Uncomplicated Operation Research Articles

Taking computer vision aloft – archaeological three‐dimensional reconstructions from aerial photographs with photoscan

AbstractStructure from motion (SFM) algorithms are known for their ability to reconstruct a sparse point cloud of scenes that were imaged by a series of overlapping photographs. When complemented by stereo‐matching algorithms, detailed three‐dimensional models can be built from such photograph collections in a fully automated way. Since 2010, a computer vision software package called PhotoScan has been available from the Russian manufacturer AgiSoft LLC. Even though the programme has a straightforward and simple interface, state‐of‐the‐art SFM and other computer vision algorithms are implemented that enable PhotoScan to generate very dense and accurate three‐dimensional meshes of various (archaeological) settings captured in two‐dimensional imagery. Using a mixture of archaeological case studies, it will be shown that this low‐cost application produces excellent results from aerial imagery in a minimum of time with almost no effort needed. Because of its solid and uncomplicated operation, it looks like this application could become an essential part of the aerial archaeologist's toolkit. Copyright © 2011 John Wiley & Sons, Ltd.

Subacute Subdural Hygroma and Presyrinx Formation After Foramen Magnum Decompression With Duraplasty for Chiari Type 1 Malformation -Case Report-

A 15-year-old girl developed a rare case of subdural hygroma after foramen magnum decompression for Chiari type 1 malformation manifesting as rapid symptom deterioration around 10 days after uncomplicated operation with uneventful immediate postoperative course. Progressive enlargement of the subdural hygroma in both supra- and infratentorial spaces was followed by the development of hydrocephalus. Syringomyelia improved shortly after the first operation but then deteriorated with massive presyrinx formation. Reoperation with wide opening of the arachnoid membrane lead to a rapid resolution of the hydrocephalus and the presyrinx. The present case shows that wide opening of the arachnoid membrane is an effective therapeutic option.

Kostenanalyse für den implantatfreien vorderen Kreuzbandersatz

Replacement of the anterior cruciate ligament (ACL) is presently routinely carried out with autologous transplantation of the ligamentum patellae (LP), semintendinosus-gracilis (SGS) or quadriceps (QS) tendons. The anatomical positioning of the drilling canals, transplant fixation, complication rate, revision aspects as well as economic aspects are still under discussion. Fixation of the transplant can be carried out mechanically with various anchoring systems or using biological implant-free healing (free of cost). The compulsory and private health insurance companies as well as staff medical insurance associations guarantee a constant remuneration according to the EBM (uniform evaluation standard), GOA (scale of fees for physicians) or UV-GOA (accident insurance scale of fees for physicians). At present all health insurances accept the costs for implantations in outpatient areas (minus 25 Euro own contribution for compulsory health insurance). For inpatient treatment remuneration is according to the flat-rate scale (diagnosis-related groups). Costs for implants, which are increasing over the years, diminish the economic result in this case. The technique of implant-free replacement of ACLs is cheaper, with fewer complications and achieves functional results for fixation of the transplant which are comparable to techniques with implants. This also applies to the double bundle technique. Implant-free replacement of ACLs with the patellar tendon is a suitable, uncomplicated operation technique with comparably low costs and belongs to the state of the art according to Hertel, Petersen and other authors. This method already has a valuable place in surgery of the ACL.

Spontaneous Pneumomediastinum After Kidney Transplantation: Case Report

Spontaneous pneumomediastinum is a rare condition with nonspecific signs and symptoms. A 39-year-old underwent cadaver kidney transplantation. After an uncomplicated operation, progressive dyspnea of unknown origin developed. Findings at chest radiography suggested pneumomediastinum, which was confirmed at computed tomography. Esophageal or tracheal injury was ruled out. The rapidly developing atelectasis of the left lung necessitated urgent bronchoscopy, which revealed occlusion of the left main bronchus. After removal of the occluding mucus plug, the clinical symptoms immediately improved, and the spontaneous pneumomediastinum resolved within 3 days. Asymptomatic increase in airway secretions in patients receiving peritoneal dialysis may result in mucus plug formation during general anesthesia, which can cause spontaneous pneumomediastinum.

