Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

Quasi-one-dimensional K-O chain in PTCDA thin films: Evidence from first-principles calculations

Using density functional theory calculations we have found that K atoms in a PTCDA (3,49,10-perylenetetracarboxylic dianhydride) crystal form a quasi-one-dimensional (1D) K-O chain interacting with carboxylic oxygen of the terminal anhydride groups of PTCDA. The K-K distance in the chain (3.72 A) is commensurate to the periodicity of the organic semiconductor. We obtain that the K-O structure is stabilized by charge transfer from K to PTCDA molecules, forming prevalently ionic bonds: the electronic density of the chemistry induced gap states is essentially delocalized on the perylene core of PTCDA, while potassium appears spoiled of its charge. Band dispersion along the direction of molecular stack is evaluated to be 0.2 eV in pure PTCDA crystal and 0.5 eV in the K-doped system, confirming that the interaction occurs between different molecular planes

Theoretical modeling of enzyme reactions: The thermodynamics of formation of compound 0 in horseradish peroxidase

In this paper, by using the perturbed matrix method (PMM) in combination with basic statistical mechanical relations both based on nanosecond time-scale molecular dynamics (MD) simulations, we quantitatively address the thermodynamics of compound 0 (Cpd 0) formation in horseradish peroxidase (HRP) enzyme. Our results, in the same trend of low-temperature experimental data, obtained in cryoenzymology studies indicate that such a reaction can be described essentially as a stepwise spontaneous process: a first step mechanically constrained, strongly exothermic proton transfer from the heme-H2O2 complex to the conserved His42, followed by a solvent-protein relaxation involving a large entropy increase. Critical evaluation of PMM/MD data also reveals the crucial role played by specific residues in the reaction pocket and, more in general, by the conformational fluctuations of the overall environment in physiological conditions

Low-dose hepatitis B immunoglobulin given "on demand" in combination with lamivudine: a highly cost-effective approach to prevent recurrent hepatitis B virus infection in the long-term follow-up after liver transplantation.

BACKGROUND: Cost of long-term prophylaxis with high-dose human hepatitis B immune globulin (HBIg) after liver transplantation is extremely high. The aim of the present study was to assess consumption rates of high (5,000 IU) and low (2,000 IU) doses of HBIg given intravenously "on demand", and determine their cost-effectiveness compared with conventional fixed monthly schedules. METHODS: The study included 11 male patients (mean age 53 years) who received transplants for hepatitis B virus (HBV)-related cirrhosis 29 to 96 months earlier, all receiving lamivudine (100 mg/day) prophylaxis. Each patient received three consecutive intravenous infusions of 5,000 IU HBIg, followed by three 2,000 IU infusions. HBIg consumption was assessed by serial measurement of serum hepatitis B surface antibody (HBsAb) titer at 2-week intervals. HBIg was readministered only when HBsAb titers dropped below 70 IU/L (i.e., "on demand"). RESULTS: Mean HBsAb peak titers after high and low HBIg doses were 1,641 +/- 385 and 848 +/- 216 IU/L, respectively (P <0.0001). Mean time to reach an HBsAb titer less than 70 IU/L was 79.5 +/- 38.2 days versus 61.6 +/- 32.1 days, respectively (P =NS). Interindividual variation coefficients were 23 +/- 18% and 32 +/- 26% (5,000 IU and 2,000 IU, respectively). Using the on demand approach, maintenance of a protective anti-HBs titer required an average number of 4.0 (5,000 IU) and 5.6 (2,000 IU) HBIg administrations per year, respectively (P =NS). CONCLUSIONS: Individual HBIg consumption profiles are highly variable. A low-dose (2,000 IU) on demand HBIg administration schedule is highly cost-effective and provides more than 50% savings compared with conventional high-dose monthly schedules

Real time evolution of unprotected protonated galactosamine probed by IRMPD spectroscopy

