Membrane Puncture Research Articles

Bevel direction, dura geometry, and hole size in membrane puncture: Laboratory report

The cylindrical shape of the dura in vivo, as well as the needle tip deviation known to occur with beveled needle insertion, might predispose to geometric effects of needle orientation on hole size and shape during dural puncture. The object of this study was to investigate such possible effects. Standard xerographic paper was used to simulate a dura mater membrane with random fiber orientation. Rigidly mounted paper cylinders of 2-cm diameter were transfixed at 90 degrees angles to the cylinder axis with 22-gauge Quincke point spinal needles. A nonrotating drill press effected linear insertion, creating entry and exit perforations at median and paramedian positions. The bevel direction was rotated at 90 degrees angles during punctures in order to determine the effects of lateral versus transverse bevel orientation (relative to the cylinder axis) on the resultant hole morphology. With median perforation, all holes (entry and exit) were of uniform size and shape regardless of bevel orientation. Paramedian perforations of the cylinder at near tangential positions, with the bevel directed lateral to the cylinder axis, resulted in formation of a flap overlapping the margins of either the entry or exit hole but not both. Flaps formed only when the bevel faced the cylinder membrane's surface during paramedian, near tangential puncture (n = 10, P = .00001). The geometric interactions of membranes with Quincke needles lend support to the practice of needle insertion with the bevel facing laterally in order to produce smaller holes. Geometry may help to explain the reduced rate of postdural puncture headache found with Quincke bevels oriented to face laterally during midline approach and during paramedian technique, particularly when a single puncture results in aspiration of cerebrospinal fluid.

The Cylindrical Electrostatic Liquid Film Radiator for Heat Rejection in Space

A new space radiator concept has been proposed (Kim et al., 1991, 1992a, b, 1993) in which a thin film of hot liquid, flowing along the inside of a closed membrane, rejects waste heat by radiation to the surroundings. In previous versions, the radiator rotates, supplying most of the driving force for the liquid flow. In the present design, the cylinder is stationary, and the liquid flows circumferentially under its initial momentum. Moderately large Reynolds numbers are required to overcome viscous drag, and prevent excessive thickening of the film. The major design consideration involves the application of an internal electrostatic field to pull the liquid away from the site of a membrane puncture due to micrometeorite impact. Calculations are presented that show that leaks can be stopped with a safety factor of two or more, while the surface wave thus produced is washed harmlessly out of the system. Some preliminary heat transfer performance characteristics are presented. The advantages of this concept include the absence of moving parts and the ease of deployment, compared to rotating units, and a factor of at least three for the reduction of the weight per unit surface area compared to heat pipes.

Cell Membrane Resealing by a Vesicular Mechanism Similar to Neurotransmitter Release

After injury to the cell membrane, rapid resealing of the membrane occurs with little loss of intracellular contents. This process has been studied by measurement of the rate of dye loss after membrane puncture in both the sea urchin embryo and 3T3 fibroblasts. Resealing of disrupted cell membranes requires external calcium that can be antagonized by magnesium. Block of multifunctional calcium/calmodulin kinase, which regulates exocytotic vesicle availability at synapses, and of kinesin, which is required for outward-directed transport of vesicles, inhibited membrane resealing. Resealing was also inhibited by botulinum neurotoxins B and A, suggesting that the two synaptosomal-associated proteins synaptobrevin and SNAP-25 also participate in resealing. This pattern of inhibition indicates that the calcium-dependent mechanisms for cell membrane resealing may involve vesicle delivery, docking, and fusion, similar to the exocytosis of neurotransmitters.

Mechanical perturbation of cultured human endothelial cells causes rapid increases of intracellular calcium.

In first-passage human umbilical vein endothelial cells (HUVEC) and bovine aortic endothelial cells (passages 13-16), exposure to gentle mechanical perturbation using a micropipette caused a transient rise in intracellular calcium concentration ([Ca2+]i). The increase in calcium concentration ([Ca2+]) occurred each time the cell was nudged. Three responses were evoked in each of 27 cells using 5 independent HUVEC harvests. Increase in [Ca2+] returned to near baseline levels within approximately 30 s. The stimulus did not cause membrane puncture, as indicated by 1) absence of rapid dye leakage, 2) regulated nature of the [Ca2+] response, 3) absence of membrane blebbing, and 4) repeatable nature of the response in the same cell. As an alternative stimulus, we created very narrow fluid streams (1- to 2-microns diam) from a pressurized pipette that generated shear stresses of approximately 0.001-0.1 dyn/cm2 on the cells. However, these low-shear streams had little effect on [Ca2+]i. The poke-induced change in [Ca2+] was not blocked by lowering extracellular [Ca2+] ([Ca2+]o; 10 microM). In the absence of [Ca2+]o, however, HUVEC did not respond to the first poke, indicating a requirement for some [Ca2+]o as a mediator of signaling. After several poke-induced responses, [Ca2+]i could still be released by caffeine (100 microM), indicating the integrity of the intracellular release mechanism(s). These studies indicate that the response of an endothelial cell to a membrane-deforming event involves a priming step utilizing [Ca2+]o, which facilitates the transient increase of [Ca2+]i.