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Insulin resistance is a transitory phenomenon of the metabolic response to trauma. In uncomplicated operations it lasts for 2-4 weeks postoperatively, and is directly related to the magnitude of the injury. The fasting status caused by conventional fasting protocols aggravates this resistance and may induce hyperglycemia. Conventional preoperative fasting time may aggravate this resistance and increment the elevation of glycemia especially because it is frequently longer than the expected 6-8h and may reach 10-16 hs. Additionally, overnight fasting may cause variable degrees of dehydration depending on the extension of the fasting period. Recently, various societies of anesthesia and nutrition have changed their guidelines to propose a reduction of preoperative fasting to 2h with clear fluids containing carbohydrates. These new protocols (ACERTO, ERAS) are based on the safety of this routine as consistently demonstrated by various randomized trials and a meta-analysis.

Total laryngectomy in patients with advanced bulbar symptoms of amyotrophic lateral sclerosis

Our objectives were to 1) increase awareness of total laryngectomy (TL) as a treatment for complications of bulbar weakness in patients with amyotrophic lateral sclerosis (ALS) and outline specific surgical indications; 2) educate physicians about the surgical procedure, peri-operative course and benefits from having a TL; and 3) retrospectively review the clinical course of Mayo Clinic-Florida patients with ALS who had a TL. The method used was a retrospective review of patients recommended to undergo TL for advanced bulbar symptoms related to ALS at the Mayo Clinic in Jacksonville, Florida. Between January 1999 and September 2008, 15 patients with severe bulbar symptoms associated with ALS were recommended to undergo TL. Only five patients opted for the surgery. All patients were aphonic at time of surgery with a multitude of bulbar symptoms. Average surgical time was 114 min (range 87-162 min). No intraoperative complications were reported. All patients and caregivers were pleased with the results of the TL. In conclusion, TL is a relatively safe, quick and uncomplicated surgical procedure that should be considered earlier and more frequently in the treatment plan of patients with advanced bulbar symptoms due to ALS. We recommend considering TL in patients with aspiration problems who are unable to phonate intelligibly.

Calcium-phosphate deposits on a hydrophilic acrylic intraocular lens after silicon oil tamponade

We report a 52-year-old man who underwent uncomplicated cataract operation and posterior chamber lens implantation (hydrophilic acrylic lens) in his left eye 5 years prior to presentation. Two years after surgery he developed pseudophakic retinal detachment which was successfully treated with pars plana vitrectomy and silicon oil tamponade. The silicon oil was removed one year after surgery. A year later he complained of increasing blurred vision in the left eye. Clinical examination revealed vesicular alterations located superficially on the intraocular lens (IOL), which could not be removed by perflourocarbon-perflourohexloctane lavage. As the patient complained about increasing visual impairment, the IOL was removed. The IOL was investigated by electronmicroscopy and biochemical analysis. During electron microscopy and following biochemical analysis the observed alterations were identified as calcium-phosphate particles located on the superficial aspect of the IOL. The occurrence of calcium-phosphate deposits on a posterior chamber IOL after silicon oil tamponade is a rare complication and has not been described so far. As these deposits interfere with visual acuity, removal of the lens has to be considered.

