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D M Dewan

Publications and source records attributed to D M Dewan.

35 records · Page 2Linked to original sources
PubMed1987

Epinephrine enhances analgesia produced by epidural bupivacaine during labor.

Reports on the analgesic and hemodynamic effects of epinephrine added to bupivacaine for epidural use in obstetrics are conflicting. In this study, healthy parturients received in a random manner either 10 ml of 0.25% bupivacaine (n = 50) or 10 ml of 0.25% bupivacaine with 1:300,000 epinephrine (n = 50) epidurally. Epinephrine enhanced the analgesia produced by bupivacaine: onset was hastened (5.8 +/- 0.6 vs 8.7 +/- 0.8 min, mean +/- SEM, P less than 0.05), duration prolonged (123 +/- 7.0 vs 92 +/- 5.0 min, P less than 0.05), and the number of women requiring additional local anesthetic for analgesia decreased (9 vs 18, P less than 0.05) compared to the group receiving plain bupivacaine. The incidence of hypotension did not differ between groups. Maternal heart rate increased only after injection of the epinephrine-containing solution. The authors conclude that epinephrine 1:300,000 modestly but statistically significantly improves the analgesic efficacy of epidurally administered 0.25% bupivacaine during labor.

Anesthesia, Epidural↗
PubMed1986

Maternal and fetal effects of epinephrine in gravid ewes.

Intravenous cannulation by an epidural catheter may complicate epidural anesthesia. Local anesthetic solutions containing epinephrine produce tachycardia and hypertension when given intravenously and may identify intravenous placement. The authors studied the maternal and fetal effects of intravenous epinephrine-containing solutions in ten chronically instrumented gravid ewes. While continuously monitoring maternal and fetal effects, epinephrine 5, 10, or 20 micrograms iv bolus was injected. Solutions of bupivacaine 5 mg and bupivacaine 5 mg combined with epinephrine 10 micrograms given iv were also examined. All epinephrine-containing solutions produced a significant increase (P less than 0.001) in maternal mean arterial pressure, which returned to baseline after 1 min. Maternal heart rates decreased transiently and returned to baseline after 1 min. All epinephrine-containing solutions decreased uterine blood flow (UBF) (P less than 0.001), and, for doses of 10 to 20 micrograms, this decrease lasted more than 3 min. Fetal heart rate and mean arterial blood pressure did not change following any test solution, nor did maternal or fetal arterial blood gas values. The authors conclude that small intravenous boluses of epinephrine decreased UBF in these animals.

Anesthesia, Epidural↗
PubMed1986

Nifedipine or verapamil counteracts hypertension in gravid ewes.

Hypertension frequently complicates endotracheal intubation in the severely preeclamptic parturient. The calcium entry-blocking drugs nifedipine (N) and verapamil (V) are effective antihypertensive agents in nonpregnant patients. The authors studied the maternal and fetal hemodynamic effects of these drugs in chronically instrumented gravid ewes made hypertensive with an infusion of norepinephrine (NE). Initially NE was infused to increase maternal mean arterial pressure (MAP) by 20%. The NE infusion was continued and either N, 2 mg, or V, 10 mg, was administered intravenously. MAP decreased promptly to control values following both drugs. Maternal heart rate (MHR) decreased significantly following NE infusion. MHR returned to control values following V administration, and increased significantly above control following N administration. Uterine blood flow decreased 50-60% during NE infusion, and there was no further change following either N or V. Fetal hemodynamics were unchanged throughout the study. These results suggest that both N and V may be effective antihypertensive agents in the parturient. V did not produce maternal tachycardia and may be the preferable drug.

Animals↗
PubMed1985

Sodium citrate pretreatment in elective cesarean section patients.

Thirty-two healthy term parturients undergoing elective cesarean section randomly received either no antacid (n = 10), 30 ml of 0.3 molar sodium citrate less than 60 min preoperatively (n = 11), or 30 ml of 0.3 molar sodium citrate longer than 60 min preoperatively (n = 11). Immediately after delivery, the stomach was emptied as completely as possible through a #18 Salem Sump tube passed orally. Mean gastric pH in the three groups was 1.8 +/- 2.7 (SD), 5.0 +/- 1.5, and 2.7 +/- 1.2, respectively. Gastric pH was significantly higher in the short interval group than in either the control group or in patients receiving their sodium citrate more than 60 min in advance. Gastric volumes were similar. All control patients had a gastric pH less than 2.5. Nine percent of patients receiving sodium citrate less than 60 min in advance and 50% of patients receiving their sodium citrate longer than 60 min in advance had a pH of less than 2.5. Volumes exceeding 25 ml occurred with equal frequency. No patient in the short interval group had a combination of both pH of less than 2.5 and a volume exceeding 25 ml. This combination occurred with equal frequency in control patients (64%) and in those patients receiving their sodium citrate more than 60 min in advance (50%). We conclude that sodium citrate effectively increases gastric pH when given less than 60 min prior to the induction of anesthesia.

