Ahmed Mukhtar

The safety of modern hydroxyethyl starch in living donor liver transplantation: a comparison with human albumin.

BACKGROUND:Intravascular volume replacement therapy is an important issue in the perioperative management of liver transplantation. There is paucity of data on the safety of hydroxyethyl starch (HES) in patients undergoing liver transplantation. We evaluated the safety of a new HES 130/0.4 in the perioperative management of liver transplantation, with a special emphasis on renal function. METHODS:Forty patients undergoing living donor liver transplantation were prospectively randomized into two groups. Patients in the ALB group (n = 20) received 5% human albumin. Patients in the HES group (n = 20) received third generation HES (6% HES 130/0.4). Total colloid administration was limited to 50 mL · kg−1 · d−1. The volume was given to maintain pulmonary artery occlusion pressure or central venous pressure between 5 and 7 mm Hg. If additional fluids were required, balanced crystalloid solution was used. Anesthetic and surgical techniques were standardized. Serum creatinine and cystatin C plasma levels were measured from arterial blood samples after induction of anesthesia, at the end of surgery, and on the first 4 postoperative days. RESULTS:All 40 enrolled patients completed the study. Demographic and intraoperative variables were comparable in both groups. Postoperatively, the mean ± sd volume was 6229 ± 1140 mL and 4636 ± 1153 mL in HES and ALB groups, respectively (P = 0.003). There was significantly larger net cumulative fluid balance in the ALB group 1100 ± 900 mL compared with the HES group 3047 ± 2000 mL, P = 0.029. Serum creatinine, creatinine clearance, and cystatin C plasma levels showed no significant differences between the two groups. One patient in each group developed acute renal failure requiring renal replacement therapy. CONCLUSION:The use of HES 130/0.4 as an alternative to human albumin resulted in equivalent renal outcome after liver transplantation.

The use of terlipressin during living donor liver transplantation: Effects on systemic and splanchnic hemodynamics and renal function.

Objectives: To assess the effect of the intraoperative use of terlipressin on splanchnic hemodynamics and postoperative renal function in patients undergoing liver transplantation. Design: Open-label, prospective, randomized study. Setting: Single-center study. Patients: Thirty patients who underwent elective, living-donor liver transplantation with portal pressure >20 mm Hg. Interventions: Patients were assigned randomly to one of two equal groups. The control group received saline, whereas the treatment group (TP group) received an initial bolus dose of terlipressin (1 mg over 30 mins) followed immediately by a continuous infusion of 2 &mgr;g·kg−1·h−1 for 48 hrs. Measurements and Main Results: Portal pressure and gas exchange (radial artery, portal vein, and hepatic vein, blood gas analyses, and lactate concentration) were assessed at baseline (after ligation of the hepatic artery) and 2 hrs after drug administration. Systemic hemodynamic data and calculated tissue oxygenation parameters were compared throughout the procedure. Renal function was assessed by measurement of serum cystatin C after induction of anesthesia and on the first 2 days postoperatively. After the infusion of terlipressin, portal venous pressure decreased significantly from 26.3 ± 3.3 to 21.3 ± 3.6 mm Hg (p < .001). The mean arterial pressure and systemic vascular resistance were significantly higher in the TP group than in the control group, whereas heart rate and cardiac index were comparable between the groups. Portal and hepatic base excess, and the level of serum lactate, did not differ between the two groups. The serum levels of both cystatin C and creatinine were significantly higher in the control group than in the TP group on postoperative day 2. Conclusion: Perioperative use of terlipressin abrogates the early postoperative decline in renal function of patients who have chronic liver disease and undergo liver transplantation without any detrimental effect on hepatosplanchnic gas exchange and lactate metabolism.

The effect of magnesium sulphate infusion on the incidence and severity of emergence agitation in children undergoing adenotonsillectomy using sevoflurane anaesthesia

This randomised, controlled, double‐blind study investigated the effects of intra‐operative magnesium sulphate administration on the incidence of emergence agitation in children undergoing adenotonsillectomy using sevoflurane anaesthesia. Seventy children were randomly allocated to receive a 30 mg.kg−1 bolus of intravenous magnesium sulphate after induction of anaesthesia followed by a continuous infusion of 10 mg.kg−1.h−1 or an equal volume of saline 0.9%. All children received titrated sevoflurane anaesthesia adjusted to maintain haemodynamic stability. The Pediatric Anesthesia Emergence Delirium scale and the Childrens Hospital of Eastern Ontario Score were used for the assessment of postoperative emergence agitation and pain, respectively. Emergence agitation was more common in the control group than in the magnesium group (23 (72%) and 12 (36%), respectively (p = 0.004)), with a relative risk of 0.51 (95% CI 0.31–0.84), an absolute risk reduction of 0.35 (95% CI 0.10–0.54), and number needed to treat of 3 (95% CI 2–9). Postoperative pain scores were comparable in the two groups. Magnesium sulphate reduces the incidence and severity of emergence agitation in children undergoing adenotonsillectomy using sevoflurane anaesthesia and is not associated with increased postoperative side‐effects or delayed recovery.

