Contamination Resulting From Aerosolized Fluid During Laparoscopic Surgery

Background and Objectives:

Aerosolized droplets of blood can travel considerable distances on release of intra-abdominal pressure during laparoscopic surgery. This creates an environmental hazard for members of the surgical team. This study describes and provides a method of measurement of aerosolized blood contamination during evacuation of the pneumoperitoneum in laparoscopic surgery.

Methods:

Samples were measured by removing a trocar from the abdomen while a pneumoperitoneum of 15 mm Hg was present. A white poster board was placed 24 inches above the incision to catch the released blood spatter. By use of machine vision, luminol fluorescence, and computerized spatial analysis, data from the boards were recorded, analyzed, and scored based on the distance, size, and quantity of particulate contamination.

Results:

We analyzed 27 boards. Spatter was present on every board. The addition of luminol to the boards increased the amount of visible spatter. Most tests created <1000 blood spatters. Fluids are typically ejected as a fine mist. Every test included at least 1 blood spatter. The range of the average blood spatter size was 0.53 × 10^–3 to 7.11 × 10^–3 sq in. The amount of spatter detected did not show any apparent correlation with the patient''s body mass index, the estimated blood loss, or the type of operation performed.

Conclusions:

Evacuation of the pneumoperitoneum during laparoscopic surgery results in consistent contamination. Most blood spatter is not visible to the naked eye. Our results suggest that all surgical participants should wear appropriate protective barriers and conscious measures should be undertaken to prevent environmental contamination during pneumoperitoneal evacuation.     

Myeloid Mineralocorticoid Receptor Activation Contributes to Progressive Kidney Disease

Clinical and experimental studies have shown that mineralocorticoid receptor (MR) antagonists substantially reduce kidney injury. However, the specific cellular targets and mechanisms by which MR antagonists protect against kidney injury must be identified. We used conditional gene deletion of MR signaling in myeloid cells (MR^flox/flox LysM^Cre mice; MyMRKO) or podocytes (MR^flox/flox Pod^Cre mice; PodMRKO) to establish the role of MR in these cell types in the development of mouse GN. Accelerated anti–glomerular basement membrane GN was examined in groups of mice: MyMRKO, PodMRKO, wild-type (WT) littermates, and WT mice receiving eplerenone (100 mg/kg twice a day; EPL-treated). At day 15 of disease, WT mice had glomerular crescents (37%±5%), severe proteinuria, and a 6-fold increase in serum cystatin-C. MyMRKO, PodMRKO, and EPL-treated mice with GN displayed proteinuria similar to that in these disease controls. However, MyMRKO and EPL-treated groups had a 35% reduction in serum cystatin-C levels and reduced crescent numbers compared with WT mice, whereas PodMRKO mice were not protected. The protection observed in MyMRKO mice appeared to result predominantly from reduced recruitment of macrophages and neutrophils into the inflamed kidney. Suppression of kidney leukocyte accumulation in MyMRKO mice correlated with reductions in gene expression of proinflammatory molecules (TNF-α, inducible nitric oxide synthase, chemokine (C-C motif) ligand 2, matrix metalloproteinase-12), tubular damage, and renal fibrosis and was similar in EPL-treated mice. In conclusion, MR signaling in myeloid cells, but not podocytes, contributes to the progression of renal injury in mouse GN, and myeloid deficiency of MR provides protection similar to eplerenone in this disease.Mineralocorticoid receptor (MR) antagonists are known to inhibit renal and cardiovascular disease (CVD) by direct blockade of MR in tissues and by reducing hypertension.¹ They can also suppress kidney damage in animal models of GN and diabetic nephropathy without affecting BP.^2–6 In addition, MR antagonists provide added protection against proteinuria and loss of renal function when used with standard antihypertensive therapies in patients with diabetic and nondiabetic CKD.^7–9The clinical use of MR antagonists is limited by the development of hyperkalemia due to the importance of the MR in tubular regulation of salt balance.¹⁰ This consequence of MR blockade in the distal tubule is most evident during renal impairment and can require a reduction in the dosage of MR antagonist or withdrawal of the agent as a therapy.^7,8 The specific renal cell types that are targeted by MR antagonists to reduce injury during kidney disease have not been clearly identified. Establishing the identity of these cells is an important step toward developing more selective inhibitors of MR signaling that do not interfere with tubular cell function.Animal studies demonstrate that the protection afforded by MR antagonists in GN and diabetic nephropathy is associated with reductions in renal inflammation, proteinuria, and glomerular injury.^2,3,5,11 These studies also link MR blockade to suppression of leukocyte recruitment and podocyte injury. This suggests that the major pathologic effects of MR signaling may occur in podocytes and inflammatory cells.Recent in vitro studies have suggested that MR signaling can induce apoptosis in podocytes and oxidative stress in macrophages,^12,13 which supports a role for MR signaling in these cell types in kidney disease. In addition, an MR deficiency in myeloid cells protects against cardiovascular injury and ischemic cerebral infarcts by reducing inflammation and fibrosis.^14–16 However, no in vivo studies have identified whether MR signaling in podocytes or macrophages is specifically important to the development of kidney disease.In this study, we created mice with a selective genetic deficiency of MR in myeloid cells or podocytes and used these strains to evaluate the hypothesis that MR signaling in macrophages or podocytes is required for the development of renal injury in a normotensive model of progressive GN.     

