Topical Benzocaine-induced Methemoglobinemia in the Pediatric Population

Topical benzocaine is an anesthetic agent that is often used before procedures and clinical tests, such as esophagoscopy, bronchoscopy, and endotracheal intubation. However, a potential deadly condition known as methemoglobinemia can occur with this agent. It causes the oxidation of hemoglobin to methemoglobinemia to occur more rapidly than the reduction of methemoglobin back to hemoglobin. Certain congenital and clinical conditions that affect oxygen delivery can increase the patient's risk of having methemoglobinemia develop with the use of benzocaine. Topical benzocaine-induced methemoglobinemia can occur in the pediatric population. Prompt management with intravenous methylene blue should be initiated for reversal.     

Biliary cystic disease

Biliary cystic disease, though uncommon, can present at a wide range of ages with a wide range of symptoms. Choledochal cysts are associated with the development of both cholangiocarcinoma and gallbladder cancer. Thus, most biliary cystic disease is best managed operatively. Many factors should be considered when performing surgery on patients with choledochal cysts, including age, presenting symptoms, cyst type, associated biliary stones, prior biliary surgery, intrahepatic strictures, hepatic atrophy/hypertrophy, biliary cirrhosis, portal hypertension, and associated biliary malignancy. When feasible, surgical treatment should consist of cholecystectomy and complete surgical excision of extrahepatic cysts with Roux-en-Y reconstruction. Because the risk of recurrent cholangitis is significant and additional symptoms and problems are common, the use of long-term soft Silastic biliary stents (Dow Corning Corp., Midland, MI) should be considered when complex intrahepatic and extrahepatic cystic disease is present. Alternatively, the Roux-en-Y jejunal limb can be marked at the fascia for future percutaneous access. Reconstruction via hepaticoduodenostomy and jejunal interposition has been associated with increased postoperative pain due to bile reflux gastritis. Thus, hepaticojejunostomy reconstruction is recommended. For choledochal cysts involving the distal bile duct, the bile duct should be excised at the intrapancreatic portion. Resection of the pancreatic head should be reserved for patients with established malignancies. Surgical excision of the intrahepatic portion of the bile duct should be individualized to include preservation of hepatic parenchyma when the liver is not cirrhotic. If cirrhosis is advanced, hepatic transplantation may be indicated, but this is rare. Oncologic principles should be followed in the presence of a malignancy. Lifelong follow-up is required because of the possibility of a "field" defect increasing susceptibility to cancer throughout the biliary tract epithelium.     

Characteristics of patients receiving vasopressors

Background

Patients receiving intensive care frequently need pharmacologic support of their blood pressure because of shock. In some patients, shock is so severe that extremely high doses of vasopressors are needed to elevate their blood pressure.

Objective

We sought to ascertain the maximal dose of vasopressors administered to patients, and to describe the population of patients receiving vasopressors in one intensive care unit.

Methods

All adult patients admitted in 2001 to a 10-bed surgical unit in a university hospital, and receiving a vasopressor agent for 1 hour or more, underwent recordings of their demographic data, diagnoses upon admission, Acute Physiological and Chronic Health Evaluation (APACHE) II scores, vasopressors (including type, initial dose, dose increases, and maximal dose), number of days administered, complications, and mortality.

Results

Of 689 patients whose charts were reviewed, 72 received vasopressors. The mean age was 65 ± 21.4 years, and 66% were male. The mean APACHE II scores were 24 ± 6.2. The administration of .5 μg/kg/minute of norepinephrine or epinephrine resulted in 96% sensitivity and a specificity of 76% for the likelihood of mortality. Using Kaplan-Meyer curves, those patients receiving less than .5 μg/kg/minute demonstrated an 80% 6-year survival. All 17 patients receiving more than 3.8 μg/kg/minute of norepinephrine, and all 5 patients receiving more than 9.6 μg/kg/minute of epinephrine, died. The length of time during which patients received less than their maximal dose of vasopressors had no influence on survival (P = .4). The elderly (aged ≥75 years) and the young (aged <75 years) had the same intensive care unit survival rates when receiving vasopressors.

Conclusion

In this study, little likelihood of intensive care unit survival was evident when patients received more than .5 μg/kg/minute of norepinephrine or epinephrine.     

Management of cervical spine injury

Field assessment, neck immobilization, oxygenation and maintenance of the airway occur in suspected cervical-spine-injured patients before transport to a regional spinal cord injury centre. After cervical spine radiography, bony alignment of the spinal column is re-established and mean blood pressure is maintained at 80–90mmHg with fluids and, if necessary, inotropic support. Predetermined guidelines are used for intubation and ventilation and for invasive monitoring of patients in spinal shock. Fluid challenge is used to assess reserve cardiac function and the need for fluid infusion, restriction or inotropic support. Evoked potential monitoring provides a non-invasive, objective and sensitive method to assess neuroconduction through a spinal cord injury and may be used to replace a wake-up test intraoperatively. There are no randomized prospective studies showing that surgical decompression and/or internal stabilization improves outcome compared with non-surgical treatment of acute cervical spine injury. Respiratory failure is managed by long-term ventilator support, diaphragm pacing or use of glossopharyngeal breathing. Chest physiotherapy is helpful in reducing the occurrence of atelectasis and pneumonia. Hyperreflexic syndromes during surgery are avoided with adequate anaesthesia during stimulation. An area with a population near one million should designate a regional spinal cord injury centre. Such centres decrease the proportion of patients with complete neurological injury.     

Validation Study of Energy Requirements in Critically Ill,Obese Cancer Patients

Background: Current guidelines from the American Society for Parenteral and Enteral Nutrition and the Society of Critical Care Medicine (ASPEN/SCCM) regarding caloric requirements and the provision of nutrition support in critically ill, obese adults may not be suitable for similar patients with cancer. We sought to determine whether the current guidelines accurately estimate the energy requirements, as measured by indirect calorimetry (IC), of critically ill, obese cancer patients. Materials and Methods: This was a retrospective validation study of critically ill, obese cancer patients from March 1, 2007, to July 31, 2010. All patients ≥18 years of age with a body mass index (BMI) ≥30 kg/m² who underwent IC were included. We compared the measured energy expenditure (MEE) against the upper limit of the recommended guideline (25 kcal/kg of ideal body weight [IBW]) and MEE between medical and surgical patients in the intensive care unit. Results: Thirty‐three patients were included in this study. Mean MEE (28.7 ± 5.2 kcal/kg IBW) was significantly higher than 25 kcal/kg IBW (P < .001), and 78% of patients had nutrition requirements greater than the current guideline recommendations. No significant differences in MEE between medical and surgical patients in the ICU were observed. Conclusions: Critically ill, obese cancer patients require more calories than the current guidelines recommend, likely due to malignancy‐associated metabolic variations. Our results demonstrate the need for IC studies to determine the energy requirements in these patients and for reassessment of the current recommendations.