Effect of irrigation fluid temperature on core body temperature and inflammatory response during arthroscopic shoulder surgery

Making the Case for Hyperosmolar Saline Arthroscopic Irrigation Fluids: A Systematic Review of Basic Science, Translational, and Clinical Evidence

Commonly used isotonic arthroscopic irrigation fluids, such as normal saline or lactated Ringer's, were initially formulated for intravenous administration so they do not replicate the physiologic properties of healthy synovial fluid. Synovial fluid plays an important role in regulating joint homeostasis such that even transient disruptions in its composition and physiology can be detrimental. Previous studies suggest that hyperosmolar solutions may be a promising alternative to traditional isotonic fluids. This manuscript sought to systematically review and synthesize previously published basic science, translational, and clinical studies on the use of hyperosmolar arthroscopic irrigation fluids to delineate the optimal fluid for clinical use. A systematic literature search of MEDLINE/PubMed and Embase databases was performed in accordance with Preferred Reporting Items for Systemic Reviews and Meta-analyses (PRISMA) guidelines. The search phrases were: ("cartilage" AND "hyperosmolar"); ("arthroscopy" OR "arthroscopic" AND "hyperosmolar"). The titles, abstracts, and full texts were screened for studies on hyperosmolar solutions and articular cartilage. Study quality was assessed, and relevant data were collected. A meta-analysis was not performed due to study heterogeneity. A risk of bias assessment was performed on the included translational and clinical studies. There were 10 basic science studies, 2 studies performed in translational animal models, and 2 clinical studies included in this review. Of the basic science studies, 7 utilized a mechanical injury model. The translational studies were carried out in the canine shoulder and equine stifle (knee) joint. Clinical studies were performed in the shoulder and knee. Multiple basic science, translational, and clinical studies highlight the short-term safety, cost-effectiveness, and potential benefits associated with use of hyperosmolar solutions for arthroscopic irrigation. Further work is needed to develop and validate the ideal formulation for a hyperosmolar irrigation solution with proven long-term benefits for patients undergoing arthroscopic surgeries.

Effect of saline irrigation temperature difference on postoperative acute pain and hypothermia during biportal endoscopic spine surgery

BACKGROUND

Recently, enhanced recovery after surgery (ERAS) protocols have attracted attention; they emphasize on avoiding intraoperative hypothermia while performing lumbar fusion surgery. However, none of the studies have reported the protocol for determining the temperature of saline irrigation during biportal endoscopic spine surgery (BESS) procedure. This study evaluated the effectiveness of warm saline irrigation during BESS in acute postoperative pain and inflammatory reactions.

MATERIALS AND METHODS

Fifty-five patients who underwent BESS procedure were retrospectively analyzed for the incidence of perioperative hypothermia (< 36oC), postoperative inflammatory factors (white blood cells (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6), serum amyloid A (SAA)), and clinical outcomes (back visual analog scale (VAS) score, postoperative shivering). The patients were divided into the warm and cold saline irrigation groups.

RESULTS

Hemoglobin, WBC, ESR, creatine kinase, and creatine kinase-muscle brain levels did not significantly differ between the warm and cold saline groups. The mean CRP, IL-6, and SAA levels were significantly higher in the cold saline group than in the warm saline group (p = 0.0058, 0.0028, and 0.0246, respectively); back VAS scores were also higher with a statistically significant difference until two days postoperatively (p < 0.001). During the entire procedure, the body temperature was significantly lower in the cold saline irrigation group, but the hypothermia incidence rate significantly differed 30 min after the operation was started.

CONCLUSIONS

Using warm saline irrigation during BESS is beneficial for early recovery after surgery, as it is associated with reduced postoperative pain and complication rates.

