Fever during anaesthesia

Peri-anaesthetic complications in 1798 equids undergoing high-field elective orthopaedic MRI at a tertiary referral hospital

BACKGROUND

Antimicrobial prophylaxis for elective orthopaedic magnetic resonance imaging (MRI) in equids is a topic of debate among practitioners and can have negative detrimental effects on patients if used unnecessarily.

OBJECTIVES

To describe the complications with elective orthopaedic MRI of horses, mules, and donkeys under general anaesthesia without the use of peri-anaesthetic antimicrobial prophylaxis at a single large tertiary referral centre. We hypothesised that horses, mules, and donkeys undergoing general anaesthesia for elective orthopaedic MRI, without antimicrobial prophylaxis, will not be at increased risk of complications, including increased risk of infectious respiratory disease.

STUDY DESIGN

Retrospective cross-sectional study.

METHODS

This retrospective study of 1798 systemically healthy equids that underwent elective orthopaedic MRI under general anaesthesia without peri-anaesthetic antimicrobial prophylaxis between January 2009 and May 2020.

RESULTS

A total of 1655 MRIs were included in the study, with 25 (1.5%) horses having complications. The most common complication was post-anaesthetic fever in 11 (0.7%) horses, of which 4 (0.2%) horses went on to develop pneumonia and one horse was diagnosed with equine herpesvirus (respiratory). Seven (0.4%) horses developed transient post-anaesthetic femoral neuropathy and 7 (0.4%) horses had mild post-anaesthetic colic that resolved with initial medical management. No horses were euthanised or died in this study.

MAIN LIMITATIONS

The retrospective nature of the study led to non-randomised case selection, and some records were incomplete.

CONCLUSIONS

These findings suggest that peri-anaesthetic antimicrobial prophylaxis may not be necessary for performance and sport horses undergoing general anaesthesia for elective orthopaedic MRI.

Antimicrobial prophylaxis is not indicated for horses undergoing general anaesthesia for elective orthopaedic MRI

BACKGROUND

Post-anaesthetic fever is a known complication of general anaesthesia, however, its incidence in horses undergoing elective magnetic resonance imaging (MRI) is unknown.

OBJECTIVE

To determine the incidence of post-anaesthetic fever in horses undergoing elective orthopaedic MRI and determine whether prophylactic antimicrobial therapy would be associated with a reduction in the incidence of post-anaesthetic fever. We hypothesised that prophylactic antimicrobials would be associated with a reduction in the incidence of post-anaesthetic fever.

STUDY DESIGN

Retrospective cross-sectional study.

METHODS

This retrospective study included 791 elective orthopaedic MRIs in systemically healthy horses between June 2006 and March 2020 that recovered from general anaesthesia and did not undergo surgery or intensive medical therapy soon after recovery. Potential factors associated with post-anaesthetic fever were evaluated using multivariable logistic regression. Case signalment, travel time, preanaesthetic haematology and fibrinogen abnormalities, use of prophylactic antimicrobials, peri-anaesthetic nonsteroidal anti-inflammatories, anaesthesia time and recovery time were all evaluated for association with post-anaesthetic fever.

RESULTS

Of 791 MRI cases, 44 (5.6%) developed a post-anaesthetic fever. Horses that received prophylactic antimicrobials were [odds ratio (OR) 3.8, 95% confidence interval (CI) 1.98-7.46; p ≤ 0.001] more likely to develop a post-anaesthetic fever than those that did not receive antimicrobials. Young horses (1-4 years of age) were (OR 2.8, 95% CI 1.26-6.17; p = 0.01) more likely to develop fever compared with adult horses (≥5 years of age).

MAIN LIMITATIONS

Limitations of this study pertain to retrospective analysis including nonrandomised case selection and incomplete data records.

CONCLUSIONS

While fever may indicate infection, the majority of early post-anaesthetic fevers resolved before discharge from the hospital with no identified cause. The use of prophylactic antimicrobials to reduce the risk of post-anaesthetic fever for elective MRI is not supported by this study.

Increase in body temperature in pediatric patients after costal cartilage harvest in microtia reconstruction: A retrospective observational study

BACKGROUND

Previous evidence has clearly shown that maintaining normothermia in children undergoing surgery is difficult and is associated with adverse outcomes. Therefore, this study aimed to retrospectively analyze the changes in body temperature over time in 2 different types of microtia reconstruction surgeries, namely, embedding, and elevation surgeries.

METHODS

We performed a retrospective chart review of patients who underwent microtia reconstruction (embedding and elevation) between July 2012 and February 2015 (n = 38). The changes in body temperature between the 2 types of surgeries were compared.

RESULTS

During microtia reconstruction, the body temperature in the embedding surgery group was significantly higher than that in the elevation surgery group from 1 hour after the start of surgery to 1 day after the surgery (P < .001). Time, group, and time-group interaction were associated with an increase in body temperature (P < .001) but not the warming method.

