Evaluation of a mechanistic model that estimates feed intake, growth and body composition, nutrient requirements, and optimum economic response of broilers

Efficient meat production is crucial in addressing global market demands and sustainability goals. Modeling production systems has gained worldwide attention, offering valuable insights for predicting outcomes and optimizing economic returns. In the poultry industry, researchers have developed mathematical models to predict animal performance and maximize profits. These models incorporate theories to explain real-world processes and enable future event predictions. One such model is the Broiler Growth Model (BGM), which serves as a predictive tool for estimating feed intake, growth, and body composition of broilers. The BGM takes into account the genetic potential of the broilers, the feed they are provided, and several constraining factors that may prevent the animal from achieving their genetic potential. To evaluate the BGM, a series of simulations were performed: (i) model behavior was evaluated by simulating the response of males and females from 22 to 35 d to feeds differing in dietary protein content and nutrient density; (ii) model prediction was evaluated using the results of a protein response trial conducted at UNESP in which six dietary protein levels were fed to male and female broilers over a 56 d period; and (iii) model optimization was used to maximize economic returns in the above trial. The model behaved as expected when feeds differing in protein content were fed, with feed intake per kg of BW increasing as protein level was decreased, resulting in lower gains and higher body lipid contents. Increasing nutrient density resulted in higher feed intake in the second level, followed by a reduction in feed intake in the highest nutrient feed. The simulated response to nutrient density resulted in increasing body lipid deposition as the nutrient density increased. In comparing the simulated and actual results of the protein response trial, the overall error of prediction was up to 15% for feed intake, BW, and body protein. The optimization routine allows the simulation of different economic scenarios, helping in decision-making. The Broiler Growth Model emerges as a valuable tool for the poultry industry, offering predictive capabilities and economic optimization potential. While minor discrepancies between simulated and actual results exist, the BGM holds significant promise for enhancing efficiency and profitability in broiler production, contributing to the broader goals of sustainable broiler meat production.

A first model of the fate of dietary calcium and phosphorus in broiler chickens

To reduce P excretion and increase the sustainability of poultry farms, one needs to understand the mechanisms surrounding P metabolism and its close link with Ca metabolism to precisely predict the fate of dietary P and Ca and related requirements for birds. This study describes and evaluates a model developed to estimate the fate of Ca and P consumed by broilers. The Ca and P model relies on three modules: (1) digestion of Ca and P; (2) dynamics of Ca and P in soft tissue and feathers; and (3) dynamics of body ash. Exogenous phytase affects the availability of Ca and P; thus, to predict the absorption of those minerals, the model also accounts for the effect of phytase on Ca and P digestibility. We used a database to estimate the consequences of dietary Ca, P, and phytase over feed intake response. This study followed a four-step process: (1) Ca and P model development and its coupling with a growth broiler model; (2) model behavior assessment; (3) sensitivity analysis to identify the most influential parameters; and (4) external evaluation based on three databases. The proportion of P in body protein and the Ca to P ratio in bone are the most sensitive parameters of P deposition in soft tissue and bone, representing 91 and 99% of the total variation. The external evaluation results indicated that body water and protein had an overall mean square prediction error (rMSPE) of 7.22 and 12.3%, respectively. The prediction of body ash, Ca, and P had an rMSPE of 7.74, 11.0, and 6.56%, respectively, mostly errors of disturbances (72.5, 51.6, and 90.7%, respectively). The rMSPE for P balance was 13.3, 18.4, and 22.8%, respectively, for P retention, excretion, and retention coefficient, with respective errors due to disturbances of 69.1, 99.9, and 51.3%. We demonstrated a mechanistic model approach to predict the dietary effects of Ca and P on broiler chicken responses with low error, including detailed simulations to show the confidence level expected from the model outputs. Overall, this model predicts broilers' response to dietary Ca and P. The model could aid calculations to minimize P excretion and reduce the impact of broiler production on the environment. A model inversion is ongoing that will enable the calculation of Ca and P dietary quantities for a specific objective. This will simplify the use of the model and the feed formulation process.