The effect of pre‐acquisition starvation on aphid transmission of potyviruses during observed and electrically recorded stylet penetrations

AbstractThe effect of pre‐acquisition starvation on stylet penetration behaviour by the aphid Myzus persicae (Sulz.) and the consequent non‐persistent transmission of the potyviruses beet mosaic virus (BMV) and potato virus Y (PVY) were investigated. Visual observations indicated that starved aphids initiated penetrations earlier and penetrated for shorter periods than non‐starved insects. Tethering with a fine gold wire did not affect these observations with either starved or non‐starved aphids, but starvation caused increased PVY and BMV acquisition efficiency, regardless of tethering. Tethered aphids were then made part of an electrical circuit and their stylet activities investigated in detail. Electrically recorded aphids also acquired and inoculated both potyviruses more efficiently when starved, and these acquisitions and inoculations were associated with stylet punctures of plant cell membranes. However, starvation did not affect the occurrence of electrically recorded membrane puncture, suggesting that non‐behavioural factors may contribute to the enhancement of virus transmission by pre‐acquisition starvation.

Stylet activities and potato virus Y vector efficiencies by the aphids Brachycaudus helichrysi and Drepanosiphum platanoidis

AbstractStylet penetration activities of two aphid species were recorded electrically and compared with their efficiency of potato virus Y transmission. B. helichrysi (Kltb.) acquired the virus during 15% of single penetrations on infected leaves. These acquisitions were associated with the occurrence of cell membrane puncture by stylets, recorded during 44% of the penetrations. D. platanoidis (Schrank) punctured membranes during only 8% of penetrations, and its acquisition efficiency was less than 1%. The frequency with which aphids puncture cell membranes appears to partially determine their vector efficiency.

L'intubation oro-trachéale par voie rétrograde

Four different techniques of retrograde tracheal intubation were studied in 77 cadavers (patients who had died less than 4 h before). None had any laryngeal disease or a previous intubation. Following techniques were evaluated: cricothyroid membrane puncture; infracricoid puncture; catheter guide inserted through the endotracheal tube; catheter guide only inserted through the distal lateral eye (Murphy eye) of the endotracheal tube. An epidural catheter was used as guide. Success rate was low (5 out of 17 attempts) when cricothyroid puncture was used, and the guide passed through the whole length of the tube. All 20 attempts were successful when infracricoid puncture was used and the guide passed through the distal lateral eye of the endotracheal tube. The different techniques and equipment needed are discussed in the light of the available literature. Retrograde tracheal intubation seems to be an easy and useful technique, which all anaesthetists should know, in case of difficult intubation.

Cricothyroid membrane puncture

A method for pediatric airway support was evaluated for the situation when mask ventilation or intubation is impossible. Mongrel dogs were sedated, intubated, and allowed to breathe room air for 30 min. Baseline variables were recorded, and the airway obstructed. After 2 to 3 min of hypoxia, arterial blood gas and hemodynamic data were again recorded. A percutaneous cricothyroid membrane puncture (PCMP) was then performed with a 12-ga iv catheter. Studies were carried out both in the presence and absence of spontaneous ventilatory efforts. With spontaneous ventilation, continuous low flow (1.0 L/min) oxygen insufflation provided oxygenation for 30 min and reversed increases in mean arterial pressure, pulmonary artery pressure (PAP), and systemic and pulmonary vascular resistance that had been produced by the obstruction. Respiratory acidosis occurred but was well tolerated. With paralyzed animals, whose ventilation was supported by a self-inflating bag with 10.0 L/min of oxygen, all hemodynamic variables except PAP returned to normal, oxygenation was excellent, and PaCO2 values were maintained at steady, but elevated levels. Complications included bilateral tension pneumothorax in one animal. This experimental study supports anecdotal experiences where PCMP has been used and has proven lifesaving when standard resuscitative measures to establish a clear airway have failed.

Transtragal, transtympanic electrode placement for intraoperative electrocochleographic monitoring.

