracorporeal circulation (ECC) were studied in comparison to midazolam during opiate analgesia. Methods. Hemodynamic effects of 2 mg/kg body weight propofol as compared to 0.15 mg/kg midazolam were studied in 34 patients during coronary artery surgery before cannulation of the large vessels (measurement of left ventricular parameters) or during ECC (measurement of arterial perfusion pressure and oxygenator volume). Results (see Table 1, Figs. 1 and 2). Propofol decreased systolic and diastolic pressures (-27%, -22%) more than midazolam (-10%, -9%). Cardiac index and stroke volume index were diminished following both drugs (propofol: -14%, -9%; midazolam: -15%, -11%); total systemic resistance was reduced significantly by propofol (-22%). Dp/dtmax was compromised more markedly by propofol (-24%) than by midazolam (-18%), but there was no significant difference.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of transurethral and transrectal microwave hyperthermia in poor surgical risk benign prostatic hyperplasia patients.

From 1987 to 1989, 36 poor surgical risk patients with benign prostatic hyperplasia (BPH) were treated with transrectal or transurethral microwave hyperthermia. Most of the 36 patients treated (85%) had severe signs and symptoms of urinary outflow obstruction. Of the patients 22 (61%) underwent transrectal and 14 (39%) underwent transurethral hyperthermia. Followup ranged from 10 to 28 months (mean 19 months) for the transrectal hyperthermia group and 7 to 16 months (mean 10 months) for the transurethral hyperthermia group. The patients were given 6 hyperthermia sessions of 30 minutes each with the temperature controlled on the rectal or urethral surface at 45C. Hyperthermia was well tolerated with mild acute toxicity and no late complications were observed. In the important subjective and objective parameters, major improvement was noted more frequently in the 14 transurethral than in the 22 transrectal hyperthermia treated patients (p less than 0.05). The Food and Drug Administration severity score, prostate volume, post-voiding residual volume and urethral flow showed substantial improvement in 79, 86, 79 and 79%, respectively, of the 14 transurethral hyperthermia treated patients compared to 41, 45, 82 and 82%, respectively, for the 22 transrectal hyperthermia treated patients. A prospective randomized trial comparing transrectal and transurethral hyperthermia is required to define the role of each treatment mode in patients with BPH.     

A comparison of surgical keratometers

Surgical keratometers were conceived as an aid that would help anterior segment surgeons minimize postoperative astigmatism, a major obstacle along the road to rapid visual rehabilitation. Two classes of surgical keratometers are commercially available at present. The first class of devices produces a keratoscopic image from which the surgeon must make a qualitative assessment of both the amount and location of astigmatism based upon distortion present in the keratoscopic image. The second class of devices quantitates corneal power at a chosen meridian and providing the surgeon with either an analogue or digital readout. Usually it is up to the surgeon to identify the meridian of greatest corneal power based on qualitative alterations of the keratoscopic image. These keratoscopes are based either on the optical principles of the von Helmholtz keratometer, or on nonparallel electronic image digitization. In this article we critically review commercially available surgical keratometers emphasizing their attributes and limitations.     

A microbiological in-use comparison of surgical hand-washing agents.

Seven different surgical hand-scrub agents (one triclosan compound, two hexachlorophene compounds, and four iodophors) were evaluated under in-use conditions by five persons for efficacy in degerming the hands and forearms prior to performing a total of 215 total hip arthroplasties. With all of the compounds tested there was a significant reduction (p less than or equal to 0.001) of indigenous skin microflora from prescrub levels at both the post-scrub and postoperative points. The two hexachlorophene compounds in general revealed a bacteriostatic effect whereas the triclosan compound and the four iodophors did not. A hexachlorophene compound applied as a foam demonstrated excellent bacteriocidal and bacteriostatic action, was less time-consuming and easier to use than compounds applied as scrubs, and did not alter a low (0.47 per cent) in-use infection rate over a period of three years.     

Tibial plateau fractures. A comparison of conservative and surgical treatment

We evaluated the long-term results of 109 tibial plateau fractures, 61 treated by skeletal traction and early knee movement and 48 treated by surgery, at an average follow-up of 70 months. The functional results were much the same, though meniscectomy had been performed in almost half of the surgical patients. Time in bed and duration of hospital stay were clearly shorter after surgery (p less than 0.0001). We concluded that conservative management is a valid alternative to surgery, but should probably be reserved for cases where operation is undesirable. Future studies should compare surgery without meniscectomy and conservative treatment using cast braces to reduce the time in traction.     

Haemodynamic comparison of sevoflurane and isoflurane anaesthesia in surgical patients

Purpose

To compare the haemodynamic responses to surgical incision during sevoflurane and isoflurane anaesthesia and to compare the haemodynamic effects of each anaesthetic alone with those obtained using an equipotent mixture of each anaesthetic plus N₂O dunng steady-state surgical stimulation.

Methods

Twenty-four patients undergoing gastrectomy were randomized to receive sevoflurane (n = 12) or isoflurane (n = 12). At 1.5 MAC. haemodynamic measurements were performed before and after surgical incision. During intestinal anastomosis, patients in each group were given (in random order) either 1.5 MAC of the designated anaesthetic or 0.85 MAC of the volatile plus 0.65 MAC N₂O. Haemodynamic measurements were repeated under each condition.

Results

One patient in the sevoflurane group and two in the isoflurane group were excluded from the incision study because of hypotension. In both groups, incision increased the heart rate (HR), mean arterial pressure, mean pulmonary artenal pressure (MPAP), pulmonary capillary wedge pressure (PCWP). cardiac index, and systemic vascular resistance index (SVRI). There were no intergroup differences in the effects of incision. Inclusion of N₂O resulted in an increase of MPAP (P < 0.05) in both groups, an increase of central venous pressure and PCWP in the sevoflurane group (P < 0.005). and a decrease of HR (P < 0.005) and an increase of SVRI (P < 0.05) in the isoflurane group. There were no intergroup differences in the effects of N₂O.

Conclusions

At 1.5 MAC, sevoflurane and isoflurane do not prevent the haemodynamic response to incision. The haemodynamic effects of each volatile anaesthetic with N₂O are minimal compared with those of equi-MAC volatile alone.