Biliary complications including single-donor mortality: experience of 207 adult-to-adult living donor liver transplantations with right liver grafts

BACKGROUND After right lobe donation, biliary complication is the main cause of morbidity. Mortality after right lobe donation has been estimated to be less than 0.5%. PATIENTS AND METHODS Between November 2001 and December 2008, 207 adult-to-adult living donor liver transplantations (ALDLT) were undertaken using right lobe grafts. Donors included 173 men and 34 women with a mean age of 28.4 +/- 5.2 years. RESULTS Siblings comprised 144 (69.6%) cases whereas unrelated donors comprised 63 (30.4%) with a mean body mass index (BMI) of 25.2 +/- 2.4. Single and multiple right hepatic ducts (RHD) were present in 82 (39.6%) and 125 (60.3%) donors, respectively. Mean operative time was 360 +/- 50 min with an estimated blood loss of 950 +/- 450 ml and returned cell-saver amount of 450 +/- 334 ml. Mean donor remnant liver volume was 33.5 +/- 3.2%. Mean intensive care unit (ICU) stay was 3 +/- 0.7 days and mean hospital stay was 14 +/- 3.5 days. Modified Clavien classifications were used to stratify all donor biliary complications The overall biliary complications occurred in 27 cases (13.0%). After modified Clavien classification, biliary complications were graded as grade I (n= 10), grade II (n= 2), grade III (n= 14) and grade V (n= 1). Grade I and II (n= 12) biliary complications were successfully managed conservatively. Grade III cases were treated using ultrasound-guided aspiration (USGA), endoscopic retrograde cholangiography (ERCP) and surgery in 10, 2 and 2 donors, respectively. Single donor mortality (Grade V) (0.4%) occurred after uncontrolled biliary leakage with peritonitis that necessitated exploration followed by ERCP with stent insertion but the donor died on day 43 as a result of ongoing sepsis. CONCLUSION Although the majority of biliary complications are minor and can be managed conservatively, uncontrolled biliary leakage is a serious morbidity that should be avoided as it could lead to mortality.

The therapeutic potential of intraoperative hypercapnia during video-assisted thoracoscopy in pediatric patients.

BACKGROUND:Although the cardiovascular effect of CO2 insufflation has not been reported in pediatric thoracoscopy, several clinical trials have demonstrated significant hemodynamic deterioration in adults. We investigated the concept of therapeutic hypercapnia for counteracting the hemodynamic effect of induced capnothorax. METHODS:Twelve pediatric patients who underwent video-assisted thoracoscopic patent ductus arteriosus closure were enrolled in the study. Cardiorespiratory variables were determined during baseline T1 and after CO2 insufflation at pressures of 2 mm Hg T2, 4 mm Hg T3, 6 mm Hg T4, 8 mm Hg T5, and 10 mm Hg T6. RESULTS:CO2 insufflation was not associated with any adverse hemodynamic effects. Cardiac output and central venous oxygen saturation increased progressively throughout the study protocol. Relative to baseline peak velocity, systolic flow time corrected for heart rate, heart rate, and central venous pressure increased significantly during insufflation, but systolic and diastolic blood pressure remained unchanged. Arterial CO2 increased from 40.7 ± 3 at T1 to 61 ± 1.6 at T6 mm Hg. Arterial oxygen tension increased from 170.9 ± 3.3 at T1 to 182 ± 2 at T6; arterial PH decreased from 7.31 ± 1.2 at T1 to 7.14 ± 4.6 at T6. CONCLUSION:Hypercapnia targeting CO2 50–70 mm Hg was associated with increased cardiac output, central venous O2, and arterial O2 tension in patients undergoing video-assisted thoracoscopic patent ductus arteriosus closure using one-lung ventilation without any deleterious cardiopulmonary effects.

Comparison of central venous oxygen saturation and mixed venous oxygen saturation during liver transplantation

Central venous catheterisation is commonly performed during major surgery and intensive care, and it would be useful if central venous oxygen saturation could function as a surrogate for mixed venous oxygen saturation. We studied 50 patients undergoing living related liver transplantation. Blood samples were taken simultaneously from central venous and pulmonary artery catheters at nine time points during the pre‐anhepatic, anhepatic, and postanhepatic phases. Four hundred and fifty sets of measurement were obtained. There was a good correlation between central venous oxygen saturation and mixed venous oxygen saturation. The mean (SD) difference (95% limit of agreement) was lowest at the first time point (1.06 (0.65)%, −1.94% to 2.7%) and then increased throughout the study but remained acceptable. The change in mixed venous oxygen and central venous oxygen saturations occurred mostly in parallel and as a result changes in mixed venous oxygen saturation were reflected adequately in the change in central venous oxygen saturation. The correlation between mixed venous oxygen saturation and cardiac output was poor.

