Fatores de risco para raquianestesia em recém-nascidos pré-termo submetidos a herniorrafia inguinal / Risk factors for spinal anesthesia in preterm infants undergoing inguinal hernia repair

OBJETIVOS: Investigar os fatores de risco e a incidência de efeitos adversos perioperatórios advindos da raquianestesia não suplementada em recém-nascidos pré-termo. Também foi avaliado o tempo decorrido até o reinício da alimentação oral e até a alta hospitalar. MÉTODOS: Foram coletados prospectivamente os dados perioperatórios de todos os recém-nascidos prematuros e ex-prematuros submetidos a herniorrafia inguinal com raquianestesia em um centro médico terciário. RESULTADOS: O grupo de estudo consistiu em 144 recém-nascidos com uma idade gestacional mediana de 30 semanas, idade concepcional de 37 semanas, peso de nascimento de 1.420 g, e peso de 2.140 g no momento da cirurgia. No total, seis (4,2%) recém-nascidos apresentaram complicações intraoperatórias, que incluíram apneia (2/1,4%), bradicardia (2/1,4%) e hipoxemia (4/2,8%). Complicações pós-operatórias ocorreram em 15 (10,4%) recém-nascidos, principalmente hipoxemia (3/2,1%), bradicardia (8/5,5%) e apneia (6/4,1%). Os fatores preditivos de desfecho desfavorável (apneia, alimentação oral > 6 h de pós-operatório, ou alta > 30 h de pós-operatório) foram displasia broncopulmonar [razão de chances (OR) = 3,2, intervalo de confiança de 95% (IC95%) 2,8-5,3; p = 0,01] e leucomalácia periventricular (OR = 2,8, IC95% 2,1-4,9; p = 0,03). CONCLUSÕES: A raquianestesia é segura e eficaz na herniorrafia inguinal em recém-nascidos pré-termo, levando a um reinício precoce da alimentação oral e a um menor período de hospitalização. Displasia broncopulmonar e leucomalácia periventricular podem acarretar risco de desfecho desfavorável.

OBJECTIVES: To investigate the risk factors and incidence of perioperative adverse effects from unsupplemented spinal anesthesia in preterm infants. Times to resumption of oral feeding and to home discharge were also evaluated. METHODS: Perioperative data were collected prospectively for all preterm and former preterm infants who underwent inguinal hernia repair with spinal anesthesia at a tertiary medical center. RESULTS: The study group consisted of 144 infants with a median gestational age of 30 weeks, postmenstrual age of 37 weeks, birth weight of 1,420 g, and weight at surgery of 2,140 g. Overall, six (4.2%) infants had intraoperative complications, which included apnea (2/1.4%), bradycardia (2/1.4%), and hypoxemia (4/2.8%). Postoperative complications occurred in 15 (10.4%) infants, mainly hypoxemia (3/2.1%), bradycardia (8/5.5%), and apnea (6/4.1%). Predictive factors of an unfavorable outcome (apnea, resumption of oral feeding > 6 h postoperatively, or discharge > 30 h postoperatively) were bronchopulmonary dysplasia (odds ratio [OR] = 3.2, 95% confidence interval [95%CI] 2.8-5.3; p = 0.01) and periventricular leukomalacia (OR = 2.8, 95%CI 2.1-4.9; p = 0.03). CONCLUSIONS: Spinal anesthesia is safe and effective for inguinal hernia repair in preterm infants, with early resumption of oral feeding and short hospitalization. Bronchopulmonary dysplasia and periventricular leukomalacia may pose risks for an unfavorable outcome.

Risk factors for spinal anesthesia in preterm infants undergoing inguinal hernia repair.

