Pre-anaesthesia assessment in cataract surgery: Recommendations from the SEDAR Working Group

INTRODUCTION AND OBJECTIVES

Cataract surgery is one of the most common procedures in outpatient surgery units. The use of information and communication technologies (ICT) in clinical practice and the advent of new health scenarios, such as the Covid pandemic, have driven the development of pre-anaesthesia assessment models that free up resources to improve access to cataract surgery without sacrificing patient safety. The approach to cataract surgery varies considerably among public, subsidised and private hospitals. This raises the need for guidelines to standardise patient assessment, pre-operative tests, management of background medication, patient information and informed consent.

RESULTS

In this document, the SEDAR Clinical Management Division together with the Major Outpatient Surgery Division SEDAR Working Group put forward a series of consensus recommendations on pre-anaesthesia testing based on the use of ITCs, health questionnaires, patient information and informed consent supervised and evaluated by an anaesthesiologist.

CONCLUSIONS

This consensus document will effectivise pre-anaesthesia assessment in cataract surgery while maintaining the highest standards of quality, safety and legality.

Use of the cumulative sum method (CUSUM) to assess the learning curves of ultrasound-guided continuous femoral nerve block

BACKGROUND

Although ultrasound is a basic competence for anaesthesia residents (AR) there is few data available on the learning process. This prospective observational study aims to assess the learning process of ultrasound-guided continuous femoral nerve block and to determine the number of procedures that a resident would need to perform in order to reach proficiency using the cumulative sum (CUSUM) method.

METHODS

We recruited 19 AR without previous experience. Learning curves were constructed using the CUSUM method for ultrasound-guided continuous femoral nerve block considering 2 success criteria: a decrease of pain score>2 in a [0-10] scale after 15minutes, and time required to perform it.

RESULTS

We analyse data from 17 AR for a total of 237 ultrasound-guided continuous femoral nerve blocks. 8/17 AR became proficient for pain relief, however all the AR who did more than 12 blocks (8/8) became proficient. As for time of performance 5/17 of AR achieved the objective of 12minutes, however all the AR who did more than 20 blocks (4/4) achieved it.

CONCLUSIONS

The number of procedures needed to achieve proficiency seems to be 12, however it takes more procedures to reduce performance time. The CUSUM methodology could be useful in training programs to allow early interventions in case of repeated failures, and develop competence-based curriculum.

Clinical protocol for the management of malignant hyperthermia

Malignant hyperthermia is a hypermetabolic syndrome that appears in susceptible patients after exposure to certain anaesthetic drugs (succinylcholine, inhalation anaesthetics). Its incidence in Spain is 1 in 40,000 adults, with a 10% mortality rate. It is induced by an abnormal regulation of the ryanodine receptors, producing a massive release of calcium from the sarcoplasmic reticulum in the striate muscle. Clinical manifestations include: CO₂ increase, tachycardia, haemodynamic instability, metabolic and respiratory acidosis, profuse sweating, hyperpyrexia, CPK increase, myoglobinuria, kidney failure, disseminated intravascular coagulation (DIC), and ending in cardiac arrest. Dantrolene sodium is a ryanodine receptor antagonist, and inhibits the release of intracellular calcium. Definitive diagnosis is achieved by the exposure of muscle fibres to caffeine and halothane. Protocols can help guarantee a reliable and secure management when this severe event occurs.

Efficacy of phytosterols and fish-oil supplemented high-oleic-sunflower oil rich diets in hypercholesterolemic growing rats

Phytosterols (P) and fish-oil (F) efficacy on high-oleic-sunflower oil (HOSO) diets were assessed in hypercholesterolemic growing rats. Controls (C) received a standard diet for 8 weeks; experimental rats were fed an atherogenic diet (AT) for 3 weeks, thereafter were divided into four groups fed for 5 weeks a monounsaturated fatty acid diet (MUFA) containing either: extra virgin olive oil (OO), HOSO or HOSO supplemented with P or F. The diets did not alter body weight or growth. HOSO-P and HOSO-F rats showed reduced total cholesterol (T-chol), non-high-density lipoprotein-cholesterol (non-HDL-chol) and triglycerides and increased HDL-chol levels, comparably to the OO rats. Total body fat (%) was similar among all rats; but HOSO-F showed the lowest intestinal, epididymal and perirenal fat. However, bone mineral content and density, and bone yield stress and modulus of elasticity were unchanged. Growing hypercholesterolemic rats fed HOSO with P or F improved serum lipids and fat distribution, but did not influence material bone quality.

Perioperative temperature control: Survey on current practices

INTRODUCTION

Prevention of perioperative hypothermia decreases morbidity and mortality, as well as hospital costs. This study was conducted to evaluate the level of implementation of protocols in 3 tertiary Spanish University Hospitals.

MATERIAL AND METHODS

A survey among anaesthesiologists assessed estimated importance and clinical practice in terms of prevention of perioperative hypothermia. Results were compared depending on their experience. P<.05 was considered significant.