Effect of pre-infusion of hypertonic saline on postoperative delirium in geriatric patients undergoing shoulder arthroscopy: a randomized controlled trial

BACKGROUND

Neuroinflammation may be a potential mechanism of postoperative delirium (POD) in geriatric patients, and hypertonic saline (HS) has immunomodulatory properties. The purpose of this study was to investigate whether HS could reduce the incidence of POD in elderly patients and its effect on neutrophil activation and inflammatory cytokine expression.

METHODS

We studied the effect of pre-infusion of 4 mL/kg 3% hypertonic saline vs. 4 mL/kg 0.9% normal saline on POD in patients undergoing shoulder arthroscopy in a prospective, randomized, double-blind, controlled trial. Neutrophil surface molecules (CD11b, CD66b and CD64) were analyzed by flow cytometry. Circulating concentrations of inflammatory factors IL-1β, IL-6, TNF-α and neurological damage factor S100β were assessed by enzyme immunoassay. The Confusion Assessment Method-Chinese Revision (CAM-CR) was applied for the assessment of POD 1-3 days after surgery.

RESULTS

The incidence of POD in group H was significantly lower than that in group N (7.14% vs 26.83%, P = 0.036). The expression levels of inflammatory cytokines ( IL-6 and TNF-α) and neutrophil surface markers (CD11b and CD66b) were significantly lower in group H than in group N at 24 h after surgery (P = 0.018, P < 0.001, P < 0.001, P = 0.024). There were no significant differences in postoperative pain, nausea and vomiting, infection, phlebitis, and patients satisfaction between the two groups.

CONCLUSION

Pre-infusion of HS can reduce the incidence of POD and the immune-inflammatory response.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (14/4/2022, registration number: ChiCTR2200058681.

Effects of Active Heating Methods on Body Temperature, Shivering, Thermal Comfort, Pain, Nausea and Vomiting During General Anesthesia: A Randomized Controlled Trial

To investigate the effect of forced-air warming and heated intravenous (IV) and irrigation fluids alone and in combination on body temperature, shivering, thermal comfort, pain, nausea and vomiting in adult patients undergoing surgery under general anesthesia in a prospective, four-group, randomized controlled trial. After induction of anesthesia, 120 patients were divided into the following groups: patients warmed with forced-air warming (n = 30), patients receiving warmed IV and irrigation fluid (n = 30), patients receiving warmed IV and irrigation fluid with forced-air warming (n = 30), and the control group without any intervention (n = 30). Body temperature, shivering, thermal comfort, pain, nausea and vomiting were monitored in the first 24 hours after surgery. The general characteristics of the groups, mean body temperature, length of stay, ambient temperature, and duration of surgery in the preoperative waiting unit were similar (p > 0.05). Compared with the other groups, patients in the control group had a significant decrease in body temperature from the 30th minute during surgery (p < 0.001), lower body temperature in the first 2 hours and thermal comfort in the first three hours after surgery (p < 0.01), and higher shivering levels in the first hour after surgery (p < 0.01). There was no significant difference between the groups in terms of postoperative pain, nausea and vomiting (p > 0.05). The study findings showed that normothermia was maintained in all three intervention groups during the surgery and in the first 24 hours after surgery. Moreover, postoperative thermal comfort increased and shivering levels decreased compared with the control group, but pain, nausea and vomiting levels were not affected. The study was registered on ClinicalTrials.gov (NCT04907617).

Efficacy and Long-Term Outcomes of Intra-Articular Autologous Micro-Fragmented Adipose Tissue in Individuals with Glenohumeral Osteoarthritis: A 36-Month Follow-Up Study

BACKGROUND

Glenohumeral osteoarthritis (GOA) is associated with disabling shoulder pain that affects everyday life. Its management comprises various treatment approaches, both conservative and surgical. Regenerative medicine has gained a major role in the conservative treatment of osteoarthritis. Intra-articular injection of adipose-derived mesenchymal stem cells (ADMSCs) is a widely used regenerative medicine approach. The aim of this retrospective study was to report the safety and clinical outcomes of intra-articular injection of ADMSCs in patients with GOA over 36-months.

