End-tidal CO2 for prediction of cardiac output following weaning from cardiopulmonary bypass

This prospective study included 32 patients undergoing cardiopulmonary bypass (CPB) for elective coronary artery bypass grafting correlates the respiratory end-tidal CO2 (ETCO2) during partial separation from CPB with cardiac output (CO) following weaning from CPB. After induction of general anesthesia, a pulmonary artery catheter was inserted for measurement of cardiac output by thermodilution. Patients were monitored using a 5-lead ECG, pulse oximeter, invasive blood pressure monitoring, rectal temperature probe, and end-tidal capnography. At the end of surgery, patients were weaned from CPB in a stepwise fashion. Respiratory ETCO2 and in-line venous oximetry were continuously monitored during weaning. The ETCO2 was recorded at quarter pump flow and after complete weaning from CPB. Following weaning from CPB, CO was measured by thermodilution. The CO values were correlated with the ETCO2 during partial bypass and following weaning from bypass. Regression analysis of ETCO2 at quarter-flow and post-bypass CO showed significant correlation (r = 0.57, p < .001). Also, regression analysis of ETCO2 after complete weaning from bypass and post-bypass CO showed significant correlation (r = 0.6, p = .002). The correlation between ETCO2 and CO showed that an ETCO2 >30 mm Hg during partial CPB will always predict an adequate CO following weaning from CPB. An ETCO2 <30 mm Hg may denote either a low or a normal cardiac output and hence other predictive parameters such as SvO2 must be added.     

Acute pancreatitis due to a metallic foreign body

We report a case of acute pancreatitis caused by a metallic foreign body located in the pancreatic head in a 38-Year-old woman. Only 15 cases of acute pancreatitis due to foreign bodies, metallic in five cases, have been published to date. In our case, diagnosis was established by the computed tomography scan. The patient declined surgery.     

Pharmacoeconomic analysis of thiopurine methyltransferase polymorphism screening by polymerase chain reaction for treatment with azathioprine in Korea

OBJECTIVES: To evaluate the value of genotype-based dosing by polymerase chain reaction (PCR)-based polymorphism screening in terms of cost-effectiveness for treatment with azathioprine in Korea. METHODS: Decision analysis was employed to compare a genotype-based dosing strategy with the conventional weight-based dosing strategy using a hypothetical cohort composed of rheumatoid arthritis and systemic lupus erythematosus patients. The time horizon was set up as 1 yr. Direct medical costs were used. Data used were obtained from previous reports, except for PCR and admission costs, which were from real cases. Cost-effectiveness analysis was conducted from a societal perspective. Outcomes were measured as a total expected cost and an incremental cost-effective ratio. RESULTS: In the base case model, total expected cost and the probability of not dropping out owing to serious adverse events of the conventional weight-based dosing and the genotype-based dosing strategy were 1339 x 10(3) Korean won (1,117 US dollars) and 1109 x 10(3) Korean won (926 US dollars), and 97.06 and 99.90%, respectively. CONCLUSIONS: Our model suggests that a genotype-based dosing strategy through PCR-based thiopurine methyltransferase (TPMT) polymorphism screening is less costly and more effective than the conventional weight-based dosing strategy in Korea, as it was associated with a marked reduction in the number of serious adverse events.     

Anesthetic management for a patient with myasthenia gravis undergoing coronary artery bypass graft

PURPOSE: Report the clinical management of a patient having Myasthenia Gravis (MG), undergoing cardiopulmonary bypass (CPB). CLINICAL FEATURES: A 71-yr-old man having MG (Osserman IIB), was admitted for coronary artery bypass graft (CABG) under CPB. Optimization of the patient was achieved preoperatively. Thymectomy was done following midsternotomy. Continuous monitoring of the neuromuscular transmission (NMT) was maintained throughout the perioperative period. The hemodilutional effect of CPB was counteracted by the hypothermia resulting in maintenance of cisatracurium requirements at the same levels as the prebypass period. Extubation of the trachea was done after ensuring adequate recovery of the NMT and respiratory function. Oral myasthenic therapy was resumed following extubation. CONCLUSION: A myasthenic patient can safely undergo CPB provided adequate preoperative optimization is achieved. Continuous monitoring of the NMT must be throughout the perioperative period. Thymectomy is recommended in the myasthenic patient since it may improve the outcome. Extubation of the trachea is to be done after ensuring adequate NMT and respiratory function.     

