Effect of feeding-tube properties on residual volume measurements in tube-fed patients

BACKGROUND: The effect of feeding tube size and port configuration on the ability to measure gastric residual volume (GRV) is poorly understood. In addition, there is confusion about the need to measure GRVs during feedings into the small bowel. This study sought to (1) compare the volume of gastric contents obtained from small-diameter feeding tubes and large-diameter sump tubes concurrently positioned in the stomach and (2) describe the distribution of GRVs during small-bowel feedings. METHODS: For the first objective, GRV measurements were made from 10-Fr tubes (n = 645) and 14-Fr or 18-Fr sump tubes (n = 645) concurrently present in 62 critically ill patients. Sixty-milliliter syringes were used to measure GRVs from the 10-Fr tubes; the fluid was returned to the stomach and measurements were repeated from the large-diameter sump tubes. To address the second research objective, 890 GRV measurements were made from 14-Fr or 18-Fr gastric sump tubes (not connected to suction) in 75 critically ill patients who were receiving small-bowel feedings. RESULTS: When GRVs were >50 mL, a linear regression equation indicated that volumes obtained from the large-diameter sump tubes were about 1.5 times greater than those obtained from the small-diameter tubes concurrently present in the stomach, p < .001. Gastric volumes > or =100 mL were found in 11.6% of the 890 measurements made in patients receiving small-bowel feedings; volumes > or =150 mL were found in 5.4% of the measurements. CONCLUSIONS: The findings suggest that GRVs obtained from large-diameter sump tubes are about 1.5 times greater than those obtained from 10-Fr tubes. Large GRVs occur in at least 5% of patients receiving postpyloric feedings.     

Secondary effects of femoral instrumentation on pulmonary physiology in a standardised sheep model: what is the effect of lung contusion and reaming?

Intramedullary nailing is the treatment of choice for patients with femoral shaft fractures. However, there is an ongoing debate in multiple trauma patients with associated lung contusion when primary or secondary definitive stabilisation of the long bone fracture should be performed, as nailing is thought to play an important role in the pathogenesis of adult respiratory distress syndrome (ARDS). In a standardised sheep model, this study aimed to quantify the development of acute pulmonary endothelial changes, to assess the activation of polymorphonuclear leucocytes (PMNL) and to observe the effects on the coagulation system associated with the reamed nailing procedure. Furthermore, the effect of coexisting lung contusion in an experimental model was evaluated. The animals were randomly assigned to one of four different groups (6 animals/group). In control groups, only a sham operation (thoracotomy) was performed, whereas in study groups, lung contusion was induced prior to femoral stabilisation either by external fixation or reamed femoral nailing. Using bronchoalveolar lavage (BAL) pulmonary permeability changes were quantified and PMNL activation was assessed by chemiluminescence. Additionally PMNL diapedesis and interstitial lung oedema were determined by histological analysis. All animals were sacrificed 4 h after the start of the femoral instrumentation. Without an associated lung injury, instrumentation of the femoral canal with the reamed nailing technique induced a transient increase in pulmonary permeability. In the face of an induced lung contusion, reamed femoral nailing resulted in significant increases in PMNL activation, pulmonary permeability and interstitial lung oedema, compared with external fixation. Without pulmonary contusion, reaming of the femoral canal was associated with a transient increase in pulmonary permeability. This was exacerbated in the presence of lung contusion along with increased PMNL activation. External fixation did not provoke similar changes. The findings of this study support the view that reaming of the femoral canal should be avoided in polytrauma patients with severe chest trauma as it could act as an additional stimulus for adverse outcome. Temporary external fixation appears to be a safe method for fracture stabilisation until inflammatory and coagulatory disturbances after trauma have been normalized.     

A mechanism of lateral flexion distraction injury of the spine

Flexion distraction fractures or Chance fractures are well described in the literature. We present an unusual pattern of injury of a pure lateral flexion distraction fracture of the T12 vertebra with no posterior element disruption following a blow to the right torso to a passenger in a road traffic accident. The diagnosis was made intra-operatively as the potential for this injury pattern following the described mechanism was not initially recognised. We suggest that this type of injury be suspected in any patient where a fulcrum has acted at any point around the torso.     