OBJECTIVES: To investigate the risk factors and incidence of perioperative adverse effects from unsupplemented spinal anesthesia in preterm infants. Times to resumption of oral feeding and to home discharge were also evaluated. METHODS: Perioperative data were collected prospectively for all preterm and former preterm infants who underwent inguinal hernia repair with spinal anesthesia at a tertiary medical center. RESULTS: The study group consisted of 144 infants with a median gestational age of 30 weeks, postmenstrual age of 37 weeks, birth weight of 1,420 g, and weight at surgery of 2,140 g. Overall, six (4.2%) infants had intraoperative complications, which included apnea (2/1.4%), bradycardia (2/1.4%), and hypoxemia (4/2.8%). Postoperative complications occurred in 15 (10.4%) infants, mainly hypoxemia (3/2.1%), bradycardia (8/5.5%), and apnea (6/4.1%). Predictive factors of an unfavorable outcome (apnea, resumption of oral feeding > 6 h postoperatively, or discharge > 30 h postoperatively) were bronchopulmonary dysplasia (odds ratio [OR] = 3.2, 95% confidence interval [95%CI] 2.8-5.3; p = 0.01) and periventricular leukomalacia (OR = 2.8, 95%CI 2.1-4.9; p = 0.03). CONCLUSIONS: Spinal anesthesia is safe and effective for inguinal hernia repair in preterm infants, with early resumption of oral feeding and short hospitalization. Bronchopulmonary dysplasia and periventricular leukomalacia may pose risks for an unfavorable outcome.

Hemodynamic changes during spinal anesthesia in premature infants with congenital heart disease undergoing inguinal hernia correction.

INTRODUCTION: There are conflicting reports on the effects of spinal anesthesia (SA) on hemodynamics. Data on the hemodynamic effects of SA in infants with congenital heart disease (CHD) are limited. METHODS: We reviewed our experience with 44 unsupplemented SA with 1 mg·kg(-1) of either hyperbaric tetracaine or bupivacaine in premature and former premature infants with noncyanotic CHD. Hemodynamics and oxyhemoglobin saturation (SpO(2)) were assessed. Neither preoperative fluid boluses nor atropine was administered to any of the infants. RESULTS: There was no significant change in systolic, diastolic, or mean blood pressures from pre-SA induction compared with end of surgery. Heart rate showed a small but systematic decline (mean change of 10 beats per minute, P < 0.01) but was within the normative range values for age. There was a small, but clinically insignificant increase in SpO(2) across the time course. Intraoperatively, two infants developed transient apneic spells. No infant developed postoperative apnea, oxygen desaturation, or bradycardia. CONCLUSIONS: The data suggest that SA with 1 mg·kg(-1) of either hyperbaric tetracaine or bupivacaine can be used safely as the sole anesthetic for inguinal hernia repair in infants with noncyanotic CHD even when fluid restricted and apparently causes minimal respiratory complications in these infants.

Blood sampling through peripheral venous catheters is reliable for selected basic analytes in children.

OBJECTIVE: The goal was to determine the interchangeability of peripheral venous catheter (PVC) and venipuncture blood sampling (BS). METHODS: Paired blood samples from hospitalized children were obtained through venipuncture and from existing PVCs, following discard of 2 mL of blood. Comparisons of 9 complete blood count indices (white and red blood cell counts, hemoglobin and hematocrit levels, mean corpuscular volume, mean corpuscular hemoglobin level, red blood cell distribution width, platelet count, and mean platelet volume) and 5 basic chemical analysis indices (sodium, potassium, glucose, chloride, and urea levels) were performed, and hemolysis was documented. RESULTS: Irrespective of gauge, blood samples were obtained successfully from 40 (85.1%) of 47 PVCs, with no abnormal hemolysis. BS through venipuncture took longer than BS from PVCs (175.8 +/- 229.6 vs 104.5 +/- 53.4 seconds; P = .053) and was associated with significantly more distress/crying (73.1% vs 0%; P < .001). There were no significant differences between venipuncture and PVC samples (paired t test). Twenty-one (6%) of 348 pairs analyzed with the Clinical Laboratory Improvement Amendment standards fell outside the range of acceptable variance (8 of 21 aberrations were attributed to glucose measurements). Bland-Altman analysis indicated that, with the exclusion of glucose measurements, BS from PVCs is reliable, with 29 (6.5%) of 448 pairs exceeding the limits of agreement. Of those, 9 cases were clinically significant, but none would have altered clinical management. CONCLUSIONS: PVC sampling was shown to be a pain-reducing method that can be used for children for selected basic analytes. The findings for glucose were unreliable.