Transtragal, transtympanic electrode placement was performed for the purpose of intraoperative electrocochleographic (ECoG) monitoring during seven suboccipital acoustic neuroma resections. The promontory, the tragus, and two external sutures stabilized the electrode during surgery. The only noted otologic sequallae of electrode placement were small circular lesions at tympanic membrane puncture sites. Satisfactory ECoG recordings were obtained in five of seven cases. Peak-to-peak N1 amplitudes were (on average) 13.4-fold larger than the corresponding amplitudes of peak I of the surface-recorded brainstem auditory evoked potential (BAEP) recordings. During acoustic neuroma resection, ECoG and BAEP recordings changed relatively independently, which suggests multiple mechanisms and/or sites of injury to the cochlea or cochlear nerve. However, once they had become manifest, none of the observed changes exhibited a tendency to return to preoperative patterns. Hearing was preserved postoperatively in only two of seven patients, one of whom could not be monitored due to technical difficulty. Transtragal, transtympanic electrode placement provided a rapid, stable, and safe method of obtaining intraoperative ECoG recordings. Although combined intraoperative monitoring of ECoG and BAEP responses appeared to provide more precise documentation of injury to the cochlea and/or cochlear nerve, it was probably not influential in preservation of hearing in this series.

High Frequency Jet Ventilation Prevents Aspiration during Cardiopulmonary Resuscitation

Ventilation is an integral part of cardiopulmonary resuscitation (CPR). Early intubation is recommended not only for the sake of better ventilation but also to prevent aspiration since aspiration is a common occurrence during CPR. It probably not infrequently contributes to an unfavorable outcome. Endotracheal intubation is sometimes very difficult especially under field conditions. Cricothyroid membrane puncture or transtracheal puncture with a 14g or 16g catheter needle enables high frequency jet ventilation (HFJV) and can often be performed more easily than intubation.

High Frequency Jet Ventilation Versus IPPV for CPR in Dogs

Investigation of High Frequency Jet Ventilation (HFJV) for cardiopulmonary resuscitation (CPR) was initiated to determine whether HFJV may be used as an alternative to conventional intermittent positive pressure ventilation (IPPV) and also to determine whether HFJV may be employed in CPR if cardiac arrest should occur during use of HFJV.The novel method of HFJV has several advantages over conventional ventilation, namely low airway pressure, no hemodynamic impairment and no need for muscle paralysis. Transtracheal HFJV offers in addition cricothyroid membrane puncture as a fast alternative to tracheal intubation in cases of difficult airway control. It is able to prevent aspiration, and allows direct intrapulmonary drug administration.

Intrapulmonary Drug Administration during High Frequency Jet Ventilation

It has previously been demonstrated that high frequency jet ventilation, via transtracheal cricothyroid membrane puncture, can maintain good gas exchange even during cardiopulmonary resuscitation. When the upper airways were filled with fluid, aspiration could be prevented without a cuffed endotracheal tube when respiratory rates of 100/min or higher and an inspiratory time of at least 50% were used. We have also shown that cricothyroid membrane puncture is relatively easy to perform and produces less tracheal damage than a cuffed endotracheal tube.In one of our studies, cardio-green dye was mixed into the jet using a Y-connector on the proximal end of the angiocath cannula (Figure 1). In two dogs, the distribution of the dye in the lungs was investigated. It was found that nebulized dye was transported by the jet stream to the most distant bronchi which could be observed. On subsequent autopsy, the dye was found in the most peripheral airways.

Experimental production of pulmonary hypoplasia following amniocentesis and oligohydramnios.

We have analyzed the impact of a single needle puncture of the fetal rat membranes on day 15 of gestation on growth and development at term (day 21). Untouched littermate fetuses served as controls. The procedure led to persistent oligohydramnios. The experimental fetuses weighed less, 94% of the weight of controls, P less than 0.01. Both lungs and liver weighed significantly less, 72% (P less than 0.01) and 89% (P less than 0.03) of controls respectively and there was no effect on brain weight. When the values were expressed as organ/body weight ratio only the lung/body weight ratio was significantly lower, 77% of controls, P less than 0.01. DNA per lung was less, 83%, as was lung DNA per gram of fetal weight, 89%, and the lung protein/DNA ratio was lower, 79%, indicating lung hypoplasia and hypotrophy (all three P values less than 0.01). There were no significant differences in either liver or brain biochemical analysis. We conclude that pulmonary hypoplasia associated with oligohydroamnios in the rat is a suitable animal model of the human condition.