Eimeria maxima infection impacts the protein utilisation of broiler chicks from 14 to 28 days of age

In floor-raised broilers, coccidiosis is responsible for reducing the use of nutrients, mainly by impairing intestinal tissue function and activating the immune system. Understanding and quantifying how balanced dietary protein (BP) is used when birds are challenged will allow nutritionists to make decisions regarding challenged flocks. This study aimed to determine the effects of Eimeria maxima on broiler performance and body composition, and to calculate changes in the maintenance and efficiency of protein utilisation (Ep). A total of 2 400 male 14-day-old Cobb500 broiler chickens were randomly allotted to ten groups with six replications of 40 birds each, with a 5 × 2 factorial arrangement of treatments. Five levels of BP in reference to digestible lysine (3.6, 7.2, 10.8, 14.4, and 18.0 g/kg) were fed to unchallenged (NCH) and challenged (CH) broilers with 7 × 103E. maxima sporulated oocysts from 14 to 28 days of age. Performance and body deposition were measured using a comparative slaughter technique to compare BP maintenance requirements and Ep. ANOVA followed by a posthoc test was performed to compare the effects of BP levels, challenge, and their interactions. A monomolecular model describing the responses of NCH and CH broilers to BP intake, maintenance, and maximum protein deposition was compared. There were significant interactions between body weight gain and digestible lysine intake among the factors studied. Infection had a negative impact on all variables analysed, proving the efficacy of the challenge. The maintenance did not differ between the CH and NCH groups. Increased levels of dietary BP did not recover the maximum protein deposition in CH broilers. Eimeria maxima significantly reduced Ep by a factor of 0.09 times on Ep compared to the control group. The Eimeria maxima challenge was responsible to modify the use of BP altering the body composition and impairing broilers performance.

Update and evaluation of the egg production model in laying hens

The egg production model (EPM) described here is a mechanistic and stochastic model that simulates the amino acid and energy requirements of laying hens. It takes into account their potential rate of laying, and egg weight over time, and the composition of the feed provided. The model predicts feed intake based on the assumption that hens will consume enough feed to reach their genetic potential. The environment is assumed to be non-limiting, although feed intake may be constrained by bulk capacity when bulky feeds are offered. The simulation model integrates a least-cost feed formulator, which enables the prediction of a feeding program that maximizes economic returns. A series of simulations were conducted to demonstrate the model behavior, external evaluation, and the economic optimization routine. The model behavior showed that as the energy content in the feed decreased, the simulated feed intake increased to compensate. Consequently, feeds with lower energy concentrations led to an overconsumption of nutrients, resulting in increased egg component weights (yolk and albumen). However, when the balanced protein was reduced while maintaining a constant energy-to-protein ratio, there was no change in egg components, consistent with published literature. The external evaluation indicated that feed intake, egg production, and egg weight were estimated with low error, and there was a similar trend observed between the estimated and observed data. This demonstrates the reliability of the model. Additionally, the paper provides a demonstration of how to use and interpret the results from the egg production model, including the economic optimization routine. The study found that a feed containing 7.8 g/kg of digestible lysine maximized economic returns. This optimization tool can be valuable in making nutritional decisions to optimize economic returns in an egg production system.

Gut capacity of broiler breeder hens

1. Broiler breeders are subjected to qualitative or quantitative feed restrictions to prevent obesity, which causes major health and welfare problems. Diluting their feed by adding inert or low nutrient, bulky materials can reduce obesity, but the capacity of the gut needs to be determined to apply this strategy successfully. Two trials were conducted to measure the bulk capacity of Ross 308 broiler breeders prior to and after the onset of lay. The trial was completely randomised, with nine individually-caged breeders, with each cage as a replicate, totalling 189 birds per trial2. Birds were given ad libitum access to one of 21 maize-soyabean based feeds, an undiluted control or progressive dilution (10, 20, 30 and 40%) with either cellulose fibre, rice husk, sand, vermiculite or sawdust. Feeds were analysed for density, crude-, acid detergent- and neutral detergent-fibre, water-holding capacity (WHC), cation-exchange capacity and oil-holding capacity.2. In general, feed intake (scaled to body weight^0.67) increased and then declined as the proportion of each diluent increased. Intake increased linearly when rice hulls and sand were used as diluents.3. Water holding capacity was the most appropriate measure to define the gut capacity of broiler breeders.4. The trial data was used to estimate the maximum-scaled feed intake (SFI_max) in broiler breeders, which was 240-56.1WHC + 4.34WHC² g/kg^0.67/d.