Gastric emptying time of oral contrast material in children and adolescents undergoing abdominal computed tomography.

OBJECTIVES: : Considering the hazards of pulmonary aspiration of oral contrast material (OCM) during general anesthesia, we investigated the gastric emptying time (GET) of OCM in children and adolescents undergoing abdominal computed tomography (CT). PATIENTS AND METHODS: : Included in the study were 101 consecutive patients ages 3.1 to 17.9 years (mean age 12.2 +/- 3.3 years), who underwent contrast-enhanced abdominal CT for suspected acute appendicitis (n = 90), abdominal trauma (n = 10), or suspected ileus (n = 1). Oral iodinated ioxithalamate was given for bowel opacification. Background data (age, sex, weight, chronic diseases, and medication intake), time of initiation and completion of OCM, and time of CT scanning were recorded. To estimate the GET of OCM, CT images were reviewed to examine whether the stomach was empty or full of OCM at the time of imaging. RESULTS: : The Kaplan-Meier curve showed that 75% of the patients had OCM in the stomach 48 +/- 5.2 minutes after its completion, 50% after 74 +/- 7.9 minutes, and 25% after 135 +/- 32.5 minutes; 1 patient still had OCM after 162 minutes. Except for the length of time taken to drink the contrast material (< or =90 minutes was associated with slower empting of the stomach; log rank, P = 0.03), GET of OCM was not correlated with sex (P = 0.16), age (P = 0.15), weight (P = 0.13), or type of diagnosis (P = 0.41). CONCLUSIONS: : Given the variability of GET of OCM and if clinically feasible, we advocate waiting at least 3 hours between completion of OCM ingestion and general anesthesia induction.

Continuous lumbar/thoracic epidural analgesia in low-weight paediatric surgical patients: practical aspects and pitfalls.

PURPOSE: Continuous epidural anaesthesia attenuates perioperative stress and avoids the need for systemic opioids. In addition, it may prevent the need for postoperative mechanical ventilation. The aim of the study was to prospectively follow the perioperative course of young infants treated with continuous thoracic/lumbar epidural anaesthesia for major surgery. METHODS: Data were collected prospectively from 44 epidural anaesthetics in 40 infants (18 premature or former premature) weighing 1,400-4,300 g who underwent major abdominal surgery (33 cases), thoracic surgery (5), or both (1), or ano-rectal surgery (5) at our centre. RESULTS: Epidural placement was achieved easily in all cases, with high quality analgesia for 24-96 h. Tracheal extubation was delayed after 4 anaesthetics due to muscle relaxant overdose (n = 1), surgeon's request (n = 2), and systemic opioid administration before epidural anaesthesia was considered (n = 1). Intraoperative complications included haemodynamic instability (n = 1) and vascular catheter placement (n = 5). Postoperative complications included meningitis (n = 1), insertion site erythema (n = 7), apnoea (n = 6; 4 premature and 2 full-term infants) and tracheal re-intubation (n = 6). CONCLUSIONS: Continuous epidural analgesia is effective in low-weight infants undergoing major surgery. The trachea may be extubated immediately after surgery. Attention should be paid to the unique anatomical, physiological, and pharmacological aspects. The patients should be monitored carefully for pain, respiratory failure, and meningitis (an extremely rare complication).

[Peri-operative stress response and peri-operative analgesia in children].

