Infektiologie

Das Kapitel Infektiologie stellt die neue Sepsis-3-Definition, Management und die letzten Sepsisleitlinien von 2012 vor und beleuchtet auch die neuen Entwicklungen seitdem. Darüber hinaus werden Therapievorschläge für die wichtigsten infektiösen Erkrankungen (intraabdominelle Infektionen, akute Pankreatitis, Harnwegsinfekt mit Urosepsis, Pneumonie etc.) auf der Intensivstation gegeben und auch auf spezielle Erkrankungen wie komplizierte Malaria, opportunistische Infektionserkrankungen bei immunsupprimierten Patienten (u. a. HIV) eingegangen. Besonderer Wert wurde auf die mikrobiologische Erregerdiagnostik gelegt (Behälter, Transportmedien, Lagerung der Proben wie auch die richtige Probengewinnung). Zuletzt wird neben den Pilzinfektionen und deren Behandlung jedes der gängigsten Antibiotika und Antimykotika steckbriefartig zusammengefasst.

[Percutaneous needle aponeurotomy for Dupuytren's disease]

OBJECTIVE

Percutaneous transverse aponeurotomy of the cord by using a hypodermic needle as a scalpel blade in order to improve function of the hand.

INDICATIONS

Symptomatic flexion contracture with positive table top test caused by a single, palpable cord within the palm (primarily Tubiana stages I and II).

CONTRAINDICATIONS

Multiple, infiltrating or broad-based cords within the palm; irritated skin conditions; exclusive digital cord localization; recurrence after aponeurectomy; previous surgical intervention at the site of interest, digital nerve lesions; lack of patient compliance.

SURGICAL TECHNIQUE

Pinpoint surface anesthesia is obtained by injecting each portal area subdermally with 0.1 ml of local anesthetic. These applications start from distally to proximally within the palm while the most distal injection site is located proximal to the distal palm crease. Then the needle tip is introduced perpendicular to the cord. Sawing movements through the cord are performed transversely. While passively extending the contracted finger, the cord is held under tension which guarantees safe cutting. Patients are encouraged to report immediate pain sensation or numbness in order to prevent injuries to neurovascular structures and active finger flexion excludes tendon lesions during the procedure. Introducing the needle tip may be performed at several sites along the cord, if necessary, from distal to proximal at least 5 mm apart with prior pinpoint surface anesthesia. Finally, cautious passive stretching may be done after each release.

POSTOPERATIVE MANAGEMENT

Bandaging allowing immediate motion; application of a hand-based extension splint-glove during the night for 3-6 months.

RESULTS

Recurrence rate was 53% in 15 retrospectively examined patients after a mean interval of 40 months postoperatively.

Operative treatment and outcome of unstable distal radial fractures using a palmar T-miniplate at a non-specialized institution

Treatment options for displaced distal radial fractures are still a controversial topic of discussion. Although good results for the palmar plating of high-volume centers have been published, evidence of its successful use in smaller institutions is still lacking. We report the clinical and radiological results of the treatment for 84 distal radial fractures with a single 2.4-mm T-miniplate in an institution performing <30 procedures per year. According to the AO classification system, there were 30 A, 5 B, and 49 C fractures with a patients mean age of 64 years. After a minimum of 12-month follow-up, we found very good and good results according to the Gardland and Sarmiento scores and a DASH of 5.6. Only five patients were classified as having a moderate outcome. A remaining intra-articular step-off of more than 1 mm was seen in 15 patients. In a comparison of grip strength between the injured and uninjured hands, we saw a difference of 6.8 % less on the injured side. We saw two instances of tendon rupture and one of tendon irritation due to prominent dorsal screws and necessitating revision surgery. Flexor tendon irritation was noted in one patient, requiring a second operation. Modern treatment for distal radial fractures can be performed successfully and with good clinical outcome in smaller institutions. Based on the high and increasing incidence of distal radial fractures, there is no need to transfer these patients into high-volume centers. Level of evidence Case study, Level IV.

