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Results for “needle bevel”

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7 recordsLinked to original sources

PubMed2026

Analyzing the impact of subcutaneous injection needle, device, and administration characteristics on patient pain, anxiety, and safety: a systematic literature review.

The subcutaneous (SC) injection route is a commonly used and important method for therapeutic delivery of a wide range of compounds, and needle characteristics have a significant influence on patient pain, anxiety, safety, and other outcomes. This systematic review evaluates the evidence on how needle-specific characteristics (e.g. gauge, length, tip design, wall thickness, concealment) and administration- or device-related factors can affect patient-reported outcomes and clinical safety indicators during and following SC injections. A comprehensive search was conducted in MEDLINE, PubMed, Embase, and ClinicalTrials.gov in June 2024. Studies were included if they assessed the relationship between needle characteristics and pain, anxiety, safety, or related outcomes in individuals receiving SC injections. A dual-reviewer process was used for study selection, data extraction, and quality assessment. Sixty-two studies met inclusion criteria. Evidence consistently indicated that thinner and shorter needles reduced patient-reported pain and adverse events such as bruising and bleeding. Tapered and lubricated needles, hidden or retractable needle designs, and use of autoinjectors or prefilled syringes also contributed to reduced anxiety and improved user satisfaction. However, results were heterogeneous, and many studies lacked sufficient power or single-variable evaluation of individual needle parameters, limiting definitive conclusions. Needle characteristics significantly influence patient experience and safety with SC delivery. While both clinical evidence and practical experience clearly favor thinner, shorter, and concealed needles, further standardized, high-quality research is needed to isolate and quantify the specific contributions of individual needle characteristics to optimize injection practices and support patient-centered device design.

Humans↗

PubMed1976

[Technic of pleural drainage (emergency pleural drainage)].

Pleural effusion is still often poorly drained: - incorrect introduction of the drain into the thorax, - ill-chosen position of the drain. Simple drainage, a minima, is considered here, that which requires no broad surgical incision and which, in cases of effusion with compression of the lung, is often a life saving procedure which any doctor should be able to carry out, especially if he deals with emergencies. The surest technique consists of placing a No. 30 drain, using a pleurotomy trocart, type Monod or Coquelet, under local anaesthesia. Introduction of the drain using a forceps after an incision with the scalpel blade is only justified if one has no trocart available. So-called disposable drains, mounted on a pointed bevelled needle prepared in advance, are practical but dangerous. Capillary drainages are methods of second choice. They are often excluded within short delays. The efficacy of the drainage depends on its position.

Anesthesia, Local↗

PubMedDate not supplied

Needle placement of myelography.

Proper placement of the entire bevel of the spinal needle within the subarachnoid space at myelography is necessary to prevent partial extra-arachnoid deposition of the contrast medium. A Cuatico aspiration cannula passed through the spinal needle at the time of spinal puncture serves to indicate the depth of the needle tip within the subarachnoid space.

Humans↗

PubMed1979

Penetration of disposable needles.

Six types of disposable injection needles were tested clinically for the intensity of pain caused, and their penetration capacity measured. The force nedded differed greatly with different needle types (120-250 mN). The design of the needle point was observed to have the greatest effect on the pentration capacity and the intensity of pain. To penetrate the tissue well, the needle point should have secondary bevels at the tip of the bevelled surface. The majority of the needles fulfilled this requirement.

Anesthesia, Dental↗

PubMed1979

Comparative evaluation of the 30-gauge dental needle.

The results of these tests demonstrated that aspiration through 30-gauge needles is possible, but since the flow rate is so diminished its clinical application is questionable. The evaluation of the physical properties of these needles proved them to be tough, durable, and suprisingly resistant to breakage, even under the most extreme manipulations and stresses. The insertion of needles into the plastic material clearly showed that the needles are always deflected toward the side without the bevel (the side that contains the point). Finally, the deposition patterns of the injected fluid in tissue have no relationship to the bevel.

Anesthesia, Dental↗

PubMed1979

Intramyocardial pH as an index of myocardial metabolism during cardiac surgery.

