Practical venipuncture techniques for the ferret

As the number of ferrets (Mustela putorius furo) used in research and kept as pets continues to rise, so does the need for simple, humane research and diagnostic techniques. We have developed venipuncture methods for the ferret utilizing the jugular and cephalic veins. Using these methods it is possible to repeatedly sample moderate volumes of blood and to perform intravenous injections in both conscious and sedated ferrets.

Infection of pulmonary artery catheters. Epidemiologic characteristics and multivariate analysis of risk factors

Sixty-nine consecutive pulmonary artery catheters (PACs) were prospectively studied in a medical-surgical intensive care unit. Fifteen (21.7 percent) and two (2.9 percent) of the PACs were associated with colonization and bacteremia, respectively. These data represent an incidence of 4.98 and 0.66 episodes per 100 catheterization-days, respectively. Coagulase-negative staphylococci were the most common isolates. The source of the colonizing microorganism was the skin in 56 percent of cases, hubs in 28 percent, and unknown in 16 percent. From multivariate analysis, only more than 5 days of catheterization was significantly associated with a greater risk of colonization. Antimicrobial use was associated with negative cultures. The most useful method to diagnose colonization was the examination of both tip and intradermal segments. In addition, we suggest associate hub cultures when catheter-related bacteremia is suspected. These data may be useful in improving efficacy in the diagnosis and prevention of PAC-related infection.

Comparison of PT and aPTT values drawn by venipuncture and arterial line using three discard volumes

BACKGROUND

Blood samples obtained through heparinized arterial catheters are used routinely for a variety of laboratory tests. Accuracy of coagulation studies performed from samples obtained in this fashion continues to be questioned, particularly in regard to the minimum discard volume necessary to clear the catheter of heparinized solution.

OBJECTIVE

To examine differences between prothrombin time and activated partial thromboplastin time values obtained from blood drawn by venipuncture and from an indwelling intra-arterial line using three discard volumes.

METHODS

Prothrombin time and activated partial thromboplastin time samples were drawn by venipuncture from 41 critically ill adult patients. Simultaneously, three consecutive blood samples of 2.3 mL were drawn from the arterial line after an initial discard volume of 3 mL (discard volumes of 3.0, 5.3 and 7.6 mL).

RESULTS

Significant differences were found between arterial and venous prothrombin time values for the 3-mL discard volume group, as well as between arterial and venous activated partial thromboplastin time values for all three discard volume groups (paired t-test, Bonferroni correction).

CONCLUSION

We recommend that when drawing prothrombin time and activated partial thromboplastin time samples from an arterial line, a 5.3-mL discard volume be used.

[Preoperative autologous blood collection under erythropoietin stimulation. Preliminary results in patient selection, erythropoietin dosage and administration]

In a randomised study we have evaluated the influence of erythropoietin (EPO) on the yield of autologous blood in elective surgery (total hip replacement). The study was performed placebo controlled in 82 patients: 25 patients received 200 IE EPO/kg 2 x/week i.v. over 3 weeks (group C), 30 patients 100 IE EPO in the same schedule (group B), and 27 patients received placebo (group A). All patients were treated with 3 x 250 mg Fe-sulfate p.o. during the study time. The number of collected blood conserves was not significantly different in these groups (5.4 in group C, 5.06 in group B, 4.8 in group A), but there was a significant difference in patients with a diminished hemoglobin (Hb < 14 g/dl): 5.2 in group C, 4.9 in group B, and 3.6 in group A. Patients with a normal hemoglobin level showed a significantly higher preoperative hemoglobin in group C against group A. We conclude that the application of EPO is suggestive in patients with a diminished hemoglobin, but also in patients with normal hemoglobin the blood picture at the time of surgery is higher in EPO treated patients.

An examination of needlestick injury rates, hepatitis B vaccination uptake and instruction on ‘sharps’ technique among medical students

A 12-question survey designed to examine venepuncture techniques and instruction and uptake of hepatitis B vaccination was completed by 172 of the 275 medical students to whom it was distributed (a response rate of 62.5%). Seventy-five injuries were reported, at an average of 0.3 per student per year. Of the respondents, 63% resheathed needles after use, a practice frequently cited as a cause of needlestick injury. However, in this sample resheathing was not significantly associated with a higher or lower injury rate (chi 2 = 2.07, P > 0.1). Of the respondents from the most recent intake, only 20 out of 57 had completed a course of hepatitis B vaccinations prior to the commencement of venepuncture duties. There was almost universal ignorance concerning the correct course of action following 'sharps' injury. Recommendations are made concerning hepatitis B vaccination and teaching strategies for medical students.

Infectious and mechanical complications of central venous catheters placed by percutaneous venipuncture and over guidewires

OBJECTIVE

To compare the frequency of infectious and mechanical complications of central venous and pulmonary artery catheters placed by initial venipuncture vs. over a guidewire at existing sites.