The response of reproducing Japanese quail to dietary valine

1. A feeding trial was conducted to measure the responses of Japanese quail to dietary valine. In total, 280 Japanese quail were randomly assigned to eight treatments giving seven replicates (cage - 35 cm length, 35 cm width × 15 cm high). Experimental diets were formulated using a dilution technique to give a range dietary Val concentration (1.97 to 9.85 g/kg).2. Feed intake was maximised at 6.66 g Val/kg and above, but declined linearly below this level. Body weight reached a maximum of 170 g on 6.66 g Val/kg. Egg output peaked at 9.5 ± 0.3 g/bird/d with an egg weight of 11 g for the 6.66 g Val/kg diet. Rate of laying for the group that received the feed with the lowest Val content was close to zero (1.40%), but egg weight on this treatment was 70% of the maximum egg weight. Valine required per gram of egg output was estimated as 10.6 mg/g, whereas the maintenance requirement was 159 mg/kg body weight. Val required for maximum egg output was estimated in 154 mg/d.3. The marginal cost of Val in Brazil currently is negative below a level of 8.0 g/kg feed, which is above that required for maximum egg output. Consequently, Val cannot be regarded as a limiting amino acid currently, as the optimum economic intake exceeds the requirements of all the individuals in the population. The price of a quail egg weighing 11 g in Brazil at the time of the experiment was R$ 0.021. Even if the marginal revenue for these eggs was doubled to 0.4 c/g, there would be no reason to increase the intake of Val.

Transdermal ketamine as an adjuvant for postoperative analgesia after abdominal gynecological surgery using lidocaine epidural blockade

We examined the postoperative analgesia of a controlled delivery ketamine transdermal patch after minor abdominal gynecological surgery using lidocaine epidural blockade. Fifty-two patients were randomized to one of two groups. Epidural anesthesia was performed with 25 mL 2% plain lidocaine. At the end of the surgical procedure, a controlled delivery transdermal patch containing either ketamine (25 mg/24 h) (Ketamine group) or placebo (Placebo group) was applied. Pain and adverse effects were assessed hourly postoperatively for 24 h. IM dipyrone was available at patient request. The two groups were demographically similar. The time to first rescue analgesic was longer in the Ketamine group (230+/-112 min) compared with the Placebo group (94+/-54 min); (P<0.00001). There were more dipyrone dose injections in 24 h in the Placebo group compared with the Ketamine group (P<0.0001). The incidence of adverse effects was similar between groups. We conclude that the transdermal-controlled delivery of ketamine prolonged the duration of analgesia after minor gynecological procedures.

IMPLICATIONS

Transdermal delivery of ketamine was an useful adjuvant to postoperative analgesia after epidural lidocaine blockade in the population studied.

Transdermal nitroglycerine enhances spinal neostigmine postoperative analgesia following gynecological surgery

BACKGROUND

Intrathecal neostigmine causes analgesia by inhibiting the breakdown of acetylcholine. Experimental data suggest that the production of endogenous nitric oxide is necessary for tonic cholinergic inhibition of spinal pain transmission. The purpose of this study was to determine whether association of transdermal nitroglycerine would enhance analgesia from a low dose of intrathecal neostigmine in patients undergoing gynecologic surgery during spinal anesthesia.

METHODS

Forty-eight patients were randomized to one of four groups. Patients were premedicated with use of 0.05-0.1 mg/kg intravenous midazolam and received 15 mg bupivacaine plus 1 ml test drug intrathecally (saline or neostigmine, 5 microgram). Twenty to 30 min after the spinal puncture, a transdermal patch of either 5 mg nitroglycerin or placebo was applied. The control (Con) group received spinal saline and transdermal placebo. The neostigmine group received spinal neostigmine and transdermal placebo. The nitroglycerin group received spinal saline and a transdermal nitroglycerine patch. Finally, the neostigmine-nitroglycerin group received spinal neostigmine and transdermal nitroglycerine. Pain and adverse effects were evaluated using a 10-cm visual analog scale.