Pitfalls in reporting sample size calculation in randomized controlled trials published in leading anaesthesia journals: a systematic review

We have evaluated the pitfalls in reporting sample size calculation in randomized controlled trials (RCTs) published in the 10 highest impact factor anaesthesia journals.Superiority RCTs published in 2013 were identified and checked for the basic components required for sample size calculation and replication. The difference between the reported and replicated sample size was estimated. The sources used for estimating the expected effect size (Δ) were identified, and the difference between the expected and observed effect sizes (Δ gap) was estimated.We enrolled 194 RCTs. Sample size calculation was reported in 91.7% of studies. Replication of sample size calculation was possible in 80.3% of studies. The original and replicated sample sizes were identical in 67.8% of studies. The difference between the replicated and reported sample sizes exceeded 10% in 28.7% of studies. The expected and observed effect sizes were comparable in RCTs with positive outcomes (P=0.1). Studies with negative outcome tended to overestimate the effect size (Δ gap 42%, 95% confidence interval 32-51%), P<0.001. Post hoc power of negative studies was 20.2% (95% confidence interval 13.4-27.1%). Studies using data derived from pilot studies for sample size calculation were associated with the smallest Δ gaps (P=0.008).Sample size calculation is frequently reported in anaesthesia journals, but the details of basic elements for calculation are not consistently provided. In almost one-third of RCTs, the reported and replicated sample sizes were not identical and the assumptions for the expected effect size and variance were not supported by relevant literature or pilot studies.

A Novel Mutation of the Ornithine Transcarbamylase Gene Leading to Fatal Hyperammonemia in a Liver Transplant Recipient

Ornithine transcarbamylase (OTC) deficiency (OTCD) is an X‐linked urea cycle disorder. Being an X‐linked disease, the onset and severity of the disease may vary among female carriers. Some of them start to develop the disease early in life, whereas others remain asymptomatic throughout their lives. Our patient was a 42‐year‐old man who developed severe hyperammonemia and fatal brain edema after receiving a right lobe graft from an asymptomatic female living donor with unrecognized OTCD. The donor developed hyperammonemia and disturbed level of consciousness that was managed successfully by hemodialysis. Molecular testing of the OTC gene in the donor revealed a heterozygous nonsense mutation (c.429T > A) in exon 5.

Modulation of splanchnic circulation: Role in perioperative management of liver transplant patients

Splanchnic circulation is the primary mechanism that regulates volumes of circulating blood and systemic blood pressure in patients with cirrhosis accompanied by portal hypertension. Recently, interest has been expressed in modulating splanchnic circulation in patients with liver cirrhosis, because this capability might produce beneficial effects in cirrhotic patients undergoing a liver transplant. Pharmacologic modulation of splanchnic circulation by use of vasoconstrictors might minimize venous congestion, replenish central blood flow, and thus optimize management of blood volume during a liver transplant operation. Moreover, splanchnic modulation minimizes any high portal blood flow that may occur following liver resection and the subsequent liver transplant. This effect is significant, because high portal flow impairs liver regeneration, and thus adversely affects the postoperative recovery of a transplant patient. An increase in portal blood flow can be minimized by either surgical methods (e.g., splenic artery ligation, splenectomy or portocaval shunting) or administration of splanchnic vasoconstrictor drugs such as Vasopressin or terlipressin. Finally, modulation of splanchnic circulation can help maintain perioperative renal function. Splanchnic vasoconstrictors such as terlipressin may help protect against acute kidney injury in patients undergoing liver transplantation by reducing portal pressure and the severity of a hyperdynamic state. These effects are especially important in patients who receive a too small for size graft. Terlipressin selectively stimulates V1 receptors, and thus causes arteriolar vasoconstriction in the splanchnic region, with a consequent shift of blood from splanchnic to systemic circulation. As a result, terlipressin enhances renal perfusion by increasing both effective blood volume and mean arterial pressure.

Prevalence of extensively drug-resistant gram negative bacilli in surgical intensive care in Egypt

Introduction The prevalence of extensively drug resistant gram negative bacilli (XDR-GNB) is rapidly progressing; however in Egypt data are sparse. We conducted the present study to quantify the incidence, risk factors and outcome of patients harboring XDR-GNB. Methods A one year prospective study was done by collecting all the bacteriological reports for cultures sent from the surgical intensive care unit, Cairo university teaching hospital. XDR-GNB were defined as any gram negative bacilli resistant to three or more classes of antimicrobial agents. Patients with XDR-GNB compared with those sustaining non extensively drug-resistant infection. A multivariate logistic regression model was created to identify independent predictors of multi-resistance. Results During one-year study period, a total of 152 samples (65%) out of 234 gram negative bacilli samples developed extensively drug resistant infection. XDR strains were significantly higher in Acinetobacterspp (86%), followed by Pseudomonas (63%), then Proteus (61%), Klebsiella (52%), and E coli (47%). Fourth generation cephalosporine (Cefipime) had the lowest susceptibility (10%) followed by third generation cephalosporines (11%), Quinolones (31%), Amikacin (42%), Tazobactam (52%), Carbapinems (52%), and colistin (90%). Relaparotomy was the only significant risk factor for acquisition of XDR infection. Conclusion Extensively drug-resistant gram negative infections are frequent in our ICU. This is an alarming health care issue in Egypt which emphasizes the need to rigorously implement infection control practices.