HYPOTHESIS

Exchange of central venous catheters and pulmonary artery catheters over a guidewire as opposed to fresh venipuncture reduces mechanical complications without increasing risk of infection.

DESIGN

Chart audit.

PATIENTS

Medical, surgical, and coronary ICU patients requiring invasive monitoring or central venous access.

INTERVENTIONS

Patients requiring prolonged catheterization underwent periodic exchange of catheters over a guidewire. Rates of catheter-related infections and mechanical complications were determined for central venous catheters placed by initial venipuncture and those catheters placed by guidewire exchange.

MEASUREMENTS AND MAIN RESULTS

Over a 12-month period, 939 catheters were inserted in 454 patients. Of these 939 catheters, 534 were placed by guidewire exchange. Use of a guidewire was associated with a decreased frequency of pneumothorax and hemothorax compared with initial venipuncture (0/405 [0%] vs. 7/534 [1.3%], respectively; p < .05) but not with increased risk of infection (9/405 [2.2%] vs. 14/534 [2.6%], respectively; NS). Guidewire-facilitated replacement of multiple consecutive catheters at the same site did not increase the risk of catheter-related infection. Catheters placed via internal jugular veins were more likely to become infected than catheters placed via subclavian veins (17/477 [3.6%] vs. 3/430 [0.7%], respectively; p < .01).

CONCLUSIONS

When prolonged central venous or pulmonary artery catheterization is necessary, periodic catheter replacement over a guidewire is associated with fewer mechanical complications than initial venipuncture. Periodic catheter replacement over a guidewire is also associated with no increase in risk of infection.

Children's venipuncture pain: influence of technical factors

Several aspects of venipuncture technique were evaluated to assess their relationship to reported pain. Subjects were 514 children aged 5-17 who had venipuncture performed by a technician in a hospital outpatient laboratory. A research assistant timed the duration of venipuncture and then obtained visual analogue pain scores from the children following venipuncture. Blood volume obtained from venipuncture was also measured. The technician who performed the procedure, amount of blood drawn, and time required to complete the venipuncture did not contribute to the prediction of children's pain. Age and anxiety, which were treated as covariates, were significant predictors of pain. The distribution of pain experienced by children was positively skewed and about one-third of children were above the mean pain score. From the results of this study, venipuncture pain can be recommended for the study of issues in children's pain. Further, the findings recommend the development and utilization of interventions to reduce children's venipuncture pain.

Use of leeches in a case of severe periorbital haematoma

A case of severe penetrating eye injury and resulting periorbital haematoma is described. Leeches applied to the eyelids enabled examination of the globe to be carried out and improved the surgical approach. Leeches provide a speedy and efficient means of reducing a periorbital haematoma.

Phlebotomy in inoculation risk patients: a questionnaire survey of knowledge and practices of hospital doctors in Liverpool

To assess the knowledge of hospital doctors about patients at increased risk of infection with human immunodeficiency virus (HIV) or hepatitis B virus, and the precautions they took during phlebotomy in such patients, an anonymous postal questionnaire was sent to all 307 hospital doctors working at two District General Hospitals in Liverpool, UK. Two hundred and thirty-eight (77.5%) of the questionnaires were returned. More than 90% of respondents considered a history of male homosexuality, intravenous drug abuse, prostitution or a child of a prostitute to indicate an inoculation risk. There was uncertainty about a previous prison sentence in the 1980s, residence in a home for the mentally handicapped, previous residence in the tropics and hospital treatment in the tropics. Thirty-eight percent of doctors would never enquire about sexual preference, 54.1% about a previous prison sentence and 15.7% about intravenous drug abuse in their clinical history. Although 97.4% of doctors would sometimes or always wear gloves during phlebotomy of an inoculation risk patient, 25.5% always resheathed the needle after phlebotomy and 20.8% would never take the sharps box to the patient. More effort is required to identify accurately inoculation risk patients and greater care is needed in phlebotomy techniques.

US-guided venipuncture for venography in the edematous leg

A technique for sonographic-guided venipuncture was developed especially for venography made difficult by gross leg edema. Five patients were evaluated in whom venography had been attempted but was initially unsuccessful because of difficult venous access. All five underwent successful venipuncture after sonographic localization of a vein. Ultrasound-guided venipuncture is simple and useful when venous access by palpation is difficult.

[Venous access in emergencies]

A reliable venous access is necessary for pharmacological treatment in case of emergency. The indication, pharmacology of the drug or the infusion and the expected period of intravascular penetration are decisive for choosing the location for the punction. As a principle all visible veins could be punctured and used for injection; all but varicose or thrombotic veins. Primarily the distal veins of the extremities should be punctured with a venous catheter and only in case of failing one should try more proximal. In case of accidently artery punction the cannula has to be left in place and a pharmacological therapy has to be started immediately. If a peripheral venous punction is impossible the central venous catheter is an alternative even of its remarkable higher rate of complications. Three ways of access to the central veins can bei recommended: the jugular interna vein, the subclavian vein and the basilic vein. Advantages as well as disadvantages are elaborated. As a result the physician in cases of emergency should use the technique of venous punction he is used too in a routine situation.