RESULTS

Patients in the groups were similar regarding age, weight, height, and American Society of Anesthesiologists status. Sensory level to pin prick at 10 min, surgical duration, anesthetic duration, and visual analog scale score for pain at the time of administration of first rescue medication were statistically the same for all groups. The time to administration of first rescue analgesic (min) was longer in the neostigmine-nitroglycerin group (550 min; range, 458-1,440 min; median, 25-75th percentile) compared with the other groups (P < 0.001). The neostigmine-nitroglycerin group required fewer rescue analgesics in 24 h than did the control group (P < 0.0005), whereas the neostigmine group required less analgesics compared with the control group (P < 0.02). The incidence of perioperative adverse effects (nausea, vomiting, headache, back pain) was similar among groups (P > 0.05).

CONCLUSION

Although neither intrathecal 5 microgram neostigmine alone nor transdermal nitroglycerine alone (5 mg/day) delayed the time to administration of first rescue analgesics, the combination of both provided an average of 14 h of effective postoperative analgesia after vaginoplasty, suggesting that transdermal nitroglycerin and the central cholinergic agent neostigmine may enhance each other's antinociceptive effects at the dose studied.

Low doses of epidural ketamine or neostigmine, but not midazolam, improve morphine analgesia in epidural terminal cancer pain therapy

STUDY OBJECTIVE

To examine analgesia and adverse effects of combination epidural pain therapy consisting of administration of morphine with either low dose of ketamine, neostigmine, or midazolam in terminal cancer pain patients.

DESIGN

Randomized double-blind study.

SETTING

Teaching hospital.

PATIENTS

48 terminal cancer patients suffering from chronic pain.

INTERVENTIONS

Patients were randomized to one of four groups (n = 12). The concept of visual analog scale (VAS), which consisted of a 10-cm line with 0 equaling "no pain at all" and 10 equaling "the worst possible pain" was introduced. All patients were taking oral amitriptyline 50 mg at bedtime. Pain was initially treated with epidural morphine 2 mg twice daily (12-hr intervals) to maintain the VAS below 4/10. Afterwards, VAS scores > or = 4/10 at any time were treated by adding the epidural study drug (2 ml), which was administered each morning, just after the 2-mg epidural morphine administration. The control group (CG) received 2 mg of epidural morphine (2 ml). The ketamine group (KG) received 0.2 mg/kg epidural ketamine (2 ml). The neostigmine group (NG) received 100 micrograms epidural neostigmine (2 ml). The midazolam group (MG) received 500 micrograms epidural midazolam (2 ml). Patients received the study drugs on a daily basis.

MEASUREMENTS AND MAIN RESULTS

Duration of effective analgesia was measured as time from the study drug administration to the first patient's VAS score > or = 4/10 recorded in days. The groups were demographically the same. The VAS pain scores prior to the treatment were also similar among groups. Only the patients in the KG demonstrated lower VAS scores compared to the MG (p = 0.018). Time since the epidural study drug administration until patient complaint of pain VAS > or = 4/10 was higher for both the KG and NG compared to the CG (KG > CG, p = 0.049; NG > CG; p = 0.0163). Only the KG used less epidural morphine compared to the CG during the period of study (25 days) (p = 0.003).

CONCLUSION

The association of either low-dose epidural ketamine or neostigmine (but not midazolam) to epidural morphine increased the duration of analgesia in the population studied (gt;20 days) compared to the CG and MG (8 to 10 days) when administered in the early stages of terminal cancer pain therapy, without increasing the incidence of adverse effects.

Study of three different doses of epidural neostigmine coadministered with lidocaine for postoperative analgesia

BACKGROUND

Intrathecal neostigmine produces analgesia in volunteers and patients. However, the use of epidural neostigmine has not been investigated. The purpose of the current study was to define the analgesic effectiveness of epidural neostigmine coadministered with lidocaine and side effects in patients after minor orthopedic procedures.

