The effect of prophylactic mesh implantation on the development of incisional hernias in patients with elevated BMI: a systematic review and meta-analysis.

BACKGROUND: Incisional hernia is a common complication after midline laparotomy. In certain risk profiles incidences can reach up to 70%. Large RCTs showed a positive effect of prophylactic mesh reinforcement (PMR) in high-risk populations. OBJECTIVES: The aim was to evaluate the effect of prophylactic mesh reinforcement on incisional hernia reduction in obese patients after midline laparotomies. METHODS: Following the PRISMA guidelines, a systematic literature search in Medline, Web of Science and CENTRAL was conducted. RCTs investigating PMR in patients with a BMI ≥ 27 reporting incisional hernia as primary outcome were included. Study quality was assessed using the Cochrane risk-of-bias tool and certainty of evidence was rated according to the GRADE Working Group grading of evidence. A random-effects model was used for the meta-analysis. Secondary outcomes included postoperative complications. RESULTS: Out of 2298 articles found by a systematic literature search, five RCTs with 1136 patients were included. There was no significant difference in the incidence of incisional hernia when comparing PMR with primary suture (odds ratio (OR) 0.59, 95% CI 0.34-1.01, p = 0.06, GRADE: low). Meta-analyses of seroma formation (OR 1.62, 95% CI 0.72-3.65; p = 0.24, GRADE: low) and surgical site infections (OR 1.52, 95% CI 0.72-3.22, p = 0.28, GRADE: moderate) showed no significant differences as well as subgroup analyses for BMI ≥ 40 and length of stay. CONCLUSIONS: We did not observe a significant reduction of the incidence of incisional hernia with prophylactic mesh reinforcement used in patients with elevated BMI. These results stand in contrast to the current recommendation for hernia prevention in obese patients.

The influence of 2 surgical bandage systems on wound tissue oxygen tension.

HYPOTHESIS: Local wound heating improves tissue oxygen tension in postoperative patients. SETTING: University hospital. PATIENTS: Forty normothermic and well-hydrated patients recovering from elective open abdominal surgery. INTERVENTIONS: A comparison between an experimental bandage system (Warm-Up; Augustine Medical Inc, Eden Prairie, Minn) and conventional gauze covered with elastic adhesive (Medipore Dress-it; 3M, St Paul, Minn). The experimental system is heated to 38 degrees C and does not touch the wound. MAIN OUTCOME MEASURES: Subcutaneous tissue oxygen tension was measured postoperatively and on the first postoperative day. In a subgroup, we also evaluated the effects of bandage pressure per se on tissue oxygen. RESULTS: Initial postoperative tissue oxygen tensions were approximately 30 mm Hg greater with the experimental bandage, even before warming. Subcutaneous oxygen tension during heating remained significantly greater in patients with the warmed bandage than the conventional elastic bandage (116 +/- 40 vs 85 +/- 34 mm Hg, respectively) while the patients were breathing approximately 50% oxygen. The difference was smaller on the first postoperative day, but still statistically significant (82 +/- 30 vs 65 +/- 22 mm Hg, respectively). In the subgroup analysis, tissue oxygen tension increased significantly by 12 +/- 4 mm Hg when the heating bandage was substituted for a conventional bandage (P<.001). CONCLUSION: In normothermic and well-hydrated surgical patients, much benefit from the heating bandage system appears to result from pressure relief. These data suggest that relieving wound pressure markedly improves tissue perfusion and oxygenation.

Early cardiorespiratory patterns in severely burned patients with concomitant inhalation injury.

Hemodynamic and oxygenation parameters were determined during the first 24 h in 13 burned patients with concomitant inhalation injury (burn surface area 40-60 percent). In all patients right ventricular function was severely compromised evidenced as a significant increase in end-diastolic volumes, decrease in ejection fractions, low stroke work indices and increased pulmonary vascular resistances. Inotropic support with dobutamine and careful titration of volume infusion according to end-diastolic volume indices improved the hemodynamics as demonstrated by significant increases in right ventricular ejection fractions in all patients without any changes in mean arterial pressures, urine output and oxygenation. Assessment of ventricular performance by a specially designed pulmonary artery catheter is helpful in the management of severely burned patients with concomitant inhalation injury.

Peri-operative thoracic epidural analgesia for thoracotomy.

