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Biomedical subjects

M Möllmann

Publications and source records attributed to M Möllmann.

31 records · Page 2Linked to original sources
PubMed1992

[The reuse of 29-gauge spinal needles following combined spinal-epidural anesthesia].

The technique of combined spinal epidural anaesthesia (CSE) combines the versatility of spinal with the variability of epidural anaesthesia. Spinal application of the local anaesthetic achieves a fast response, reliable sensorial and motor block at a low dose with little toxicity. The epidural catheter allows for the duration of surgical anaesthesia to be extended and provides analgesia for the postoperative period. As the incidence of post dural puncture headache (PDPH) is inversely related to the size of the spinal needle, PDPH rarely or never occurs when 29 gauge needles are used. In 1775 parturients receiving spinal anaesthesia for caesarean section, Dittmann et al. [4] reported an incidence of PDPH of 1.37% with 29 gauge needles. The 29 gauge needle produced by Becton-Dickinson is the one now most frequently used for this technique. It is recommended that these needles be reused after resterilization. The objective of this study was to examine how clean 29 gauge spinal needles really are after resterilization. MATERIALS AND METHODS. Fifteen needles (29 gauge; Becton-Dickinson) were routinely used for combined spinal epidural anaesthesia. After identification of the epidural space at the L3-4 spinal segment with the 18 gauge Tuohy needle, the 29 gauge needle was advanced through the Tuohy needle. Immediately after use the needles were cleaned, rinsed with 20 ml distilled water, dried with pressurized air and subsequently resterilized in gas. Preparation of the used needles was in accordance with the manufacturer's recommendations ("wash, rinse, dry, sterilize before initial and each subsequent use") and with generally accepted principles [6]. Two needles were additionally cleaned in an ultrasonic bath for 15 min. The needles were examined using a scanning electron microscope. After this analyses, eight needles were sterilized again and then taken for hygienic examination. They were incubated with trypticase soy broth and checked for bacterial growth. RESULTS. Scanning electron microscopy (ScEM) showed organic impurities on all needles. These impurities were equally distributed among all needles. Even the two cleaned in the ultrasonic bath were not free of organic particles. However, no material defects or damage could be seen. Hygienic evaluation proved sterility as no bacterial growth could be detected. CONCLUSION. Owing to the possibility of medico-legal consequences, which sometimes occur a long time after anaesthesia has been given, we think it is unwise to reuse such needles. We hope that disposable and cheap 29 gauge needles will soon become available.

Anesthesia, Epidural↗
PubMed1991

[CSE--the combination of spinal and epidural anesthesia].

The availability of very fine-bore, long spinal needles (28/10 Ga) has stimulated a new wave of interest in the technique of combined spinal-epidural anesthesia. The original double-puncture technique has progressed due to special combination needles to the current spinal-needle-through-epidural-needle technique. The availability of adapted Tuohy needles, special combination sets, and long spinal needles indicates a lack of standardization. An appropriate introduction technique via Tuohy needle allows identification of the anatomic landmarks and contributes to successful anesthesia. The spinal component allows a rapid onset and intense analgesia with appropriate muscle relaxation. The epidural catheter allows the administration of agents into the epidural space as well as optimization and prolongation of analgesia in the postoperative phase. Confirming the position of the epidural catheter introduced after spinal anesthesia has been established remains a matter of concern.

Anesthesia, Epidural↗
PubMed1990

Percutaneous venous cannulation and central venous line placement by means of ultrasonography and ultrasonic Doppler.

Ultrasonography is being increasingly used in the field of anesthesiology. One major indication is visualization of central venous vessels, in particular the internal jugular vein before and during cannulation by means of ultrasonography or ultrasonic Doppler. This should facilitate puncture with a higher rate of successful cannulations and decreased rate of complications related to needle probing during catheterization attempts. Furthermore, by using ultrasonography central venous catheters can be located in the vessels. The picture quality of various central venous catheters currently used in anesthesia and intensive care does not show any noticeable difference.

Catheterization, Central Venous↗
PubMed1989

[Duplex sonography in the diagnosis of renal artery stenoses following allogenic kidney transplantation].

Posttransplant renal artery stenosis (TRAS) as a cause of secondary hypertension is reported with an incidence of 1 to 10%. Early diagnosis of TRAS should be made by non-nephrotoxic and non-invasive means to lower the risk of hypertension. One to 66 months after kidney transplantation 335 patients underwent Duplex-scanning, 38 of cases for clinical tentative diagnosis of TRAS. Parameters for clinical diagnosis of TRAS were diastolic hypertension greater than 100 mm Hg with resistance to therapy (A), an abdominal bruit over the transplant (B), disturbance of renal function (serum-creatinine greater than 2 mg/dl) (C). Admission to study followed the parameter-combination A + B. A + C, B + C. Rejection crisis was excluded in 18/38 cases by fine needle biopsy, cyclosporine over-dosage was negative in 38/38 cases, 20/38 cases had normal renal function. Duplex-/Doppler-ultrasound criteria for TRAS were systolic peak velocity greater than 100 cm/s-1 and broadening of the diastolic frequency spectra with a smooth decline in diastole to an elevated diastolic level. In 32/38 cases (84.2%, n = 38) diagnosis of TRAS was made by duplex-scanning, angiography confirmed the result in 30/32 cases (93.75%, n = 32); sensitivity was 88.2% with a specificity of 66.6%. Duplex-scanning as a primary diagnostic means for TRAS seems a promising method compared to e.g. radionuclide imaging or angiography. Duplex-scanning is a non-nephrotoxic and non-invasive procedure repeatable at any time with only few preliminary conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Image quality of various venous catheters in ultrasound under standardized conditions].