METHODS

After Institutional Review Board approval and informed consent, 48 patients (n = 12) undergoing knee surgery were randomly allocated to one of four groups and studied in a prospective way. After 0.05-0.1 mg/kg intravenous midazolam premedication, patients were randomized to receive 20 mg intrathecal bupivacaine plus epidural lidocaine (85 mg) with saline (control group); 1 microg/kg epidural neostigmine (1 microg group); 2 microg/kg epidural neostigmine (2 microg group); or 4 microg/kg epidural neostigmine (4 microg group). The concept of the visual analog scale, which consisted of a 10-cm line with 0 equaling "no pain at all" and 10 equaling "the worst possible pain" was introduced. Postoperatively, pain was assessed using the visual analog scale, and intramuscular 75 mg diclofenac was available at patient request.

RESULTS

Groups were demographically the same and did not differ in intraoperative characteristics (blood pressure, heart rate, ephedrine consumption, oxyhemoglobin saturation, sensory loss before start of surgery, or duration of sensory motor block). The visual analog scale score at first rescue analgesic and the incidence of adverse effects were similar among groups (P > 0.05). The time (min +/- SD) to first rescue analgesic was as follows: control group: 205+/-48; 1-microg group: 529+/-314; 2-microg group: 504+/-284; 4-microg group: 547+/-263 (P < 0.05). The analgesic consumption (number of intramuscular diclofenac injections [mean, 25th-75th percentile]) in 24 h was as follows: control group: 3 [3 or 4]; 1-microg group: 1 [1 or 2]; 2-microg group: 2 [1 or 2]; 4-microg group: 2 [1-3] (P < 0.05). The 24-h-pain visual analog scale score (cm +/- SD) that represents the overall impression for the last 24 h was as follows: control group: 5+/-1.6; 1-microg group: 1.6+/-1.8; 2-microg group: 1.4+/-1.6; 4-microg group: 2.2+/-1.9 (P < 0.005). The incidence of adverse effects was similar among groups (P > 0.05).

CONCLUSION

Epidural neostigmine (1, 2, or 4 microg/kg) in lidocaine produced a dose-independent analgesic effect (approximately 8 h) compared to the control group (approximately 3.5 h), and a reduction in postoperative rescue analgesic consumption without increasing the incidence of adverse effects.

Oral ketamine and transdermal nitroglycerin as analgesic adjuvants to oral morphine therapy for cancer pain management

BACKGROUND

Guidelines for cancer pain management include nonsteroidal antiinflammatory drugs with opioids administered in a time-contingent manner. This study was designed to evaluate the role of oral ketamine or transdermal nitroglycerin polymer, a nitric oxide donor, as coadjuvants to oral morphine in cancer pain therapy.

METHODS

After institutional approval and informed patient consent were obtained, 60 patients with cancer pain were randomized to one of four groups (n = 15) and studied prospectively to evaluate analgesia and any adverse effects. A visual analog scale that consisted of a 10-cm line with 0 representing "no pain at all" and 10 representing "the worst possible pain" was introduced. All patients were regularly taking oral amitriptyline 50 mg at bedtime. The morphine regimen was adjusted individually to a maximal oral dose of 80-90 mg/day to keep the visual analog scale score less than 4. When patients reported pain (visual analog scale of 4 or more), despite taking 80-90 mg oral morphine daily, the test drug was added as follows: the control group (CG) received an additional 20 mg oral morphine (10 mg at 12-h intervals); the nitroglycerin group (NG) received a 5-mg nitroglycerin patch daily; the ketamine group (KG) received 0.5 mg/kg oral ketamine at 12-h intervals; and the dipyrone group (DG) received 500 mg oral dipyrone at 6-h intervals. Patients were free to manipulate their daily morphine consumption when the test drug was introduced to keep their visual analog scale score less than 4.