[Anatomic relationship between the pronator quadratus and brachioradialis muscle insertion: implications for repair of the muscle after volar plate fixation of distal radius fractures]

BACKGROUND

In open reduction and volar plate fixation of distal radius fractures, the pronator quadratus (PQ) muscle is usually detached at the radial edge of the distal radius. Repair of the muscle is reasonable for coverage of the plate and to maintain normal pronation of the forearm. However, repair of the muscle is not always satisfactory. In this study, the topographic relationship of both the PQ and the brachioradialis muscle (BR) insertions are investigated with regard to optimising the repair of the PQ in open reduction and volar plate fixation of distal radius fractures.

MATERIALS AND METHODS

Twelve forearm pairs fixed in formalin were examined. The muscular boundaries of the PQ and the insertion of the BR were dissected, photographs were taken and measured digitally.

RESULTS

The average distance of the PQ insertion was 4.75 cm. Distally, a close topographic relationship exists between the insertions of both the PQ and BR. A fascial connection of both muscles was detected in all specimens. The average distance of the common insertion was 1.75 cm. After removal of the PQ fascia, 0.85 cm of common insertion remained. In 25 % a muscular connection between both the PQ and BR was detected after removal of the PQ fascia.

CONCLUSION

Both the PQ and BR have a common connective tissue and partially a common muscular insertion. Detaching the PQ insertion with a part of the BR insertion in open reduction and volar plate fixation of distal radius fractures can presumably lead to a more stable repair of the PQ in contrast to a repair within the muscle.

[Appearance of complex regional pain syndrome after intramedullary nailing of a clavicle fracture]

After operative correction of a clavicle fracture using an elastic stable intramedullary nail the patient presented signs of delayed fracture healing after 2 months. During the sixth postoperative month the 28-year-old obviously pain-ridden female patient showed dystonia of the shoulder girdle and allodynia surrounding the operation field. Upon these findings, we decided - as a result of the complex regional pain syndrome that had not been previously described in this location - to treat the patient by administering bisphosphonates, multimodal analgetic therapy, physiotherapy and occupational therapy. Fourteen months after surgery, the patient showed no remaining symptoms, and the fracture had consolidated at that time.

Poor functional recovery and muscle polyinnervation after facial nerve injury in fibroblast growth factor-2-/- mice can be improved by manual stimulation of denervated vibrissal muscles

Functional recovery following facial nerve injury is poor. Adjacent neuromuscular junctions (NMJs) are "bridged" by terminal Schwann cells and numerous regenerating axonal sprouts. We have recently shown that manual stimulation (MS) restores whisking function and reduces polyinnervation of NMJs. Furthermore, MS requires both insulin-like growth factor-1 (IGF-1) and brain-derived neurotrophic factor (BDNF). Here, we investigated whether fibroblast growth factor-2 (FGF-2) was also required for the beneficial effects of MS. Following transection and suture of the facial nerve (facial-facial anastomisis, FFA) in homozygous mice lacking FGF-2 (FGF-2(-/-)), vibrissal motor performance and the percentage of poly-innervated NMJ were quantified. In intact FGF-2(-/-) mice and their wildtype (WT) counterparts, there were no differences in amplitude of vibrissal whisking (about 50°) or in the percentage of polyinnervated NMJ (0%). After 2 months FFA and handling alone (i.e. no MS), the amplitude of vibrissal whisking in WT-mice decreased to 22±3°. In the FGF-2(-/-) mice, the amplitude was reduced further to 15±4°, that is, function was significantly poorer. Functional deficits were mirrored by increased polyinnervation of NMJ in WT mice (40.33±2.16%) with polyinnervation being increased further in FGF-2(-/-) mice (50.33±4.33%). However, regardless of the genotype, MS increased vibrissal whisking amplitude (WT: 33.9°±7.7; FGF-2(-/-): 33.4°±8.1) and concomitantly reduced polyinnervation (WT: 33.9%±7.7; FGF-2(-/-): 33.4%±8.1) to a similar extent. We conclude that, whereas lack of FGF-2 leads to poor functional recovery and target reinnervation, MS can nevertheless confer some functional benefit in its absence.

[Revision arthroplasty of the elbow]

Total elbow arthroplasty (TEA) is gaining in popularity. An elbow prosthesis is nowadays no longer regarded as a salvage procedure for low demand patients but is increasingly used in younger, active patients with higher demands. In elderly patients TEA is more and more accepted as a primary treatment method for osteoporotic complex distal humerus fractures. Nevertheless, TEA is technically demanding and associated with a higher complication and revision rate compared to e.g. hip prostheses. Increasing implantation rates in a juvenescent population will lead to a considerable increase in revision rates. Most common causes are aseptic and septic loosening as well as implant failure and instability. Cemented semi-constrained prostheses are mostly used for revision elbow arthroplasty. This article deals with the causes of revision elbow arthroplasty and describes the operative technique of revision of total elbow arthroplasty.

