Impedance cardiography: can it replace thermodilution and the pulmonary artery catheter?

Clinical assessment of cardiac output (CO) is inaccurate, yet the use of the pulmonary artery catheter (PAC) for thermodilution (TD) measurement of CO (CO(TD)) has declined significantly. Can noninvasive impedance cardiography (ICG) now be used to measure CO (CO(ICG)) in place of CO(TD)? A literature review of recent CO(ICG) correlations with CO(TD) (r = 0.73-0.92) were similar to ours, r = 0.81. A search for conditions interfering with CO(ICG) revealed no serious problems with patient position, cardiac or pulmonary assist devices, "wet lungs," body mass index > or = 30, or age > or = 70 years. A prospective randomized study was initiated beginning with a record of physician assessment of CO as high, normal, or low; concordance was 57%. Data from ICG was revealed only in the study group, resulting in a 49 per cent change in treatment compared with 29 per cent in the control group. Length of stay was shorter in the study than the control group in the intensive care unit (2.4 +/- 8.8 vs 3.3 +/- 7.3 days) and on the floor (9.8 +/- 10.6 vs 15.7 +/- 19.0 days). In conclusion, ICG is comparable with TD, is easily, accurately, and safely performed, enhances clinical assessment of CO, and improves care in hemodynamically compromised patients.     

Traumatic rupture of the urinary bladder: is the suprapubic tube necessary?

BACKGROUND: Although surgical principles are well accepted for the treatment of an intraperitoneal or extraperitoneal rupture of the urinary bladder, the type and number of drainage catheters needed to obtain a satisfactory outcome with minimal patient morbidity have yet to be determined. METHODS: This was a retrospective review of data on injured patients with the diagnosis of an intraperitoneal or extraperitoneal rupture of the urinary bladder from penetrating or blunt trauma. RESULTS: Of the 51 patients identified, 28 were treated with suprapubic and transurethral catheters, whereas 23 received a transurethral catheter only. Complications and catheter duration times were similar regardless of type of bladder injury or drainage catheter used (p > 0.5). CONCLUSION: These data suggest that there are similar outcomes and complication rates for patients treated with suprapubic and transurethral catheters versus transurethral catheter only. Transurethral catheters alone seem effective in draining all types of bladder injuries.     

Bacterial adherence to surgical sutures: can antibacterial-coated sutures reduce the risk of microbial contamination?

BACKGROUND: Surgical site infections are associated with severe morbidity and mortality. The role of surgical sutures in the etiology of surgical site infection has been the objective of discussion for decades. This study used a standardized in vitro microbiologic model to assess bacterial adherence and the antibacterial activity of a triclosan-coated polyglactin 910 (braided) suture against selected Gram-positive and Gram-negative clinical isolates that may infect surgical wounds. STUDY DESIGN: Standardized cultures (2.0 log(10) colony forming units/mL and 5.0 log(10) colony forming units/mL of three clinical strains, Staphyllococcus aureus (methicillin-resistant S aureus [MRSA]), S epidermidis (biofilm-positive) and Escherichia coli (extended-spectrum beta-lactamase [ESBL]-producer) were inoculated to triclosan-coated and noncoated polyglactin 910 sutures to evaluate comparative adherence of bacterial isolates to the antibacterial coated and noncoated surgical sutures; to assess the impact of serum proteins (bovine serum albumin) on antibacterial activity of triclosan-coated suture; and to document the duration of antibacterial activity of the triclosan-coated material. Selected suture samples were prepared for scanning electron microscopy to demonstrate bacterial adherence. RESULTS: Substantial (p < 0.01) reductions in both Gram-positive and Gram-negative bacterial adherence were observed on triclosan-coated sutures compared with noncoated material. Pretreatment of surgical sutures with 20% BSA did not diminish antibacterial activity of the triclosan-coated braided device compared with noncoated suture (p < 0.01), and antibacterial activity was documented to persist for at least 96 hours compared with controls (p < 0.01). CONCLUSIONS: The in vitro model demonstrated a considerable reduction (p < 0.01) in Gram-positive and Gram-negative bacterial adherence to a triclosan-coated braided suture, which was associated with decreased microbial viability (p < 0.001). Because bacterial contamination of suture material within a surgical wound may increase the virulence of a surgical site infection, treating the suture with triclosan provides an effective strategy for reducing perioperative surgical morbidity.     