RESULTS

The groups were similar with respect to demographic data and visual analog scale pain scores before treatment. The visual analog scale scores after the test drug was introduced were similar among the groups. The daily consumption of oral morphine was as follows: on day 15: CG = DG = NG (P > 0.05), CG > KG (P = 0.036); on day 20: CG > NG = KG (P < 0.02) (CG > KG, P < 0.005; CG > NG, P < 0.02), DG > KG (P < 0.05); on day 30: CG = DG > KG = NG (P < 0.05). Patients in the CG and DG groups reported somnolence, but patients in the NG and KG groups did not.

CONCLUSIONS

Low-dose ketamine and transdermal nitroglycerin were effective coadjuvant analgesics. In conjunction with their opioid tolerance-sparing function, joint delivery of ketamine or nitric oxide donors with opiates may be of significant benefit in cancer pain management.

Transdermal nitroglycerine enhances spinal sufentanil postoperative analgesia following orthopedic surgery

BACKGROUND

Sufentanil is a potent but short-acting spinal analgesic used to manage perioperative pain. This study evaluated the influence of transdermal nitroglycerine on the analgesic action of spinal sufentanil in patients undergoing orthopedic surgery.

METHODS

Fifty-six patients were randomized to one of four groups. Patients were premedicated with 0.05-0.1 mg/kg intravenous midazolam and received 15 mg bupivacaine plus 2 ml of the test drug intrathecally (saline or 10 microg sufentanil). Twenty to 30 min after the spinal puncture, a transdermal patch of either 5 mg nitroglycerin or placebo was applied. The control group received spinal saline and transdermal placebo. The sufentanil group received spinal sufentanil and transdermal placebo. The nitroglycerin group received spinal saline and transdermal nitroglycerine patch. Finally, the sufentanil-nitroglycerin group received spinal sufentanil and transdermal nitroglycerine. Pain and adverse effects were evaluated using a 10-cm visual analog scale.

RESULTS

The time to first rescue analgesic medication was longer for the sufentanil-nitroglycerin group (785+/-483 min) compared with the other groups (P<0.005). The time to first rescue analgesics was also longer for the sufentanil group compared with the control group (P<0.05). The sufentanil-nitroglycerin group group required less rescue analgesics in 24 h compared with the other groups (P<0.02) and had lesser 24-h pain visual analog scale scores compared with the control group (P<0.005), although these scores were similar to the sufentanil and nitroglycerin groups (P>0.05). The incidence of perioperative adverse effects was similar among groups (P>0.05).

CONCLUSIONS

Transdermal nitroglycerine alone (5 mg/day), a nitric oxide generator, did not result in postoperative analgesia itself, but it prolonged the analgesic effect of spinal sufentanil (10 microg) and provided 13 h of effective postoperative analgesia after knee surgery.

Combined intrathecal fentanyl and neostigmine: therapy for postoperative abdominal hysterectomy pain relief

STUDY OBJECTIVE

To evaluate the analgesic action of spinal neostigmine as part of a multimodal analgesic therapy approach including spinal neostigmine and spinal fentanyl for postoperative pain relief

DESIGN

Randomized, prospective study.

SETTING

Teaching hospital.

PATIENTS

50 ASA physical status I and II patients undergoing abdominal hysterectomy.

INTERVENTIONS

Patients were assigned to one of five groups (n = 10) to receive 15 mg bupivacaine plus 1 ml of the test drug intrathecally. The control group (CG) received saline as the test drug, the fentanyl group (FG) received 25 microg fentanyl; the neostigmine group (NG) received 25 microg neostigmine; the fentanyl-neostigmine 10 microg group (FNG10) was given 10 microg fentanyl plus 10 microg neostigmine; and the fentanyl-neostigmine 25 microg group (FNG25) received 25 microg fentanyl plus 25 microg neostigmine. Pain and nausea were evaluated using a 10-cm visual analog scale (VAS).

MAIN RESULTS

The analgesic consumption, in 24 hours was greatest in CG, next highest in NG, FG, and FNG10 where consumption was the same in the three groups; and least in FNG25 (p < 0.05). The time to first rescue analgesic medication was greatest for FNG25 compared with the other groups (>5 hours compared with 2 to 3 hours; p < 0.05). VAS showed no statistically significant differences for pain impression, intraoperative and postoperative nausea, or occurrence of vomiting (p > 0.05).