Predictors of Pulmonary Oxygenizing Function during Uncomplicated Operations under Extracorporeal Circulation

Objective: to reveal the statistically significant predictors affecting the oxygenation index (PaO2/FiO2) in the post-perfusion period during uncomplicated operations under extracorporeal circulation (EC). Subjects and methods. Seventy-eight patients aged 37 to 73 years in whom myocardial revascularization was made during uncomplicated operations under EC were examined. The parameters of artificial ventilation (AV) and lung biomechanics were recorded in real time on a KION 6.h. or a Servo-i monitoring system. Demographic and clinical indices, such as age, body mass index (BMI), baseline PaO2/FiO2, and statistical thoracopulmonary compliance (Cst), a history of chronic obstructive pulmonary diseases, smoking, operation duration, EC, myocardial ischemia, mammary coronary anastomosis (MCA), and blood hydrobalance at the end of an operation, were assessed for impact on PaO2/FiO2. Univariate regression analysis calculating the pair linear correlation coefficient (r) and multiple linear regression were made to comparatively assess the predictive values of different indices in decreasing PaO2/FiO2. Results. Univariate regression analysis indicated that the significant predictors of uncomplicated pulmonary oxygenizing function were BMI (p=0.008), PaO2/FiO2 (p<0.001), and Cst (p<0.001) after tracheal intubation. Multiple linear regression evaluating the influence of pre- and intraoperative factors on PaO2/FiO2 showed that the significant predictors were BMI (p=0.012), MCA (p=0.006), and EC duration (p=0.044). A significant correlation was found between the duration of EC and the level of PaO2/FiO2 (r=-0.87; p=0.00045) under more than 130-min EC. Conclusion. During uncomplicated operations under EC for coronary heart disease, the statistically significant predictors of postperfusion PaO2/FiO2 are mainly the state of the respiratory system (the values of PaO2/FiO2 and Cst just after tracheal intubation), BMI, more than 130-min EC, and MCA.

Respiratory Biomechanics, Intrapulmonary Water, and Pulmonary Oxygenizing Function During Uncomplicated Operations under Extracorporeal Circulation

Objective: to study the time course of changes in the respiratory biomechanics, extravascular water of the lung (EVWL) and its oxygenizing function and their relationship at different stages of surgical interventions under extracorporeal circulation (EC). Subjects and methods. 29 patients aged 37 to 72 years were examined during uncomplicated operations under EC. The parameters of artificial ventilation (AV) and lung biomechanics were recorded in real time on a Servo-I monitoring apparatus. PaO2/FiO2, Qs/Qt, and body mass index (BMI) were calculated. The EVWL index (EVWLI) was determined by the transpulmonary thermodilution technique. Studies were conducted at stages: 1) after tracheal intubation and the initiation of AV; 2) before sternotomy; 3) after sternal uniting at the end of surgery. Results. Pressures in the airways and their resistance were statistically significantly unchanged. There were significant reductions in Cdyn and Cst at the end of surgery (Stage 3). The mean values of PaO2/FiO2, Qs/Qt, and EVWLI did not undergo considerable changes. There was a significant correlation between PaO2/FiO2 and Qs/Qt (r=-0.5 to -0.8; p<0.05). At Stage 1, BMI proved to be a significant predictor of the level of PaO2/FiO2 and Qs/Qt (r=-0.5 and 0.65; p<0.05). A significant moderate relationship between Qs/Qt and Cdyn was found at Stage 3 (r=-0.44; p<0.05). There were no statistically significant correlations between the parameters of respiratory biomechanics, PaO2/FiO2, Qs/Qt, and EVWLI. At the end of surgery, pulmonary oxygenizing dysfunction (POD) was detected in 5 (17.2%) patients with increased BMI. Alveolar mobilization with a steady-state effect was used to correct POD. Conclusion. When cardiac surgery is uncomplicated and the AV and EC protocols are carefully followed, the rate of intraoperative POD is not greater than 20%, its leading causes are obesity and, most likely, microatelectasis under AV. Key words: pulmonary oxygenizing dysfunction, extracorporeal circulation, extravascular water of the lung, artificial ventilation, cardiosur-gical patients, pulmonary complications.