METHODS

This retrospective observational study involved patients with chronic shoulder pain resistant to standard conservative treatment and a diagnosis of concentric GOA, who received an intra-articular injection of autologous micro-fragmented adipose tissue (μFAT). The values of the Constant-Murley score (CMS), the visual analog scale (VAS), and the simple shoulder test (SST), collected at baseline and at 12, 24, and 36 months, were analyzed to assess treatment efficacy. The single assessment numeric evaluation (SANE) was used to rate patient satisfaction. The Friedman test was used to compare observations of CMS, VAS, and SST values repeated on the same subjects. The significance threshold was set at 0.05.

RESULTS

The participants were 65 patients with a mean age of 54.19 years and a nearly equal gender distribution. Most had mild concentric GOA classified as Samilson-Prieto grade 1. The mean follow-up duration was 44.25 months. The postoperative clinical scores showed significant improvement. At 36 months, the CMS was 84.60, the VAS score was 3.34, and the SST score was 10.15 (all p < 0.0001). The SANE score at 36 months indicated that 54 patients (83.08%) were completely satisfied with the treatment.

CONCLUSION

ADMSC treatment exerted favorable effects on the clinical outcomes of patients with GOA, providing pain relief and improving shoulder function. Our data support its use as a conservative treatment option for osteoarthritis.

Prospective Randomized Controlled Clinical Trial Comparing Hyperosmolar Saline to Standard Isotonic Irrigation Fluid for Arthroscopic Knee Surgery: Initial Clinical Outcomes

Numerous in vitro studies suggest higher osmolarity irrigation fluids potentiate a chondroprotective environment, and a recent clinical study using hyperosmolar saline for shoulder arthroscopy reported potential clinical advantages. This prospective randomized double-blind controlled clinical trial was designed to assess initial clinical outcomes associated with use of a hyperosmolar irrigation solution in patients undergoing arthroscopic knee surgery. With institutional review board approval and informed consent, patients scheduled for arthroscopic knee surgery were randomized to surgery with either isotonic lactated Ringer's (273 mOsm/L) or hyperosmolar saline (593 mOsm/L) irrigation solution. Outcomes included perioperative blood pressure, knee girth, visual analogue scale (VAS) pain scores, and narcotic pain medication consumption. Forty-six patients underwent arthroscopic knee surgery with isotonic (n = 23) or hyperosmolar (n = 23) irrigation fluids. There were 11 males and 12 females (mean age = 44.0 years) in the isotonic cohort and 8 males and 15 females (mean age = 40.2 years) in the hyperosmolar cohort. There were no significant differences with respect to surgical duration (pump time) or amount of irrigation fluid used between the two cohorts. There were no significant differences with respect to change in knee girth, blood pressure, or VAS pain scores. However, patients treated with hyperosmolar saline consumed less narcotic medication on postoperative day 3 (4.0 ± 7.6 vs. 15.5 ± 17.4 mg, p = 0.01). The results of this randomized clinical trial suggest that a hyperosmolar irrigation solution is safe and relatively inexpensive for use in patients undergoing arthroscopic knee surgery and contributes to a reduction in initial postoperative narcotic pain medication consumption. A hyperosmolar saline irrigation fluid was not associated with any detrimental effects on the execution of the surgical procedure, postoperative pain, or periarticular fluid extravasation. Taken together with previous basic science, translational, and clinical studies, hyperosmolar saline irrigation fluid is promising alternative to traditional isotonic irrigation fluids for knee arthroscopy. This study is a prospective trial and reflects level of evidence I.

Comparison of two different uses of underbody forced-air warming blankets for the prevention of hypothermia in patients undergoing arthroscopic shoulder surgery: a prospective randomized study

Background

Forced-air warming (FAW) is an effective method of preventing inadvertent perioperative hypothermia (IPH). However, its warming effects can be influenced by the style and position of the FAW blanket. This study aimed to compare the effects of underbody FAW blankets being placed under or over patients in preventing IPH.

