Room Temperature Normal Saline Research Articles

The influence of needleless connectors and inserted catheters on flow rates through vascular introducer sheaths.

SummaryA vascular introducer sheath is often used for rapid volume replacement. However, common manipulations such as the addition of needleless connectors to infusion ports and the insertion of catheters or other devices through the introducer sheath may impede flow. In this study we utilised a rapid infuser to deliver room-temperature normal saline through two introducer sheath configurations with and without the addition of needleless connectors and the placement of catheters through the introducer sheaths. The maximal flow rate delivered by the rapid infuser was 1000 mL/min, which was observed with both introducer sheath sizes tested without additional resistive elements. However, with the addition of a needleless connector, flow rates through the introducer sheaths were substantially lower (64 (standard deviation (SD) 6) mL/min and 61 (SD 7) mL/min for the 8.5 Fr and 9 Fr introducers, respectively). Flow rates were also reduced when catheters were placed within the sheaths (298 (SD 9) mL/min with the 7 Fr catheter and 74 (SD 9) mL/min with the 8 Fr catheter placed in an 8.5 Fr sheath; 649 (SD 6) mL/min with the 7 Fr catheter and 356 (SD 14) mL/min with the 8 Fr catheter placed in the 9 Fr sheath). These findings indicated that both needleless connectors and the placement of catheters through vascular introducer sheaths substantially reduced potential flow rates. Even 'large' vascular introducer sheaths capable of delivering high flow rates could be rendered minimally effective for rapid fluid administration when used in this way. Clinicians should consider these impediments to flow when rapid fluid administration is required, and obtain alternative vascular access if necessary.

Spontaneous Intrinsic Hepatic Vascular Oscillations

The liver is well known as a large blood reservoir that can shift both stressed and unstressed volumes passively and actively in response to changes in portal venous and hepatic arterial blood flow, inflow and outflow blood pressures, autonomic nervous stimulation, and various humoral and pathophysiological factors. Not described is the characteristic of the liver to intrinsically modulate its own vascular pressure and volume independent of extrinsic factors.METHODSMale Holtzman rats (n=5) were anesthetized (30 mg/kg sodium pentobarbital, i.p.) and heparinized (500 IU/kg, i.v.), the portal vein and inferior vena cava were isolated and cannulated, the liver was flushed with room temperature normal saline, and the liver quickly removed. Each liver was mounted on a scale in a 37°C chamber (95% O2‐5% CO2) and pump‐perfused (Masterflex) with donor rat blood at a baseline 1 ml/min/g of tissue. The hepatic venous pressure (Phv) was regulated by raising and lowering the blood reservoir. At each Time (see table), portal venous oscillations were counted over 3 to 12 min and the portal venous wavelet pulse pressures (Ppv) were measured over at least 40 wavelets.RESULTSThe portal venous pressures of 3 of the 5 livers oscillated spontaneously. One lasted only 26 min while the others went on for over 200 min. The characteristics of these oscillations varied widely from animal to animal, but there usually was an irregular cycle length and uneven wavelet magnitude that tended to degrade to a diminished size with higher frequency over time (see Figure 1). Rat Time (Min) Maneuver Mean Portal Venous Pulse Pressure (mmHg) Frequency (Wavelets/Min) Frequency (Hz) Cycle Length (Sec) 1 0 Baseline 2.1 ± 0.9 (SD) 8.08 0.135 7.42 95 Baseline 1.5 ± 0.8 16.10 0.268 3.73 107 Change Phv 2.5 ± 1.3 17.00 0.283 3.53 (0 to 10 mmHg) (P<0.001 vs. 95 Min Baseline) 180 Baseline 1.3 ± 0.5 18.67 0.311 3.21 2 0 Baseline 0.8 ± 0.4 14.42 0.240 4.16 60 Baseline 0.4 ± 0.3 20.00 0.333 3.00 130 Baseline 0.4 ± 0.2 23.78 0.396 2.52 3 0 Baseline 0.6 ± 0.3 8.67 0.144 6.92 CONCLUSIONSThis is a very limited data set, providing more questions than answers, but it opens a curiosity to much more investigation to understand the function of these intrinsic hepatic vascular oscillations under normal, reflex, and pathophysiological conditions.

A Prospective, Randomized, Double-Masked Controlled Clinical Trial of Postoperative Pain after Transepithelial Photorefractive Keratectomy (Trans-PRK).