CONCLUSION

The combination of 25 microg neostigmine with 25 microg fentanyl given intrathecally with 15 mg of hyperbaric bupivacaine delayed postoperative pain and lowered the number of rescue analgesics. Because the better quality of analgesia was obtained with an increased (although not statistically significant difference) incidence of untoward side effects, larger samples should be studied before its routine use is recommended.

Intrathecal neostigmine for postoperative analgesia after orthopedic surgery

STUDY OBJECTIVE

To establish a dose-response curve for the analgesic effect of intrathecal neostigmine in patients undergoing below knee surgery with spinal anesthesia. To assess adverse effects, principally nausea and vomiting.

DESIGN

Randomized, double-blind, prospective study.

SETTING

Teaching hospital.

PATIENTS

60 ASA physical status I and II premedicated patients undergoing orthopedic surgery (tibial or ankle reconstruction).

INTERVENTION

Spinal anesthesia was performed at the sitting position, L3-L4 interspace, 4 ml final volume, injected at a rate of 1 ml/10 sec. The control group (CG) received 15 mg hyperbaric bupivacaine 0.5% plus saline. The 25 micrograms neostigmine group (25NG) received 15 mg hyperbaric bupivacaine plus 25 micrograms neostigmine; the 50 micrograms neostigmine group (50NG) received 15 mg hyperbaric bupivacaine plus 50 micrograms neostigmine; and the 100 micrograms neostigmine group (100NG) received 15 mg hyperbaric bupivacaine plus 100 micrograms neostigmine. Patients were placed supine after the spinal punction.

MEASUREMENTS AND MAIN RESULTS

Time to first rescue analgesics, analgesia, and adverse effects at constant intervals were assessed using the 10 cm visual analog scale (VAS). Intrathecal neostigmine produced a dose-independent reduction in the postoperative rescue analgesic consumption (p < 0.0001). The time to first rescue analgesics was similar among groups (p > 0.05), and the overall 24-hour VAS pain scores were lowest for patients who had spinal neostigmine (p < 0.02). The 100NG group had the highest incidence of postoperative nausea and vomiting of all the groups (p < 0.05).

CONCLUSION

Intrathecal neostigmine produced a dose-independent analgesia and a dose-dependent incidence of adverse effects with the doses studied.

Postoperative analgesia and antiemetic efficacy after subarachnoid neostigmine in orthopedic surgery

BACKGROUND AND OBJECTIVES

The efficacy of operatively administered spinal neostigmine to provide analgesia and that of different antiemetics to prevent neostigmine-related nausea and vomiting were evaluated in patients undergoing tibial or ankle reconstruction.

METHODS

One hundred patients were randomized to five groups (n = 20). The intravenous antiemetic test drug (except propofol) was given as premedication in the holding room, after intravenous midazolam, 0.05 mg/kg. The subarachnoid drugs administered were 20 mg bupivacaine (0.5%) in conjunction with 100 micrograms neostigmine, except for the saline group (S group), which received bupivacaine and saline. The S group, the neostigmine group (N group), and the propofol group (P group) received saline as the intravenous test drug. The droperidol group (D group) received intravenous droperidol 0.5 mg, and the metoclopramide group (M group) received intravenous metoclopramide 10 mg. The P group had a continuous intravenous propofol infusion (2-4 mg/kg/hr), started 10 minutes after the spinal injection. Nausea, emetic episodes, and the need for analgesic (disclofenac) or antiemetic medication were recorded for the first 24 hours following surgery and scored by a 10-cm visual analog scale (VAS).

RESULTS

Subarachnoid neostigmine 100 micrograms did not affect subarachnoid bupivacaine analgesia as measured by time to first rescue analgesic in most patients, but it decreased the overall 24-hour visual analog scale (VAS) scores and the need for postoperative analgesics in 24 hours (P < .001). The incidence of intraoperative nausea and vomiting was higher in the N, D, and M groups than in the S group (P < .001). Following surgery, the 3-hour VAS assessment for emesis was higher for the N, P, and M groups than for the S group (P < .05). The overall 24-hour assessment was similar among groups.