Adult↗
PubMed1984

Three per cent 2-chloroprocaine for caesarean section: appraisal of a standardized dose technique.

We evaluated 2-chloroprocaine, three per cent, in 44 women having epidural anaesthesia for Caesarean section. All subjects received a minimum dose of 25 ml (750 mg) in increments designed to allow early recognition of accidental subarachnoid or intravascular injection. Further increments were given as needed to achieve a T5 sensory level or higher. We recorded pulse and blood pressure at two-minute intervals and used a simple pain scale to assess analgesia. Ninety-three per cent of subjects had acceptable analgesia. Seventeen mothers required more than 25 ml to attain a T5 level; subjects having a BMI (body mass index) equal to or greater than 35, or over 35 years of age, demonstrated more cephalad spread. Hypotension (MAP 80 per cent of control or less) occurred in 24, mothers (54 per cent), often transiently, but an infused fluid volume exceeding 30 ml X kg-1 at delivery significantly reduced post-delivery hypotension. Nausea and vomiting accompanied the hypotension in 12 mothers. No neonatal depression occurred. We conclude the incremental administration of chloroprocaine, as described, permits safe administration of the drug, with excellent analgesia in most parturients.

Adult↗
PubMed1984

Neonatal neurobehavioral responses after epidural anesthesia for cesarean section using lidocaine and bupivacaine.

We compared the early neonatal neurobehavioral responses after lumbar epidural anesthesia for elective cesarean section using 2% lidocaine (n = 10) and 0.5% bupivacaine (n = 21). We tested the infants at 4 and 24 hr after birth and found that the neonates in the lidocaine group scored as well as those in the bupivacaine group on all parameters of the early neonatal neurobehavioral score (ENNS). In fact on one parameter, sucking response at 24 hr, the neonates in the lidocaine group scored significantly higher than those in the bupivacaine group. We concluded that 2% lidocaine does not compromise newborn outcome when compared to 0.5% bupivacaine and that it provides a satisfactory choice for use during elective cesarean section in healthy pregnancies. This conclusion is important in the light of the current concern over the safety of the use of chloroprocaine and bupivacaine in obstetric anesthesia.

Adult↗
PubMed1982

Sodium citrate premedication in elective caesarean section patients.

The pH and volume of gastric contents from thirty-three patients undergoing elective caesarean section with thiopentone, nitrous oxide, succinylcholine anaesthesia were examined. Twenty patients received Gelusil 30 ml by mouth and thirteen patients received 30 ml of a 0.15 molar solution of sodium citrate. Following tracheal intubation, gastric fluid was sampled through an 18 French Salem sump tube place orally. Mean pH following Gelusil was 4.54 +/- 2.45 (SD) and 2.29 +/- 1.77 following sodium citrate. This difference was statistically different (P less than 0.05). There was no difference in gastric volume between the two groups. Thirty five per cent of patients receiving Gelusil had a pH less than 2.5. This low pH was more likely to occur with prolonged intervals between drug administration and sampling. Significantly more patients receiving sodium citrate had a low pH (85 per cent) and this low pH was not related to the duration of interval between administration and sampling. This study demonstrates that 30 ml of 0.15 molar sodium citrate is not a satisfactory alternative to 30 ml of Gelusil for increasing gastric pH in the paturient when given sixty minutes before operation.

Adult↗
PubMed1982

Antacid anticholinergic regimens in patients undergoing elective caesarean section.

The pH and volume of gastric contents were examined in 60 patients undergoing elective Caesarean Section under thiopentone, nitrous oxide-oxygen, succinylcholine anaesthesia. All patients received Gelusil 30 ml per os preoperatively, while 20 were given atropine 7 microgram X kg-1 and another 20 glycopyrrolate 4 microgram X kg-1 intramuscularly along with Gelusil. Following tracheal intubation, gastric fluid was sampled through an orally placed 18 French Salem Sump tube. After Gelusil alone, the mean gastric fluid pH was 4.54 +/- 2.45 (SD) while it was significantly higher following the combined use of antacid and atropine (6.78 +/- 1.20) or antacid and glycopyrrolate (6.42 +/- 1.72), (P less than 0.01). Differences in gastric fluid volume between the groups were insignificant. All three regimens produced a gastric pH greater than 2.5 when given less than 75 minutes before sampling. When the premedication to sampling interval exceeded 75 minutes the addition of atropine or glycopyrrolate decreased the incidence of gastric pH less than 2.5 from 47 per cent in patients given Gelusil alone to 6 per cent and 14 per cent, respectively. In comparison to Gelusil alone, this difference was significant with atropine (P less than 0.05) but not with glycopyrrolate. Atropine and glycopyrrolate respectively produced 6 per cent and 7 per cent incidences of pH lower than 2.5 combined with gastric volume greater than 25 ml, which were significantly lower than was observed with Gelusil alone (P less than 0.05). This study demonstrates that the addition of atropine or glycopyrrolate to Gelusil premedication provides additional protection against the consequences of aspiration, especially when the premedication to anaesthetic induction period is prolonged.