Recovery of whisking function promoted by manual stimulation of the vibrissal muscles after facial nerve injury requires insulin-like growth factor 1 (IGF-1)

Recently, we showed that manual stimulation (MS) of denervated vibrissal muscles enhanced functional recovery following facial nerve cut and suture (FFA) by reducing poly-innervation at the neuro-muscular junctions (NMJ). Although the cellular correlates of poly-innervation are established, with terminal Schwann cells (TSC) processes attracting axon sprouts to "bridge" adjacent NMJ, molecular correlates are poorly understood. Since quantitative RT-PCR revealed a rapid increase of IGF-1 mRNA in denervated muscles, we examined the effect of daily MS for 2 months after FFA in IGF-1(+/-) heterozygous mice; controls were wild-type (WT) littermates including intact animals. We quantified vibrissal motor performance and the percentage of NMJ bridged by S100-positive TSC. There were no differences between intact WT and IGF-1(+/-) mice for vibrissal whisking amplitude (48 degrees and 49 degrees ) or the percentage of bridged NMJ (0%). After FFA and handling alone (i.e. no MS) in WT animals, vibrissal whisking amplitude was reduced (60% lower than intact) and the percentage of bridged NMJ increased (42% more than intact). MS improved both the amplitude of vibrissal whisking (not significantly different from intact) and the percentage of bridged NMJ (12% more than intact). After FFA and handling in IGF-1(+/-) mice, the pattern was similar (whisking amplitude 57% lower than intact; proportion of bridged NMJ 42% more than intact). However, MS did not improve outcome (whisking amplitude 47% lower than intact; proportion of bridged NMJ 40% more than intact). We conclude that IGF-I is required to mediate the effects of MS on target muscle reinnervation and recovery of whisking function.

[Successive ruptures of patellar and Achilles tendons. Anabolic steroids in competitive sports]

Derivatives of testosterone or of 19-nor-testosterone are used as anabolics for the purpose of improving performance although the effect of anabolics is known still to be under discussion. The use of anabolic steroids continues among competitive athletes despite increased controls and increasingly frequent dramatic incidents connected with them. Whereas metabolic dysfunction during anabolic use is well documented, ruptures of the large tendons are rarely reported. Within 18 months, a 29-year-old professional footballer needed surgery for rupture of the patellar tendon and of both Achilles tendons. Carefully directed questioning elicited confirmation that he had taken different anabolic steroids regularly for 3 years with the intention of improving his strength. After each operation anabolic steroids were taken again at a high dosage during early convalescence and training. Minimally invasive surgery and open suturing techniques led to complete union of the Achilles tendons in good time. Training and anabolic use (metenolon 300 mg per week) started early after suturing of the patellar tendon including bone tunnels culminated in histologically confirmed rerupture after 8 weeks. After a ligament reconstruction with a semitendinosus tendon graft with subsequent infection, the tendon and reserve traction apparatus were lost. Repeated warnings of impaired healing if anabolic use was continued had been given without success. In view of the high number of unrecorded cases in competitive and athletic sports, we can assume that the use of anabolic steroids is also of quantitative relevance in the operative treatment of tendon ruptures.

Superior muscle reinnervation after autologous nerve graft or poly-L-lactide-epsilon-caprolactone (PLC) tube implantation in comparison to silicone tube repair