Major Groin Complications Following the Use of Synthetic Grafts

The ideal results of vascular reconstructive surgery include an uncomplicated operation, symptomatic relief, prompt wound healing, rapid return to pre-operative functional status without long term functional consequences. Long term complications are often not emphasized. This study describes false femoral aneurysms (FFA) and infection following use of synthetic graft in the groin. All patients under the care of one surgeon, undergoing synthetic graft insertion involving the groin between January 1988 and December 2005 were included. Some 489 patients were included (745 at risk groins). A total of 34 patients developed either FFA or infection, involving 39 groins (5.2%). There were 18 FFA, presenting a median of four years after the original operation. FFA was more common following aortofemoral bypass grafts than femorofemoral or femorodistal bypasses (P=0.0084). Repair with interposition grafting was carried out in 17 cases. There was one death postoperatively. The remainder remained satisfactory at a median follow up of 60 months. Median time from original operation to 21 groin infections presenting was 12 months. Infection was commonest after femorofemoral cross over grafts P=0.023. Four major amputations were carried out. Debridement and sartorius transposition was useful in about half of the cases treated. Serious groin complications occur in about 5% of cases following use of a synthetic graft. This can result in significant morbidity long after the original operation has been carried out. Patients need to be made aware of this when obtaining informed consent.

Complication of Central Venous Catheterization

A retraction has been published: N Engl J Med 2007;356(10):1075. A man with Crohn's disease underwent an uncomplicated operation involving lysis of adhesions. A central venous catheter was placed through the left subclavian vein. Six months later he presented with posterior cervical pain.

Optimal Timing of Surgery in Aortic Regurgitation

Criteria for choosing the optimum time for operation in patients who have aortic regurgitation (AR) have changed in recent years, including a number of notable new components [1,2]. In the 1970s and 1980s, selecting patients for valvular surgery entailed waiting as long as possible until symptoms became substantial [3], which usually meant New York Heart Association (NYHA) class III symptoms that were not controllable with medical management. At that time, the primary surgical option was aortic valve replacement for which the perioperative mortality was high and postoperative problems with ‘‘prosthetic valve diseases’’ were substantial. In stable patients, clinicians watched for measurements of left ventricular (LV) size and function as the primary clinical indicators for surgical timing. In current medical practice, the process of selecting patients is different in a variety of ways. Improved diagnostic methods are available to understand changes in the structure of the aortic valve itself, often including the etiology and mechanism of the dysfunction. Acute cardiac imaging allows a better understanding of a patient’s aortic valve and allows better prediction of the likely future progression of the disease based on natural history studies. Improved quantitation of the severity of the AR is feasible using Doppler echocardiography and other methods. The effects of AR on cardiac function and the potential complications that occur with medical or surgical management can be anticipated. Operative mortality has declined remarkably. For isolated, uncomplicated aortic valve operations at Cleveland Clinic, in-hospital mortality decreased from 2.4% during 1980 to 1989 to 1.7% during 1990 to 1999 and to 1.2% during 2000 to 2005. Surgical options have improved, including more nonprosthetic options such as valve repair. Available prosthetic valves are more durable than in the past. In patients needing isolated primary aortic valve surgery, minimally invasive techniques [4] can be used, avoiding some the discomfort, bleeding, and other temporary disabilities resulting from a full midsternal thoracotomy. Newly developed percutaneous [5–7] and robotic [8] methods have already been used in limited numbers of patients, and their future role is hopeful. Accordingly, the threshold for valve surgery has been progressively reduced. It is now reasonable to do valve surgery for AR in some asymptomatic patients. The clinician must carefully consider each patient individually, including his or her current state of health and fitness, all noncardiology problems, and the available resources for medical treatment, surgery, and recovery. Decisions for surgery or medical management should be based on a comparison between the likely outcomes of immediate surgery and the natural history of the disease if surgery is delayed.