CONCLUSIONS

Subarachnoid neostigmine reduced postoperative pain scores and analgesic requirements. Whether it prolonged the duration of action of diclofenac or enhanced the mechanisms involved in spinal analgesia cannot be determined from these data. Although propofol and droperidol appeared to be more effective during and after surgery, respectively, all neostigmine groups were associated with a high consumption of antiemetics.

Subarachnoid neostigmine does not affect blood pressure or heart rate during bupivacaine spinal anesthesia

BACKGROUND AND OBJECTIVES

Intraspinal administration of neostigmine has been shown to prevent induction of hypotension in rats by bupivacaine spinal block, and thus to provide greater hemodynamic stability. This study was undertaken to determine whether subarachnoid neostigmine would prevent bupivacaine spinal anesthesia from causing hypotension or bradycardia in patients undergoing abdominal hysterectomy.

METHODS

Of 40 patients scheduled for abdominal hysterectomy under spinal anesthesia, 20 were randomly assigned to each of two groups. The control group (CG) received 1.5 mL subarachnoid saline followed by 15 mg (3 mL) of hyperbaric bupivacaine 0.5%. The neostigmine group (NG) received 75 micrograms (1.5 mL) of subarachnoid neostigmine followed by 15 mg (3 mL) of hyperbaric bupivacaine 0.5%. No preload was given. Hypotension was treated with 4-mg intravenous boluses of ephedrine to keep blood pressure above 75% of the baseline value. The skin body temperature was measured with probes at the suprascapular region and at the foot.

RESULTS

Spinal neostigmine (75 micrograms) failed to prevent bupivacaine-induced hypotension. There was no statistical difference in the incidence of brady-cardia between the groups (NG, 2/20; CG 1/20), although the bradycardia appeared to be qualitatively different, being somewhat delayed in the NG. Spinal neostigmine did not alter the onset or duration of sensory block and did not affect skin body temperature in either anesthetized or unanesthetized sites. The incidence of intraoperative nausea was 20% in the NG and 5% in the CG.

CONCLUSION

A 75-micrograms subarachnoid neostigmine dose does not affect blood pressure or heart rate during bupivacaine spinal anesthesia.

Dose-response study of intrathecal morphine versus intrathecal neostigmine, their combination, or placebo for postoperative analgesia in patients undergoing anterior and posterior vaginoplasty

This study was designed to examine postoperative analgesia with intrathecal neostigmine in a randomized, blinded trial with morphine as the active control in patients undergoing anterior and posterior vaginoplasty. A secondary aim was to provide preliminary data on the interaction between these two drugs. The incidence of adverse effects was also assessed. Forty-eight patients were divided into eight groups (50 micrograms, 100 micrograms, and 200 micrograms morphine [M]; saline; 50 micrograms, 100 micrograms, and 200 micrograms neostigmine [N]; and 50 micrograms morphine + 50 micrograms neostigmine). Anesthesia was provided with a balanced technique. All patients stayed 24 h in the recovery room where adequacy of postoperative analgesia and side effects were assessed. Increasing doses of intrathecal morphine (50 micrograms, 100 micrograms, and 200 micrograms) and intrathecal neostigmine (50 micrograms, 100 micrograms, and 200 micrograms) showed a dose-dependent pattern of analgesia (P < 0.001). The M50 + N50 combination resulted in a better analgesic effect with fewer side effects than M50, N50, and control groups. These preliminary data suggest that spinal neostigmine produces analgesia for vaginoplasty surgery similar in duration to spinal morphine and that the combination of morphine and neostigmine may allow a reduction in the dose of each component for postoperative analgesia.

[Primary non-Hodgkin's lymphoma of the duodenum]

We report a case of duodenal primary non-Hodgkin lymphoma classified as a polymorphic B lymphoma with a low degree of malignancy. It was studied by ultrasound, computed tomography and simple contrast study. We review the radiologic appearance, sites of origin, and the role of Imagiology in staging and differential diagnosis.