Comparison of complications,costs, and length of stay of three different lumbar interbody fusion techniques: an analysis of the Nationwide Inpatient Sample database

Background contextLumbar interbody fusion (LIF) techniques have been used for years to treat a number of pathologies of the lower back. These procedures may use an anterior, posterior, or combined surgical approach. Each approach is associated with a unique set of complications, but the exact prevalence of complications associated with each approach remains unclear.PurposeTo investigate the rates of perioperative complications of anterior lumbar interbody fusion (ALIF), posterior/transforaminal lumbar interbody fusion (P/TLIF), and LIF with a combined anterior-posterior interbody fusion (APF).Study design/settingRetrospective review of national data from a large administrative database.Patient samplePatients undergoing ALIF, P/TLIF, or APF.Outcome measuresPerioperative complications, length of stay (LOS), total costs, and mortality.MethodsThe Nationwide Inpatient Sample database was queried for patients undergoing ALIF, P/TLIF, or APF between 2001 and 2010 as identified via International Classification of Diseases, ninth revision codes. Univariate analyses were carried out comparing the three cohorts in terms of the outcomes of interest. Multivariate analysis for primary outcomes was carried out adjusting for overall comorbidity burden, race, gender, age, and length of fusion. National estimates of annual total number of procedures were calculated based on the provided discharge weights. Geographic distribution of the three cohorts was also investigated.ResultsAn estimated total of 923,038 LIFs were performed between 2001 and 2010 in the United States. Posterior/transforaminal lumbar interbody fusions accounted for 79% to 86% of total LIFs between 2001 and 2010, ALIFs for 10% to 15%, and APF decreased from 10% in 2002 to less than 1% in 2010. On average, P/TLIF patients were oldest (54.55 years), followed by combined approach (47.23 years) and ALIF (46.94 years) patients (p<.0001). Anterior lumbar interbody fusion, P/TLIF, and combined surgical costs were $75,872, $65,894, and $92,249, respectively (p<.0001). Patients in the P/TLIF cohort had the greatest number of comorbidities, having the highest prevalence for 10 of 17 comorbidities investigated. Anterior-posterior interbody fusion group was associated with the greatest number of complications, having the highest incidence of 12 of the 16 complications investigated.ConclusionsThese data help to define the perioperative risks for several LIF approaches. Comparison of outcomes showed that a combined approach is more expensive and associated with greater LOS, whereas ALIF is associated with the highest postoperative mortality. These trends should be taken into consideration during surgical planning to improve clinical outcomes.     

Femoral malrotation after intramedullary nailing in obese versus non-obese patients

Objective

Intramedullary nailing (IMN) of obese patients with femoral fractures can be difficult due to soft tissue considerations and overall body habitus. Complications including malrotation can occur and have significant impact on postoperative function. The purpose of this study was to evaluate femoral rotation after intramedullary nailing of obese and non-obese patients to see if there was a difference in rotation, complications and any risk factors for malrotation.

Materials and methods

Between 2000 and 2009, 417 consecutive patients with femur fractures treated with IM nail at Level I trauma and tertiary referral center. Of these, 335 with postoperative computed tomography (CT) scanogram of the bilateral lower extremities were included in this study. Baseline demographic, perioperative and postoperative femoral version calculations were included in the dataset. Statistical analysis included chi-squared test for categorical data, t-test for continuous data, and univariate and multivariate regression analysis. Significance was set at p < 0.05.

Results

Of the 417 patients with femur fractures between 2000 and 2009, 335 met criteria for this study. There were 111 patients with a BMI <25, 129 with BMI 25–29.9, and 95 patients with a BMI >30. When BMI was categorised into 3 groups (<25, 25–29.9, or 30+), none of these groups were predictive of version in univariate or multivariate regressions. Among only obese patients (BMI 30+), BMI of 35+ was not a significant predictor of version when compared to BMI 30–34.9. There were no significant differences in femoral version based on entry point (antegrade vs. retrograde) in any BMI category. There were also no significant difference between groups of patients with a DFV of >15? (p = 0.212).

Conclusions

Based on this study, BMI did not have an effect on postoperative difference in femoral version. In fact, in our multivariate regression analysis, BMI of over 30 was actually predictive of significantly lower difference in femoral version. While other studies have documented the intraoperative difficulties encountered with obese patients with femur fractures, the outcome of femoral rotation is not affected by an increasing BMI.