Translaryngeal absorption of lidocaine

Our study was conducted to determine the appropriate dose of lidocaine using the larynx and to characterize the onset and duration of therapeutic serum levels. A mean dose of 5.67 +/- 1.2 mg/kg was topically administered to the subglottic region of seven comatose patients through a cricothyroid membrane puncture. Serial serum lidocaine levels showed that therapeutic levels were attained in 5.1 +/- 3.2 minutes with a mean maximum level of 3.16 +/- 1.52 micrograms/ml and were reached at 18.71 +/- 8.71 minutes. Therapeutic serum levels were maintained for 68.4 +/- 29.7 minutes. Absorption of lidocaine via the airway yields sustained levels, although the duration of onset is less rapid and the maximum serum level is lower than that from an equivalent intravenous dose.

A piezoelectric device to aid penetration of small nerve fibers with microelectrodes

A small piezoelectric device for cell penetration is described. It retracts the micropipette slowly by electrostriction, and pushes it very fast (< 5 μsec) forward by short-circuiting the transducer. The design, operation circuit, and performance under test conditions are described. Penetration examples from small nerve fibers (< 5 μm) show that membrane puncture occurs only with the fast forward push. Cells are not noticeably damaged, even if the device is repeatedly operated after cell penetration.

Acute otitis media in children eight years old and older: A reappraisal of the role of Hemophilus influenzae

The bacteriology of acute otitis media in 18 children eight to 17 years of age was investigated through the use of culture of middle ear exudate obtained by tympanic membrane puncture. Equal numbers of children had either Hemophilus influenzae (six) or Streptococcus pneumoniae (six) in the middle ear exudate. Acute otitis media in children through adolescence should be treated with antibiotics known to be effective against H. influenzae.

918 SELECTIVE PARENCHYMAL GROWTH RETARDATION IN EXPERIMENTAL OLIGOHYDRAMNIOS

Puncture of the fetal membranes was performed on rat fetuses during the last third of gestation; the puncture was considered adequate when withdrawal of the needle was followed by continued leakage of amniotic fluid. All animals (n=54) were allowed to develop until term and were delivered abdominally, the littermates serving as controls (n=84). Weights and measurements of the fetus, placenta and various organs were recorded. Total lung DNA, RNA and protein were determined in 14 treated and control animals. The length of the umbilical cord was markedly reduced in the experimental group, (p<0.001). Lung weight and lung/body ratio were lower in he treated animals, (P<0.001). Total lung DNA was significantly less in the treated animals, confirming lung hypoplasia. RNA/DNA and protein/DNA ratios were not affected, indicating that cell size remained constant. The pathogenetic mechanism leading to hypoplasia appears different from that observed in models of utero-placental insufficiency since the brain/liver ratio was not affected. The same pattern of selective parenchymal growth retardation was noted in 7 newborn infants with documented oligohydramnios. In addition, congenital deformities resembling those seen in infants born after prolonged oligohydramnios were noted in the treated animals. This model should prove useful to clarify the pathogenesis of the oligohydramnios syndrome and lung hypoplasia, and to study the kinetics of lung catch-up growth.

Perihatching behaviour patterns of chick embryos ( Gallus domesticus)

Perihatching behaviour is analysed in terms of changes in the frequency of performance of three behaviours; vocalization, eyelid raising and head raising. Three distinct phases of development are described. Though 79 per cent of the animals displaying phase 1 behaviour do enter phases 2 and 3 of development, we could not predict from phase 1 performance patterns the time at which phase 2 would occur. The manipulations of chorio-allantoic membrane puncture at 432 and 451 hr of incubation, and removal of the chorio-allantoic and amniotic fluids at 451 hr of incubation afforded a greater predictability of hatching times than did the control groups. None of the above experimental groups however differed from one another in their distributions of hatching times. As a result of these experiments we postulate that at a given stage of development, chicks become responsive to some change in function in the chorio-allantoic membrane. A process then is instituted within the animal that continues for a minimum time before hatching can occur. We then suggest possible sources of the chorio-allantoic stimulus to which the animals respond, and sources of the response processes themselves that finally lead to hatching. Finally we suggest experimental approaches that can lead to the identification of these stimuli and response processes.

Cricothyroid membrane puncture with special cannula.

Cricothyroid membrane puncture with special cannula.

Emergency airway--a plan of action.

An orderly plan of action for correcting the occasional critical airway obstruction is essential; otherwise irreversible brain damage and even death may occur before effective action is taken. A safe, simple, and effective plan has been developed for restoring ventilation in critical airway emergencies. The four basic steps are: recognition of obstruction; nonsurgical maneuvers to relieve obstruction; mouth-to-mouth breathing to overcome obstruction or to diagnose persistent obstruction; and establishment of emergency surgical airway. Cricothyroid membrane puncture is the safest and simplest method for establishing a satisfactory airway under adverse and serious conditions.