Adult↗
PubMed1980

Effects of nitroglycerin and nitroprusside on the uterine vasculature of gravid ewes.

The effects of nitroglycerin (TNG) and sodium nitroprusside (SNP) on mean aortic pressure (MAP), uterine blood flow (UBF), uterine vascular conductance (UVC), and pulse rate (PR) were compared when the two agents were infused to prevent and treat hypertension induced by norepinephrine (NE) in gravid ewes. When infused alone, TNG, 19 microgram/kg/min, decreased MAP 19 per cent and increased PR 33 per cent from control values (P less than 0.05), but did not significantly change UBF or UVC. In comparison, SNP, 3 microgram/kg/min, decreased MAP 20 per cent and increased PR 43 per cent (P less than 0.05), and did not significantly change UBF or UVC. When given alone, four successive 2-min infusions of NE produced dose-related increase in MAP and decreases in UBF, UVC, and PR; values were significantly different from control with the two higher doses of NE. Although MAP, UBF, and UVC were still significantly changed from control levels when NE was given in the presence of the above infusions of TNG or SNP, MAP was lower and UBF and UVC were higher compared with when NE was given alone (P less than 0.05). When given to control hypertension induced by a continuous infusion of NE, TNG or SNP produced uterine vasodilatation and significantly increased UBF. Nitroglycerin and SNP were equally effective in counteracting the maternal hypertension and antagonizing the uterine vascular effect of NE. It is concluded that TNG and SNP counteract uterine vasoconstriction resulting from alpha-adrenergic stimulation and do not produce a shunt of blood flow away from the uterine vasculature when used to control hypertension in gravid ewes.

Animals↗
PubMed1980

Chloroprocaine vs. bupivacaine for lumbar epidural analgesia for elective cesarean section.

The incidence and degree of hypotension, time to establish surgical analgesia, and several other maternal and fetal variables were studied when 2-chloroprocaine, 3 per cent, and bupivacaine, 0.5 per cent, were used for epidural analgesia in 30 women undergoing elective cesarean section. Surgical analgesia occurred 8 min sooner (P less than 0.001) with chloroprocaine (14 +/- 1 min) than with bupivacaine (22 +/- 2 min). Blood pressure values were significantly lower with chloroprocaine than with bupivacaine during the 18--to-32 min interval after local anesthetic injection, while pulse rates were higher (P less than 0.05) at 18, 20, and 22 min. Hypotension necessitating treatment with ephedrine occurred in 33 per cent of chloroprocaine-treated subjects, compared with 13 per cent of those receiving bupivacaine. Newborn outcome was excellent in both groups, as reflected by umbilical vessel blood-gas values, times to sustained respiration, and 5-min Apgar scores. The authors conclude that chloroprocaine disturbs maternal cardiovascular status more than does bupivacaine when used for cesarean section epidural analgesia. However, chloroprocaine can be employed safely in normal pregnancies if maternal hypotension is corrected rapidly.

Analgesia↗
PubMedDate not supplied

Status epilepticus amauroticus secondary to meningitis as a cause of postpartum cortical blindness.

BACKGROUND AND OBJECTIVES: A patient who underwent cesarean delivery with epidural anesthesia presented 6 days postpartum with acute cortical blindness. METHODS: Initial studies included an ophthalmology consultation as well as a full neurologic workup, including cranial computed tomography, diagnostic lumbar puncture, magnetic resonance imaging, body fluid cultures, and electroencephalography. Early broad-spectrum antibiotic coverage was initiated, and because of possible epileptic activity on electroencephalogram, phenytoin was added to the treatment regimen. RESULTS: Soon after beginning the initial phenytoin dose, the patient reported full return of her vision. She was eventually discharged from the hospital in good condition. CONCLUSIONS: This case report illustrates how blindness can be related to seizure activity.

Acute Disease↗