Pharmacokinetics and pharmacodynamics of atracurium obtained with arterial and venous blood samples

To determine the influence of sampling site on atracurium pharmacokinetic-pharmacodynamic relationships, blood was drawn simultaneously from the radial artery and peripheral vein during a 20-minute period after injection of atracurium, 0.2 mg/kg, in eight patients. Atracurium and laudanosine concentrations were measured by HPLC. Neuromuscular blockade was measured at the adductor pollicis, after stimulation of the ulnar nerve. Venous levels were lower than corresponding arterial values for up to 20 minutes, and this difference was marked for the early samples. Neuromuscular blockade was maximum after 5 to 7 minutes, much later than the peak venous concentration (1 to 3 minutes). Nonparametric analysis yielded (mean +/- SEM) a rate constant, concentration for 50% blockade, and slope of the effect-concentration relationship of 0.092 +/- 0.01 min-1, 379 +/- 27 ng/ml, and 7.3 +/- 1.67, respectively, when based on arterial samples. The values were statistically different (0.135 +/- 0.011 min-1, 235 +/- 42 ng/ml, and 3.41 +/- 0.37, respectively) when venous levels were used (p less than 0.05). It is concluded that forearm venous levels do not correspond to adductor pollicis neuromuscular blockade and the kinetics and kinetic-dynamic relationship for atracurium are heavily dependent on sampling site.

Physiological response to phlebotomies for autologous transfusion at elective hip-joint surgery

In order to study the physiological response to phlebotomies for autotransfusion, an autotransfusion program was designed for 10 patients undergoing hip-joint replacement surgery for arthrosis. 4 phlebotomies of 450 ml each were performed within 12 days. Blood samples were taken immediately before phlebotomy for blood hemoglobin (Hb), serum erythropoietin (Epo), reticulocyte count (ret) and erythrocyte 2,3-diphosphoglycerate (DPG). All 4 phlebotomies could be performed in 9/10 patients, and only 1 patient had significant symptoms (fatigue). The operation was performed 2 weeks after the last phlebotomy. None of the patients had recovered the initial Hb level at operation (24.8 +/- 9 per liter lower than initially), and they were all even more anemic after the operation (36.8 +/- 16.9 g/l lower than initially). Serum Epo increased from 13.6 +/- 7.2 IU to 30.6 +/- 12.2 (SD) IU per liter, and reticulocyte counts increased to a maximum of 3.68 +/- 1.69%. DPG increased in all patients except the one who had significant fatigue. It is concluded that the patients tolerated the phlebotomy program well but that a significant anemia developed. The compensatory increase in erythropoietin and reticulocyte count, adequate for this degree of anemia, was small compared to the increase seen at more severe anemia, indicating that there may be a role for pharmacological stimulation of erythropoiesis in blood predeposit programs.

The use of medicinal leeches in microsurgery

Medicinal leeches have been used to treat a variety of ailments for thousands of years. During the past decade the leech has become valuable for salvaging surgically uncorrectable venous insufficiency which is occasionally encountered after microsurgical free flap and replantation procedures. Leech anatomy and physiology are reviewed. Indications and the technique for application of medicinal leeches is discussed, as well as potential complications of leeching.

[Use of iontophoretic anesthesia for venipuncture]

The usefulness of iontophoretic anesthesia with 10% lidocaine was evaluated on insertion of venous catheters on 38 blood donors in a blood bank and on 41 patients in a hospital, after the arm was charged for 3, 6 or 9 minutes with 1.5 mA of electricity by using a hand-made iontophoretic anesthesia apparatus. In the blood donor group, the pain-relief effect was observed in 25% of donors after charging for 3 min; in 68% after 6 min; and in 93% after 9 min. In the patient group, anesthesia was observed in 14% of patients after 6 min and in 65% after 9 min though the effect was observed in 81% after 6 min and in 65% after 9 min. But only 45-48% of subjects in both groups requested the anesthesia after charging for either 6 or 9 min. This suggests that the duration for 9 min was not liked by the subject despite the pain on insertion. Therefore it is concluded that the charging duration of the iontophoresis must be shorter for this method to become useful as local anesthesia.

[The significance of preoperative autologous blood donation in general surgery]

In the surgical department of a county hospital, the total number of heterologous blood transfusions has been reduced by transfusing autologous blood units in elective surgery. Orthopedic, urologic, vascular and plastic surgery qualify mainly for autologous blood transfusion.