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.     

Congestive heart failure: new paradigms and therapeutic targets

Congestive heart failure is a major clinical and public health challenge. With increased aging, and advanced care of almost all other cardiac diseases, myocardial failure has become the single most common reason for hospitalization for patients older than 65. Conventional wisdom addressed heart failure as a hemodynamic perturbation consisting of congestion and limited cardiac output. Efforts intuitively focused on augmenting systolic function and clearing excessive pulmonary and systemic edema. Despite symptomatic improvement, mortality and functional deterioration continued unabated. Afterload reducing therapy emerged as an effective modality of improving cardiac function. Selective targeting of renin-angiotensin-aldosterone system (RAAS) was shown to be superior to alternative nonhormone-based approaches. These clinical observations gave impetus to the neurohumoral paradigm of heart failure. Whereas attention to the congestive aspects of heart failure remains an essential component of therapy, it is by no means sufficient to neutralize the complex and interactive pathogenic mechanisms which underlie this syndrome. Particularly relevant, is the asymptomatic stage of ventricular dysfunction which portend significant future structural and functional deterioration. Mounting evidence confirm the benefit of ACEI and ARB in attenuating ventricular remodeling and improving survival. This paper aims at reviewing the evidence which has led to the strongly held paradigm of neurohormonal basis of heart failure. Appropriate and evidence based therapeutic strategies are presented.     

The specific role of isoflavones in reducing prostate cancer risk

AIMS: To evaluate the effectiveness of supplementing a group of early stage prostate cancer patients, with 60 mg of soy isoflavones in producing a change in hormonal and proliferative risk parameters that are implicated in prostate cancer promotion. METHODS: Seventy six eligible prostate cancer patients with a Gleason score of 6 or below, between ages 50 and 80 were admitted and supplemented with soy isoflavones or placebo for a 12 week period and changes in PSA and steroid hormones were analyzed at baseline and post intervention. RESULTS: Fifty-nine patients completed the 12-week intervention. Serum free testosterone was reduced or showed no change in 61% of subjects in the isoflavone group compared to 33% in the placebo group. Serum total PSA decreased or was unchanged in 69% of the subjects in the isoflavone treated group compared to 55% in the placebo group. However, we did not see an increase in SHBG levels. Nineteen percent of subjects receiving soy isoflavones reduced total PSA by two points or more during the intervention period. CONCLUSIONS: These data suggest that supplementing early stage prostate cancer patients with soy isoflavones, even in a study of short duration, altered surrogate markers of proliferation such as serum PSA and free testosterone in a larger number of subjects in the isoflavone supplemented group than the group receiving placebo. The study establishes the need to explore further the effects of prolonged and consistent soy consumption, which could potentially delay onset of histologic disease in this patient population.     

Necessity of ureteral catheter during laparoscopic partial nephrectomy

PURPOSE: Laparoscopic partial nephrectomy (LPN) is a relatively recently introduced method of treating renal tumors and, as such, surgical technique is evolving. In open series urinary fistula formation represents a common postoperative complication. In the laparoscopic approach investigators have advocated the placement of a ureteral catheter with retrograde dye injection to visualize caliceal entry to aid in closure. In this study we assessed the necessity of ureteral catheter placement during LPN in decreasing urinary leakage. MATERIALS AND METHODS: From February 1998 until November 2002 laparoscopic partial nephrectomy was performed in 103 patients with renal tumors. The patients were assessed retrospectively and divided into 2 groups according to placement (group 1) or no placement (group 2) of an external ureteral catheter. Group 1 included 54 patients (mean age +/- SD 57.4 +/- 13.4 years) and group 2 included 49 patients (mean age +/- SD 57.5 +/- 10.9). Intraoperative and postoperative parameters including blood loss, operative time, ischemia time, mass size, complications and hospital stay were reviewed and compared between the 2 groups. RESULTS: There were no differences between the 2 groups in mean estimated blood loss (group 1, 394.7 cc vs group 2, 291.5 cc, p = 0.07), postoperative serum creatinine (group 1, 0.95 mg/dl vs group 2, 0.89 mg/dl, p = 0.12), requirement for pain medication (group 1, 8.9 mg vs group 2, 4.9 mg morphine equivalents, p = 0.12), hospital stay (group 1, 3.1 vs group 2, 2.9, p = 0.29) and warm ischemia time (group 1, 28 minutes vs group 2, 26.5 minutes, p = 0.18). Mean total operative time was significantly longer for group 1 compared to group 2 (191.1 vs 149.4 minutes, respectively, p = 0.001). Postoperative urinary leakage requiring prolonged drainage occurred in 1 patient in group 1 and 1 in group 2. In both cases caliceal entry was identified and sutured. CONCLUSIONS: With experience caliceal entry can be identified without the need for a ureteral catheter in patients undergoing LPN for a tumor less than 4.5 cm. Urinary fistula may occur despite caliceal entry and repair. A ureteral catheter may not decrease urinary fistula in patients undergoing LPN.     

