Beyond incidence: clarifying the evidence-based predictors of failed spinal anesthesia.

Lumbar puncture is a minimally invasive procedure that utilizes a spinal needle to puncture the lumbar epidural space to take a sample from the cerebrospinal fluid or inject drugs for diagnostic and therapeutic purposes. Physicians rely on their expertise to localize epidural space. Due to its critical procedure, the failure rate can reach up to 28%. Hence, a high level of experience and caution is required to correctly insert the needle without puncturing the dura mater, which is a fibrous layer protecting the spinal cord. Failure of spinal anesthesia is, in some cases, related to faulty needle placement techniques since it is blindly inserted. Therefore, advanced techniques for localization of the epidural space are essential to avoid any possible side effects. As for epidural space localization, various ideas were carried out over recent years to provide accurate identification of the epidural space. Subsequently, several methodologies based on mechanical and optical schemes have been proposed. Several research groups worked from different aspects of the problem, namely, the clinical and engineering sides. Hence, the main goal of this paper is to review this research with the aim of remedying the gap between the clinical side of the problem and the engineering side by examining the main techniques in building sensors for such purposes. This manuscript provides an understanding of the clinical needs of spinal needles from an anatomical point of view. Most importantly, it discusses the mechanical and optical approaches in designing and building sensors to guide spinal needles. Finally, the standards that must be followed in building smart spinal needles for approval procedures are also presented, along with some insight into future directions.

BackgroundDrug addiction remarkably increases morbidity and mortality among patients. Several cases of failed spinal anesthesia have been discovered in the clinical practice among addict patients. Different causes of failed spinal blocks have been mentioned in the literature.The aim of the study was to compare the success rate of spinal anesthesia in adult addicts and non-addicts.MethodologyThe study was conducted in Kasr al Ainy teaching hospital, Cairo University, Egypt. One hundred patients aged 20–50, ASA 1-2, both genders, undergoing lower abdominal or limbs surgeries under regional anesthesia, were included in the study. They were divided into 2 equal groups, relative to the addiction history to Marijuana, Cannabis, Tramadol, and Clonazepam. Group [NAD] non-addicts (n = 50); and Group [AD] addicts (n = 50). The success rate, onset, duration of sensory and motor blocks were evaluated. Hemodynamic data were collected, and any complications due to the drugs used or due to spinal anesthesia were recorded.ResultsThe incidence of failure of the spinal anesthesia was higher in Group [AD] (33%) than Group [NAD] (4%), (p < 0.05). There was delay in the onset time and decreased duration of both sensory and motor blocks in the addict groups compared to non-addicts. All previous findings showed statistical significant difference (P < 0.05). Hypotension (p < 0.05) and nausea occurred more in addict groups than in non-addicts. No other complications were encountered in the study.ConclusionThe incidence of failure of the intrathecal anesthesia seemed to be higher in the addict than in non-addict patients. Redo intrathecal injection with a top up 1/2 of the initial dose resulted in success of the block in all failed cases. There was a slower onset and decreased duration of both sensory and motor blocks, with higher incidence of hypotension and nausea more in the addict patients than in non-addicts.

Background: Pregnancy in dwarfism generally present with contracted pelvis and cephalopelvic disproportion. Cesarean section is generally indicated for deliver. However, Anaesthesia management in dwarf pregnant patient is difficult and challenging as they are other concurrent conditions like atlanto-axial instability, spine deformities like kyphoscoliosis and narrowed pharynx leading to higher risk for both general as well as regional anaesthesia. Here, we are presenting a successful case of anaesthesia management in dwarf patient with failed spinal anaesthesia and unanticipated difficult airway for emergency cesarean section.

IntroductionXeroderma pigmentosum is a rare autosomal recessive disease that causes changes in skin pigmentation, precancerous lesions and neurological abnormalities. It is a defect in the nucleotide excision repair mechanism. It has been reported that volatile anesthetics has a possible genotoxic side effect and deranged nucleotide excision repair in cells obtained from a patient with xeroderma pigmentosum.We report an unusual case of postoperative neurological aggravation in a patient with xeroderma pigmentosum anesthetized with sevoflurane.Case presentationA 24-year-old African woman, who has had xeroderma pigmentosum since childhood, was admitted to our hospital for a femoral neck fracture. A preoperative physical examination revealed that she had a resting tremor with ataxia. She had cutaneous lesions such as keratosis and hyperpigmentation on her face and both hands. There was no major alteration of cognitive function, muscular strength was maintained and her osteotendinous reflexes were preserved. Surgical fixation was performed under general anesthesia after the failure of spinal anesthesia. All parameters were stable during surgery. When she woke up four hours later, the patient presented with confusion and psychomotor agitation, sharpened reflexes and the Babinski reflex was present. Her postoperative test results and a magnetic resonance imaging scan were unremarkable. It was suggested that sevoflurane had had a probable deleterious effect on the neurological status of this patient.ConclusionThe anesthetizing of a patient with xeroderma pigmentosum is associated with a risk of worsening neurological disorders. At present, there are no clear recommendations to avoid the use of volatile agents in the anesthetic management of patients with xeroderma pigmentosum. More clinical and experimental research is needed to confirm the sensitivity of patients with xeroderma pigmentosum to sevoflurane and other halogenated anesthetics.