Objective To determine the effect of aqua astricta flushing on ocular pain after Trans-PRK. Method Three hundred and seventy eyes from 185 myopic patients were prospectively recruited for the study. Patients underwent Trans-PRK in both eyes. Postsurgically, one eye from each patient was randomly assigned to the trial group, and refrigerated normal saline was used to rinse the eye. The contralateral eye was assigned to the control group, and room temperature normal saline was used to rinse the eye. The primary target was postoperative pain experienced at the end of surgery and on the first, second, and third days after surgery. Secondary targets were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refractive spherical equivalent (MRSE), and haze. Results Patient pain scores gradually decreased over time, and the difference between time points of all patients was statistically significant (P < 0.05). Postoperative pain was not affected by patient cooperation, education level, refractive SE, optical zone, corneal bed, or cutting depth (P > 0.05). The level of pain at the end of surgery was affected by intraoperative rinsing. The pain level of the aqua astricta group was lower than the normal temperature saline group, and the difference was statistically significant (P < 0.01). Pain scores on the first, second, and third days after surgery were not affected by intraoperative rinse (P > 0.05). Conclusion Trans-PRK is an important means of corneal refractive surgery, but postoperative pain remains unavoidable. These findings suggest that the use of cooled fluid during surgery reduces postoperative pain at the end of surgery.

Assessment of Pain at Different Steps of Diagnostic Hysteroscopy Using Room Temperature Normal Saline versus Warmed Normal Saline Solution as Distension Medium: A Randomized Controlled Trial.

Objectives:Compare pain intensity at entry into the cervical os, during uterine distension and 15 min after the procedure, in patients undergoing diagnostic hysteroscopy with room temperature normal saline versus that with saline warmed to 38–40°C, using visual analog scale (VAS) score. Furthermore, compare the time taken and failed procedures between them.Materials and Methods:This was a randomized controlled, prospective study conducted at a Tertiary Care Center on 100 patients planned for diagnostic hysteroscopy with a 4 mm 30° hysteroscope using vaginoscopy technique. They were divided into two groups of 50 each, with control undergoing the procedure using normal saline at room temperature and the test with saline warmed to 38–40°C as distension medium. Primary outcomes were VAS at the point of entry into the internal os (T0), 1 min later (T1), and 15 min after the procedure (T15). Secondary outcomes were procedural acceptance, time taken, and failed procedures.Results:The mean VAS in the control group at T0, T1, T15 was 3.31 (1.461;‒0.870–0.245), 2.46 (1.398;‒0.539–0.498), 0.75 (0.911;‒0.379–0.338), respectively, as compared to the test group of 3.62 (1.282;‒0.870–0.245), 2.48 (1.148;‒0.540–0.498), 0.77 (0.911;‒0.379–0.379), respectively. About 73.5% of controls and 68.8% in the test group were willing to undergo the procedure again. About 93.9% of controls would recommend it further as against 93.8% among the test controls. The time taken and number of failed procedures showed no statistical difference.Conclusion:No significant difference was noted in terms of outcomes measured by warming the distension medium.

Effect of intra-canal cryotherapy on post-endodontic pain in single-visit RCT: A randomized controlled trial

AimTo evaluate the effect of cold and room-temperature normal saline as a final irrigation on post-endodontic pain and to compare the post-endodontic pain level between the different protocols. Materials and methodsA randomized controlled trial was conducted on 105 patients who underwent RCT and were distributed blindly and randomly into three equal groups (n = 35): Group 1, Cryotherapy group; Group 2, Room- temperature normal saline group; and Group 3, Control group. The patients were asked to fill out the VAS questionnaire and register their post-endodontic pain at 6, 24, and 48 h. One-way analysis of variance (ANOVA) and was used to determine statistical difference (α = 0.05) among the groups. Tuckey’s test was used to calculate P-value (α = 0.05) between two each group. ResultsThe highest post-endodontic pain was in Group 3. There was no significance difference between Group 1 and Group 2. ConclusionFinal flushing of the canal with saline either cold or at room temperature was effective for post-endodontic pain control. This can be promising as an essential step in endodontic treatment to reduce post-endodontic pain. The room-temperature saline as final irrigation showed comparable results to intra-canal cryotherapy.