Development, implantation, in vivo elution, and retrieval of a biocompatible, sustained release subretinal drug delivery system

A biocompatible, sustained-release subretinal drug-delivery platform was developed to overcome the therapeutic accessibility limitations of current retinal disease treatments. The prototype implants were fabricated by coating nitinol, poly(methyl methacrylate) or chromic gut core filaments, with a drug-eluting polymer matrix. The polymer coatings are manufactured and coated by SurModics. The coating is a mixture of poly(butyl methacrylate) and poly(ethylene-co-vinyl acetate). The drug is either triamcinolone acetonide or sirolimus. The rods were successfully implanted into the subretinal space of 20/24 rabbits. Four rabbits were lost to early surgery from a dysfunctional infusion line and hemorrhage. No serious complications were observed during the 4-week follow-up period. Slight conjunctival redness was reported in all rabbits by 1-day follow-up, but the redness had subsided by the following week. Intraocular lens touch occurred in six rabbits during the implantations; of these, four had a lensectomy at the time of surgery, and the remaining two developed cataract. Corneal edema developed in three rabbits by 1-week follow-up, but subsided within 2 weeks. Initial observations of the implantation and elution characteristics revealed that the implants are well tolerated by the retinal tissue and that the implant can elute triamcinolone acetonide for a period of at least 4 weeks without eliciting an inflammatory response or complications. There were adverse clinical indications with the sirolimus-loaded implants at the delivered dose. Device retrieval required an uncomplicated surgical procedure, and revealed no associated or adherent tissue. Implant drug content analysis and opacity changes to the polymer matrix coating following retrieval demonstrated the sustained elution of the drug.

Fusion energy from plasma block ignition

Generation of high speed dense plasma blocks is well known from hydrodynamic theory and computations (PIC) with experimental confirmation by Badziaket al.(2005) since ps laser pulses with power above TW are available. These blocks may be used for fusion flame generation (thermonuclear propagation) in uncompressed solid state deuterium and tritium for very high gain uncomplicated operation in power stations. Hydrodynamic theory from computations from the end of 1970s to recent, genuine two fluid computations support the skin layer accelerations (SLA), by nonlinear (ponderomotive) forces as measured now in details under the uniquely selected conditions to suppress relativistic self-focusing by high contrast ratio and to keep plane geometry interaction. It is shown how the now available PW-ps laser pulses may provide the very extreme conditions for generating the fusion flames in solid state density DT.

Critical appraisal of femorofemoral crossover grafts

The aim of this study was to determine how often femorofemoral crossover grafting for critical ischaemia or intermittent claudication gives an ideal result. An ideal result is an uncomplicated operation with primary wound healing, relief of ischaemic symptoms without recurrence and no need for further intervention. All patients undergoing primary femorofemoral crossover grafting between January 1988 and December 2003 were studied. Some 144 operations were analysed; 51 patients had critical ischaemia and 93 claudication. There was one postoperative death (0.7 per cent). Complications occurred within 30 days in 32 patients (22.2 per cent), including graft occlusion in three (2.1 per cent); six patients (4.2 per cent) required early reoperation. Primary patency for patients with critical ischaemia was 88, 82 and 74 per cent at 1, 3 and 5 years respectively. Respective figures for those who presented with claudication were 93, 92 and 90 per cent (P = 0.034). Late symptoms included graft occlusion (20 patients), disease progression (25), ongoing ulceration (six), graft infection (nine), false aneurysm formation (two) and late donor-site stenosis (two). When obtaining informed consent, simply describing patency and limb salvage rates does not provide an accurate picture of the outcome of femorofemoral grafting.

Systematic review and meta-analysis of interventions for postoperative fatigue.

Postoperative fatigue is common, even after uncomplicated operations. Various theories have been presented regarding its aetiology, each suggesting different possible interventions. The purpose of this review was to identify all studies that have assessed interventions for postoperative fatigue and to evaluate these interventions using meta-analytical techniques. Randomized controlled trials of interventions, identified from a systematic search of relevant databases, were evaluated according to standardized criteria and categorized according to intervention modality. Data relating to the efficacy of each intervention at four different postoperative time-points were collated and data synthesis by meta-analysis was performed. Analgesia is effective in reducing fatigue immediately after operation. Perioperative administration of human growth hormone reduces fatigue between 8 and 30 days after abdominal surgery. Weaker evidence was found to suggest an influence of glucocorticoid administration and of surgical technique on fatigue in the first week after operation. No evidence was found to support the theory that psychosocial or nutritional interventions affect the symptom. While the results demonstrate that improved analgesia can attenuate immediate postoperative fatigue in most patient groups, further research is needed to determine whether the efficacy of human growth hormone and glucocorticoids extends beyond abdominal surgery. The paucity of research into cognitive-behavioural, sleep and activity-based interventions also needs to be addressed.