Methods

Patients (n=100) undergoing elective arthroscopic shoulder surgery in the lateral decubitus position were randomized into either under body (UB) group or the over body (OB) group (50 per group). The body temperature of the patients was recorded from baseline to the end of anesthesia. The incidences of postoperative hypothermia and shivering were also collected.

Results

A steady decline in the body temperature was observed in both groups up to 60 minutes after the start of FAW. After 60 minutes of warming, the OB group showed a gradual increase in the body temperature. However, the body temperature still decreased in UB group until 75 minutes, with a low of 35.7℃ ± 0.4℃. Then the body temperature increased mildly and reached 35.8℃ ± 0.4℃ at 90 minutes. After 45 minutes of warming, the body temperature between the groups was significantly different (P < 0.05). The incidence of postoperative hypothermia in the UB group was significantly higher than that in the OB group (P = 0.023).

Conclusions

The body temperature was significantly better with the use of underbody FAW blankets placed over patients than with them placed under patients. However, there was not a clinically significant difference in body temperature. The incidence of postoperative hypothermia was much lower in the OB group. Therefore, placing underbody FAW blankets over patients is recommended for the prevention of IPH in patients undergoing arthroscopic shoulder surgery.

Trial registration

This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 13/1/2021 with the registration number ChiCTR2100042071. It was conducted from 14/1/2021 to 30/10/2021 as a single, blinded trial in Sichuan Provincial Orthopedic Hospital.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01597-6.

Treatment of partial rotator cuff lesions is associated with a higher frequency of post-operative shoulder stiffness. A prospective investigation on the role of surgery-related risk factors for this complication

PURPOSE

Post-operative shoulder stiffness (SS) is a common complication after arthroscopic rotator cuff (RC) repair. The aim of this prospective study is to evaluate the role of surgical risk factors in the development of this complication, with special focus on the characteristics of the RC tears.

METHODS

Two-hundred and twenty patients who underwent arthroscopic RC repair for degenerative posterosuperior RC tears were included. Surgery-related risk factors for development of post-operative SS belonging to the following five categories were documented and analyzed: previous surgery, RC tear characteristics, hardware and repair type, concomitant procedures, time and duration of surgery. The incidence of post-operative SS was evaluated according to the criteria described by Brislin and colleagues.

RESULTS

The incidence of post-operative SS was 8.64%. The treatment of partial lesions by tear completion and repair technique was significantly associated with development of post-operative SS (p = 0.0083, pc = 0.04). A multivariate analysis revealed that treatment of partial lesions in patients younger than 60 years was associated to a higher risk of developing post-operative SS (p = 0.007). Previously known pre-operative risk factors such as female sex and younger age were confirmed. No other significant associations were documented.

CONCLUSION

The treatment of partial lesions of the RC may lead to a higher risk of post-operative SS than the treatment of complete lesions, in particular in patients younger than 60 years. Possible explanations of this finding are the increased release of pro-inflammatory cytokines caused by the additional surgical trauma needed to complete the lesion and the different pain perception of the subgroup of patients who require surgical treatment already for partial tears.

EVIDENCE

A higher risk of post-operative SS should be expected after tear completion and repair of partial lesions, especially in young patients. Appropriate pre-operative counseling and post-operative rehabilitation should be considered when approaching this subgroup of RC tears.

LEVEL OF EVIDENCE

Prognostic study, level II.

A Hyperosmolar Saline Solution Fortified with Anti-Inflammatory Components Mitigates Articular Cartilage Pro-Inflammatory and Degradative Responses in an In Vitro Model of Knee Arthroscopy

OBJECTIVE

To evaluate differences in pro-inflammatory and degradative mediator production from osteoarthritic knee articular cartilage explants treated with a hyperosmolar saline solution supplemented with anti-inflammatory components (l-glutamine, ascorbic acid, sodium pyruvate, epigallocatechin gallate [EGCG], and dexamethasone) or normal saline using an in vitro model for knee arthroscopy.