Mammalian target of rapamycin inhibition after solid organ transplantation: can it,and does it,reduce cancer risk?

The mammalian target of rapamycin (mTOR) inhibitors sirolimus and everolimus has been increasingly used as immunosuppressants for recipients of solid organ transplants. Over the years, potential advantages unique to this class of immunosuppressants have been recognized, including chemoprevention by virtue of their antiproliferative effects. Prevention of malignancy after transplant through mTOR inhibitor‐based immunosuppression may have a specific practical application in transplant recipients with preexisting malignancy including hepatocellular carcinoma or cholangiocarcinoma. This review will reveal how the biochemistry of the mTOR pathway, as it pertains to chemoprevention, can support a clinical role for mTOR inhibitors in the prevention of malignancies, recurrent or de novo, after solid organ transplantation in selected patients.     

Lamina propria: The functional center of the bladder?

The bladder mucosa consists of the urothelium, basement membrane, and lamina propria (LP). Although the urothelium has been given much attention, it may be regarded as one part of a signaling system involving another equally important component of the bladder mucosa, namely, the LP. The LP lies between the basement membrane of the mucosa and the detrusor muscle and is composed of an extracellular matrix containing several types of cells, including fibroblasts, adipocytes, interstitial cells, and afferent and efferent nerve endings. In addition, the LP contains a rich vascular network, lymphatic vessels, elastic fibers, and smooth muscle fascicles (muscularis mucosae). The roles of the LP and its components in bladder function have not been definitively established, though it has been suggested to be the capacitance layer of the bladder, determining bladder compliance and enabling adaptive changes to increasing volumes. However, the bladder LP may also serve as a communication center, with an important integrative role in signal transduction to the central nervous system (nociception, mechanosensation). The LP may also, by means of its different components, make it possible for the urothelium to transmit information to other components of the bladder wall, contributing to activation of the detrusor muscle. In addition, the LP may serve as a source for production of factors influencing the growth of both the overlying urothelium and the underlying detrusor muscle. Neurourol. Urodynam. 33:9–16, 2014. © 2013 The Authors. Neurourology and Urodynamics published by Wiley Periodicals, Inc.     

Noninvasive Doppler ultrasonography for assessing cardiac function: can it replace the Swan-Ganz catheter?

Background

Cardiac function, including cardiac index (CI), traditionally has been measured by a pulmonary artery catheter (PAC). A noninvasive alternative for measuring cardiac function would offer obvious advantages.

Methods

A prospective study of trauma and nontrauma patients was performed in a surgical intensive care unit over a 3-month period. CI was determined using both a standard PAC and a continuous-wave Doppler ultrasound (UTS). The study had 2 phases: phase I was nonblinded and phase II was blinded; the correlation between UTS- and PAC-derived CI was assessed.

Results

A total of 120 paired measurements of CI were observed in 31 patients. The UTS-derived CI measurements showed agreement with PAC measurements in both phase I and phase II of the study with a bias of .06 L/min/m² ± .4 L/min/m². Paired measurements correlated well in both phase I (r = .97, R2 = .95, P < .0001) and phase II (r = .93, R2 = .86, P < .0001) of the study.

Conclusions

Doppler UTS correlates well with PAC measurements of CI. This noninvasive modality is an accurate and safe alternative to PAC.     

Fesoterodine in patients with overactive bladder syndrome: can the severity of baseline urgency urinary incontinence predict dosing requirement?

Study Type – Therapy (RCT)
Level of Evidence 1b

OBJECTIVES

To determine whether baseline urgency urinary incontinence (UUI) episodes predict the need for increased doses of fesoterodine in patients with overactive bladder (OAB), as clinicians would benefit from data that help to predict which patients require higher doses of antimuscarinics to manage UUI episodes.

PATIENTS AND METHODS

In this pooled analysis of data from two double‐blind, placebo‐controlled trials, patients were randomized to placebo or fesoterodine 4 or 8 mg for 12 weeks and stratified into tertiles (>0–<2, 2–<4, or ≥4) according to the number of UUI episodes/24 h as recorded in 3‐day bladder diaries at baseline. The change in mean UUI episodes/24 h from baseline to end of study was assessed using analysis of covariance.