Non-operative management of the primary tumour in patients with incurable stage IV colorectal cancer.

Excision of primary colorectal cancer associated with irresectable synchronous metastases confers high morbidity and mortality with uncertain benefit. For patients with incurable stage IV colorectal cancer, minimally symptomatic primary tumours were left in situ and 5-fluorouracil-based chemotherapy was administered systemically. Primary tumour-specific complications and survival were monitored. There were 13 men and 11 women with primary tumours in the right colon (eight), transverse colon (one), sigmoid colon (eight) or rectum (seven). Eleven patients had metastases limited to the liver (liver replacement less than 25 per cent in one, 25-50 per cent in four and more than 50 per cent in six) and 13 patients had extrahepatic disease (lung or peritoneum). Four patients with sigmoid colon tumours developed bowel obstruction, which required an uncomplicated operation in two and deployment of colonic stents in two patients, at 1, 3, 12 and 20 months from diagnosis. Three further patients underwent right hemicolectomy for abdominal pain of uncertain aetiology, with poor symptomatic relief, and another had a potentially curative operation following disease downstaging. The overall median survival was 10.3 months with a 1-year actuarial survival rate of 44 per cent. A policy to defer resection of minimally symptomatic primary colorectal cancer is associated with a low risk of complications before death from progressive systemic disease.

Role of the neutrophil in the development of sepsis following abdominal aortic aneurysm surgery

Abstract Background There is evidence to suggest that the neutrophil (PMN) plays a critical early step in development of the ischaemia–reperfusion syndrome and sepsis. Not all patients undergoing aortic aneurysm repair develop these postoperative complications. The PMN receptor CD16 plays an important role in phagocytosis, cell-mediated cytotoxicity and the release of free radicals and proteolytic enzymes. This study determined if there is any relationship between PMN CD16 expression, phagocytosis and the development of sepsis. Methods Some 50 patients (39 men and 11 women, median age 70 years) who underwent elective infrarenal abdominal aortic aneurysm repair were studied. Venous blood was taken before operation, throughout surgery and for 7 days afterwards. CD16 was measured, unstimulated and following further stimulation with phorbol myrisate, lipopolysaccharide and N-formyl-methionyl-leucyl-phenylalanine using flow cytometry. Phagocytosis was measured using flow cytometry and the production of elastase using an enzyme-linked immunosorbent assay. Sepsis was defined according to the ACCP/SCCM definition. Results There were 36 uncomplicated operations and 14 patients with sepsis. There was no difference between the two groups in respect of nutritional, co-morbid or technical factors. In the group that developed septic complications, the level of PMN CD16 expression was significantly higher before operation (30·2 versus 10·4 mcf; P < 0·05, Mann–Whitney U test) and throughout the postoperative period. Surgery produced no change in CD16 expression in either the septic or uncomplicated group. Stimulation of the PMNs before operation caused an increase in CD16 expression in both groups. After operation, stimulation of PMNs in the septic group resulted in a fall in CD16 expression (40·8 versus 20·4 mcf; P < 0·05, Mann–Whitney U test); surgery produced no change in the level of expression in the uncomplicated group. Phagocytic ability was comparable before operation (91·2 versus 94·2 mcf), but showed a greater reduction in the septic group after operation (73·4 versus 86·2 mcf; P < 0·05, Mann–Whitney U test). Elastase concentration was also similar before operation (48 versus 49 μg l−1); after operation, there was a greater increase in the septic group (166 versus 104 μg l−1; P < 0·05, Mann–Whitney U test). Conclusion This study provides evidence of functional differences in PMN behaviour in patients who subsequently develop sepsis following aneurysm surgery. This difference occurs early in the postoperative course and it may be possible to identify these patients before operation.