DESIGN

Full-thickness 6 mm articular cartilage explants (n = 12/patient) were created from femoral condyle and tibial plateau samples collected from patients who received knee arthroplasty. One explant half was treated for 3 hours with hyperosmolar saline (600 mOsm/L) supplemented with anti-inflammatory components and the corresponding half with normal saline (308 mOsm/L). Explants were cultured for 3 days and then collected for biomarker analyses. Media biomarker concentrations were normalized to the wet weight of the tissue (mg) and were analyzed by a paired t test with significance set at P < 0.05.

RESULTS

Cartilage was collected from 9 females and 2 males (mean age = 68 years). Concentrations of MCP-1 (P < 0.001), IL-8 (P = 0.03), GRO-α (P = 0.02), MMP-1 (P < 0.001), MMP-2 (P < 0.001), and MMP-3 (P < 0.001) were significantly lower in explant halves treated with the enhanced hyperosmolar solution. When considering only those cartilage explants in the top tercile of tissue metabolism, IL-6 (P = 0.005), IL-8 (P = 0.0001), MCP-1 (P < 0.001), GRO-α (P = 0.0003), MMP-1 (P < 0.001), MMP-2 (P < 0.001), MMP-3 (P < 0.001), and GAG expression (P = 0.0001) was significantly lower in cartilage explant halves treated with the enhanced hyperosmolar solution.

CONCLUSIONS

Treatment of cartilage explants with a hyperosmolar saline arthroscopic irrigation solution supplemented with anti-inflammatory components was associated with significant decreases in inflammatory and degradative mediator production and mitigation of proteoglycan loss.

Use of a Hyperosmolar Saline Solution to Mitigate Proinflammatory and Degradative Responses of Articular Cartilage and Meniscus for Application to Arthroscopic Surgery

PURPOSE

This study was designed to evaluate differences in proinflammatory and degradative mediator production and extracellular matrix degradation from osteoarthritic knee articular cartilage and meniscus explants treated with either hyperosmolar saline or isotonic saline.

METHODS

6 mm-diameter full-thickness explants were created from articular cartilage and menisci recovered after patients underwent knee surgery. One explant half was treated for 3 hours with hyperosmolar saline (600 mOsm/L) and the corresponding half with isotonic saline (300 mOsm/L). Explants were subsequently cultured for 3 days in tissue culture media. On day 3, media were collected for biomarker analyses. Results were normalized to tissue wet weight and analyzed statistically.

RESULTS

Articular cartilage was collected from 10 patients (5 male, 5 female; mean age = 66.9 years) and menisci were collected from 8 patients (2 male, 6 female; mean age = 66 years). Articular cartilage media concentrations of monocyte chemoattractant protein-1 (P = .001) and interleukin (IL)-6 (P = .049) were significantly lower in explants treated with hyperosmolar saline. Meniscus media concentrations of prostaglandin E₂ (P = .008), monocyte chemoattractant protein-1 (P = .011), IL-6 (P = .029), IL-8 (P = .012), matrix metalloproteinase-2 (P = .011), and glycosaminoglycan (P = .008) were significantly lower in explants treated with hyperosmolar saline.

CONCLUSIONS

Treatment of cartilage and meniscus explants with hyperosmolar saline effectively mitigated key proinflammatory mediator production, as well as degradative mediator production and glycosaminoglycan loss from meniscus, with no detrimental effects noted compared to isotonic saline.

CLINICAL RELEVANCE

These results suggest that hyperosmolar saline irrigation fluid may provide a safe alternative to standard isotonic saline irrigation fluid, and could mitigate untoward effects associated with inflammatory responses after standard-of-care knee arthroscopy.