At present, a practical method for continuous monitoring of the state of tissue metabolism in the individual patient's heart during cardiac operations is not available. We have explored the use of miniature electrode measurements of myocardial interstitial pH to provide this monitoring capability, making comparisons with intracellular pH in left ventricular biopsy specimens and with tissue PCO2 measured by mass spectrometry. The electrode system consisted of a hydrogen ion-sensitive glass miniature electrode, housed in the beveled end of a 21 gauge (0.8 mm diameter) hypodermic needle, and a 2 mm diameter reference electrode, with an internal silver-silver chloride electrode coupled to tissue through a saline bridge (150 mM/L sodium chloride) saturated with silver chloride. Accuracy in blood at 37 degrees C was compared with conventional instrumentation (Radiometer BMS-3 MK-2 Blood Micro System) over a pH range of 7.4 to 6.4 with linear regression analysis (n = 26) revealing a high correlation (r = 0.997) and a mean difference in paired observations of only 0.01 +/- 0.004 (mean +/- SEM) pH units. In two groups of dogs on cardiopulmonary bypass, the pH needle and reference electrodes were inserted into the anterior wall of the left ventricle. Ischemic arrest of the heart at 37 degrees C was used to vary myocardial pH. In Group 1 (n = 8), intracellular pH was estimated from left ventricular biopsy specimens (400 mg each) taken over a microelectrode pH range of 7.37 to 6.37, snap frozen, and homogenized. In Group II (n = 6), tissue PCO2 in the anterior wall of the left ventricle was determined by mass spectrometry (sampling catheter 1.3 mm diameter). Miniaturized electrode (interstitial) pH exceeded biopsy (intracellular) pH under control conditions by 0.28 +/- 0.025 pH units (p less than 0.001), but below an electrode pH of 6.8 the results of the two techniques did not differ significantly. The tissue PCO2 rose from 69 +/- 2 mm Hg to a final plateau of 419 +/- 25 mm Hg, which was similar to the predicted value of 427 +/- 28 mm Hg calculated from the pH change (7.37 +/- 0.01 to 6.01 +/- 0.07), providing a further independent check on the pH electrode technique. These data indicate that our intramyocardial pH measurements do reflect intracellular metabolism during elective arrest of the heart and may have potential for clinical use.

Animals↗

PubMed1977

Management of lacerations and scars.

The purpose of this paper is to review and update the subject of management of scars and lacerations. The surgion who accepts responsibility for management of soft tissue injuries must be aware of fundamental surgical principles as well as detailed technique. Knowledge of basic anatomy and wound physiology is utilized and applied. Emphasis is placed on management of the total pateint. The specialist must accept the role of team captain and establish an order of priority in management and in wound analysis. By having a basic knowledge of wound healing and the lines of favorable contracture, one is better able to prognosticate the eventual healing of the wound after proper management. By being able to predict wound contracture and scar maturation, the patient can be better informed as to what to expect during the period of healing. With lacerations immediate repair is carried out. With scars there is more time for planning and photographic analysis. The contracting forces will by this time have identified themselves and the degree of release of the contracture or camouflage can be determined. Specific wound management emphasized meticulous closure in layers and the use of skin hooks with the interrupted subcuticular suture. Skin sutures with both the continuous subcuticular suture and interrupted sutures of monofilament nylon using the spring-loop are described. Emphasis is placed on the preparation of the skin margins with slight beveling of the skin edges and undermining with precise even thickness of the skin especially at the wound margin. For scar revisions a minimum time of six months should elapse, and 12-18 months is better. Complications include infection, hematoma, wound separation, and rejection of suture materials. Keloids are discussed briefly, particularly regarding the use of intralesional injection steroids. Broken line camouflage techniques are discussed with the regard to breaking up contracture without lengthening. Lengthening either existing or anticipated contractures is accomplished with Z-plasty. The multiple Z-plasty, W-plasty, and Zig-Zag plasty are aimed towards creating a less conspicuous scar and creating some diffusion of the forces of contracture. A technique for a "practical Z-plasty" is described. Both free grafts and skin flaps sometimes must be utilized to fill tissue defects and break up line of contracture. The materials presented and conclusions drawn are based on 25 years of active emergency room coverage and long term follow-up of treated patients. It is the responsibility of the physician to act within the first few hours and to take the time necessary for accurate approximation and realignment of both soft tissue and bone injuries. Minimal scarring depends on accurate approximation of skin margins without tension. The need for early meticulous repair, so that unsightly scars and disfigurements may be prevented, cannot be overemphasized.

Cicatrix↗