Spinal anaesthesia (SA) has enjoyed a long history of success, celebrating soon its 125th anniversary. Puncturing the dura mater is considered a simple procedure, followed by a subarachnoid injection of a local anaesthetic (LA) agent into the cerebrospinal fluid (CSF). Even when the technique is performed perfectly, there is no guarantee that the block sits perfectly. Failure is not uncommon and encompasses a range from total absence of any neuraxial blockade, a partial block (insufficient height, quality or duration) or a patchy block. Table 1 lists a large number of potential causative factors that may result in a failed spinal anaesthetic, providing suggestions of solutions. Analysing each distinct phase of the procedure, i.e., spinal puncture, injection of local anaesthetic solution, spread of the local anaesthetic solution through the cerebrospinal fluid, action of the drug on subarachnoid neural tissue and patient management, are the keys to success at each stage. Mechanisms of failure of spinal anaesthesia include insufficient preparation and check of equipment and drugs, suboptimal positioning of the patient, unsuccessful puncture due to inadequate training or experience and inadequate use of needles and local anaesthetic solution.1-5 Besides operator, preparation, technique-dependent and patient-related factors (anatomical variations), there are also organisational factors (lack of block room, lack of adequate monitoring and trained personnel, insufficient time between block and onset of surgery, subsequent management following block). The use of the correct local anaesthetic (dose, volume, concentration) injected at the correct lumbar interspace is of paramount importance to produce an adequate spinal block for the right surgical intervention. Nevertheless, failures may still occur. Therefore, the anaesthetist should always have a contingency plan for a failed spinal block. Indeed, patients expect reliable surgical anaesthesia when undergoing an operation

Spinal anesthesia is the most common mode of anesthesia utilized during caesarian sections worldwide. Despite its many advantages over general anesthesia in the pregnant cohort, uncommon and even catastrophic complications could occur due to patient-related, equipment-related, and procedure-related complications. One such uncommon event of a broken spinal needle during failed spinal anesthesia for a caesarian section and subsequent successful management is described here.

Bupivacaine is an amide local anesthetic used in hyperbaric and plain forms administered as spinal anesthesia for cesarean delivery. In this systematic review, we summarized the effectiveness and safety of hyperbaric versus plain bupivacaine in providing anesthesia for cesarean delivery. We considered the adequacy of anesthesia for completion of cesarean delivery and the need for interventions to treat complications. We searched the CENTRAL, MEDLINE, and EMBASE databases. We imposed no language restriction. We included all randomized controlled trials involving patients undergoing spinal anesthesia for elective cesarean delivery that compared the use of hyperbaric bupivacaine with plain bupivacaine. We included 6 studies with a total of 394 patients in this review. These studies have small sample size, few observed events, differences in methodology, and insufficient information pertaining to assessment of risk of bias. This prevented us from calculating pooled estimates. Results show that there is no compelling evidence in favor of the use of intrathecal plain or hyperbaric bupivacaine for spinal anesthesia for cesarean delivery. There is a lack of clear evidence regarding the superiority of hyperbaric compared with plain bupivacaine for spinal anesthesia for cesarean delivery. The need for conversion to general anesthesia because of failed spinal anesthesia is an important clinical outcome, but current data are insufficient to compare spinal anesthesia induced with hyperbaric compared with plain bupivacaine for this outcome. Further research is required.

The impact of gestational age and fetal weight on the risk of failure of spinal anesthesia for cesarean delivery

The incidence of failed spinal anesthesia varies widely in the obstetric literature. Although many risk factors have been suggested, their relative predictive value is unknown. The primary objective of this retrospective cohort study was to determine the incidence of failed spinal anesthesia for cesarean deliveries at a tertiary care obstetric hospital, and its secondary objectives were to identify predictors of failed spinal anesthesia in the obstetrics population and quantify their relative importance in a predictive model for failure. With local institutional ethics committee approval, a retrospective review of our hospital database identified the incidence of failed spinal anesthesia for 5361 cesarean deliveries between 2010 and 2019. We performed a multivariable analysis to assess the association of predictors with failure and a dominance analysis to assess the importance of each predictor. The incidence of failed spinal anesthesia requiring an alternative anesthetic was 2.1%, with conversion to general anesthesia occurring in 0.7% of surgeries. Supplemental analgesia or sedation was provided to an additional 2.0% of women. The most important predictors of a failed spinal anesthetic were previous cesarean delivery (odds ratio [OR], 11.33; 95% confidence interval [CI], 7.09-18.20; P < .001), concomitant tubal ligation (OR, 8.23; 95% CI, 3.12-19.20; P < .001), lower body mass index (BMI) (kg·m -2 , OR, 0.94; 95% CI, 0.90-0.98; P = .005), and longer surgery duration (minutes, OR, 1.02; 95% CI, 1.01-1.03; P = .006). Previous cesarean delivery was the most significant risk factor, contributing to 9.6% of the total 17% variance predicted by all predictors examined. Spinal anesthesia failed to provide a pain-free surgery in 4.1% of our cesarean deliveries. Previous cesarean delivery was the most important predictor of spinal failure. Other important predictors included tubal ligation, lower BMI, and longer surgery duration.