Concentrations of leucocyte-associated chemotaxin C5a correlate with the mobilisation of polymorphonuclear leucocytes during operations for rectal cancer.

To describe the profile of potential chemotaxins C5a, interleukin 8 and tumour-necrosis factor alpha, and the peripheral blood leucocyte (PBL) response in five patients having uncomplicated operations for rectal cancer. Prospective study. University hospital, Norway. Five patients, four men and one woman, median age 66 years (range 48-77) who were operated on for rectal cancer. Four had low anterior resections and total mesorectal excision (TME) and one patient had a diverting end sigmoidostomy because of local perirectal spread of the cancer and liver metastases. Blood samples were taken at the start of the operation; peroperatively after 1, 2, and 3 hours; postoperatively at 5, 8, and 24 hours, for analysis of potential chemotaxins. The number of PBL tripled between the start and end of the operation and declined to a slightly lower plateau between 5 and 24 hours. Peroperatively, the association of C5a with PBL increased six-fold resulting in a doubled concentration of C5a/PBL, whereas the corresponding concentration of C5a in plasma remained relatively constant. Postoperatively, the concentration of C5a associated with the PBL and in plasma fluctuated with the maximums being at 8 and 24 hours, respectively. In contrast to C5a in plasma, the concentration of cell-associated C5a correlated with number of PBL or polymorphonuclear leucocytes (PMN). The plasma concentration of IL-8 doubled during the operation, reached a six-fold maximum at 5 hours, and declined after 24 hours to twice the initial concentration. There were no correlations between plasma IL-8 and either number of PBL, plasma C5a, or PBL-associated C5a. No TNF alpha was detected in the plasma. Tissue trauma caused by uncomplicated excision of rectal cancer leads to leucocyte mobilisation peroperatively, probably partly by complement activation and subsequent generation and binding of the chemotaxin C5a to PBL. However, other chemotaxins may also play a role.

Nutrition for ill neonates.

1. Danna M. Premer, MD* 2. Michael K. Georgieff, MD* 1. 2. *Department of Pediatrics, Division of Neonatology, University of Minnesota, Minneapolis, MN. After completing this article, readers should be able to: 1. List the factors on which the nutritional needs of the neonate depend. 2. Describe the factors that illnesses alter, thereby changing nutrient requirements. 3. Describe the levels of amino acids that can be initiated without causing intolerance or toxicity in most ill infants. 4. Delineate the adverse effects of protein malnutrition following an acute or prolonged illness or insult. From early in this century, investigators have attempted to determine the optimal nutrient delivery for term infants to promote normal growth and development. In the past 25 years, nutritional investigators have concentrated on the needs of the ideal, healthy preterm infant to try to mimic intrauterine growth and body composition. Although great progress has been made in characterizing the needs of healthy preterm and term infants, the needs of ill, physiologically unstable infants largely have been neglected. The primary reasons for this lack of investigation are the assumption that the needs of ill infants are similar to those of healthy infants and the difficulty of studying metabolic needs in ill infants. The persistent efforts of several groups of investigators and the development of new techniques to study metabolism now have begun to delineate the specific nutritional needs of this particular patient population. Drawing on models generated in the adult surgical intensive care literature of the 1980s makes it possible to try to elucidate the effect of common illnesses and conditions (eg, acute pulmonary disease, bronchopulmonary dysplasia[BPD], congenital heart disease[CHD], sepsis, and surgery) on neonatal metabolism and, therefore, nutritional requirements. The assumption is that changes from the norm in metabolism require alterations in substrate delivery (ie, nutrition). As with adults, it is likely that each illness induces characteristic changes in metabolism. The task for the practitioner is to customize nutritional delivery to fit the specific infant’s …