Efficacy,tolerability, and kinetics of lamotrigine in infants

OBJECTIVES: To investigate the efficacy, tolerability, and kinetics of lamotrigine during the first year of life. STUDY DESIGN: We studied 13 infants with intractable seizures; 7 had partial seizures and 7 had infantile spasms (1 had both). Patients received open-label lamotrigine as add-on therapy for 3 months. Seizure frequency, response ratio, and side effects score were determined and compared with the baseline period. RESULTS: The rate of partial seizures per day decreased from 8.57 +/- 2.29 to 4.00 +/- 2.15 (P =.027) and infantile spasms from 8.71 +/- 2.15 to 3.61 +/- 2.762 (P =.028). Apparent clearance increased during the first year of life, with a break point at 2 months of age (mean, 0.119 +/- 0.021, 0.217 +/- 0.094 L/h per kilogram for infants <2 months and those 2 to 12 months old, respectively,P <.001). Twenty-four-hour concentration to time plots of three 3- to 4-week-old neonates showed a half-life of 23.44 +/- 3.57 hours. Compared with a group of 17 older children, LTG had similar efficacy (response ratios, -0.68 +/- 0.12 and -0.74 +/- 0.11, P =.504), and similar adverse effects scores (0.67 +/- 0.67 and 0.23 +/- 0.166, P =.95). CONCLUSIONS: Lamotrigine is a useful and well tolerated drug for partial seizures and infantile spasms in infants <1 year of age. However, lamotrigine has age-dependent kinetics that must be taken into consideration.     

A preliminary study on the effect of pharmacist counseling on awareness of and willingness to quit smoking in Malaysian population

Objectives This paper presents an outcome of pharmacist counseling among Malaysian smokers for their awareness of and willingness to quit smoking. Method It was a cross-sectional study during a 3-day public health campaign at a shopping complex. Each self-referred participant was asked to complete a questionnaire apart from the question regarding improvement, and if any in their awareness and willingness to quit smoking, were asked to respond after counseling. Pharmacists counseled each participant about smoking cessation strategies and smoking related diseases. The data were analyzed by χ ² test. Results Among respondents, 25.5% had been smoking for more than 10 years, 31% for 5–10 years, 25.4% for 2–5 years and 18.3% for 1–2 years. The participants declaring no awareness about smoking were 22.9%, with little awareness 44.3%, having moderate awareness 25.7% and with considerable awareness were 7.1%. After counseling, 4.1% revealed unawareness, 17.8% little awareness, 43.8% moderate and 34.2% had considerable awareness on the above aspects. The post counseling awareness on smoking was observed to be significantly higher (P< 0.01). Among smokers studied, 67% showed willingness to quit smoking. Conclusion Increase in awareness of and willingness to quit smoking reflects that pharmacist counseling seems to be helpful in cessation of smoking.     

Laparoscopic renal-adrenal surgery in patients on oral anticoagulant therapy

PURPOSE: Patients requiring chronic anticoagulation are theoretically at increased risk for hemorrhage or thromboembolism perioperatively. Experience with laparoscopic renal/adrenal surgery in patients on chronic warfarin is limited. We assessed hemorrhagic/thromboembolic complications in this group of patients. MATERIALS AND METHODS: The records of 787 patients undergoing laparoscopic renal/adrenal surgery were retrospectively reviewed. A total of 25 patients on chronic oral anticoagulation with warfarin were identified. The indications for warfarin therapy as well as perioperative management were reviewed. Clinical parameters, including operative time, estimated blood loss, hemorrhagic/thromboembolic complications and transfusions, were documented and compared with those in patients not receiving chronic anticoagulation. RESULTS: Atrial fibrillation (56% of cases) and a prosthetic mitral valve (28%) were the most frequent indications for chronic anticoagulation. Bridging anticoagulation with unfractionated heparin was the most frequent management method (68% of cases). Patients with anticoagulation were older (p <0.001) and hospitalized longer (<0.001) than those without anticoagulation. Operative time, estimated blood loss and the conversion rate were not significantly different between the groups. However patients on chronic warfarin significantly more often required transfusion (24% vs 5.2%, p <0.005) and had more postoperative bleeding episodes (8% vs 0.9%, p <0.05) than patients not on chronic anticoagulation. No thromboembolic events occurred in the anticoagulated group, while 3 occurred in the nonanticoagulated group (p = 1). CONCLUSIONS: Laparoscopic renal/adrenal surgery in patients requiring chronic anticoagulation therapy can be performed safely. The risk of intraoperative bleeding is not increased, although the incidence of postoperative bleeding as well as transfusions is higher.