Recovery after peripheral nerve injury depends not only on the amount of reinnervation, but also on its accuracy. The rat sciatic nerve was subjected to an 8 mm long gap lesion repaired either by autograft (AG, n = 6) or tubulization with impermeable silicone tube (SIL, n = 6) or permeable tube of poly-L-lactide-epsilon-caprolactone (PLC, n = 8). Recordings of the compound muscle action potential (CMAP) from gastrocnemius (mGC), tibialis anterior (mTA) and plantar (mPL) muscles were performed 90 days after injury to assess the amount of muscle reinnervation. The CMAP amplitude achieved in mGC, mTA and mPL was similar in after nerve autograft (39%, 42%, 22% of control values) and PLC tube implantation (37%, 36%, 24%) but lower with SIL tube (29%, 30%, 14%). The nerve fascicles projecting into each of these muscles were then transected and retrograde tracers (Fluoro Gold, Fast Blue, DiI) were applied to quantify the percentage of motoneurons with single or multiple branches to different targets. The total number of labeled motoneurons for the three muscles did not differ in autografted rats (1186 +/- 56; mean +/- SEM) with respect to controls (1238 +/- 82), but was reduced with PLC tube (802 +/- 101) and SIL tube (935 +/- 213). The percentage of neurons with multiple projections was lower after autograft and PLC tube (6%) than with SIL tube (10%). Considering the higher CMAP amplitude and lower number of neurons with multiple projections, PLC nerve conduits seem superior to SIL tubes and a suitable alternative to autografts for the repair of long gaps.

Evaluation of muscle re-innervation employing pre- and post-axotomy injections of fluorescent retrograde tracers

In experimental studies on peripheral nerve repair, the possibility to objectively compare original and post-operative innervation is of decisive importance for the selection of the proper nerve-reconstruction strategy. Herewith we report serious drawbacks encountered with the standard method of pre- and post-operative intramuscular injections of widely used retrograde neuronal tracers. Labeling of rat facial motoneurons by injection of Fast-Blue (FB; Group 1), Dil (Group 2), or Fluoro-Gold (FG; Group 3) into the whisker pad muscles was followed by transection and suture of the facial nerve. Two months later, the same rats received Dil (Group 1), FG (Group 2), and FB (Group 3) injections with the same parameters as the pre-operative injections. By quantitative evaluation of single- and double-retrogradely labeled perikarya of facial motoneurons, we tried to estimate the accuracy of re-innervation. Observations through a "UV-filter" (for FB-labeled perikarya) and a "rhodamine-filter" (for Dil-labeled perikarya) in Group 1 revealed an unexpected axotomy-triggered leakage of FB which compromised the counts. After pre-operative Dil labeling, nerve suture, and post-operative FG labeling (Group 2), Dil created an extracellular deposit in the whisker pad. Thus, the uptake of pre-operative tracer by sprouts of re-growing axons compromised counts of retrogradely labeled motoneurons. Employing the "UV-filter" in Group 3 (FG-, FB-, FG+FB-labeled perikarya), the emission of FB obscured that of FG and also compromised cell counts. The use of filter sets constructed ad hoc for detection of FG and FB rendered possible an objective comparison.

Contralateral trigeminal nerve lesion reduces polyneuronal muscle innervation after facial nerve repair in rats

Functional recovery after facial nerve surgery is poor. Axotomized motoneurons (hyperexcitable upon intracellular current injections, but unable to discharge upon afferent stimulation) outgrow supernumerary branches which are misrouted towards improper muscles. We hypothesized that alterations in the trigeminal input to axotomized electrophysiologically silent facial motoneurons might improve specificity of reinnervation. To test this we compared, in the rat, behavioural, electrophysiological, and morphological parameters after transection and suture of the buccal facial nerve (buccal-buccal anastomosis, BBA) with those after BBA plus excision of the ipsi- or contralateral infraorbital nerve (ION). After BBA, the mystacial vibrissae dropped and remained motionless until 18-21 days post operation (days PO). After BBA plus ipsilateral ION excision, there was no recovery of vibrissae whisking at all. Following BBA plus contralateral ION excision, full restoration of whisking occurred at 7-10 days PO. Electromyography of whiskerpad muscles showed normal waveform and amplitude was also most rapidly restored after BBA plus contralateral ION excision. Neuron counts after retrograde tracing showed that the intact buccal nerve contained axons of the superior (91%) and inferior (9%) buccolabial nerves. After BBA, the superior nerve comprised 56%, the inferior 21%, and 23% of the motoneurons projected within both nerves. After BBA plus ipsilateral ION excision, misdirection worsened and values changed to 48, 39 and 13%, respectively. After BBA plus contralateral ION excision, portions improved to 69, 23 and 8%. We conclude that, by reducing the redundant axon branching, lesion of contralateral ION provides the best conditions for recovery of vibrissae rhythmical whisking after reconstructive surgery on the facial nerve.