Risk factors for the intermediate outcome of morbid obesity after laparoscopically placed adjustable gastric banding

BACKGROUND: The overall long-term results of medical treatment for morbid obesity are poor. Surgery is the only treatment option to obtain long-term weight reduction. Analysis of risk factors for treatment success of laparoscopically placed gastric banding (LGB) has not been available until now. METHODS: Prospective study with 99 patients with LGB between January 1997 and July 2003. The parameters assessed as risk factors included onset of obesity, feeling of postprandial satiety, and initial body mass index (BMI). RESULTS: Median follow-up was 36 months (3 to 72). Independent prognostic factors of excess body weight reduction (>25%) were for the first postoperative year: onset of obesity as an adolescent (relative risk [RR] 0.21), an initial BMI <45 kg/m(2) (RR 4.76), and a BMI between 45.1 and 50 kg/m(2) (RR 3.23). After the second year, independent prognostic factors were as follows: feeling of postprandial satiety (RR 5.26) and an initial BMI <45 kg/m(2) (RR 3.03). CONCLUSION: LGB is suitable to achieve intermediate weight reduction in patients with morbid obesity. To obtain the best results, patients should be treated before they achieve a BMI >45 kg/m(2). Additionally a postprandial feeling of satiety after LGB is mandatory for good long-term results.     

Vertebral body stapling procedure for the treatment of scoliosis in the growing child

Thirty-nine consecutive patients have had vertebral body stapling of 52 curves (26 patients with one curve stapled and 13 with two). For the group with patients who were 8 years or older with less than 50 degrees preoperative curve and a minimum 1-year followup, coronal curve stability was 87% when defined by progression less than or equal to 10 degrees . Fusion was necessary in two patients. No curves less than 30 degrees at the time of stapling progressed greater than or equal to 10 degrees . Major complications occurred in one patient (2.6%, diaphragmatic hernia) and minor complications occurred in five patients (13%). Further followup of the patient cohort and further research into efficacy and indications are warranted.     

Arteriovenous fistula outcomes in the era of the elderly dialysis population

BACKGROUND: The growth of patients > or =65 years on hemodialysis is increasing. Guidelines recommend arteriovenous fistula (AVF) access but their outcomes in elderly patients are controversial. This study compared the outcomes of AVF in patients <65 years old (65- group) versus those > or =65 years old (65+ group). METHODS: This retrospective analysis of prospectively collected data included 444 incident, first-time AVF created in a large dialysis center between January 1, 1995 and July 1, 2003. The primary outcome of AVF cumulative patency was evaluated using Kaplan-Meier survival analysis with log-rank test comparison. A Cox model determined factors associated with AVF loss. RESULTS: One hundred ninety-six patients (44%) were in the 65+ group. In total, there were 230 (52.2%) radiocephalic, 186 (42.2%) brachiocephalic, and 25 (5.6%) basilic vein transposed AVF. The one-year AVF cumulative survival was 75.1% (65+ group) and 79.7% (65- group); the five-year survival was 64.7% (65+ group) and 71.4% (65- group). The overall total procedure, angioplasty, thrombolysis, and revision rates per access-year were 0.83, 0.30, 0.66, and 0.16, respectively. The 65+ group had a relative risk of 1.7 of their AVF failing to mature compared with the 65- group. Multivariate analysis yielded these variables significant for AVF loss: male sex HR 0.63 (95% CI 0.44-0.91), coronary artery disease HR 2.1 (95% CI 1.5-3.0), and Caucasian ethnicity HR 0.63 (95% CI 0.44-0.91). CONCLUSION: Age should not be a limiting factor when determining candidacy for AVF creation due to equivalent survival and procedural rates. Failure of fistula maturation is a primary concern to patients of all ages and demands further study.     