Procedure length is independently associated with overnight hospital stay and 30-day readmission following anterior cruciate ligament reconstruction

PURPOSE

The purpose was to characterize the independent effect of procedure length on the rates of 30-day perioperative complications, hospital readmissions, and overnight hospital stay in patients undergoing arthroscopic anterior cruciate ligament reconstruction (ACLR). We hypothesized that longer procedure length in primary ACLR increases the risk for post-operative complications.

METHODS

Primary ACLR cases from 2005 to 2015 were identified in the American College of Surgeons National Surgical Quality Improvement Program registry. Patients were categorized into two cohorts based on procedure length, either less than or greater than 90 min. Two equal-sized propensity-matched cohorts were generated to account for differences in baseline and operative characteristics. Thirty-day clinical outcomes were compared using bivariate analyses between propensity-matched groups that controlled for patient-specific factors and concurrent meniscal repair. Multivariate logistic regression models were used to identify independent predictors of hospital readmission and overnight hospital stay.

RESULTS

In total, 12,077 ACLR cases were identified. The rate of any 30-day complication was increased in longer procedures relative to shorter procedures (1.6% vs 0.9%, p = 0.006), as were the rates of returning to the operating room (0.6% vs 0.3%, p = 0.03), hospital readmission (1.0% vs 0.3%, p = 0.001), and overnight hospital stay (16.2% vs 6.0%, p < 0.001). Obesity was a risk factor for both hospital readmission and overnight hospital stay, while hypertension, diabetes, chronic obstructive pulmonary disease, and a smoking history were associated with increased rates of overnight hospital stay. The most common reasons for hospital readmission were deep vein thrombosis or pulmonary embolism (25.0% of all readmitted patients), surgical site infection (25.0%), and post-operative pain (14.1%).

CONCLUSIONS

In this propensity-matched analysis adjusting for baseline patient characteristics and operative factors, procedure length of greater than or equal to 90 min in ACLR was independently associated with an increased risk of hospital readmission and overnight hospital stay. As a surrogate measure of surgical complexity, operative time may be a useful perioperative variable for post-operative risk stratification and patient counseling.

LEVEL OF EVIDENCE

III.

Room Temperature Versus Warm Irrigation Fluid Used for Patients Undergoing Arthroscopic Shoulder Surgery: A Systematic Review and Meta Analysis

PURPOSE

The aim of this study was to analyze whether warm irrigation fluid could reduce postoperative adverse effects in patients undergoing arthroscopic shoulder surgery compared with room temperature irrigation fluid.

DESIGN

A systematic review and meta-analysis of clinical trials was performed.

METHODS

A computerized search of electronic databases was performed. The inclusion criteria were studies comparing the clinical effects of room temperature and warm irrigation fluid on patients undergoing arthroscopic shoulder surgery.

FINDINGS

Warm irrigation fluid reduced the degree of core body temperature drop and the incidence of hypothermia. A statistically lower incidence of shivering also occurred in the warm irrigation fluid group.

CONCLUSIONS

The use of warm irrigation fluid better maintains core body temperature and reduces incidence of shivering than room temperature irrigation fluid. Therefore, warm irrigation fluid is a better choice for arthroscopic shoulder surgery.

The influence of the irrigating solution on articular cartilage in arthroscopic surgery: A systematic review

Purpose

Arthroscopic surgery has become an important and popular orthopedic procedure for numerous joint disorders. Continuous irrigation is performed to replace synovial fluid for optimal joint distension and clear visualization of the synovial cavity. Irrigation solutions may, however, negatively impact articular cartilage and chondrocyte viability. This systematic review aims to compare different irrigating solutions and their properties to determine whether one is superior in its effects on articular cartilage and chondrocytes.

Methods

A systematic literature review was conducted. The online databases: Embase, Medline, HealthStar, Emcare and PubMed were searched from 1946 to August 2018. Methodological index for non-randomized studies (MINORS) was used to assess methodological quality of the included studies.