In a prospective study, experiences with peri-operative thoracic epidural analgesia (TEA) for thoracic surgery were documented. Two hundred and seven patients scheduled for elective thoracotomy were investigated. All patients received thoracic epidural catheters 2 h pre-operatively. The catheters were inserted between T4-5 and T8-9 intervertebral spaces. Epidural medication with bupivacaine and fentanyl was started preoperatively, maintained throughout surgery and was continued post-operatively via patient controlled analgesia (PCA) devices. Patients were anaesthetized with propofol and tracheal intubation was performed following neuromuscular blockade with vecuronium. Ninety-five percent of the patients were extubated immediately after surgery. 70.5% of all the patients had excellent post-operative analgesia (VAS pain scoring 0-2) on the day of surgery, 78% the day after surgery and 91% on the second day after surgery. Additionally early post-operative mobilization could be started in 63% of all patients. No neurological sequelae caused by thoracic epidural catheterization was seen in the early post-operative period.

Influence of prostaglandin E1 on tissue ischemia during surgical repair of the abdominal aorta.

OBJECTIVE: To evaluate tissue protection by PGE1 during leg ischemia in patients undergoing aortic surgery. DESIGN: Randomized, controlled prospective clinical trial. SETTING: Single university hospital. PARTICIPANTS: 19 consecutive patients undergoing abdominal aortic aneurysm repair. INTERVENTIONS: Patients received infusions of 30 ng/kg/min of PGE1 or saline. MEASUREMENTS AND MAIN RESULTS: Hemodynamic variables, lactate, creatine phosphokinase, and thromboxane B2 (TXB2) were measured. In the control group, the decrease in cardiac index (CI) after aortic cross-clamping (AXC) persisted until unclamping together with a decrease in femoral venous O2 content (CfvO2). In the PGE1 group, CI returned to baseline with a trend toward greater CfvO2 levels. During reperfusion in the PGE1 group, O2 consumption and lactate levels exceeded preclamp values. Pulmonary hypertension occurred equally in both groups but did not correlate with TXB2, which was not altered by surgery or by PGE1 infusion. CONCLUSIONS: Intraoperative PGE1 treatment offers no benefit and may exacerbate tissue ischemia during AXC by redistributing microcirculatory flow or limiting cellular oxygen utilization in a manner that overwhelms any possible protective effect.

Pharmacodynamics of mivacurium in severely burned patients.

The pharmacodynamics of mivacurium, a new short-acting non-depolarizing muscle relaxant, were studied in nine severely burned patients with concomitant inhalation injury. Complete neuromuscular blockade was achieved within 1.3 min (controls 3.0 min) following the usually recommended intubating dose (0.15 mg/kg/BW 2 x ED95) of mivacurium. The clinical duration of neuromuscular blockade and the recovery times were slightly prolonged, due to significantly reduced serum cholinesterase activity (clinical duration 24.6 min vs. 15.3 min). This pharmacodynamic profile makes mivacurium preferable for intermittent on-demand neuromuscular blockade in the severely burned patient.

Anticoagulation with prostacyclin and heparin during continuous venovenous hemofiltration.

OBJECTIVES: To investigate anticoagulation with prostacyclin (prostaglandin I2 [PGI2]) and/or heparin during continuous venovenous hemofiltration, and the role of in vitro tests of primary hemostasis in controlling anticoagulation. DESIGN: Prospective, randomized, controlled trial. SETTING: Intensive care unit. PATIENTS: Forty-six consecutive, critically ill, mechanically ventilated patients with postoperative acute renal failure. INTERVENTIONS: Anticoagulation of the patient's blood was accomplished using heparin (6.0 +/- 0.3 IU/kg/hr for group 1), PGI2 (7.7 +/- 0.7 ng/kg/min for group 2), or both PGI2 and heparin (6.4 +/- 0.3 ng/kg/min, 5.0 +/- 0.4 IU/kg/hr, respectively, for group 3), administered into the extracorporeal line before the hemofilter during continuous venovenous hemofiltration. MEASUREMENTS AND MAIN RESULTS: After Ethics Committee approval and informed consent were obtained, tests of primary and secondary hemostasis, plasma concentrations of 6-ketoprostaglandin F1 alpha (by radioimmunoassay), and hemodynamic measurements were performed before hemofiltration and 24 hrs after hemofiltration. In groups 1 and 3, hemodynamic parameters remained stable, whereas in group 2 (the PGI2 group), there were significant reductions in systemic and pulmonary vascular resistances and mean arterial pressure. Platelet function was unchanged in group 1, and was inhibited in groups 2 and 3. Corresponding with the prolongation of in vitro bleeding time, the 6-ketoprostaglandin F1 alpha concentration was increased, indicating an effective inhibition of platelet aggregation within the hemofilter. Platelet counts remained stable in all patients. Plasma coagulation tests were stable in groups 2 and 3, and were prolonged in group 1. In all patients, no major bleeding complications were observed and there was no clinically important bleeding. Mean hemofilter duration lasted longest in group 3. Blood urea nitrogen and circulating creatinine concentrations decreased significantly in groups 2 and 3 within the study period. CONCLUSIONS: Patients receiving both PGI2 and heparin showed better hemodynamic profiles and enhanced hemofilter duration compared with the other groups and no bleeding complications were observed. Therefore, we recommend anticoagulation with PGI2 and heparin during continuous venovenous hemofiltration with close monitoring of platelet function, coagulation profile, and overall hemodynamics.