Pain assessment during outpatient hysteroscopy using room temperature versus warm normal saline solution as a distention medium – a prospective randomized study

To assess the efficacy of warm normal saline distention solution versus a standard, room-temperature normal saline as distention medium for pain relief during outpatient hysteroscopy. A prospective randomized case-placebo controlled study was conducted in tertiary care centre - Central Clinical Hospital of Ministry of Interior and Administration. Study group consisted of 100 women referred for outpatient hysteroscopy between January 2015 and July 2015. Every patient, who was referred for an office hysteroscopy, was offered to participate in the study to receive a sterile, 0.9% normal saline warmed up to 36⁰C as distention medium. Control group were women receiving sterile, room temperature of 25⁰C, 0.9% normal saline solution as a distention medium. No pre-medication nor analgesia were used. A visual analogue scale (VAS) was used for one-dimensional pain assessment. Women were asked to mark a VAS score before, during, and five and 15 minutes following the procedure. Median VAS scores during and directly after the anaesthesia-free hysteroscopy were no different between two groups. (p = 0.554 and p = 0.121, respectively). There were also no differences in the procedure time between groups (p = 0.845). Warm normal saline distention solution does not reduce the pain during and at the end of the outpatient hysteroscopy. The effect does not depend on the age of women, menopausal status, parity or type of outpatient hysteroscopy (operative or diagnostic).

Effect of cortical cooling on interictal epileptiform activities

Objective To determine if applying chilled solution to exposed cerebral cortex can reduce interictal epileptiform activities in patients during surgery. Methods Electrocorticography was used to record the epileptiform activity of 12 patients (ages 18–53) undergoing cortical mapping and resection surgery. Interictal spikes were counted at baseline and compared with spikes after applying room temperature and chilled Lactated Ringer's or normal saline solution. Results Cortical irrigation with 150-cm 3, chilled (4 °C) normal saline solution reduced the mean number of interictal spikes from 11.46 to 4.87 spikes per minute ( p = 0.04). There was no significant reduction in the epileptic spike frequency when room temperature normal saline was used. Conclusion The application of chilled solution directly to the cortex can reduce interictal epileptiform activities, suggesting that seizure potential can be suppressed to avoid evoked seizures during intraoperative surgery.

A prospective, randomized study of cryotherapy during administration of high-dose melphalan to decrease the severity and duration of oral mucositis in patients with multiple myeloma undergoing autologous peripheral blood stem cell transplantation

Forty patients with multiple myeloma scheduled to receive melphalan 200 mg/m(2) followed by autologous stem cell transplantation were randomly assigned to receive oral cryotherapy or room temperature normal saline rinses 30 min before and for 6 h after high-dose therapy. Patients were evaluated for the development of mucositis using the National Cancer Institute grading system as well as evaluation of secondary measures such as days of total parenteral nutrition (TPN), narcotic use, hospitalization, weight loss and resumption of oral caloric intake for 28 days after transplant. Patients self-scored their pain, swallowing, drinking, eating, sleeping and taste alterations for 28 days. The primary end point of this trial was the incidence of grades 3-4 mucositis. Compared to the normal saline group, patients using cryotherapy experienced less grade 3-4 mucositis, 14 vs 74%, P=0.0005. Patients receiving cryotherapy also had statistically lower uses of narcotics and TPN, although there were no differences in length of hospitalization or weight loss. Patient-reported pain was significantly lower and activities were significantly better in the cryotherapy group.

Comparison of irrigated electrode designs for radiofrequency ablation of myocardium.

Previous reports have demonstrated that radiofrequency energy delivered to myocardium via an irrigated electrode results in a more voluminous ablation lesion than a non-irrigated electrode. Different irrigated electrode designs have been utilized; no direct comparisons have been reported. To compare different irrigated electrode designs. Three irrigation electrode designs were compared to a control (non-irrigated electrode) group: 1. internal; 2. showerhead; 3. sheath. For each electrode, prior to ablation Doppler echocardiographic assessment of the irrigant flow along the electrode outer surface was performed. Ablation was performed in vitro utilizing a whole blood-superfused system. Electrode, electrode-endocardial interface, and intramyocardial temperatures were assessed, as were ablation circuit impedance, total delivered energy, and lesion and electrode morphology. Room temperature normal saline was utilized as the irrigating fluid, delivered at 20 cc/min. Electrode-endocardial interfacial blood flow was assessed at rates of 0 and 0.26 m/s. Irrigant was contained within the internal electrode design and therefore the electrode outer surface manifested no significant flow during irrigation. Irrigant spread primarily radially away from the showerhead electrode design, yielding relatively high electrode outer surface flow at the irrigation holes, but low elsewhere. Irrigant traveled in parallel to and enveloped the electrode outer surface of the sheath electrode design, yielding relatively moderate but uniform flow. Ablation via each of the irrigated electrodes yielded greater ablation energy deposition and larger lesion dimensions than the non-irrigated electrode. Irrigation did not necessarily prevent interfacial boiling, which could occur during uninterrupted radiofrequency energy deposition and lesion growth. The results for the 3 irrigation designs were incongruent. The duration of radiofrequency energy application via the internal electrode design was significantly shorter than the other designs, curtailed by impedance rise. This yielded the smallest total radiofrequency energy deposition and smallest ablation lesion volume. Relative to this, duration using the showerhead design was significantly longer, associated with greater total energy deposition and larger lesion volume. The sheath design permitted the longest duration, associated with the largest total energy deposition and lesion volume. Although each of the irrigated electrode designs yielded larger lesions than the non-irrigated electrode, they were not comparable. Ablation duration and lesion size were directly correlated with flow along the electrode outer surface.