Results

Sixteen studies met the inclusion/exclusion criteria and were included in this review. Although the studies used different criteria to define superiority, solution superiority was based on results that focused on articular cartilage and chondrocyte viability. Seven of the sixteen included studies compared Ringer's/lactate solution or Ringer's lactate to normal saline. Three found Ringer's solution or Ringer's lactate to be superior to saline, whereas, three studies found no significant differences and one study found Ringer's lactate to be inferior to saline only when their osmolarities differed. Four studies compared ionic to non-ionic solutions. Two of the four studies demonstrated non-ionic solutions to be superior, one had demonstrated no significant differences between solutions, while one had mixed results. Six of the sixteen included studies compared differing osmolarities. One found no statistically significant differences between solutions of differing osmolarities, whereas, the remaining five studies found superiority with hyperosmolarity. Two of the sixteen included studies examined the effects of different temperatures. Both studies concluded that the use of a warmer (more physiological) temperature is more ideal. Two of the sixteen studies included in this review compared solutions with differing pH levels. Both studies concluded on the importance of utilizing the more physiological solutions for arthroscopic procedures.

Conclusion

Ringer's Lactate and Ringer's Solution as well as non-ionic solutions may have merit over the use of the normal saline for irrigation. Hyperosmolarity, warmer solutions and ones with more physiological pH values may be beneficial when considering potential effects on articular cartilage and chondrocytes. The current review demonstrated trends found in the current literature, which require human studies - preferably high quality RCTs -to make recommendations that aid surgeons in making the best decision regarding the ideal irrigation solution to use on their patients.

Level of evidence

Level IV, Systematic review of Level IV studies.

Warming of Irrigation Fluids for Prevention of Perioperative Hypothermia During Arthroscopy: A Systematic Review and Meta-analysis

PURPOSE

To determine whether warming of irrigation fluids (32°C-40°C) compared with using room-temperature irrigation fluids (20°C-22°C) decreases the risk of perioperative hypothermia (<36°C) for patients undergoing shoulder, hip, or knee arthroscopy.

METHODS

One reviewer, with the assistance of a medical librarian, searched the following databases: PubMed, Embase, Cochrane Central, SPORTDiscus, Web of Science, and CINAHL (Cumulative Index to Nursing and Allied Health Literature). Level I and II studies involving shoulder, hip, or knee arthroscopy were included. Two reviewers screened the abstracts and titles. Two reviewers assessed the risk of bias of selected studies using The Cochrane Collaboration tool. Meta-analyses were conducted on the following outcomes: hypothermia, lowest temperature, maximum temperature drop, and shivering.

RESULTS

Seven studies of patients undergoing arthroscopy were included in the qualitative synthesis (5 shoulder studies, 1 hip study, and 1 knee study; 501 patients). The study involving knee arthroscopy was excluded from the meta-analyses because of insufficient data and high clinical heterogeneity (surgical site distal to the core, not involving extravasation of large amounts of fluid). The remaining 6 studies were included in 1 or more meta-analyses: hypothermia (5 shoulder and 1 hip study), lowest temperature (3 shoulder and 1 hip study), maximum temperature drop (2 shoulder and 1 hip study), and shivering (5 shoulder and 1 hip study). Warming of irrigation fluids for shoulder or hip arthroscopy significantly decreased the risk of hypothermia (odds ratio, 0.15; 95% confidence interval [CI], 0.06-0.40; P = .0001), increased the lowest mean temperature (mean difference, 0.46°C; 95% CI, 0.11°C-0.81°C; P = .01), decreased the maximum temperature drop (mean difference, -0.64°C; 95% CI, -0.94°C to -0.35°C; P < .0001), and decreased the risk of shivering (odds ratio, 0.25; 95% CI, 0.07-0.86; P = .03).

CONCLUSIONS

When irrigation fluids are warmed for shoulder and hip arthroscopy, the risk of hypothermia is less, the drop in intraoperative temperature is less, the lowest body temperature is higher, and the risk of postoperative shivering is reduced.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.