Effects of norepinephrine and phenylephrine on intestinal oyxgen supply and mucosal tissue oxygen tension

OBJECTIVES

To investigate effects of intravenous norepinephrine (NE) and phenylephrine (PE) on intestinal oxygen supply in an autoperfused, innervated jejunal segment.

DESIGN AND SETTING

Prospective, randomized animal study in an animal research laboratory.

MATERIALS AND METHODS

In 24 anesthetized and normoventilated pigs a segment of the jejunal mucosa was exposed by midline laparotomy and antimesenteric incision. Mucosal oxygen tension (PO2muc; Clark-type surface oxygen electrodes), microvascular hemoglobin oxygen saturation (HbO2, tissue reflectance spectrophotometry), and microvascular blood flow (perfusion units, PU; laser Doppler velocimetry), systemic hemodynamics, mesenteric-venous acid base and blood gas variables, and systemic acid base and blood gas variables were recorded after a resting period and at 20-min intervals during infusion of NE (0.01, 0.05, 0.1, 0.5, 1, 2 micrograms x kg-1 x min-1; n = 8) or PE (0.1, 0.5, 1, 2, 5, 10 micrograms x kg-1 x min-1; n = 8) and in controls (n = 8) without treatment.

RESULTS

NE infusion led to significant tachycardia, an increase in cardiac output, and systemic oxygen delivery and consumption while PE progressively increased mean arterial pressure with only small effects on systemic blood flow. NE or PE infusion did not affect mesenteric venous oxygen tension (baseline: PE 53 +/- 5, NE, 52 +/- 4.2 mmHg), mesenteric oxygen extraction ratio (baseline: PE 0.29 +/- 0.08, NE 0.3 +/- 0.06), jejunal microvascular blood flow (baseline: PE 254 +/- 127, NE 282 +/- 72 PU), PO2muc (baseline: PE 31 +/- 9.1, NE 33 +/- 11 mmHg), and HbO2 (baseline: PE 52 +/- 9.6%, NE 58 +/- 11.6%).

CONCLUSION

Despite major differences in systemic hemodynamics jejunal tissue oxygen supply is not affected by progressively increasing intravenous infusion of norepinephrine and phenylephrine.

Primary ovarian carcinoid heart disease curatively treated with a two-stage procedure

Primary ovarian carcinoid disease with cardiac involvement is a very rare syndrome, which requires interdisciplinary management. We report on a patient with primary ovarian carcinoid tumor with severe tricuspid valve insufficiency who was curatively treated after successful tumor resection and tricuspid valve replacement.

Infectious complications following 72 consecutive enteric-drained pancreas transplants

New immunosuppressive protocols and advanced surgical technique resulted in an improved outcome of pancreatic transplantation (PTx) with infection remaining the most common complication. Seventy-two enteric-drained whole PTxs performed at the Innsbruck University Hospital between September 2002 and October 2004 were retrospectively analyzed. Prophylactic immunosuppression consisted of either the standard protocol consisting of single bolus antithymocyteglobulin (ATG) (Thymoglobulin, Sangstat or ATG Fresenius) induction (9 mg/kg), tacrolimus (TAC), mycophenylate mofetil (MMF) and steroids (38 patients) or a 4-day course of ATG (4 mg/kg) tacrolimus and steroids with MMF (n = 19), or Sirolimus (n = 15). Perioperative antimicrobial prophylaxis consisted of Piperacillin/Tazobactam (4.5 g q 8 h) in combination with ciprofloxacin (200 mg q 12 h) and fluconazole (400 mg daily). Ganciclovir was used for cytomegalovirus (CMV) prophylaxis if donor was positive and recipient-negative. Patient, pancreas, and kidney graft survival at 1 year were 97.2%, 88.8%, and 93%, respectively, with no difference between the groups. All retransplants (n = 8) and single transplants (n = 8) as well as all type II diabetics and nine of 11 patients older 55 years received standard immunosuppression (IS). The rejection rate was 14% and infection rate 46% with no difference in terms of incidence or type according to the three groups. Severe infectious complications included intra-abdominal infection (n = 12), wound infection (n = 7), sepsis (n = 13), respiratory tract infection (n = 4), urinary tract infection (n = 12), herpes simplex/human herpes virus 6 infection (n = 5), CMV infection/disease (n = 7), post-transplant lymphoproliferative disorder (PTLD, n = 3), invasive filamentous fungal infection (n = 4), Clostridial/Rotavirus colitis (n = 1), and endocarditis (n = 1). All four patients in this series died of infectious complications (invasive aspergillosis n = 2) (one with Candida glabrata superinfection), invasive zygomycosis (n = 1), PTLD (n = 1). Five grafts were lost (vascular thrombosis n = 3, pancreatitis n = 1, noncompliance n = 1). Infection represented the most frequent complication in this series and all four deaths were of infectious origin. Better prophylaxis and management of infections now should be the primary target to be addressed in the field of pancreas transplantation.