RESULTS

In a post hoc analysis of data from two clinical trials, there were significant reductions from baseline in UUI episodes for fesoterodine 4 and 8 mg vs placebo in patients (n) with >0–<2 (422), 2–<4 (424) and ≥4 (481) UUI episodes at baseline (all P < 0.01). In patients with 2–<4 and ≥4 UUI episodes at baseline, fesoterodine 8 mg gave significantly greater mean reductions (?1.92 and ?4.17, respectively) vs fesoterodine 4 mg (?1.43 and ?3.31) (P < 0.05). The most common adverse events were dry mouth (placebo, 8%; fesoterodine 4 mg, 19%; and 8 mg, 35%) and constipation (placebo, 2%; fesoterodine 4 mg, 5%; and 8 mg, 6%).

CONCLUSION

Fesoterodine 4 and 8 mg significantly reduced UUI episodes vs placebo; this effect appeared to be greater with fesoterodine 8 mg in patients with ≥2 UUI episodes/24 h at baseline. Fesoterodine was well tolerated, although higher doses increased the incidence of adverse events. These findings might aid the clinical identification of patients with OAB who would most benefit from increasing the dose of fesoterodine from 4 to 8 mg.     

Dimethyl sulfoxide: does it change the functional properties of the bladder wall?

PURPOSE: Dimethyl sulfoxide (DMSO) is used in a 50% solution to treat interstitial cystitis. Symptomatic relief occurs in about two-thirds of cases. The mechanism of action and effects of DMSO on bladder tissue function are poorly understood. Therefore, the effect of DMSO on bladder muscle compliance and contractility was evaluated. MATERIALS AND METHODS: Contractility and compliance were evaluated in rat bladder strips exposed to various concentrations of DMSO for 7 minutes, followed by 7 to 60-minute washout periods. The effect of DMSO at concentrations of 25%, 30%, 35%, 40% and 50% on electrical field stimulation induced contractions was assessed. Acetylcholine and high KCl (Sigma Chemical Co.) induced contractions were measured after exposure to 30% DMSO. Compliance was evaluated after exposure to 30% and 50% DMSO. RESULTS: Exposure to 40% DMSO completely abolished electrical field stimulation contractions, while 30% DMSO decreased the electrical field stimulation contraction to 40% +/- 6% of the initial force but there was almost complete recovery within 30 minutes. Contractile force was unaltered by 25% DMSO. Acetylcholine and KCl stimulation after exposure to 30% DMSO produced contractile forces of 78% +/- 6% and 39% +/- 6% of pre-DMSO control contractions, respectively. Compliance decreased by 2.4 and 4.6-fold following 30% and 50% DMSO exposure, respectively. CONCLUSIONS: DMSO completely and irreversibly abolishes contractions at a 40% concentration. Compliance is altered at even lower concentrations (30%). These findings bring into question the current practice of treating patients who have IC with 50% DMSO. Lower concentrations (25%) of DMSO may serve as a safe, effective analgesic and anti-inflammatory treatment for IC and other bladder pathologies.     

Tolerance: is it worth the risk?

BACKGROUND: The success of orthotopic liver transplantation (OLT) has been limited by the adverse effects of immunosuppression. The purpose of this study was to determine the safety and feasibility of withdrawing immunosuppression in OLT recipients to achieve tolerance. METHODS: Eighteen adult OLT recipients in our steroid-free protocol without rejection were selected for this protocol. All patients chosen for this trial were on tacrolimus monotherapy with normal liver function tests (LFTs). Tacrolimus was weaned as long as LFTs remained stable. Weaning was halted for elevations of liver enzymes and tacrolimus was increased to the last dosage at which the patients had normal LFTs. Rejection was treated by increasing tacrolimus to levels of 10-15 ng/ml. Mycophenolate mofetil (MMF) or sirolimus was added if there was severe rejection by biopsy. Steroids were used if there was no improvement. RESULTS: One patient has been weaned off immunosuppression. Three additional patients were weaned completely off but had tacrolimus resumed because of mild elevations in LFTs. Eleven of 18 (61%) patients had rejection. Two patients required steroid therapy and one required rabbit antithymocyte globulin in addition to MMF and steroids. One of the patients with rejection developed diabetes and one patient had renal failure, which subsequently resolved. One patient died following a stroke. CONCLUSIONS: Clinical tolerance can be achieved in a minority of patients, even when being maintained on minimum immunosuppression. The potential benefit of achieving tolerance must be weighed against the risks of rejection therapy in patients doing well on low-dose immunosuppression.