The level of neuromuscular block needed to suppress diaphragmatic movement during tracheal suction in patients with raised intracranial pressure: a study with vecuronium and atracurium.

The effects of tracheobronchial suction before and after neuromuscular blockade with vecuronium (0.12 mg.kg-1; ED95 x 2; group A) and atracurium (0.4 mg.kg-1; ED95 x 2; group B) on intracranial pressure were studied in 18 neurosurgical patients with a Glasgow Coma Scale < 7. Despite adequate sedation, moderate to severe diaphragmatic movements (bucking and coughing) in response to carinal stimulation with significant increases in intracranial pressure (A: 18 SD 7 to 24 SD 8 mmHg; B: 19 SD 7 to 27 SD 5 mmHg) and subsequent decreases in cerebral perfusion pressure (group A: 69 SD 11 to 63 SD 8 mmHg; group B: 63 SD 11 to 59 SD 17 mmHg) could be observed without muscle relaxation. After a bolus dose of vecuronium or atracurium, profound neuromuscular paralysis quantified by the post-tetanic count, was observed after an onset time of 253 SD 72 s (vecuronium) and 159 SD 54 s (atracurium). Slight diaphragmatic movements could be elicited in only two patients in group A and in two patients in group B during tracheal suction; intracranial pressure (group A: 20 SD 8 to 20 SD 8 mmHg; group B: 19 SD 7 to 19 SD 7 mmHg) and cerebral perfusion pressure (group A: 65 SD 13 to 65 SD 13 mmHg; group B: 66 SD 12 to 65 SD 11 mmHg) remained unchanged. When coordinating respiratory therapy in neurosurgical intensive care patients, profound neuromuscular block, quantified by a post-tetanic count of at least 5 for vecuronium and 1 for atracurium, it is necessary to rule out any impact of diaphragmatic movement on intracranial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Coeliac plexus block with bupivacaine reduces intestinal dysfunction in neurosurgical ICU patients.

Coeliac plexus block, an established method of treatment for pain associated with pancreatitis and cancer, was used in neurosurgical patients with gastrointestinal dysfunction. The study was performed in 16 patients whose gastric reflux volume exceeded 600 ml per day for 3 consecutive days. Patients were allocated to a block group (n = 8) or a control group (n = 8). Coeliac plexus block was accomplished with a modified Moore technique using 50 ml bupivacaine 0.25%. In the block group, gastric reflux volumes for 3 days preceding coeliac plexus block and 3 consecutive days following coeliac plexus block were analysed. In the control group, gastric reflux volumes were observed over a period of 6 days. Mean (SEM) gastric reflux volume decreased significantly following coeliac plexus block from 770 (50) ml to 60 (30) ml (p < 0.01). In the control group, gastric reflux remained unchanged over the corresponding periods (730 (60) ml c.f. 670 (50) ml). The response of gastric reflux volume to coeliac plexus block suggests that the mechanism is related to inhibition of sympathetic activity in patients whose sympathetic drive is increased due to the underlying neurological disease, and possibly due to sedation withdrawal symptoms.

Porcine model for studying the passage of non-depolarizing neuromuscular blockers through the blood-brain barrier.

A method has been developed for blood-brain barrier disruption to provide reproducible access to the cerebrospinal fluid of the cerebello-medullary cistern. The technique was used successfully to investigate transfer of pancuronium to the cerebral CSF compartment in pigs. After osmotic disruption of the blood-brain barrier, pancuronium concentrations increased significantly in the cerebrospinal fluid.