Peri-operative surgical stress (SS) is characterized by increased secretion of pituitary hormones and sympathetic activation and is correlated with changed blood levels of stress hormones and metabolites. Adverse effects of perioperative stress include mortality and morbidity and a negative nitrogen balance. Although peri-operative analgesia and stress response-free period are commonly considered as synonyms, pain seems not to be the only factor determining the hormonal-metabolic response to surgery. Other factors playing a role in the creation of SS in newborns include blood loss, site of surgery, superficial and visceral trauma, surgery duration, hypothermia, infection, prematurity and factors related to cardiac surgery. Potent semi-synthetic opioids attenuate the SS better than morphine. However, supplementation of general anesthesia (GA) with local anesthetics either by way of regional or local anesthesia seems to decrease SS more effectively than GA with IV opioids. Hemodynamic monitoring may not suffice for SS or analgesia quality estimation. The most accessible laboratory measure for the monitoring of the stress response for non-cardiac surgery and pre-bypass phase of cardiac surgery may be blood glucose. Blood glucose increases with stress and when analgesia is inadequate; it is easily measured and treated almost immediately once an excessive response is identified. This individualized approach and real-time feedback may be far better than using either excessive opioid doses (hoping to ablate stress response) or minimal opioid dosages.

[Lumbar epidural anesthesia in a very-low-birth-weight infant].

In this case study two combined, light-general and lumbar epidural anesthetics were administered to a premature neonate for the repair of gastroschisis. The female infant's body weight was 1400 grams (first operation) and 1700 grams (second operation). The epidural catheter was inserted between the low-lumbar vertebrae using the "loss of resistance" for saline technique. Intra- and postoperative analgesia were based on epidural administration of bupivacaine and fentanyl. No systemic opioids were administered. The infant recovered from general anesthesia at the end of both operations. Excellent analgesia was accomplished throughout the peri-operative course except for short periods during and after the second operation that resolved after the epidural catheter was withdrawn by a few centimeters. Neither respiratory or hemodynamic depression, nor bupivacaine toxicity were observed. The anesthetic and analgesic management is presented in the article. Technical aspects of lumbar epidural anesthesia, it's advantages over the caudal approach and dosages of epidural anesthetics in small infants, as well as complications and risks are emphasized.

The distance from the skin to the subarachnoid space can be predicted in premature and former-premature infants.

PURPOSE: Spinal anesthesia can be technically challenging in young infants. We studied whether the distance between the skin and the lumbar subarachnoid space in premature and former-premature young infants could be predicted prior to lumbar puncture. METHODS: The distance from skin entry point to tip of the spinal needle was measured using a caliper after lumbar spinal anesthesia at the L4-5 interspace. This distance was correlated to the patient's weight, postconceptual age and lumbar ultrasonographic measurement of the skin-to-subarachnoid space and predictive statistical models were sought. RESULTS: Thirty-five premature or former-premature infants were studied. Three models were examined: all three independent variables, weight and postconceptual age only, and weight only. The model selected contained the weight and postconceptual age, because it had the highest value for adjusted R squared, as well as the lowest value for the mean squared error. Adding the ultrasonic measurement to the model worsened the results. The statistical model that described the depth of the subarachnoid space at the L4-5 level was Y = 13.19 + 0.0026 x W - 0.12 x PCA, where Y is the distance (mm) from the skin to the subarachnoid space, W is the patient's weight (g) and PCA is the postconceptual age (weeks). Adjusted R squared was 0.72, mean square error was 2.63 and P < 10(-9). CONCLUSION: The distance between the skin and the subarachnoid space at the level of L4-5 interspace can be predicted using a statistical model based on the infant's weight and postconceptual age. Spinal ultrasound has no value in L4-5 subarachnoid space depth prediction.

Anaesthetic management of children with tuberous sclerosis.