Experience with ATG short course high dose induction therapy in a series of 112 enteric drained pancreatic transplants

BACKGROUND

New immunosuppressive protocols and advanced surgical technique resulted in a major improvement in the outcome of pancreatic transplantation.

PATIENTS AND METHODS

112 enteric drained whole pancreas transplants (PTx) performed at the Innsbruck University Hospital between 3.1997 and 10.2001 were retrospectively analysed. Prophylactic immunosuppression consisted of FK506, MMF and steroids. A short course of high dose ATG induction was given additionally. Perioperative antimicrobial prophylaxis consisted of Amoxicillin/Clavulanic (32 PTx), Pipercillin/Tazobactam (68 PTx), quinolones (10 PTx) or macrolide (2 PTx). 64 patients additionally received fluconazole.

RESULTS

Actuarial patient, pancreas and kidney graft survival at one year were 96.4%, 86.7% and 95.3%, surgical complication rate was 28%, rejection rate 40%. Eight grafts were lost due to intraabdominal infection, seven due to rejection. Median perioperative observation days (OD) were 29 (range 14-125), patients were on antibiotics for 68% of OD, and developed fever on 33% of OD. Incidence of CMV infection was 42% (but only five patients developed CMV disease), HSV 24%, intraabdominal infection 22%, UTI 11%, wound infection 9% and pneumonia: 5%.

CONCLUSION

ATG short course induction is well tolerated after enteric drained PTx. Infection represents a frequent and at least for IA sepsis serious complication after PTx with enteric drainage.

Fleroxacin uptake in ischaemic limb tissue

Antibiotic application to patients with ischaemia of lower limbs may be indicated to avoid or treat infection of soft tissues. Fleroxacin, a fluoroquinolone, active against various Gram-negative and Gram-positive organisms may be used for this purpose. We evaluated the diffusion of fleroxacin into bone, subcutaneous fat, muscle and tendon tissues of lower limb tissue after a 400 mg i.v. dose. Concentrations in ischaemic tissues were similar to those found in non-ischaemic sites. Since the maximum antibiotic levels found were lower than the MICs of various pathogens relevant for infection, we suggest to increase the dose used for this peri-operative prophylaxis to 800 mg.

Effects of epinephrine on intestinal oxygen supply and mucosal tissue oxygen tension in pigs

OBJECTIVE

To study the effects of increasing dosages of epinephrine given intravenously on intestinal oxygen supply and, in particular, mucosal tissue oxygen tension in an autoperfused, innervated jejunal segment.

DESIGN

Prospective, randomized experimental study.

SETTING

Animal research laboratory.

SUBJECTS

Domestic pigs.