In vitro NMR investigation of controlled single and repeated isoflurane anesthesia.

Immobilization of laboratory animals is a basic requirement for experimental in vivo NMR measurements. The effect of single and repeated isoflurane anesthesia on proton NMR relaxation times T1 and T2 in rat liver was studied. Furthermore, physiological monitoring was performed to evaluate the influence of isoflurane anesthesia (up to 2 hr) on biological parameters. Neither single nor repeated isoflurane application over the observed time produce relevant alterations of physiological parameters or relaxation times, compared with untreated control groups. Therefore, we conclude that isoflurane anesthesia is appropriate for in vivo NMR investigations, especially of the liver.

[Preclinical management of patients with intracerebral hemorrhage]. / Präklinische Versorgung von Patienten mit intrazerebraler Blutung.

The prehospital treatment of patients with intracerebral hemorrhage must be aimed at prevention of secondary brain damage and provision of an optimal physiologic environment to maximize the potential of recovery. Adequate cerebral oxygenation and the prevention of hypercarbia is a priority. This can only be managed by early intubation and artificial ventilation in patients with a Glasgow-coma-scale below eight, together with the restoration of normal hemodynamics to guarantee adequate cerebral perfusion.

[Requisite muscle relaxation using vecuronium for tracheobronchial suction in neurosurgical intensive care patients]. / Bedarfsgerechte Muskelrelaxation mit Vecuronium zur Tracheobronchialtoilette beim neurochirurgischen Intensivpatienten.

Coordination of respiratory care with protection of the brain is critical in neurosurgical intensive care. Therefore, in addition to hyperventilation, adequate sedation and muscle relaxation are applied to mitigate the difficulties with control of intracranial pressure (ICP) during routine tracheobronchial suctioning (TBS). Although hypnotics have been shown to be effective in mitigating increases in ICP in response to endotracheal suctioning in paralyzed patients, brisk bucking and coughing with further increases in ICP may occur without muscle relaxation. Long-term neuromuscular (nm) paralysis may be undesirable in neurosurgical critical care because clinical evaluation with early detection of neurological deterioration will be impossible in the paralyzed patient. Therefore, the effects of TBS without and after nm blockade with an intermediate-acting nondepolarizing muscle relaxant on ICP were studied. PATIENTS AND METHODS. Nine patients with moderate increases in mean ICP of 19.2 +/- 8 mmHg due to head injuries and spontaneous subarachnoid hemorrhage were investigated. All patients were on-line sedated with midazolam and sufentanil and controlled ventilation was adjusted to maintain a paCO2 of 30 +/- 2 mmHg. Respiratory and hemodynamic parameters and ICP (epidural probe) were continuously monitored and recorded on an integrated data bank. After a bolus dose of propofol, routine TBS was performed without the use of muscle relaxants. Before the next TBS, nm monitoring was initiated and train-of-four (TOF) stimulation was imposed at the ulnar nerve using supramaximal pulses. The response of the adductor pollicis muscle was recorded by accelerometry. After supramaximal stimulation had been achieved, a bolus dose of 2 times the ED95 of vecuronium (0.12 mg/kg) was given. Depth of nm blockade was quantified by the posttetanic count (PTC). ICP and CPP were measured before, during, and after TBS. Diaphragmatic movement, bucking, and coughing were registered by visual observation and graded as absent, slight, moderate, or severe. STATISTICS. Student's t-test and the Wilcoxon test for paired data (P less than 0.05; values as mean +/- SD) were used. RESULTS. (see Table and Figure). Despite adequate sedation, moderate to severe diaphragmatic movements in response to carinal stimulation with significant increases in ICP (18.2 +/-7 to 24 +/- 8 mmHg) an d subsequent decreases in cerebral perfusion pressure (CPP) (68.9 +/- 2 to 62.4 +/- 8 mmHg) could be observed without muscle relaxation. After a bolus of vecuronium, profound nm paralysis quantified by a PTC of 5 was observed after an onset time of 4.2 +/- 1 min. ICP (20.2 +/- 8 vs. 20.1 +/- 8 mmHg) and CPP (64.0 +/- 13 vs. 64.8 +/- 13 mmHg) remained unchanged. Slight diaphragmatic movements could be elicited in only two patients during TBS. DISCUSSION. TBS is a potent trigger of diaphragmatic movement, bucking, and coughing by reflex activation of the phrenic nerve. A major determinant of the magnitude of ICP increase during TBS is the transmission of the cough-induced increase in intrathoracic pressure to the cerebral venous system. Vecuronium was utilized for nm blockade because of its proven lack of cerebral and cardiovascular side effects, its relatively short onset, and its intermediate duration of action. Despite the postulated faster onset of nm blockade in the diaphragm, suppression of thumb-twitch response to TOF stimulation does not necessarily predict absence of diaphragmatic movement elicited by excessive tracheal stimulation. As demonstrated, intense nm blockade quantified by a PTC of 5 is necessary to rule out any bucking and coughing, i.e., to ensure total diaphragmatic paralysis in response to tracheal stimulation. On-line neurological evaluation, one of the essentials in the approach to the neurosurgical patient, will not be prevented by the intermittent bolus regime utilized in this study.