RESULTS

A total of 116 anaesthesiologists answered the survey, of whom 48 (41.3%) were residents, 32 (27.6%) were staff with less than 10 years of experience, and 36 (31.1%) staff with 10 years or more of experience, In a 0-10 importance scale, prevention of hypothermia was scored 7.49±1,79, with no difference between groups (P=.58). Younger staff were more concerned of the end surgery temperature than other colleagues (P=.02). The most usual practice was a combination warming the intravenous fluids and an electric blanket (55%). Only 20% of the anaesthesiologists monitored temperature intra-operatively, even though 75% considered it an important parameter. No unit had a written protocol for prevention of perioperative hypothermia.

DISCUSSION AND CONCLUSION

Despite the absence of prevention protocols, the anaesthesiologists were aware of the importance maintaining a normal peri-operative temperature, but this awareness is still not enough to influence their perioperative management to diagnose and prevent hypothermia. A harmonisation of practice at local, regional and national level could improve this practice in the future.

Monounsaturated fatty acids-rich diets in hypercholesterolemic-growing rats

The effects of replacing dietary saturated fat by different monounsaturated fatty acid (ω-9MUFA) sources on serum lipids, body fat and bone in growing hypercholesterolemic rats were studied. Rats received one of the six different diets: AIN-93G (control, C); extra virgin olive oil (OO) + C; high-oleic sunflower oil (HOSO) + C or atherogenic diet (AT) for 8 weeks; the remaining two groups received AT for 3 weeks and then, the saturated fat was replaced by an oil mixture of soybean oil added with OO or HOSO for 5 weeks. Rats consuming MUFA-rich diets showed the highest body fat, hepatic index and epididymal, intestinal and perirenal fat, and triglycerides. T-chol and non-HDL-chol were increased in HOSO rats but decreased in OO rats. Bone mineral content and density were higher in both OO and HOSO groups than in AT rats. This study casts caution to the generalization of the benefits of MUFA for the treatment of hypercholesterolemia.

[Maternal hypotension with low doses of spinal bupivacaine or levobupivacaine and epidural volume expansion with saline for cesarean section]

BACKGROUND AND OBJECTIVE

Epidural volume extension (EVE) with saline solution can contribute to greater cephalad spread of drugs injected into the subarachnoid space during cesarean section. We studied the incidence of material hypotension with spinal bupivacaine or levobupivacaine (L-bupivacaine) and the spread after epidural saline injection.

MATERIAL AND METHODS

After ethics committee approval, we randomized women scheduled for cesarean section to 4 groups to receive 5 mg of 0.25% bupivacaine with (n=51) or without (n=6) saline EVE; 5 mg of 025% L-bupivacaine (n=50); or 6 mg of 03% L-bupivacaine (n=50). All patients also received 25 microg of fentanyl per 2 mL of local hyperbaric spinal anesthetic. In all except the non-EVE group, 10 mL of saline was infused through an epidural catheter 5 minutes after anesthetic infusion. We recorded patient demographic data, procedural and anesthetic times, incision-clamping times, occurrence of hypotension, ephedrine dose required, motor and sensory blockade, requirement for rescue analgesics, and neonatal outcome.

RESULTS

After 6 patients had been randomized to the non-EVE group, no further patients were assigned because all the women required rescue analgesics. Demographic data, duration of procedure, time between. incision and delivery, and Apgar scores were similar in all the groups. The incidence of hypotension was lower in the group receiving 5 mg of L-bupivacaine (26% vs. 52.9% in the bupivacaine 5-mg group, and 56% in the 6-mg L-bupivacaine group, P = .04). More women given 5 mg of L-bupivacaine required rescue analgesia (46%) than did those receiving 5 mg of bupivacaine (235%) or 6 mg of L-bupivacaine (28%) (P = .039). Hypotension was associated with a lower umbilical cord pH (P = .001). Ephedrine doses over 20 mg were also associated with a lower umbilical cord pH (P = .031).

CONCLUSIONS

The incidence of hypotension was lowest in the group anesthetized with 5 mg of L-bupivacaine, but the need for rescue analgesia was greater in this group. Doses of 5 mg and 6 mg may be sufficient for cesarean section, as they provide a good level of sensory blockade.

Observational study of continuous spinal anesthesia with the catheter-over-needle technique for cesarean delivery

BACKGROUND

Few studies have assessed the efficacy and safety of continuous spinal anesthesia in obstetrics, although placement of a catheter in the intrathecal space theoretically offers advantages in these patients.

METHODS

Ninety-two women scheduled for elective cesarean delivery using continuous spinal anesthesia with the catheter-over-needle technique (22- or 24-gauge Spinocath) were included in the study. The doses of local anesthetic used, hemodynamic variables, use of ephedrine and other drugs, and incidence of complications such as technical failure and postdural puncture headache (PDPH) were recorded.

RESULTS

The mean (+/-SD) dose of hyperbaric bupivacaine used was 8.2+/-1.8 mg. The incidence of hypotension was 30% and the mean total dose of ephedrine was 4+/-7 mg. The continuous spinal anesthetic technique failed in 18 women (20%). The overall incidence of post-dural-puncture headache was 29%; 18% of patients with post-dural-puncture headache required a blood patch.

CONCLUSIONS

Compared to previous reports, the incidence of block failure and PDPH in this study was unacceptably high and therefore the risks of the technique appear to outweigh the advantages of continuous spinal anesthesia in obstetric practice.