BACKGROUND: Tuberous sclerosis (TS) is a hamartomatous disease that usually presents with cutaneous and intracranial lesions, but can also affect other organ systems. METHODS: In this report, we retrospectively reviewed the perioperative course of 24 children with TS who had medically intractable seizures as the primary disease process. RESULTS: Cardiac rhabdomyoma was detected in 11 of 18 patients who had a cardiac evaluation, and coexisting congenital heart defects were diagnosed in six. Ten of 17 patients who had a renal evaluation were diagnosed with renal TS, presenting with azotaemia in one and hypertension in four. The major perioperative complications in the 52 anaesthetics, included death (a neonate after cardiac rhabdomyoma resection), seizures (five patients) and bradyarrhythmias (two patients). CONCLUSIONS: Patients with TS and neurological disorders frequently have coexisting cardiac and renal disease as well. Patients with TS should be evaluated for these organ specific disorders prior to surgery.

[Spinal anesthesia in premature infants--indications, technical aspects and results].

PURPOSE: To present our experience with spinal anesthesia in premature and former premature infants, and to focus on technical aspects and pitfalls enlightened with increasing experience. METHODS: The perioperative course of all premature and former premature infants below 60 weeks postconceptual age undergoing spinal anesthesia within an 35-month-period was analyzed. Lumbar puncture was performed while the patient was held seated at L4-5 or L5-S1. Anesthetics included hyperbaric tetracaine or bupivacaine, dose 1 mg/kg with adrenaline. The patients were positioned in the reverse Trendelenburg for 2-3 minutes, and later horizontally. RESULTS: Sixty seven infants (gestational age 30.1 +/- 3.6 weeks, postconceptual age 42.9 +/- 3.4, weight 3234 +/- 1165 grams) underwent spinal anesthesia and surgery. Thirty two had other diseases, including congenital heart (12), lung (15) brain pathology (8) and urological findings (6). Sixty five patients underwent hernia repair and two underwent pyloromyotomy. N2O was added in three infants, and two required general anesthesia. All were found to have lower limb motor blockade postoperatively. Intraoperatively, hypoxemia was diagnosed in two infants, short apnea in two cases and bradycardia in one. The apnea and hypoxemia episodes were successfully treated by reverse Trendelenburg positioning and bag and mask ventilation and the bradycardia that did not respond to tactile stimulation was relieved by atropine. Postoperatively, a short episode of apnea and hypoxemia (one patient) and hypoxemia (one patient) responded to free oxygen administration with/without tactile stimulation. Brief bradycardia (three infants) terminated without intervention. Supplementation and postoperative complication rates resembled previous studies. CONCLUSION: Successful spinal anesthesia in premature and former premature infants depends on close attention to preoperative assessment, patient positioning during and immediately after anesthetic induction, drug dosing and perioperative monitoring. A relatively high dose of local anesthetic should be administered.

Spinal anesthesia in 62 premature, former-premature or young infants--technical aspects and pitfalls.

PURPOSE: To highlight technical aspects and pitfalls of spinal anesthesia (SA) in infants. METHODS: The medical history and perioperative course of all infants who underwent SA over a 28-month period were collected (retrospectively in the first 20). RESULTS: Sixty-two infants underwent surgery under SA. Fifty-five were premature and former-premature, postconceptional age 43.3 +/- 5.0 weeks, weight 3261 +/- 1243 g. Of these, 21 had co-existing disease: cerebral (six), cardiac (nine), pulmonary (11) and urological (six). Hyperbaric tetracaine or bupivacaine 1 mg x kg(-1) with adrenaline was administered. Four infants (three premature) required N(2)O supplementation and three needed general anesthesia. The supplementation rate was similar or lower than in previous studies. Postoperatively, all seven were shown to have lower limb motor and sensory blockade. Complications in premature patients included intraoperative hypoxemia (two), apnea (two) and bradycardia (one). Postoperative complications included bradycardia (three), hypoxemia (one) and apnea and hypoxemia (one). The postoperative complication rate was similar to previous studies. CONCLUSION: Successful SA in infants depends on close attention to preoperative assessment, appropriate patient positioning during and after lumbar puncture, drug dosing and intra- and postoperative cardiorespiratory monitoring. A relatively high dose of hyperbaric solution of tetracaine or bupivacaine with adrenaline should be administered.