Conformational characterization of single α- and β-epimers of galactosamine in solution still remains an intriguing task because of their flexibility and ability to interconvert. This difficulty was circumvented by recording several "snapshots" of the epimerization process by means of fast ESI vaporization of a galactosamine·HCl sample solution at different times. Consequently, the so generated gaseous mixtures were spectroscopically investigated and the specific conformational features of both α- and β-epimers were assigned, despite the overlapping of several IR signals. Interestingly, from a comparison with time-resolved 1H-NMR data obtained for the same solutions, the catalyzing effect of the applied ESI technique in the anomerization process clearly emerges. Finally, the experimental data were supported using both the Density Functional Theory (DFT) and Block-Localized Wavefunction (BLW) approaches: the latter method was applied here for the first time for the investigation of charged species

Low-dose hepatitis B immunoglobulin given "on demand" in combination with lamivudine: a highly cost-effective approach to prevent recurrent hepatitis B virus infection in the long-term follow-up after liver transplantation

Cost of long-term prophylaxis with high-dose human hepatitis B immune globulin (HBIg) after liver transplantation is extremely high. The aim of the present study was to assess consumption rates of high (5,000 IU) and low (2,000 IU) doses of HBIg given intravenously "on demand", and determine their cost-effectiveness compared with conventional fixed monthly schedules

Low-dose hepatitis B immunoglobulin given "on demand" in combination with lamivudine: a highly cost-effective approach to prevent recurrent hepatitis B virus infection in the long-term follow-up after liver transplantation.

BACKGROUND: Cost of long-term prophylaxis with high-dose human hepatitis B immune globulin (HBIg) after liver transplantation is extremely high. The aim of the present study was to assess consumption rates of high (5,000 IU) and low (2,000 IU) doses of HBIg given intravenously "on demand", and determine their cost-effectiveness compared with conventional fixed monthly schedules. METHODS: The study included 11 male patients (mean age 53 years) who received transplants for hepatitis B virus (HBV)-related cirrhosis 29 to 96 months earlier, all receiving lamivudine (100 mg/day) prophylaxis. Each patient received three consecutive intravenous infusions of 5,000 IU HBIg, followed by three 2,000 IU infusions. HBIg consumption was assessed by serial measurement of serum hepatitis B surface antibody (HBsAb) titer at 2-week intervals. HBIg was readministered only when HBsAb titers dropped below 70 IU/L (i.e., "on demand"). RESULTS: Mean HBsAb peak titers after high and low HBIg doses were 1,641 +/- 385 and 848 +/- 216 IU/L, respectively (P <0.0001). Mean time to reach an HBsAb titer less than 70 IU/L was 79.5 +/- 38.2 days versus 61.6 +/- 32.1 days, respectively (P =NS). Interindividual variation coefficients were 23 +/- 18% and 32 +/- 26% (5,000 IU and 2,000 IU, respectively). Using the on demand approach, maintenance of a protective anti-HBs titer required an average number of 4.0 (5,000 IU) and 5.6 (2,000 IU) HBIg administrations per year, respectively (P =NS). CONCLUSIONS: Individual HBIg consumption profiles are highly variable. A low-dose (2,000 IU) on demand HBIg administration schedule is highly cost-effective and provides more than 50% savings compared with conventional high-dose monthly schedules

Liver transplantation in the presence of portal vein thrombosis: Report from a single center

Portal vein thrombosis (PVT) is a frequent finding in liver transplantation, the management of which depends mainly on its extent. In cases of mild to moderate PVT, a low dissection of the portal trunk, a jump graft, or direct implantation of graft portal vein into large venous collaterals or thrombectomy offer alternatives. For severe PVT anecdotal reports suggest that cavoportal hemitransposition, portal arterialization, or combined liver and intestine transplantation may be attempted, although the results to date are not satisfactory. When extensive perivenous and venous inflammatory changes reach the infrapancreatic region, liver transplantation probably should not be performed due to the high mortality rate