Oxygenation using tidal volume breathing after maximal exhalation

We compared, in volunteers, the oxygenation achieved by tidal volume breathing (TVB) over a 3-min period after maximal exhalation with that achieved by TVB alone. Twenty-three healthy volunteers underwent the two breathing techniques in a randomized order. A circle absorber system with an oxygen flow of 10 L/min was used. The end-expiratory oxygen concentration (EEO(2)) was monitored at 15-s intervals up to 3 min. TVB after maximal exhalation produced EEO(2) values of 68% +/- 5%, 75% +/- 5%, and 79% +/- 4% at 30, 45, and 60 s, respectively, which were significantly larger (P < 0.05) than the corresponding values obtained with TVB alone (58% +/- 5%, 66% +/- 6%, and 71% +/- 5%, respectively). In both techniques, the EEO(2) increased exponentially, with time constants of 35 s during TVB after maximal exhalation versus 58 s during TVB without prior maximal exhalation. In conclusion, maximal exhalation before TVB can hasten preoxygenation by decreasing the nitrogen content of the functional residual capacity, with a consequent increase of EEO(2) to approximately 70% in 30 s and 80% in 60 s. IMPLICATIONS: Oxygenation by using maximal exhalation before tidal volume breathing produced a significantly faster increase in end-expiratory oxygen concentration than oxygenation with tidal volume breathing alone.     

Intravenous lidocaine as adjuvant to sevoflurane anesthesia for endotracheal intubation in children

IMPLICATIONS: Supplementing a sevoflurane induction of anesthesia in children with IV lidocaine 2 mg/kg can suppress cough after tracheal intubation and thus improve intubating conditions. In addition, lidocaine minimizes blood pressure fluctuations after tracheal intubation.     

HIV-positive injection drug users who leave the hospital against medical advice: the mitigating role of methadone and social support

BACKGROUND: Leaving the hospital against medical advice has been associated with increased morbidity and readmission. Factors associated with the risk of leaving against medical advice among HIV/AIDS patients or injection drug users have not been examined in detail. OBJECTIVES: To examine the clinical and social factors associated with leaving against medical advice (AMA) from a specialized HIV/AIDS ward among patients who reported a history of injection drug use. METHODS: All patients with a history of injection drug use admitted to the HIV/AIDS ward at St. Paul's Hospital, Vancouver, British Columbia (the largest specialized HIV/AIDS hospital ward in Canada) between April 1997 and October 2000 were reviewed retrospectively. A multivariate logistic regression model utilizing a generalized estimating equation algorithm identified factors associated with leaving the hospital AMA. RESULTS: Of the 1056 hospital admissions to the HIV/AIDS ward by patients with a history of injection drug use, 263 (24.9%) resulted in leaving the hospital AMA. Independent positive predictors of leaving AMA included recent injection drug use (adjusted odds ratio [AOR] = 2.08, 95% confidence interval [CI]: 1.41-3.07) and aboriginal ethnicity (AOR = 1.55, 95% CI: 1.05-2.28). Discharge AMA was also more likely to occur on weekends (AOR = 2.27, 95% CI: 1.49-3.48) and on days when social assistance payments were issued (AOR = 2.95, 95% CI: 1.70-5.10). Factors that independently reduced the odds of hospital discharge AMA included in-hospital methadone use (AOR = 0.49, 95% CI: 0.32-0.76), social support (AOR = 0.33, 95% CI: 0.21-0.51), and older age (per 10-year increment, AOR = 0.56, 95% CI: 0.43-0.73). CONCLUSIONS: Among HIV-positive patients with a history of injection drug use, the odds of leaving the hospital AMA were reduced for subjects who received inpatient methadone treatment, were of older age, or had social supports. Addiction treatment and interventions that enhance social supports in marginalized populations at risk for hospital discharge AMA should be further explored.     

Clinical, biological and genetic study of 24 patients with ataxia telangiectasia from southern Tunisia

Ataxia telangiectasia is a multisystem disease with an autosomal recessive inheritance. It is characterized by progressive cerebellar ataxia, oculocutaneous telangiectasia, humoral and cellular immunodeficiencies and high incidence of neoplasia and radiosensitivity. A 5 year retrospective survey included 24 patients belonging to 17 families. Cerebellar ataxia was the first clinical symptom and was usually noticed when the child began to walk. Mean age of onset was 2.9+/-1.8 years. Oculocutaneous telangiectasia was present in 17 cases and appeared between 2 and 8 years and then spread in a characteristic symmetrical pattern. When ocular telangiectasia was absent (6 cases), the diagnostic of ataxia telangiectasia was retained on oculomotor apraxia (2 cases), recurrent sinopulmonary infections (3 cases) and/or a sib with typical ataxia telangiectasia (1 case). Recurrent sinopulmonary infections, absence or low serum level of IgA (78 p.100) and lymphopenia revealed immunodeficiency. Among 12 patients, chromosomal instability was observed in 5. Balanced rearrangements involving chromosomes 2, 7, 14, 22, 1, 3 and 11. The responsible gene, ATM, encodes a large protein kinase with a phosphatidylinositol 3-kinase-like domain. Ataxia telangiectasia patients have a 100 fold higher risk of cancer than the general population. We reported, in the same family two patients who developed neoplasia, (lymphoma and leukemia). During follow-up, a progressive worsening was observed in all cases. Three patients have died.