[Traumatic spinal cord lesion. An interdisciplinary challenge--a synopsis of the early trauma phase]. / Die traumatische Querschnittsläsion. Eine interdisziplinäre Herausforderung--eine Synopsis der frühen Traumaphase.

Increased morbidity and mortality in patients with spinal cord injuries present the anesthesiologist with many problems. The extent of neuronal damage is determined not only by the initial trauma, but also by subsequent activation of lipid peroxidation and lipase reactions due to local ischemia of the spinal cord. Complete transection of the spinal cord is characterized by impairment of diaphragmatic function and cardiovascular depression due to functional sympathectomy. Since hypoxemia is a common finding in high tetraplegics, immediate, careful intubation is mandatory at the trauma site. Because of rotational instability of the cervical spine, any brisk movement of the neck must be avoided. Therefore, orotracheal intubation may be performed only after sufficient stabilization of the spine in a neutral position has been guaranteed. Functional sympathectomy of the cardiovascular system is responsible for the hypotension frequently seen in high tetraplegics. Adequate volume replacement is provided based on central venous and pulmonary capillary wedge pressures. Reduced sympathetic tone causes increased sensitivity to volatile and intravenous anesthetics, so that myocardial depressants (e.g. halothane) should preferably be avoided. Opioid-induced anesthesia and nondepolarizing muscle relaxants should, therefore, be the anesthetic technique of choice.

[Atrial arrest and intraventricular conduction disorders due to accidental hyperkalemia during kidney transplantation]. / Vorhofstillstand und intraventrikuläre Leitungsstörung durch akzidentelle Hyperkaliämie bei einer Nierentransplantation.

Besides anemia, coagulopathies, and hypertension, electrolyte disturbances are among the most significant features of end-stage renal disease. Although plasma potassium represents only 1.5%-2% of the whole-body content, hyperkalemia has definite effects on cardiac pacemaker cells and myocardial conduction. The typical ECG findings and therapeutic management will be discussed. Case report. A 64-year-old man with chronic renal failure due to phenacetin abuse was scheduled for transplantation of a 41-h-old cadaver kidney. The preoperative laboratory check revealed BUN 51 mg% and creatinine 11.5 mg%; serum sodium and potassium were within normal limits (sodium 141 mmol/l, potassium 5.11 mmol/l). A central-venous blood gas sample after induction of anesthesia and intubation revealed pH of 7.32, pCO2 43 mmHg, HCO3 22.1 mmol/l, base excess - 3.4 mmol/l, and venous oxygen saturation 84%. Plasma potassium (5.22 mmol/l) was within the normal range. As an endarterectomy of the left common and external iliac arteries had to be performed, the arterial cross-clamping time was longer than normal (73 min). After declamping an ECG pattern (modified V5 lead) typical of hyperkalemia (atrial arrest, idioventricular rhythm, right bundle-branch block-like QRS, AV dissociation, AV block I) was observed. Plasma potassium had increased to 6.77 mmol/l (+1.55 mmol/l). Immediate treatment was started with a bolus injection of 20 ml 10% calcium gluconate, rapid infusion of 200 ml 8.4% sodium bicarbonate, and glucose-insulin infusion (glucose 33 1/3%, 15 U regular insulin). After 25 min sinus rhythm was restored and potassium levels decreased to normal. Despite the observed ECG changes the cardiovascular status remained stable.(ABSTRACT TRUNCATED AT 250 WORDS)