INTERVENTIONS

Sixteen pigs were anesthetized, paralyzed, and normoventilated. A small segment of the jejunal mucosa was exposed by midline laparotomy and antimesenteric incision. Mucosal oxygen tension was measured by using Clark-type surface oxygen electrodes. Microvascular hemoglobin oxygen saturation and microvascular blood flow (perfusion units) were determined by tissue reflectance spectrophotometry and laser-Doppler velocimetry. Systemic hemodynamics, mesenteric-venous acid-base and blood gas variables, and systemic acid-base and blood gas variables were recorded. Measurements were performed after a resting period and at 20-min intervals during infusion of increasing dosages of epinephrine (n = 8; 0.01, 0.05, 0.1, 0.5, 1, and 2 microg x kg(-1) x min(-1)) or without treatment (n = 8). In addition, arterial and mesenteric-venous lactate concentrations were measured at baseline and at 60 and 120 mins.

MEASUREMENTS AND MAIN RESULTS

Epinephrine infusion led to significant tachycardia; an increase in cardiac output, systemic oxygen delivery, and oxygen consumption; and development of lactic acidosis. Epinephrine significantly increased jejunal microvascular blood flow (baseline, 267 +/- 39 perfusion units; maximum value, 443 +/- 35 perfusion units) and mucosal oxygen tension (baseline, 36 +/- 2.0 torr [4.79 +/- 0.27 kPa]; maximum value, 48 +/- 2.8 torr [6.39 +/- 0.37 kPa]) and increased hemoglobin oxygen saturation above baseline. Epinephrine increased mesenteric venous lactate concentration (baseline, 2.9 +/- 0.6 mmol x L(-1); maximum value, 5.5 +/- 0.2 mmol x L(-1)) without development of an arterial-mesenteric venous lactate concentration gradient.

CONCLUSIONS

Epinephrine increased jejunal microvascular blood flow and mucosal tissue oxygen supply at moderate to high dosages. Lactic acidosis that develops during infusion of increasing dosages of epinephrine is not related to development of gastrointestinal hypoxia.

Renal allograft rupture is associated with rejection or acute tubular necrosis, but not with renal vein thrombosis

BACKGROUND

Whereas rejection was reported to be the most common cause of renal allograft rupture (RAR) in the pre-cyclosporin era, renal vein thrombosis (RVT) is purported to be the main cause of RAR in patients taking cyclosporin. The extremely low incidence of RVT in our series (0.11%) prompted us to analyse our collective with regard to RAR.

METHOD

Between 1974 and 1999, 1811 renal transplants were performed. Patients with RAR, defined as a tear of the renal capsule and parenchyma, were identified and possible underlying factors studied.

RESULTS

RAR was diagnosed in nine male and five female recipients (0.8%) with a median age of 36 years. Immunosuppression consisted of azathioprine and prednisolone in seven patients and of cyclosporin-based therapy in the seven others. At exploration five grafts were removed immediately: three because of irreversible rejection, one because of deep wound infection, and one with a twisted renal vein. Six of the nine salvaged kidneys have been functioning after a mean observation time of 45 months. In the pre-cyclosporin era RAR was associated with acute rejection in five out of seven cases as compared with only three of the seven on cyclosporin treatment. Core biopsies might have been the cause in three cases.

CONCLUSION

RAR is a rare complication after renal transplantation. Acute rejection still represents the most frequent cause of RAR in the cyclosporin era.

Capnocytophaga pleural empyema following laparoscopic Nissen fundoplication. A rare complication, a rare pathogen

Empyema complicating laparoscopic fundoplication is exceedingly rare, as is Capnocytophaga infection in the immunocompetent host, with the exception of gingivitis. We report a 29-year-old healthy man who presented with Capnocytophaga empyema 10 days after uneventful elective, laparoscopic Nissen fundoplication for gastroesophageal reflux disease. The exact mechanism of this complication is not known, but hypotheses, including a mini-Boerrhave's syndrome, can be drawn based on knowledge of the operation, the involvement of Capnocytophaga sp., and a patient history that included severe gingivitis. Because of prompt operative evacuation of the empyema and expedient identification of Capnocytophaga in the empyema fluid, appropriate antibiotic therapy was initiated. The infection was adequately treated, and the patient recovered fully. To the best of our knowledge, this is the first report of such a complication.