Endotracheal Suctioning of the Newborn Piglet

Suctioning of the endotracheal tube (ET) is a necessary procedure to remove secretions and debris that naturally accumulate over time. Endotracheal suctioning protocols often call for the injection of small (< or = 0.5 ml) amounts of normal saline down the ET tube just prior to commencing the suctioning procedure. Comparisons of room temperature and body temperature normal saline injectate protocols and their impact on arterial blood gas parameters and heart rate alterations prior to, during, and following the endotracheal suctioning procedure were conducted. Eleven newborn Yorkshire piglets less than 24 hours of age were randomly exposed to both the room temperature (RT) and body temperature (BT) normal saline suctioning protocols. The analysis and interpretation of the results revealed that the RT normal saline injectate caused a greater decline in heart rate and greater alterations in arterial blood gas parameters than did the BT normal saline injectate.

Amnioinfusion

Amnioinfusion is a commonly practiced technique used for intrapartum improvement of the fetal condition. Room temperature normal saline (0.9 per cent) infused through an intrauterine pressure catheter has been used to alleviate variable decelerations, dilute thick meconium, and improve the intrauterine environment. Randomized studies comparing amnioinfusion to no therapy have shown that amnioinfusion is associated with lower cesarean delivery rates, decreased numbers of operative deliveries, and improved umbilical artery and venous blood gas values. Amnioinfusion also has been suggested as means to instill antibiotics into an infected uterine cavity, or the uterine cavity of a woman with preterm premature rupture of the membranes. Transabdominal amnioinfusion may be used to improved prenatal ultrasound evaluation in pregnancies associated with oligohydramnios. Complications of amnioinfusion include umbilical cord prolapse, uterine overdistention, fetal bradycardia, and one report of possible amniotic fluid embolism. Overall, amnioinfusion seems to be a safe and effective technique to improve the intrauterine milieu.

Validation of bedside measurements of absolute human renal blood flow by a continuous thermodilution technique.

There is a clinical need for a system that would allow rapid assessment of renal blood flow in patients with oliguric circulatory shock. A local, continuous thermodilution technique for the measurement of renal venous blood flow, using readily available equipment, was developed. To test the hypothesis that this system would allow measurement of renal blood flow in clinical situations, we compared simultaneous measurements made by the continuous thermodilution technique with measurements of: a) absolute flow measured by volumetric collection in an in vitro flow model; b) renal arterial blood flow measured by electromagnetic flow probe under changing hemodynamic conditions in nine pigs; and c) calculated renal blood flow derived from a clearance technique in 16 patients after cardiac catheterization. The technique utilizes a short-duration, constant infusion of room temperature normal saline into the renal vein via a retrograde thermodilution catheter, with measurement of flow at a thermistor 1 cm back from the tip of the catheter. The method measured absolute blood flow in an in vitro model, with a correlation coefficient of .99 over blood flows ranging from 55 to 885 mL/min (r2 = .98). There was a .92 correlation coefficient with renal arterial blood flow measured by electromagnetic flow probe in a pig model (r2 = .85), and a .8 correlation with simultaneous measurement of renal blood flow by corrected iodohippurate clearance in humans (r2 = .64). Compared with electromagnetic flow probe measurements, a single measurement by the thermodilution technique would be accurate to within 80 mL/min in 95% of cases. Variability between individual measurements, expressed as the mean of the coefficient of variance for each patient, was 5.5 +/- 3.7%. This technique is simple to use, requires only venous cannulation and injection of normal saline, and allows rapidly repeatable, immediately available measurements of renal blood flow in a wide range of clinical circumstances, including severe renal impairment or anuria.