Effects of JAK3 inhibition with CP-690,550 on immune cell populations and their functions in nonhuman primate recipients of kidney allografts

BACKGROUND: Janus Kinase (JAK) 3 is a tyrosine kinase essential for proper signal transduction downstream of selected cytokine receptors and for robust T-cell and natural killer cells activation and function. JAK3 inhibition with CP-690,550 prevents acute allograft rejection. To provide further insight into the mechanisms of efficacy, we investigated the immunomodulatory effects of CP-690,550 in vitro and in vivo in nonhuman primates. METHODS: Pharmacodynamic assessments of lymphocyte activation, function, proliferation and phenotype were performed in three settings: in vitro in whole blood isolated from untransplanted cynomolgus monkeys (cynos), in vivo in blood from untransplanted cynos dosed with CP-690,550 for 8 days, and in vivo in blood from transplanted cynos immunosuppressed with CP-690,550. Cell surface activation markers expression, IL-2- enhanced IFN-gamma production, lymphocyte proliferation and immune cell phenotype analyzes were performed with multiparametric flow cytometry. RESULTS: In vitro exposure to CP-690,550 resulted in significant reduction of IL-2-enhanced IFN-gamma production by T-cells (maximum inhibition of 55-63%), T-cell surface expression of CD25 (50% inhibitory concentration (IC50); 0.18 microM) and CD71 (IC50; 1.6 microM), and T-cell proliferative capacities measured by proliferating cell nuclear antigen expression (IC50; 0.87 microM). Similar results were observed in animals dosed with CP-690,550. In addition, transplanted animals displayed significant reduction of NK cell (90% from baseline) and T-cell numbers whereas CD8 effector memory T-cell populations were unaffected. CONCLUSIONS: Potent in vitro and in vivo immunomodulatory effects of the JAK3 inhibitor CP-690,550 likely contribute to its efficacy in the prevention of organ allograft rejection.     

Renal transplantation from non-heart-beating donors: a single-center 10-year experience

BACKGROUND: Reluctance to accept non-heart-beating donors (NHBD) as a source of kidneys, is due to medical, ethical, and logistical reasons. Evidence suggest that the short-term graft survival is similar to that of kidneys obtained from heart-beating donors (HBD). However, few studies, with long-term follow-up are available. We conducted a single-center study of kidneys obtained from NHBD, in a 14-year period. METHODS: We studied 100 patients transplanted with kidneys between 1989 and 2004, using NHBD, supported by heart compression and mechanical ventilation (n = 24), intravascular in situ cooling (n = 59), or cardiorespiratory resuscitation plus manual abdominal counterpulsation without cooling (n = 17), the last technique being used from 1998. The median follow-up was 51 +/- 51 months (range, 1 to 170). The outcomes of these procedures were compared to those of 1025 transplantations of kidneys from HBD performed during the same period. RESULTS: The characteristics of the recipients did not differ significantly between the two groups. Kidneys from NHBD showed a significantly higher rate of delayed graft function (DGF; 84% vs 26%; (P < .001), furthermore, the primary nonfunction (PNF) incidence was significantly higher with NHBD vs HBD (16% vs 10%; P < .001). The incidence of acute rejection episodes (ARE) within 3 months and at 1 year did not differ between the groups of donors; however, more NHBD kidneys were lost from ARE. The short-term (3-month and 1 year) and long-term (5 and 10 years) renal function, determined by the serum creatinine levels, and patient and graft survival were not different for kidneys obtained from NHBD. CONCLUSIONS: The incidences of PNF and DGF were significantly higher with NHBD, which produced poorer renal function at the time of hospital discharge. One-, 5-, and 10-year graft survivals and renal function did not differ between NHBD and HBD grafts. In our series, PNF was the main barrier to the use of NHBD.     

Factors involved in baseline hyperhomocysteinemia in renal transplantation

Hyperhomocysteinemia (hyperHcy) is one cardiovascular risk. The objective of this study was to establish the prevalence demographic, and clinical and analytical factors related to hyperhomocysteinemia among renal transplant patients. The mean Hcy level was 17.3 micromol/L; the prevalence of hyperHcy was 61.2%. The population was categorized as hyperHcy and normal-homocysteinemia (Hcy) patients. Those subjects with hyperHcy were mostly men, with lower intraerythrocyte folate and vitamin B(12) levels, higher fibrinogen levels, and poorer renal function. Multivariate evaluation showed that creatinine clearance, plasma intraerythrocyte folate and vitamin B(12) levels, and plasma fibrinogen levels were independently associated with Hcy levels. Even though the Hcy level was slightly higher among patients who suffered a posttransplantation cardiovascular event, this was statistically significant.