CONCLUSION

We found an increase in body temperature in patients with microtia who underwent embedding surgery (autologous costal cartilage harvest surgery), and this was related to the type of surgery and not to the warming method. Therefore, further research is warranted to determine the cause of the increase in body temperature during this surgery.

Febrile convulsions during recovery after anesthesia in an infant with history of MMR vaccination: A case report

RATIONALE

Seizures are rare during the perioperative period; in most cases, there is a previous history of epilepsy or surgery-associated seizures. Febrile convulsions may occur when the body temperature rises above 38°C; this is the most common cause of seizures in children. Febrile convulsions after general anesthesia in the postanesthetic care unit (PACU) without a past or family history are rare. Some reviews suggest that since anesthesia changes immunity, elective surgery should be postponed three weeks after live vaccination.

PATIENT

A 12-month-old female with bilateral hearing loss underwent cochlear implantation under general anesthesia. She did not have any history of convulsions or developmental disorders. However, 1 week before surgery, measles-mumps-rubella (MMR) vaccination was given as a regular immunization.

DIAGNOSES

Forty minutes after arrival at the PACU, sudden generalized tonic-clonic movement occurred during recovery and the patient's measured body temperature exceeded 38.0°C.

INTERVENTIONS

Thiopental sodium was administered intravenously as an anticonvulsant, and the tonic-clonic movement stopped immediately. Endotracheal intubation was performed to secure the airway, and tepid massage and diclofenac β-dimethylaminoethanol administration were performed to lower the patient's body temperature.

OUTCOMES

There was no further fever and no seizures, and no other neurological deficits were observed until discharge.

LESSONS

The anesthesiologist should check the recent vaccination history even if the patient has not developed particular symptoms after vaccination. It is important to know that febrile convulsions may occur in patients who have recently received MMR vaccination.

Postoperative Fever Evaluation Following Lumbar Fusion Procedures

Objective

This study aimed to determine the incidence of postoperative fever, the workup conducted for postoperative fever, the rate of subsequent fever-related diagnoses or complications, and the risk factors associated with fever following lumbar fusion.

Methods

A retrospective review of patients undergoing lumbar fusion was performed. For patients in whom fever (≥38.6°C) was documented, charts were reviewed for any fever workup or diagnosis. Multivariate regression was used to identify independent risk factors for the development of postoperative fever.

Results

A total of 868 patients met the inclusion criteria, of whom 105 exhibited at least 1 episode of fever during hospitalization. The first documentation of fever occurred during the first 24 hours in 43.8% of cases, during postoperative hours 24–48 in 53.3%, and later than 48 hours postoperatively in 2.9%. At least 1 component of a fever workup was conducted in 47 of the 105 patients who had fever, resulting in fever-associated diagnoses in 4 patients prior to discharge. Three patients who had fever during the inpatient stay developed complications after discharge. On multivariate analysis, operations longer than 150 minutes (relative risk [RR], 1.66; p=0.015) and narcotic consumption greater than 85 oral morphine equivalents on postoperative day 0 (RR, 1.53; p=0.038) were independently associated with an increased risk of developing postoperative fever.

Conclusion

The results of this study suggest that inpatient fever occurred in roughly 1 in 8 patients following lumbar fusion surgery. In most cases where a fever workup was performed, no cause of fever was detected. Longer operative time and increased early postoperative narcotic use may increase the risk of developing postoperative fever.

Postoperative Fever

BACKGROUND

Fever is common in surgical patients. The list of potential causes is long and includes many noninfective etiologies.

CAUSES

Only about 40% of fever episodes in hospitalized patients are caused by infection. Any fever in a surgical patient is a cause for concern. New or continuing fever more than three days after surgery should raise a strong suspicion of persistent illness or a new complication. On rare occasions, these fevers can be attributed to potentially life-threatening occult infections, including acute cholecystitis, antibiotic-related pseudomembranous colitis, systemic candidiasis, or transfusion-related cytomegalovirus disease. A change in the microbiology of postoperative infections has also been noticed, characterized by a greater incidence of infections caused by methicillin-resistant Staphylococcus aureus, by polymicrobial flora, and by fungi.

TREATMENT

Control of nosocomial infections has become more challenging recently because of widespread bacterial resistance to antibiotics and to more frequent surgical indications in elderly patients at higher risk. Early recognition and appropriate treatment of these infections relieves anxiety, reduces hospital costs, and increases patient survival rates.

CONCLUSIONS

The workup and therapy for the individual patient may differ, depending on the underlying disease and clinical appearance and the clinician's suspicion for infection. Subsequent testing should be based on the clinical findings. Perhaps more money is wasted in the evaluation of early postoperative fever than on any other aspect of postoperative care.