Seven different types of venous catheters were visualised under standardised conditions with a 5 mHz linear scanner for comparison of their respective imaging qualities. Under these conditions, all catheters were readily identifiable regardless of fabric and width. Any formation of loops or knots could also be visualised.

Catheterization, Central Venous↗
PubMed1989

Erythropoietin in polycystic kidneys.

Erythropoietin (EPO) formation in kidneys of 18 patients with autosomal dominant polycystic kidney disease (ADPKD) was investigated. In 12 patients on hemodialysis and in 6 patients with preterminal renal failure serum, EPO was 29 +/- 7 and 16 +/- 1.5 mU/ml and hemoglobin concentrations were 11.0 +/- 0.6 and 12.7 +/- 1.2 g/dl, respectively. Cyst fluid from a total of 357 renal cysts was obtained by either in vivo aspiration or immediately after nephrectomy. The cysts contained variable concentrations of bioactive EPO from undectable values up to 3.2 U/ml. A pronounced enrichment of EPO was observed in cysts with sodium concentrations greater than 100 mmol/liter, suggesting an association with proximal tubular malformations. The EPO concentrations in the cysts were neither correlated with the protein concentration nor with the oxygen pressure of the cyst fluid. Using a cDNA probe for human EPO, mRNA for EPO was localized in stroma cells of the cyst walls by an in situ hybridization technique. Our findings suggest that single interstitial cells juxtaposed to proximal tubular cysts may produce EPO independent of the oxygen pressure inside the cysts, which ameliorates the anemia during end-stage polycystic kidney disease.

Animals↗
PubMed1987

[Sensitivity and specificity of sonography and sialography in relation to the diagnosis of parotid tumors].

The results of parotid sialography from a group of patients between 1980 and 1982, were subjected to retrospective evaluation, and compared with sonographic results from another group between 1983 and 1985. In the first period studied sialography showed 75% sensitivity and 100% specificity. Both sensitivity and specificity of sonography were 100% in the second group. Thus, sonography appears superior with regard to diagnosis of intraglandular tumours of the parotid.

Humans↗
PubMedDate not supplied

Intrathecal local anesthetic distribution with the new spinocath catheter.

BACKGROUND AND OBJECTIVES: Microcatheters have been linked in some cases to the development of cauda equina syndrome, which may be further traced to the maldistribution of the local anesthetic. A long injection time via the microcatheters contributes to the inadequate mixing. With the new Spinocath catheter, considerably shorter injection times can be achieved due to larger internal size. This study examined whether this leads to more homogeneous intrathecal distribution without causing greater trauma to the dura. METHODS: In an in vitro model of the spinal canal, the distribution of hyperbaric and isobaric 0.5% bupivacaine (2.5 mL) as well as 5% lidocaine (2.5 mL) was examined after injection via the 28-gauge CoSpan catheter (Kendall, Healthcare, Mansfield, MA), the 22-gauge Spinocath catheter (Braun, Melsungen, Germany), and a 29-gauge Quincke needle (Becton Dickinson, Rutherford, NJ). The local anesthetic concentration in the vertebral interspaces T12-L1 to L5-S1 was measured via gas chromatography 3 and 10 minutes after injection. In addition, the morphologic puncture characteristics of human dura were examined with the halftone electron microscope, after puncture with the catheters and needle. RESULTS: After injection through the 28-gauge CoSpan catheter, caudal segments of the spinal canal showed peak concentrations up to a maximum of 1,147 microg/mL bupivacaine or 8.5 mg/mL lidocaine with hyperbaric solutions, which did not decrease over the 10 minutes of measurement. After injection through the Spinocath catheter, there was a homogeneous distribution with data peaks of approximately 350 microg/mL bupivacaine or 4.2 mg/mL lidocaine similar to the data found after injection through the spinal needle. CONCLUSIONS: The new Spinocath catheter allows a better mixing of the local anesthetic with the cerebrospinal fluid. Because of significantly shortened injection times, hyperbaric solutions also show a more homogeneous distribution. Although the Spinocath catheter has a larger inner diameter than the other microcatheters, it appeared to cause less trauma to the dura.

Anesthesia, Spinal↗
PubMedDate not supplied

Continuous spinal anesthesia: mechanical and technical problems of catheter placement.

BACKGROUND AND OBJECTIVE: Although continuous spinal anesthesia with microcatheters has a number of advantages, there are also some drawbacks: technical problems in advancing the catheter, the possibility of traumatizing neural structures, the development of cauda equina syndrome, and maldistribution of the local anesthetic. METHODS: Spinaloscopy was performed with a 2-mm-diameter endoscope in fresh cadavers to visualize the fate of the catheters, as well as the distribution of the local anesthetic administered through these fine-bore catheters. Midline and paramedian approach achieved an easy insertion of the 28-gauge catheter as long as the 22-gauge needle was not advanced too far into the subarachnoid space, thereby making it impossible for the catheter to bend at the anterior wall of the dura mater. RESULTS: Injection of methylene blue-colored hyperbaric local anesthetic through the catheter revealed an inhomogenous distribution with pooling in the caudal segments. After the catheter tip leaves the needle, the catheter should be advanced only 2-3 cm to avoid coiling, possible damage of the nerve roots, or malpositioning in preformed pouches. CONCLUSION: To take advantage of continuous spinal anesthesia, a meticulous technique is required.

Anesthesia, Spinal↗